SU1685321A1 - Method for production of drught-resistant forms of maize - Google Patents

Abstract

The invention relates to agriculture, in particular to the process of selection of cross-pollinated and optional self-pollinated cultures. The purpose of the invention is the simplification and acceleration of the method. Before pollination, pollen is dried to a residual water content of 12-25% at low atmospheric pressure. The plants are then dehydrated with pollen and then the seeds are collected. 1 tab.

Description

The invention relates to agriculture, in particular to the process of selection of cross-pollinated and optionally self-fertilized crops.

The purpose of the invention is to simplify and accelerate the way

The method is carried out as follows.

Pollen from heterozygous drought tolerant donor plants is collected.

Collected pollen is dehydrated. In this case, only those pollen grains remain viable, the genome of which contains factors determining drought tolerance, the remaining pollen grains die. Dehydration is carried out to a residual water content of 12-15% at low atmospheric pressure.

Dehydrated pollen is dusted with the pistils of the mother plant, previously closed with insulators.

Seeds obtained as a result of pollination (they possess enhanced drought resistance) are planted in the soil according to the usual technology for carrying out the subsequent selection process on plants by field methods.

Heterozygous plants of the original population, from which the selection of drought-resistant forms is made, form millions of pollen grains, representing virtually all variants of the distribution of characters of the parental genome. Carrying out the pollen sampling allows a much larger sample size (compared to the sample size on the seeds) and thus improves the selection efficiency. In addition, the galloid state of the microgametophyte genome (pollen grain) eliminates the negative effect on

00

eat s

Yu

selection of allelic interactions that occur in a diploid organism and reduce the accuracy of selection. An increase in productivity and a reduction in the laboriousness of the method with respect to the known method occurs due to the elimination of a long and laborious seed germination operation and the introduction of a pollen dewatering operation.

Example. As the initial heterozygous form, a simple interlinear hybrid of corn P 165x5760 was chosen, the parental forms of which are different in drought resistance lines (P165 is not drought resistant, X 5760 is drought resistant). During the bloom of plants, the freshly harvested pollen of the hybrid is divided into two parts. One part is directly used to pollinate the coils of the P165 line (control) that were previously closed with insulators. Another part of the pollen is subjected to dehydration at low atmospheric pressure (0.7 KPa) for 20-30 minutes to a residual water content of 12-25%. Dehydrated pollen was also pollinated by the cob of the P165 line previously covered with insulators (test).

Pollen dehydration mode was selected based on the following considerations.

At low atmospheric pressure, the process of removing moisture from the pollen is more intense. This is necessary to reduce processing time, since corn pollen (and other cereals) has a high metabolic activity and rather quickly loses viability during storage.

With a residual water content in pollen of more than 25%, the efficiency of selection decreases, and less than 12-15% (depending on the genotype), the number of viable pollen grains decreases significantly, and, accordingly, the number of seeds consumed.

The drought resistance of seeds obtained from the pollination of the P165 line with dehydrated and undehydrated pollen of the lines and hybrids of corn is given in the table.

Fatherly Dehydrated SeedsQuantity

sprung

boron pollen on osmotic sem nx,%

one

J

19.6 ± 1.1

P165HHNe check P165

Den Х5750ХХХ - -П165ХХ5760 41, 4 ± 1.8

one

Continued table.

 four

- -

(experience)

L165 (П165х 27.4 ± 1,9ХХХХ Х5760)

П165х (П165х 43,0 ± 1,9ХХХХ Х5760)

five

5 0 5

0 5

0

five

0

five

Spreading of seeds was carried out xxxNon-drought-resistant line (according to field estimates) xxx3 drought-resistant line (according to field estimates) xxxxDifferent are reliable at a significance level of 0.001

The seeds obtained after pollination (control and experiment) were tested for drought resistance by germination on solutions with high osmotic pressure by a known method. The test showed that in the control variant 27.4 ± 1.9% of seeds sprouted, and in the experimental variant - 43.0 ± 1.9% of seeds. For comparison, the results of determining the germination of seeds in the parental forms of the hybrid are given: in the line A165, 19.6 ± 1.1% of the Gu line X576041.4 ± 1.8.

Thus, the use of the method allows for the effective selection of drought-resistant forms: the drought resistance of the selected samples affected the level of the best parent component (line X5760).

The method allows, with high efficiency and productivity, the preliminary selection of drought-resistant maize samples, and, in connection with this, significantly reduces the amount of subsequent field assessments and selections.

The method can be used to select for drought resistance of other cross-pollinated and optional self-pollinated crops, in which the resistance of microgametophytes (pollen) to dehydration is determined (at least partially) by the genes responsible for the drought resistance of the plant - sporophyte.

Claims (1)

Claim method for producing drought-tolerant forms of corn, including the effect of dehydration factor, characterized in that, in order to simplify and speed up the method, the dewatering factor affects the pollen before pollination, while dehydration is carried out to a residual water content of 12-25% at low atmospheric pressure the plants are then dehydrated with pollen and then the seeds are collected.