Improve the method for seed production efficiency of hybrid rice by kernel miniaturization improvement of male sterile line
Technical field
The present invention relates to a kind of producing method for seed of hybrid rice, relate in particular to a kind of method that improves seed production efficiency of hybrid rice by kernel miniaturization improvement of male sterile line.
Background technology
Plant hybrid vigour has generality, and can this advantage be used effectively, and depends on to a great extent producing crossbreed is whether the cost of the production of hybrid seeds is cheap, and can the user have purchasing power.Hybrid rice had more than 30 year at China's success utilization and extention, for trying to achieve higher hybrid rice yield potentiality, the grain that improves the paddy seed heavily is at present by one of means of more employing, but this has also caused the increase of rice farming sowing quantity (weight) simultaneously and has dropped into the costs that are used to purchase kind more.
A kind of by the mutagenic obtained little particle mutant (ZH-sg) of r-ray, it is subjected to single recessive gene (sg) control, and sg gene pairs plant height, tillering ability, small ear fertility, seed shape etc. do not produce any related influence.Because the granule characteristic is controlled by single recessive gene, being modified to the F1 crossbreed of producing behind the male sterile line with this mutant material is granule, because it is that the genotype of male sterile line is controlled that crossbreed is subjected to parent, being sold to the paddy (F2 seed) that rice farming plantation F1 hybrid rice produces is normal grain type, thereby does not influence the output and the income of rice farming plantation hybrid rice.
This catastrophe characteristics can import granule gene sg in any different material by sexual hybridization.If is that male sterile line, two is in male sterile line or the other forms of male sterile line with the granule characteristic by the hybridization and the importing three of backcrossing, can improve the seed production efficiency of hybrid rice.This granule is used for yield potentiality in conventional rice breeding improvement is unsuitable, but the improvement that is used for the hybrid rice male sterile line is fully feasible.
Summary of the invention
It is big to the present invention is directed in the prior art seed, cause planting problems such as efficient is low, cost is big, a kind of method that improves seed production efficiency of hybrid rice by kernel miniaturization improvement of male sterile line is provided, the method is by sexual hybridization, sg transduces into male sterile line with the granule mutator gene, and the seed of male sterile line self is diminished, and does not change the seed size of the paddy that hybrid rice produces, thereby reduce production of hybrid seeds area and improve land utilization efficiency, reduce the rice farming and purchase the income that the cost of planting increases the rice farming.
The utilization of crop hybrid superiority must be can the cheap F1 of acquisition crossbreed being prerequisite, and the plantation hybrid rice can obtain output and income after the user bought crossbreed.The so-called parent that crossbreed is 2 inheritance stabilities, genotype is different, the seed that sexual hybridization produced (crossbreed F1).
Crossbreed is bought in rice farming, and measurement unit be a kilogram (kg), and comes down to satisfy the granule number of the crossbreed that certain area plants.Be 1000 seeds equally, the varying in weight of every seed, final total weight is different.If the seed of crossbreed is a granule, and the hybridization paddy of producing is big grain (or normal grain type), just can raise the efficiency to some degree and benefit.
The present invention imagination is by sexual hybridization, and sg transduces into male sterile line with the granule mutator gene, and the seed of male sterile line self is diminished, and does not change the seed size of the paddy that hybrid rice produces.So, maybe can reduce production of hybrid seeds area and improve land utilization efficiency, maybe can reduce the rice farming and purchase the income that the cost of planting increases the rice farming.
The objective of the invention is to be implemented by the following technical programs:
The present invention is the method that improves seed production efficiency of hybrid rice by kernel miniaturization improvement of male sterile line, and its step comprises:
A) be donor parents to contain granule gene sg mutant hybrid rice, with three be that sterile maintenance line hybrid rice, two is the hybridization of male sterile line hybrid rice or other types male sterile line hybrid rice receptor parent, obtain hybrid F1, plantation hybrid F1, obtain F2 from generation to generation, it is that sterile maintenance line hybrid rice, two is when being male sterile line hybrid rice or other types male sterile line hybrid rice level that the thousand grain weigth that the present age, F2 bore on the plant from generation to generation shows as three, separating from generation to generation at F2 has 1/4 individuality to carry granule gene sg, and it still is granule from generation to generation that the individuality of band sg gene is planted into F3; Contain the ZH-sg that granule gene sg mutant hybrid rice is paddy rice (Oryza sativa) (in spend 11 little particle mutants), be preserved in CGMCC, deposit number No.2741 on November 07th, 2008;
B) select form to carry the individuality of granule gene sg like receptor parent from generation to generation at F2; backcross with receptor parent or can backcross as the execution of A step procedure; once backcross BC1F2 from generation to generation or the secondary BC2F2 that backcrosses still can isolate from generation to generation under the situation of 1/4 granule individuality; select the form individuality that seed diminishes as receptor parent substantially; promptly carry the individuality of sg gene, can stablize maintenance line or the male sterile line that obtains to carry mutator gene sg through the selection of 5~7 generations.
As preferably, carry the hybrid rice seed of granule gene sg, its thousand kernel weight is 19~21 grams, and is littler by 25%~45% than the thousand kernel weight of general male sterile line.It is that sterile maintenance line, two is that male sterile line or its average thousand kernel weight of other types male sterile line receptor parent are 25~30 grams that seed size is hybridized paddy three normally.As shown in Figure 1.
As preferably, in selection course, can carry out the background selection of receptor parent to the individuality of the isolated sg of carrying gene by the nationality molecular marking technique, the genotype with receptor parent during selection serves as to use for reference to carry out molecular marker assisted selection.The maintenance line that carries the sg gene that final choosing obtains or the number of grain per ear of male sterile line obviously surpass receptor parent, with the miniaturization and the equilibrium output level of compensation seed.
In order to remedy the output decline that granule brings, in the individual choice of carrying the sg gene, select the individuality of number of grain per ear, so that the number of grain per ear of maintenance line that carries the sg gene that final choosing obtains or male sterile line is obviously above receptor parent above receptor parent.The output of grass family class crops generally is made of the real grain number of the number of productive ear of unit are, every fringe and heavy these 3 key elements of grain of seed.As long as increase the proportion of some key elements, output is increased in 3 key elements.But generally speaking, increase one of them key element, can make another one or two key element declines in various degree, the increase of ultimate output is extremely limited.Therefore, utilize granule mutant ZH-sg to carry out the rice sterile line improvement, reduce when grain weighs and correspondingly to increase number of grain per ear or tiller number, i.e. number of productive ear.
Granule mutant sg both can be used on nuclear-matter, and to do sterile three mutually be the improvement of approach male sterile line (A or B), also can be used for environment and make the light of inducing mutually (Wen) quick caryon sterile line (S) and other modes are produced in the male sterile line improvement of crossbreed (as " chemical emasculation " approach).The present invention compared with prior art has the following advantages:
The present invention is mainly used in the sport technique segment of cross breeding seed, and production does not have any impact to hybrid rice.Be described as follows:
The thousand kernel weight of mutant ZH-sg is 20g (former parent is the 24g/1000 grain), and the thousand kernel weight of general rice sterile line " golden 23A " (trade name) is 25g, and bigger is 30g as " interior fragrant 2A " (trade name).The F1 crossbreed of supposing the production of 1 mu of hybrid rice seed farm is 200kg, and thousand kernel weight is that the F1 of 20g, 25g, 30g is respectively 1,000 ten thousand, 8,000,000,6,660,000 for seed amount.China's rice farming generally is 1 cave, 1 seedling when the plantation hybrid rice, and 1 mu of field plants 1.5 ten thousand seedlings of seedling, and in 20,000 F1 seeds of every mu of sowing, the equivalent weight crossbreed of above-mentioned 3 kinds of thousand kernel weight types can be planted 500 mu, 400 mu, 333 mu respectively.Every mu of sowing quantity of above-mentioned 3 kinds of thousand kernel weight is converted to weight by quantity and is respectively 400g, 500g, 600g, and when seed price (by weight) was all 16 yuan/kg, cost was respectively 6.4 yuan, 8.0 yuan, 9.6 yuan.
If rice sterile line is and carries granule gene sg and carry out the production of hybrid seeds, on national aspect, can save a large amount of production of hybrid seeds rice fields; On kind of industry company aspect, can reduce the quantity and the cost of storage, transportation; From producing on user's aspect, it is agricultural in the cost of buying hybrid rice seed to reduce rice.
Description of drawings
Fig. 1 is the maintenance line that utilizes after the granule mutant improvement, and utilizes the paddy behind the hybrid rice combined grow of this material configuration; Figure is right for carrying the seed of granule gene sg, and its thousand kernel weight is 20 grams; Figure is hybridized paddy and rice normally for seed size in a left side, and its thousand kernel weight is 25 grams.
Fig. 2 is embodiment 1 flow chart.
Embodiment
Below be the specific embodiment of the present invention, technical characterictic of the present invention is described further, but the present invention is not limited to these embodiment.
Embodiment 1:
As shown in Figure 2, contain the ZH-sg that granule gene sg mutant hybrid rice is paddy rice (Oryza sativa) (in spend 11 little particle mutants), be preserved in CGMCC, deposit number No.2741 on November 07th, 2008; With ZH-sg is donor parents, can (three be male sterile line with main male sterile line II-32A in China present hybrid rice production of hybrid seeds, thousand kernel weight 28 grams), (three is male sterile line to interior fragrant 2A, thousand kernel weight 30 grams), (two is male sterile line extensively to account for 63S, thousand kernel weight 28 gram) improvement of male sterile line kernel miniaturization is carried out in hybridization such as.
Be example with II-32A and corresponding maintenance line II-32B (receptor parent) thereof below, the embodiment of this patent is described.
1. with corresponding maintenance line II-32B and the hybridization of granule mutant of II-32A, obtain F1 from generation to generation, the size of F1 grain type similar to II-32B (normal seed), general planting F1 obtains F2 from generation to generation.
2.1F2 isolate 1/4 granule type individuality, and backcross once, obtain BC1F1 from generation to generation with II-32B.Can the isolated sg individuality that contains be carried out the genotypic background of II-32B with molecular marking technique and detect, or select the individuality similar as far as possible to II-32B with morphological characters before backcrossing.
2.2 general planting F2 obtains F3 from generation to generation, the rest may be inferred, obtains F4 generation, F5 generation, F6 from generation to generation.
If 3.1 once backcross, then general planting BC1F1 obtains BC1F2 from generation to generation, and the rest may be inferred, obtains the BC1F3 generation, obtains the BC1F4 generation, obtains BC1F5 from generation to generation.
3.2 can in BC1F2, select the individuality that contains the sg gene, with II-32B again row backcross for the 2nd time, obtain BC2F1 from generation to generation.Carrying out the similitude of background or row and II-32B when backcrossing once more selects.
4. general planting BC2F1 obtains BC2F2 from generation to generation, and the rest may be inferred, obtains BC2F3 from generation to generation.
5. be maternal with II-32A, with the individuality that carries sg gene and agronomic shape excellence, promptly F4~F5, BC1F2~BC1F3, BC2F2 are hybridized, i.e. nucleus substitution.It is F5~F6 generation, BC1F3~F4 generation, BC2F3 generation with the individuality that carries sg gene and agronomic shape excellence later on.Such nucleus substitution hybridization need be carried out 5 times at least.Thereby obtain with the sg gene and genetic background novel male sterile line (the A)/maintenance line (B) similar to II-32.
For reducing the time that improved, process consumed, can just set about with II-32A hybridization, backcross and carry out nucleus substitution in lower generation such as F4.
Being characterized as of new sterile line/maintenance line: thousand kernel weight is 20 grams, and form is shown in Fig. 1 right side.
The selection of receptor parent, can be three be maintenance line, also can be two to be male sterile line or other forms of male sterile line, all can do maternal and donor parents ZH-sg hybridization, the seed of the paddy of tying is similar to receptor parent on the first-filial generation plant of plantation.F2 isolates ratio for meeting and accounts for 1/4 the individuality that carries the sg gene, because of be subjected to after the hybridization, donor both sides' gene recombinates, if the ameliorator wishes that the offspring is alike with receptor parent as far as possible, the selection of acceptor gene type background can be in the individuality that carries the sg gene, carried out, efficiency of selection can be improved like this with molecular marking technique.Genotype is similar to receptor parent as far as possible if wish that the offspring only keeps the sg gene, and the individuality of optional band sg gene and receptor parent are backcrossed 1~2 time or 3~5 times, can make offspring's genotype revert to receptor parent so rapidly.
When separating the offspring and carry the sg gene, note selecting the fringe type type bigger than receptor parent, maintenance line (male sterile line) is remedied, with balance or keep original yield potentiality by increasing number of grain per ear in the grain back that heavily descends.
Specific embodiment described in the present invention only is that the present invention's spirit is illustrated.The technical staff of the technical field of the invention can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present invention or surmount the defined scope of appended claims.
Although the present invention has been made detailed explanation and has quoted some instantiations as proof, to those skilled in the art, only otherwise leave that the spirit and scope of the present invention can be done various variations or correction is obvious.