CN109601369B

CN109601369B - Recurrent selection population creating and selecting method for breeding high-quality multi-resistance new tobacco strain

Info

Publication number: CN109601369B
Application number: CN201811564592.4A
Authority: CN
Inventors: 曹景林; 程君奇; 李亚培; 吴成林; 张俊杰
Original assignee: Tobacco Research Institute of Hubei Province
Current assignee: Tobacco Research Institute of Hubei Province
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2022-04-19
Anticipated expiration: 2038-12-20
Also published as: CN109601369A

Abstract

The invention relates to a method for creating and selecting a recurrent selection group for breeding a high-quality multi-resistance tobacco new strain. Then the plants in the group are selected for selfing, disease resistance identification and screening of excellent plants, economic character and quality character identification and screening of excellent plants for hybridization and then plant selection and intercrossing are carried out in sequence to form the next round of selection group. The heterogeneous germplasm can be introduced into each recurrent selection group, and the required individual can be extracted for strain identification. By adopting the method, a plurality of target characters can be improved simultaneously, and the breeding efficiency is obviously improved.

Description

Recurrent selection population creating and selecting method for breeding high-quality multi-resistance new tobacco strain

Technical Field

The invention belongs to the technical field of tobacco breeding, and particularly relates to a recurrent selection population creating and selecting method for breeding a new high-quality multi-resistance tobacco strain.

Background

Tobacco is a self-pollinating crop. For a long time, the improvement of tobacco varieties mainly depends on conventional crossbreeding methods, which is quite effective for achieving recent breeding targets. However, due to the long-term adoption of cross breeding of a few parents and the pedigree selection of offspring, a plurality of main genes for controlling the same target shape are difficult to combine together, and the potential effects of recombination and accumulation of a plurality of micro-effect genes are difficult to play, so that a large number of favorable genes are lost, and the genetic basis of cultivated varieties becomes narrow day by day, for example, the main cultivated varieties of flue-cured tobacco in China, namely Yunyan 87, Yunyan 85 and K326, have closer genetic relationship. As the parent sources are the same and the genetic basis is poor, the 3 varieties have unobvious differences of the aroma quality characteristics of the tobacco leaves in the same ecological area and do not form unique aroma styles. Meanwhile, the bred species with narrow genetic base is also easy to suffer from loss due to sudden drought, virus or parasitic bacteria (worms), and the like, thereby bringing great potential danger to tobacco production. In addition, in the face of the increasingly diversified tobacco breeding targets, the traditional breeding method is more and more inexhaustible. Therefore, breaking the routine, the search for new breeding approaches is imperative.

Recurrent selection refers to that on the basis of populations with rich genetic bases, adverse gene linkage is broken through circular selection, intercrossing, reselection and intercrossing, and favorable gene frequency with wide genetic bases and target traits is continuously developed, so that the average value of the traits is improved, and the populations continuously obtain a genetically improved breeding system. It is derived from cross-pollinated corn and has been widely used in corn population improvement in the United states, and later in breeding of many self-pollinated and normally cross-pollinated crops. Crop breeding practices have proved that recurrent selection is the most effective method for crop population improvement and germplasm innovation, and particularly has stronger superiority than the conventional crossbreeding method when different target traits in the population need to be improved simultaneously. Most of the tobacco breeding target characters are quantitative characters, and recurrent selection is particularly suitable for improving the characters with quantitative inheritance. Therefore, recurrent selective breeding on tobacco is needed to be developed, and main effect gene recombination for controlling different excellent properties is superposed, so that the method has great significance for expanding material foundation and cultivating high-quality multi-resistance widely-applicable and high-efficiency new varieties, and is bound to become the material, material and method foundation necessary for making breakthrough progress in tobacco breeding.

There are some research documents related to recurrent selection on tobacco, but these documents have two general properties: firstly, the establishment method of the recurrent selection basic population is simple, a single cross or double cross mode is mostly adopted, only a few parents are involved, the genetic basis of germplasm in the population is not abundant, and the advantage of recurrent selection is not easily exerted; and secondly, almost all the genes are selected in a recurrent selection population according to individual characters or a few characters (only relating to black shank resistance, single fresh leaf weight, plant height, leaf number, total alkaloid content, carotenoid content and particle proportion) so as to verify the improved selection effect of recurrent selection on the individual characters or the few characters. As is known to those skilled in the art, tobacco breeding goals are complex. Although the overall target of tobacco breeding can be summarized as "high quality, multiple resistance, high yield, high efficiency, wide adaptability", each overall target corresponds to a plurality of specific traits, and relates to various aspects such as resistance to different tobacco diseases (common 12 diseases such as black shank, bacterial wilt, root black rot, root knot nematode disease, brown spot disease, climatic spot disease, powdery mildew, wildfire disease, angular leaf spot disease, common mosaic virus disease, cucumber mosaic virus disease, potato virus Y and the like), tobacco plant growth traits, tobacco plant morphological traits, economic traits, appearance quality, chemical components, physical properties, sensory quality, adaptability, stability and the like. Therefore, simple crossing with only a few parents and selection of individual or a few traits is very difficult to achieve current tobacco breeding goals. Therefore, the research reports on tobacco recurrent selection so far have little significance in actual tobacco breeding.

As the tobacco belongs to the crops with large plant spacing, the number of single-grain seeds is large, the related characters of the breeding target are various, the land area occupied by recurrent selection is large, and the workload is large, so that the report of applying the recurrent selection to the breeding of the new high-quality multi-resistance tobacco variety is not seen so far. Although sporadic literature is discussed theoretically, the concept and generalization of the recurrent selection population are compared, so that the recurrent selection breeding scheme which is practical and strong in operability in tobacco breeding is not proposed until now, as for how to create the recurrent selection population on the tobacco and how to select and process the recurrent selection population, the cloud is still unknown.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a recurrent selection group creating and selecting method suitable for breeding of a new high-quality multi-resistance tobacco strain.

The recurrent selection population creating and selecting method for breeding the high-quality multi-resistance new tobacco strain comprises the following steps:

(1) selecting m parents with target characters, wherein the m parents comprise quality character parents, adaptive parents, high-yield easily-modulated parents and a plurality of disease-resistant parents; the high-yield easy-to-modulate parent is selected from one or two of a broad leaf high-yield easy-to-modulate parent and a leafy high-yield easy-to-modulate parent; each of the disease resistant parents having at least one of black shank resistance, bacterial wilt resistance, root knot nematode resistance, root black rot resistance, brown spot resistance, powdery mildew resistance, wildfire resistance, angular leaf spot resistance, climatic spot resistance, common mosaic resistance, cucumber mosaic resistance, and potato Y disease resistance;

(2) hybridizing by taking a quality character parent and an adaptive parent as female parents and other (m-2) parents as male parents to obtain 2 x (m-2) hybrid combined seeds;

(3) hybridizing (m-2) hybridization combinations taking the quality character parent as one of the hybridization combination parents and (m-2) hybridization combinations taking the adaptive parent as one of the hybridization combination parents by adopting a (m-2) x (m-2) hybridization mode to obtain [ (m-2) x (m-2) ] double-cross combination seeds;

(4) respectively planting the double-cross combination seeds obtained in the step (3) in the field in the tobacco growing season, wherein 4 x (m-3) double-cross combinations containing high-yield easy-to-modulate parents are expressed according to the tobacco plant growth potential and morphological characters, each combination selects [ (m-2) x (m-2) -4 x (m-3) ] single plants with relatively good tobacco plant growth potential and relatively ideal morphological characters, the other [ (m-2) x (m-2) -4 x (m-3) ] double-cross combinations containing no high-yield easy-to-modulate parents are expressed according to the tobacco plant growth potential and morphological characters, each combination selects 4 x (m-3) single plants with relatively good tobacco plant growth potential and relatively ideal morphological characters, and when flowering, the 4 x (m-3) double-cross combinations containing high-yield easy-to-modulate parents are respectively planted with [ (m-2) x (m-3) single plants 2) Carrying out plant-to-plant pairwise hybridization on 4 (m-3) selected single plants which do not contain double-cross combinations of high-yield easily-prepared parents to obtain [4 (m-3) ] multiplied [ (m-2) multiplied (m-2) -4 multiplied (m-3) ] composite hybrid combination seeds, and respectively taking 50-150 seeds from each composite hybrid combination to mix fully and equally to form a group A;

(5) selecting 2000-3000 tobacco plants with relatively ideal growth potential and morphological character expression in the population A, carrying out pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and respectively taking 50-150 seeds from each hybrid combination to fully mix the seeds in equal parts to form a recurrent selection basic population C0;

(6) selecting 1500-plus-3000 tobacco plants with ideal tobacco plant growth character and morphological character performances in a recurrent selection basic population C0, selfing during flowering, and harvesting seeds according to the individual plants to obtain 3000 individual seeds of 1500-plus-3000 tobacco plants;

(7) respectively taking 50-150 seeds obtained in the step (6) from each individual plant seed, fully mixing the seeds in equal size to form a group B, and dividing the group B into 3 parts to form a group C, a group D and a group E; identifying the population C sequentially for wildfire resistance, black shank resistance, common mosaic disease resistance, climatic spot disease resistance, root-knot nematode resistance and red star disease resistance, and screening 500-1000 tobacco plants; sequentially identifying angular leaf spot resistance, bacterial wilt resistance, cucumber mosaic disease resistance, climatic spot disease resistance, root-knot nematode resistance and brown spot disease resistance of the population D, and screening 500-1000 tobacco plants; sequentially identifying powdery mildew resistance, root black rot resistance, potato Y disease resistance, climatic spot disease resistance, root-knot nematode resistance and red star disease resistance of the population E, and screening 500-1000 tobacco plants; equally dividing the selected individual plants of the population C, the selected individual plants of the population D and the selected individual plants of the population E into two individual parts, hybridizing the individual parts of different populations pairwise to obtain 750-1500 hybridization combined seeds, and respectively taking 50-150 seeds from each hybridization combination to be fully equally mixed to form a population F; selecting 2000-3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics in the population F, carrying out pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and respectively taking 50-100 seeds from each hybrid combination to fully mix the seeds in equal parts to form a population G;

(8) planting each individual seed obtained in the step (6) into a strain line in a field according to the individual plant in the tobacco growing season, expressing according to the growth character and the morphological character of the tobacco plant, keeping 3 tobacco plants with more ideal growth character and morphological character expression of the tobacco plant in each strain line, selfing during blooming, harvesting according to the individual plant, topping and remaining leaves and wiping branches of the rest individual plants according to the conventional tobacco leaf production technology, harvesting and modulating when the tobacco leaves are mature, identifying the economic character and the quality character of the modulated tobacco leaves, screening out 500 strain lines with better comprehensive expression of the economic character and the quality character, and respectively taking 50-100 grains of the selfing seed-reserving individual plants of the selected strain line and fully mixing the 3000 individual plants to form a group H; planting the group H seeds in the field in the tobacco growing season, selecting the 3000 tobacco plants with more ideal tobacco plant growth characters and morphological character performances, carrying out pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and respectively taking 50-100 seeds from each hybrid combination to fully and equally mix to form a group I;

(9) performing paired hybridization on 1000-plus-1500 tobacco plants which are relatively ideal in the growth character and morphological character expression of the tobacco plants in the group G and 1000-plus-1500 tobacco plants which are relatively ideal in the growth character and morphological character expression of the tobacco plants in the group I to obtain 1000-plus-1500 hybrid combination seeds, and respectively taking 50-150 seeds from each hybrid combination to fully and equally mix to form a group J;

(10) selecting 2000-3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics in the group J, performing pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and mixing 50-100 seeds in each hybrid combination to form a first round selection group C1;

(11) and (4) adopting the seeds of the first round selection population C1 obtained in the step (10), repeating the steps (6) to (10) to obtain a second round selection population C2, and the like until the phenotypes of the tobacco plants in the population are close to consistency and the genotypes are highly heterozygous, and finally obtaining an nth round selection population Cn with fully balanced genes in the population.

In the present invention, the quality trait parent may be K326, K346, NC82, G28, RG11, RG17, NC102 and NC 297.

In the present invention, the adapted parent may be yunyan 85, yunyan 87, yunyan 97, yunyan 99, yunyan 110, yunyan 116, yunyan 119, zhongyan 100, zhongyan 103 and zhongyan 104.

In the invention, the high-yield easy-to-modulate parents can be Zhongyan 103, Zhongyan 104, Coker139, sapphire No. 1, Bina No. 1 and K326 LF.

In the present invention, the disease resistant parent may be yunyan 311, yunyan 317, K346, G80, zhongyan 98, DB101, TI448A, yan 97, G3, reid No. 3, K730, RG17, zhongyan 100, CV87, CV91, CF225, Kutsaga M10, Kutsaga 51E, Kutsaga E1, jasper No. 1, Coker176, taiyan No. 8, ant 88, C151, Coker319, NC95, LA Burley21, Burley49, TN86, TN90, Kentucky15, Kentucky17 and Kentucky 8959.

Furthermore, a multi-resistant parent with a plurality of disease resistant varieties is selected as a disease resistant parent, and at least 1 disease resistance is used as an anti-source of the disease.

Further, the growth traits of the tobacco plants specifically comprise the rising speed of the tobacco plants, the field growth vigor, the axillary bud growth vigor, the cluster stage, the flourishing stage, the bud stage, the central flower open stage, the flat top stage, the bottom leaf maturation stage, the upper leaf maturation stage, the days from transplanting to topping, the days of the field growth stage and the leaf maturation speed; the morphological characters of the tobacco plants specifically comprise the typical characteristics of the tobacco plants, plant types, plant heights, stem thicknesses, total leaf numbers, extractable leaf numbers, leaf distribution uniformity, pitch distances, leaf shapes, leaf sizes, leaf opening potential at the upper part, leaf thicknesses, leaf colors, smooth or shrinking degrees of leaf surfaces, fine or rough mesophyll tissues, leaf flexibility, leaf main vein thicknesses, stem/leaf ratio sizes, leaf maturation uniformity, leaf maturity resistance, stem leaf angles, the distance between the uppermost-end extractable leaf implantation points and central flowers and the number of twigs of tobacco.

Further, the economic traits specifically comprise single leaf weight, yield, output value, average price, first-class tobacco proportion and second-class tobacco proportion; the quality traits specifically comprise the appearance quality, chemical components, physical characteristics and sensory quality of the modulated tobacco leaves.

Further, when a certain round of selection population Ci also comprises a measure for introducing heterologous germplasm after being created, the following steps are carried out:

(1) planting Ci group seeds and heterologous germplasm seeds in a field in a tobacco growing season, selecting 500-plus-1000 tobacco plants with relatively ideal tobacco plant growth traits and morphological trait expressions from the Ci group, selecting 500-plus-1000 tobacco plants from the heterologous germplasm group, performing pairwise hybridization on selected single plants of the Ci group and selected single plants of the heterologous germplasm group during flowering to obtain 500-plus-1000 hybrid combination seeds, and mixing 50-150 seeds of each hybrid combination sufficiently equally to form a group K;

(2) selecting 2000-3000 tobacco plants with relatively ideal growth potential and morphological character expression in the population K, carrying out pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and respectively taking 50-150 seeds from each hybrid combination to fully mix the seeds in equal parts to form a population L;

(3) performing paired hybridization on 1000-plus 1500 tobacco plants with relatively ideal tobacco plant growth potential and morphological character expression in the Ci group and 1000-plus 1500 tobacco plants with relatively ideal tobacco plant growth potential and morphological character expression in the group L to obtain 1000-plus 1500 hybrid combination seeds, and respectively taking 50-150 seeds from each hybrid combination to mix fully and equally to form a group M;

(4) selecting 2000-3000 tobacco plants with relatively ideal growth potential and morphological character expression in the population M, performing pairwise hybridization during flowering to obtain 1000-1500 hybrid combination seeds, and fully mixing 50-150 seeds in each hybrid combination to form a new recurrent selection basic population C0';

(5) continuously repeating the steps (6) to (10) of claim 1 by using a new round of selecting seeds of the basic population C0', to obtain a new selected population C1', C2', C3'. cndot.;

wherein i is more than or equal to 1 and less than or equal to n, and the heterologous germplasm comprises a new resistance source, a new quality character source, a new adaptability source and a new high-yield easy modulation source.

Further, when 2 heterologous germplasm needs to be introduced simultaneously after the creation of a round of selection population Ci, the 2 heterologous germplasm can be hybridized firstly to obtain a hybrid F1 generation, and then the hybrid F1 generation is used as a single heterologous germplasm to be hybridized in pairs with the Ci population seeds.

Furthermore, the method also comprises the steps of identifying the single plants which are well expressed in the round selection basic population C0, the new round selection basic population C0', the round selection population Ci or the round new selection population Ci', and incorporating the single plants into a conventional breeding program, so as to breed the high-quality multi-resistance new line.

Further, identifying the strain with better comprehensive performance of the economic character and the quality character obtained in the step (8) and introducing the strain into a conventional breeding program, thereby cultivating a high-quality multi-resistance new strain.

The conventional breeding program of the invention can be: firstly, identifying the disease-resistant character, screening out a disease-resistant single plant, selfing when blooming, and harvesting seeds according to the single plant; then identifying the growth character and the morphological character of the tobacco plant, screening out a strain line with proper growth and morphological character of the tobacco plant, selecting a single plant with ideal growth and morphological character of the tobacco plant from the selected strain line, selfing the single plant during flowering, and mixing the single plant into single plant seeds according to the strain line; then carrying out economic character identification, screening out strains which are suitable for production and have comprehensive economic characters exceeding standard reference varieties, and simultaneously carrying out self-breeding and seed-reserving on the selected corresponding strains in each strain seed-reserving area; and finally, performing multi-year multi-point tests on the selected strains, identifying quality traits, adaptability and stability, screening out strains with relatively suitable quality traits, adaptability and stability, and promoting the strains to participate in national tobacco variety regional tests.

The adaptability specifically comprises the adaptive environment range of the new strain and the adaptive degree in a certain environment range; the stability specifically includes the stability of the quality character of the tobacco leaves and the stability of the economic character of the tobacco leaves.

The invention has the beneficial effects that:

(1) the method comprises the steps of selecting m parents with target characteristics including quality characteristic parents, adaptive parents, broad leaf and leafy high-yield easy-to-prepare parents and various main disease resistant parents according to breeding targets, hybridizing the quality characteristic parents and the adaptive parents serving as female parents and other parents serving as male parents, hybridizing a hybridization combination taking the quality characteristic parents as one of hybridization combination parents with a hybridization combination taking the adaptive parents as one of the hybridization combination parents, hybridizing a double-cross combination containing the high-yield easy-to-prepare parents with a double-cross combination containing no high-yield easy-to-prepare parents, selecting strains in a composite hybridization combination population to form paired hybridization offspring, and constructing a recurrent selection base population. Therefore, the recurrent selection group created by the method has wide inheritance basis, leads the gene polymerization degree to be high through the sufficient repeated hybridization of various hybridization forms, can lead the genes with different target characters to be fully recombined so as to break the linkage relationship of the genes and create abundant genetic variation, thereby creating new germplasm resources and creating conditions for continuously improving the level of the bred varieties.

(2) On one hand, the method of the invention has wide hereditary basis of the created recurrent selection group, and can lead the genes with different target characters to be fully recombined by carrying out repeated hybridization among individuals in a plurality of rounds under the control condition through various hybridization forms, thus leading the dose effect of the main effective genes controlling certain characters to be enhanced, leading the micro effective genes controlling good characters to be fully accumulated in certain individuals and leading the good characters to be more excellent; on the other hand, in each selection period of the recurrent selection, disease resistance identification and economic character and quality character identification are carried out, disease-resistant single plants are selected and intercrossed, single plants with better comprehensive performance of economic character and quality character are selected and intercrossed, then tobacco plants with more ideal growth character and morphological character performance are selected in disease-resistant single plant intercross progeny populations and single plant intercross progeny populations with better comprehensive performance of economic character and quality character, single plant pairwise hybridization among the populations is carried out, and then tobacco plants with more ideal growth character and morphological character performance are selected in pairwise hybridization progeny populations to carry out pairwise hybridization. Disease-resistant single plants are selected for intercrossing through disease resistance identification, the disease resistance characteristics of the recurrent selection population can be directly improved, the economic characteristics and the quality characteristics of the recurrent selection population can be directly improved through identifying and selecting excellent plants through the economic characteristics and the quality characteristics, the growth characteristics and the morphological characteristics of tobacco plants are directly related to the easy modulation, the economic characteristics and the quality characteristics of tobacco leaves, and the easy modulation, the economic characteristics and the quality characteristics of the tobacco leaves of the recurrent selection population can be indirectly improved through selecting the growth characteristics and the morphological characteristics of the tobacco plants. Therefore, the method can improve a plurality of target traits simultaneously, and can aggregate a plurality of excellent genes into one individual, thereby further cultivating a variety with excellent comprehensive traits.

(3) The parents set by the method of the invention not only comprise quality character parents, adaptive parents and high-yield easily-modulated parents, and comprises a root disease resistant parent, a leaf surface disease resistant parent and an antiviral parent, concretely comprising a black shank disease resistant parent, a bacterial wilt resistant parent, a root knot nematode disease resistant parent, a root black rot resistant parent, an brown spot resistant parent, a powdery mildew resistant parent, a wild fire resistant parent, an angular leaf spot resistant parent, an air-resistant spot disease resistant parent, a common mosaic virus disease resistant parent, a cucumber mosaic virus disease resistant parent and a potato Y virus disease resistant parent, wherein the total of 12 common diseases in tobacco leaf production are involved, and the total of 5 diseases are more than 7 diseases (including black shank disease, bacterial wilt disease, root knot nematode disease, brown spot disease, common mosaic virus disease, cucumber mosaic virus and potato Y virus disease) identified by national tobacco variety test regulations. Moreover, in order to prevent unknown diseases and meet new quality character requirements, and breed varieties resisting the unknown diseases and varieties meeting the new quality character requirements, the method also designs a method for introducing new resistance sources or new quality character sources for recurrent selection populations. Meanwhile, the method also designs a method for extracting the required phenotype individuals at any time from recurrent selection basic groups or each recurrent selection group to carry out strain identification so as to breed a new variety meeting the current tobacco breeding target requirement as soon as possible. Therefore, the method of the invention not only considers the long-term breeding target, but also considers the short-term breeding target.

(4) The method comprises the steps of hybridizing a quality character parent and an adaptive parent serving as female parents and other parents serving as male parents, hybridizing a hybridization combination taking the quality character parent as one of hybridization combination parents and a hybridization combination taking the adaptive parent as one of the hybridization combination parents, hybridizing a double-cross combination containing high-yield easily-modulated parents and a double-cross combination containing no high-yield easily-modulated parents, selecting plants in a compound hybridization combination progeny population for pairwise hybridization to construct a recurrent selection basic population, enabling the genetic shares of the quality character parent and the adaptive wide parent in the recurrent selection population to be two dominant genetic components, enabling the genetic shares of the easily-modulated parents in the recurrent selection population to be second to the genetic shares of the quality character parent and the wide parent, and performing disease resistance selection in each recurrent selection cycle, The selection of the growth character and the morphological character of the tobacco plant and the selection of the economic character and the quality character can ensure the excellence and the universality of the recurrent selection group, simultaneously ensure the multi-resistance and the economic character prominence of the recurrent selection group, and obviously improve the tobacco breeding efficiency.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the present invention, but are merely exemplary. The test methods used in the following examples are all conventional methods unless otherwise specified.

Example 1: creation and selection of flue-cured tobacco recurrent selection population

In order to give consideration to both long-term and short-term breeding targets, when the parents of the original population are selected and selected in the flue-cured tobacco recurrent selection process, the high quality and wide adaptability are mainly selected, and the resistance of common main diseases of all flue-cured tobaccos is considered as much as possible. According to the breeding goal, the selected parents include quality character parents, adaptive parents, high-yield easy-baking parents and disease-resistant parents, the quality character parent is a recognized production use variety with good quality, the adaptability parent is a production use variety with wide adaptability, the high-yield easy-baking parent strain comprises a broad leaf high-yield easy-baking parent strain and a multi-leaf high-yield easy-baking parent strain, the disease resistance parent strain comprises a root disease resistance parent strain, a leaf disease resistance parent strain and a virus disease resistance parent strain, the rootstock diseases comprise black shank disease, bacterial wilt disease, root knot nematode disease and root black rot disease, the foliar diseases include brown spot, powdery mildew, wildfire, angular leaf spot and climatic spot, the virus diseases include common mosaic virus (TMV) disease, Cucumber Mosaic Virus (CMV) disease, and Potato Virus Y (PVY) disease. In order to shorten the cycle of population improvement of recurrent selection and reduce the workload of hybridization, parents with more advantages and less defects are selected as much as possible, and disease-resistant parents are selected as much as possible to serve as multi-resistant parents for resisting various diseases. Based on the reasons, 11 germplasm materials are selected from a tobacco germplasm resource library and used as parents constructed by the original group selected by the tobacco recurrent selection, wherein the 11 parents comprise a well-known high-quality parent K326, a well-known widely-suitable parent Yunyan 87, a leaf broad high-yield easy-baking parent tobacco 103, a leafy high-yield easy-baking parent Lanyu No. 1, a black shank disease resistant parent Yunyan 317, a bacterial wilt resistant parent G3, a root black rot disease, a wildfire disease and angular leaf disease resistant parent Kentucky8959, a root knot nematode resistant parent NC95, TMV, a red spot disease and climatic speckle disease resistant parent CV87, a CMV and PVY resistant parent CV91 and a powdery mildew resistant parent KE1, wherein the K326 is a high-quality variety widely used in production, and the Yunyan 87 is a wide-adaptability variety used in production. The uses and characteristics of each selected parent are shown in Table 1.

Table 1 construction of tobacco recurrent selection of parents for use of the original population

In 2 months of 2010, the 11 selected parents are sown and cultured in a Lichuan test base of the tobacco science research institute in Hubei province, and the seedlings are transplanted to a field after being grown. In order to increase the genetic shares of quality character parents and adaptive parents in the population, the high-quality parent K326 and the eurytopic parent Yunyan 87 are respectively used as female parents and the other 9 parents are used as male parents for hybridization during flowering to obtain 18 hybrid combined seeds. In winter in the same year, 18 hybrids are combined to be sown and cultured in a south breeding base of a tobacco science research institute in Hubei province of Suan province, namely Hainan province, and then transplanted into a field after seedlings are formed. In order to enable each hybridization combination to contain quality character parent and adaptive parent genes, 9 hybridization combinations taking K326 as one of the parents and 9 hybridization combinations taking Yunyan 87 as one of the parents are hybridized in a 9 x 9 hybridization mode during flowering to obtain 81 double-cross combined seeds.

In 2 months of 2011, 81 double crosses are combined and sown in a Lichuan test base for raising seedlings, and the seedlings are transplanted into a field after being grown. In order to increase the genetic share of the tobacco 103 and the leafy high-yield easy-curing parent sapphire No. 1 in the broad leaf high-yield easy-curing parent, 49 single plants with relatively good tobacco plant growth potential and relatively ideal morphological characters are selected for each combination of 32 double-cross combinations taking the high-yield easy-curing parent as the parent according to the tobacco plant growth potential and morphological character performance during blooming, and for 49 double-cross combinations without taking the high-yield easy-curing parent as the parent, 32 single plants with relatively good tobacco plant growth potential and relatively ideal morphological character are selected for each combination. And carrying out plant-to-plant pairwise hybridization on 32 double-cross hybrid selected single plants taking the high-yield easy-baking parents as parents and 49 double-cross hybrid selected single plants not taking the high-yield easy-baking parents as the parents to obtain 1568 composite hybrid combined seeds, and fully mixing 100 seeds in each composite hybrid combination to form a group A. In winter in the same year, sowing and raising seeds of the group A in the Miannan breeding base, and transplanting the seeds into the field after the seedlings are formed. In order to make the recurrent selected parents carry out sufficient intercross, so as to avoid losing the excellent genes carried by each parent in the group selection due to selection omission and further make the excellent genes lose the opportunity of separation, recombination and accumulation, 3000 tobacco plants with relatively ideal tobacco plant growth vigor and morphological character performance are selected in a group A during flowering, and are subjected to pairwise hybridization to obtain 1500 hybrid combination seeds, and 150 seeds are respectively taken from each hybrid combination and mixed fully and equally to form a recurrent selected basic group C0;

and 3, in 2012, sowing and raising the recurrent selected basic population C0 seeds in a Lichuan test base, and transplanting the seedlings into a field after the seedlings are grown. Considering that the growth characters and the morphological characters of tobacco plants are directly related to the easy-to-bake property, the economic characters and the quality characters of tobacco leaves, the prospects of the selected individual plants in the aspects of the easy-to-bake property, the economic characters and the quality characters can be pre-judged in advance through the investigation of the growth characters and the morphological characters of the tobacco plants, and then the tobacco leaf easy-to-bake property, the economic characters and the quality characters of the individual plants can be indirectly selected, so that the selection of the recurrent selection group field is mainly carried out through plant selection and pairwise hybridization according to the growth characters and the morphological character expressions of the tobacco plants. 1500 tobacco plants with comparatively ideal growth characteristics and morphological characteristics of the tobacco plants are selected in a recurrent selection basic population C0 during the flowering, selfing is carried out, and seeds are harvested according to the individual plants to obtain 1500 individual plant seeds.

In 1 month of 2013, 100 seeds are respectively taken from each individual seed selected in the recurrent selection basic population C0 and fully equally mixed to form a population B. In order to make the disease-resistant genes carried by each disease-resistant parent have the expression opportunity and avoid the loss of the good genes, the seeds of the group B are divided intoAnd 3 parts of the mixture are used for constituting a group C, a group D and a group E so as to respectively identify different disease resistances. And (2) sowing seeds of the group C, the group D and the group E in a Lichuan test base for seedling culture in 2 months, wherein 50000 plants are planted in each group. For C group tobacco seedlings, the wild fire disease resistance is identified by inoculating the tobacco seedlings at the age of about 8 weeks and the concentration is 1 multiplied by 10⁶Spraying cfu/mL of wildfire bacterium liquid to inoculate seedlings, investigating the area of leaf spots after 10 days, selecting 4000 seedlings resistant to wildfire according to the investigation result, transplanting the seedlings into a black shank disease garden, and investigating the incidence of the black shank before the flowering period. Meanwhile, after transplanting for 4 weeks, identifying the resistance of the common mosaic virus by using TMV virus juice and adopting a young leaf friction virus inoculation method, and observing the pathological change condition after 5 weeks. Investigating the resistance of the climatic spot disease in the field, and identifying the resistance of the root-knot nematode and the brown spot disease by using an in vitro leaf method. The isolated leaf is impregnated with the bacterial liquid of Agrobacterium LBA4404/PVX: pND108-NIB or the bacterial liquid of Agrobacterium GV3101/PVX: pND108-NIB, and the resistance of the root-knot nematode is judged according to whether the tobacco leaf shows the allergic necrosis reaction (spot) or not after about 1 week. With a concentration of 1X 10⁶The in vitro leaf blade is inoculated by cfu/mL alternaria alternata bacterial liquid in a spraying way, and the scab area of the leaf blade is investigated after 10 days, so that the resistance of the alternaria alternata is judged. Through disease resistance identification, 500 tobacco plants which simultaneously resist black shank, common mosaic virus, climatic spot disease, root-knot nematode and brown spot are selected; for D-group tobacco seedlings, the resistance of angular leaf spot is identified by inoculating the D-group tobacco seedlings at the age of about 8 weeks and the concentration of the D-group tobacco seedlings is 1 multiplied by 10⁶Spraying and inoculating the seedlings with the cfu/mL angular leaf spot bacterial liquid, investigating the area of the disease spots of the leaves after 10 days, selecting 4000 seedlings with angular leaf spot resistance according to the investigation result, transplanting the seedlings into a bacterial wilt disease garden, and investigating the disease condition of the bacterial wilt before the flowering period. Meanwhile, after transplanting for 4 weeks, identifying the resistance of cucumber mosaic virus by using CMV virus juice through a young leaf rubbing virus inoculation method, and observing the pathological change condition after 5 weeks. Investigating the resistance of the climatic spot disease in the field, and identifying the resistance of the root-knot nematode and the brown spot disease by using an in vitro leaf method. Through disease resistance identification, 500 tobacco plants which simultaneously resist bacterial wilt, cucumber mosaic virus, climatic spot disease, root-knot nematode and brown spot are selected; for E group tobacco seedlings, the powdery mildew resistance is identified by inoculating the E group tobacco seedlings after the seedling age is about 8 weeksThe concentration is 1X 10⁶Spraying and inoculating the seedlings with cfu/mL powdery mildew liquid, investigating the disease area of leaves after 10 days, selecting 4000 seedlings with powdery mildew resistance according to the investigation result, transplanting the seedlings into a root black rot disease garden, and investigating the disease condition of the root black rot before the flowering period. Meanwhile, after transplanting for 4 weeks, identifying the resistance of the potato virus Y by using PVY virus juice through a young leaf friction virus inoculation method, and observing the pathological change condition after 5 weeks. Investigating the resistance of the climatic spot disease in the field, and identifying the resistance of the root-knot nematode and the brown spot disease by using an in vitro leaf method. Through disease resistance identification, 500 tobacco plants which simultaneously resist black rot, potato virus Y, climatic spot disease, root-knot nematode and brown spot are selected. When in flowering, 1/2 tobacco plants of the selected individuals of the C group and 1/2 tobacco plants of the selected individuals of the D group are hybridized in pairs, another 1/2 tobacco plants and 1/2 tobacco plants of the selected individuals of the E group are hybridized in pairs, another 1/2 tobacco plants of the selected individuals of the D group and another 1/2 tobacco plants of the selected individuals of the E group are hybridized in pairs to obtain 750 hybridized combination seeds, and 100 seeds are respectively taken from each hybridized combination to be fully equally mixed to form a group F. In the same season, 1500 inbred seeds which are selected from the recurrent selection basic population C0 in 2012 are sown and raised in a single plant in a Lichuan test base. In order to accumulate excellent genes favorable for economic traits and quality traits and further improve the economic traits and the quality traits of a population, after seedling establishment, the individual plant progeny tobacco seedlings are respectively planted into plant rows (namely plant lines) in a field, and 50 plants are planted in each plant line. According to the growth character and morphological character expression of tobacco plants, each strain line retains 3 tobacco plants with ideal growth character and morphological character expression of tobacco plants, selfing is carried out during blooming, seeds are harvested according to single plants, the rest single plants are topped, leaves are left and are wiped according to the conventional tobacco leaf production technology, the tobacco leaves are harvested and cured when mature, and the economic character and quality character of the cured tobacco leaves are identified. Through comprehensive evaluation of economic characters and quality characters of the roasted tobacco leaves, 500 lines with better comprehensive performances of the economic characters and the quality characters are selected, and 1500 individual plants of each self-bred seed-reserving individual plant of the selected lines are respectively selected to fully and equally mix 50 seeds to form a group G.

And in 2013, in 10 months, sowing the seeds of the group F and the seeds of the group G in a Miannan breeding base respectively for seedling culture, and transplanting the seedlings into a field respectively after the seedlings are grown. When the flower blooms, 3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics are selected from the group F, the tobacco plants are hybridized in pairs to obtain 1500 hybridized combination seeds, and 50 seeds are respectively taken from each hybridized combination and mixed to form a group H. 3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics are selected from the group G, paired hybridization is carried out to obtain 1500 hybridization combination seeds, and 50 seeds are respectively taken from each hybridization combination and mixed fully and equally to form a group I.

And in 2 months in 2014, respectively sowing and raising the seeds of the group H and the seeds of the group I in a Lichuan test base, and transplanting the seeds into a field after the seedlings are formed. During blooming, 1500 tobacco plants with relatively ideal tobacco plant growth characteristics and morphological characteristics are selected from the group H and the group I respectively, selected individuals of the group H and selected individuals of the group I are subjected to paired hybridization to obtain 1500 hybridized combination seeds, and 100 seeds of each hybridized combination are fully equally mixed to form a group J. In winter in the same year, sowing and raising seeds of the group J in a Miannan breeding base, and transplanting the seeds into a field after the seedlings are formed. 3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics are selected during blooming, paired hybridization is carried out to obtain 1500 hybrid combination seeds, and 150 seeds are respectively taken from each hybrid combination and fully equally mixed to form a first round selection population C1.

Example 2: introduction of tobacco recurrent selection group heterogenous germplasm

In summer 2014, the recurrent selection population is found to have defects in quality characters, black shank resistance and bacterial wilt resistance, so that in the same winter, in the third generation base of trilinan, a high-quality parent K326 is used as a female parent, and a germplasm DB101 capable of resisting the black shank and the bacterial wilt is used as a male parent to prepare a hybrid combination K326 multiplied by DB 101.

In 2015, the first round of selected population C1 seeds obtained in 2014 and F1 generation seeds of a hybrid combination K326 XDB 101 are respectively sown and cultured in a Lichuan test base, and are respectively transplanted into a field after seedlings are formed. During flowering, 500 tobacco plants with relatively ideal tobacco plant growth property and morphological property performances are selected from the first round selection population C1 and the F1 generation population of the hybridization combination K326 xDB 101, the selected individuals of the first round selection population C1 and the selected individuals of the F1 generation population of the hybridization combination K326 xDB 101 are subjected to pairwise hybridization to obtain 500 hybridization combination seeds, and 150 seeds are taken from each hybridization combination and fully mixed to form the population K. In winter in the same year, sowing and raising the seeds of the group K in the Miannan breeding base, and transplanting the seedlings into a field after the seedlings are formed. 3000 tobacco plants with ideal tobacco plant growth characteristics and morphological characteristics are selected during blooming, paired hybridization is carried out to obtain 1500 hybridization combination seeds, and 150 seeds are respectively taken from each hybridization combination and mixed to form a group L.

And in 2016 for 2 months, respectively sowing and raising seedlings of the first round selected population C1 seeds and population L seeds in a Lichuan test base, and transplanting the seedlings into a field after the seedlings are formed. During flowering, 1500 tobacco plants with relatively ideal tobacco plant growth vigor and morphological character performance are selected from the first round selection population C1 and the population L respectively, the selected individuals of the first round selection population C1 and the selected individuals of the population L are subjected to paired hybridization to obtain 1500 hybrid combination seeds, and 100 seeds of each hybrid combination are fully equally mixed to form the population M. In winter in the same year, sowing and raising seeds of the group M in the Miannan breeding base, and transplanting the seeds into a field after the seedlings are formed. When the flower is bloomed, 3000 tobacco plants with relatively ideal growth vigor and morphological character expression are selected, paired hybridization is carried out to obtain 1500 hybridization combination seeds, and 150 seeds are respectively taken from each hybridization combination and fully equally mixed to form a new recurrent selection basic population C0.

In 2017 and 2019, the seeds of the basic population C0 are selected in a new round, and the work from 2012 to 2014 is repeated to obtain a first round of selection population C1. Thereafter, the work from 2012 to 2014 is continuously repeated to obtain new recurrent selection populations C2 and C3. cng until the genes in the populations are fully balanced.

Example 3: identification of excellent single plants in flue-cured tobacco recurrent selection population

In 2013, 500 tobacco plants which are identified and selected through disease resistance and simultaneously resist wildfire, black shank, common mosaic virus, climatic spot, root-knot nematode and alternaria alternate with each other, and simultaneously leave tobacco cross for selfing to obtain hybrid F3 generation seeds, and the seeds are harvested according to the single plants.

In 2014, 500F 3 seeds are sown and cultured in a greenhouse seedbed of a Lichuan test base in single plants, and each single plant comprises 50 tobacco seedlings, which is called a strain. And (3) inoculating the seedlings for about 8 weeks to identify the resistance of angular leaf spot, firstly selecting a strain with better overall resistance, and then selecting tobacco seedlings resistant to angular leaf spot in the selected strain. A total of 451 angular leaf spot resistant strains were selected. Transplanting the angular leaf spot resistant tobacco seedlings into a bacterial wilt disease nursery according to the strains, and investigating the incidence of bacterial wilt before the flowering period. Meanwhile, after transplanting for 4 weeks, identifying the resistance of cucumber mosaic virus by using CMV virus juice through a young leaf rubbing virus inoculation method, and observing the pathological change condition after 5 weeks. Investigating the resistance of the climatic spot disease in the field, and identifying the resistance of the root-knot nematode and the red star disease again by using an in vitro leaf method. Through disease resistance identification, 128 strains which simultaneously resist angular leaf spot, bacterial wilt, cucumber mosaic virus disease, climatic spot disease, root-knot nematode and brown spot are selected, and disease-resistant single strains 2764 are selected in each strain. The selected 2764 tobacco plants were selfed at flowering to obtain hybrid F4 generation seeds, and the seeds were harvested as individual plants.

In 2015, 2764F 4 seeds are sown and cultured in a greenhouse seedbed of a Lichuan test base in a single plant, and each single plant has 20 tobacco seedlings per part and is called a strain. And (3) inoculating and identifying powdery mildew resistance after the seedling age is about 8 weeks, firstly selecting a strain with better overall resistance, and then selecting powdery mildew resistant tobacco seedlings in the selected strain. 901 powdery mildew resistant strains are screened out in total. Transplanting the powdery mildew resistant tobacco seedlings into a root black rot disease nursery according to the strains, and investigating the incidence condition of the root black rot before the flowering period. Meanwhile, after transplanting for 4 weeks, identifying the resistance of the potato virus Y by using PVY virus juice through a young leaf friction virus inoculation method, observing the pathological change condition after 5 weeks, and investigating the resistance of the climatic spot disease in the field. Through disease resistance identification, 88 strains which simultaneously resist powdery mildew, root black rot, potato virus Y and climatic spot disease are selected, and disease-resistant single strains 917 strains are selected in all the strains. Selected 917 tobacco plants were selfed at flowering to obtain hybrid F5 seed, and the seeds were harvested as individual plants.

In 2016, seeds of No. 917F 5 were sown and raised in greenhouse bed of Lichuan experiment base in 15 seedlings per cigarette. Planting 917 single seedlings into 917 plant rows (i.e. strains) in a field after the seedlings grow, comprehensively identifying the growth characters and morphological characters of tobacco plants, screening 59 strains with appropriate growth characters and morphological characters of the tobacco plants, selecting 2-3 single plants with more ideal growth characters and morphological characters of the tobacco plants in each selected strain, selfing during flowering, and mixing the strains into single plant seeds to form strains;

in 2 months of 2017, dividing seeds of 59 lines into 2 parts, respectively sowing and raising seedlings on a greenhouse seedbed of a test base, wherein 1 part of tobacco seedlings of the seeds are transplanted into a field for seed reproduction after becoming seedlings, the other 1 part of tobacco seedlings of the seeds are transplanted into the field after becoming seedlings, repeating for 3 times, taking a variety Yunyan 87 which is commonly planted in production as a contrast, carrying out an economic character identification comparison test on each line, and the result shows that 10 lines have proper yield and other economic character indexes comprehensively evaluate more than the control variety Yunyan 87, respectively giving codes HB1701, HB1702, HB1703, HB1704, HB1705, HB1706, HB1707, HB1708, HB1709 and HB1710, and reserving seeds for selfing of the corresponding lines in a seed reproduction field.

In 2018, new strains HB1701, HB1702, HB1703, HB1704, HB1705, HB1706, HB1707, HB1708, HB1709 and HB1710 are set in Xuan Bei province, respectively, comparison tests of the new strains are set, the quality traits, adaptability and stability of each strain are identified by taking Yunyan 87 which is a production common planting variety as an economic trait and an adaptability control and taking a high-quality variety K326 as a tobacco leaf quality control, the baked tobacco samples are taken at each point for identifying appearance quality, chemical components, physical characteristics and sensory evaluation quality, and the adaptability of each strain and the stability of the tobacco leaf quality traits and the economic traits are statistically analyzed. Through comprehensive evaluation, lines HB1706, HB1709 and HB1710 with outstanding quality traits, wide adaptability and good stability are preliminarily screened, and a multipoint comparison test is performed on the 10 lines in 2019.

In each embodiment of the invention, the growth traits of the tobacco plant specifically comprise the rising speed of the tobacco plant, the field growth potential, the axillary bud growth potential, the cluster stage, the vigorous growth stage, the bud stage, the central flower open stage, the flat top stage, the bottom leaf mature stage, the upper leaf mature stage, the days from transplanting to topping, the days of the field growth stage and the leaf mature speed; the morphological characters of the tobacco plants specifically comprise the typical characteristics of the tobacco, plant type, plant height, stem thickness, total leaf number, extractable leaf number, leaf distribution uniformity, pitch spacing, leaf shape, leaf size, leaf stripping potential at the upper part, leaf thickness, leaf color, smooth or shrinking degree of leaf surfaces, fine or rough mesophyll tissue, leaf flexibility, leaf main vein thickness, stem/leaf ratio size, leaf maturation uniformity, leaf maturity resistance, stem leaf angle, distance between the uppermost extractable leaf implantation point and central flower and the number of twigs of the tobacco; the economic traits specifically comprise single leaf weight, yield, output value, average price, first-class tobacco proportion and first-class tobacco proportion; the quality traits specifically comprise the appearance quality, chemical components, physical characteristics and sensory evaluation quality of the tobacco leaves after modulation, the adaptability specifically comprises the environmental adaptation range of the new strain and the adaptation degree in a certain environmental range, and the stability specifically comprises the stability of the quality traits of the tobacco leaves and the stability of the economic traits of the tobacco leaves.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The recurrent selection group creating and selecting method for breeding the high-quality multi-resistance new tobacco strain is characterized by comprising the following steps of: comprises that

(11) adopting the seeds of the first round selection population C1 obtained in the step (10), repeating the steps (6) to (10) to obtain a second round selection population C2, and so on until the phenotypes of the tobacco plants in the population are close to consistency and the genotypes are highly heterozygous, and finally obtaining an nth round selection population Cn with fully balanced genes in the population;

selecting multi-resistance parents with a plurality of disease resistance varieties as disease resistance parents, and using at least 1 disease resistance as an anti-source of the disease;

the growth traits of the tobacco plants specifically comprise the rising speed of the tobacco plants, the field growth vigor, the axillary bud growth vigor, the cluster stage, the flourishing stage, the bud stage, the central flower open stage, the flat top stage, the bottom foot leaf maturation stage, the upper leaf maturation stage, the days of transplanting to topping, the days of the field growth stage and the leaf maturation speed; the morphological characters of the tobacco plants specifically comprise the typical characteristics of the tobacco, plant type, plant height, stem thickness, total leaf number, extractable leaf number, leaf distribution uniformity, pitch spacing, leaf shape, leaf size, leaf stripping potential at the upper part, leaf thickness, leaf color, smooth or shrinking degree of leaf surfaces, fine or rough mesophyll tissue, leaf flexibility, leaf main vein thickness, stem/leaf ratio size, leaf maturation uniformity, leaf maturity resistance, stem leaf angle, distance between the uppermost extractable leaf implantation point and central flower and the number of twigs of the tobacco;

the economic traits specifically comprise single leaf weight, yield, output value, average price, first-class tobacco proportion and first-class tobacco proportion; the quality traits specifically comprise the appearance quality, chemical components, physical characteristics and sensory quality of the modulated tobacco leaves.

2. The method for creating and selecting recurrent selection populations for breeding new lines of high-quality multi-resistance tobacco according to claim 1, wherein the method comprises the following steps: when a certain round of selection group Ci also comprises a measure for introducing heterologous germplasm after being created, the method comprises the following steps:

3. The method for creating and selecting recurrent selection populations for breeding new lines of high-quality multi-resistance tobacco as claimed in claim 2, wherein the method comprises the following steps: when 2 heterologous germplasm needs to be introduced simultaneously after the creation of a round of selection population Ci, the 2 heterologous germplasm can be hybridized firstly to obtain a hybrid F1 generation, and then the hybrid F1 generation is used as a single heterologous germplasm to be hybridized in pairs with the Ci population seeds.

4. The method for creating and selecting recurrent selection populations for breeding new lines of high-quality multi-resistance tobacco as claimed in claim 3, wherein the method comprises the following steps: and identifying the single plants well represented in the round selection basic population C0, the new round selection basic population C0', the round selection population Ci or the round new selection population Ci', and introducing the single plants into a conventional breeding program to further breed the high-quality multi-resistance new strain.

5. The method for creating and selecting recurrent selection populations for breeding new lines of high-quality multi-resistance tobacco according to claim 4, wherein the method comprises the following steps: and (4) identifying the strain with better comprehensive performance of the economic character and the quality character obtained in the step (8) and bringing the strain into a conventional breeding program so as to breed a high-quality multi-resistance new strain.