CN1401219A - Method for breeding light- and temp.-sensitive nucleus sterile line rice with plant age regulatory fertility - Google Patents

Abstract

The invention belongs to the field of rice breeding. In particular, the breeding of rice photothermosensitive genic male sterile lines whose plant age regulates fertility. By selecting rice varieties (lines) with plant-age-regulating fertility genes and photothermo-sensitive genic male sterile lines to cross each other, through selection, more plant-age-regulating fertility genes and photothermo-sensitive genic male sterile genes are aggregated into one body, which can be A photothermosensitive genic male sterile line with obvious plant age-regulated fertility characteristics was bred. The sterile light and temperature critical value of the seed plants of this sterile line is low, and the sterility period is long, which can be used for local safe seed production; at the same time, due to the high sterile light and temperature critical value of the old plant regenerated plants, it can be used for normal breeding in the local area. , better solve the contradiction between practical CMS seed production and multiplication, eliminate the conditional restrictions of off-site breeding or cold-irrigation breeding, save manpower and material resources, and improve the safety of CMS utilization. At the same time, due to In the breeding process, it can be propagated and added on the spot, which also speeds up the breeding process.

Description

Breeding method of rice photothermosensitive genic male sterile line with plant age regulating fertility

The invention belongs to rice breeding technology, in particular to the selection and breeding of rice light-temperature-sensitive nuclear male sterile lines and the utilization of rice heterosis.

At present, there are two ways to utilize heterosis in rice: the three-line method and the two-line method. In my country, the three-line method utilizes rice heterosis, and it has been widely used in production as early as the 1970s. It uses the interaction between the nucleus and the male sterility to realize the three-line matching and reproduce the sterile line through the hybridization of the sterile line and the maintainer line. Line seeds, male sterile lines and restorer lines are crossed to produce the first generation of hybrid seeds for production and application. The use of rice heterosis by the two-line method is also the first in China. It has been widely used in production since the 1990s. It is used to cultivate rice by using the new germplasm of rice photothermosensitive genetic male sterility discovered in the early 1970s. Photothermosensitive genic male sterile line, this sterile line is sterile under long-light and high-temperature environment and used for seed production, and it is fertile under short-light and low-temperature environment for seed propagation, one line is dual-purpose, thus simplifying seed production In addition, the fertility of the photothermosensitive genic male sterile line is controlled by the recessive homozygous gene, and normal varieties can be used as a restorer line to match with it, without being restricted by the restorer gene, so the recovery method is better than the three-line method. There are many lines, the combination is relatively free, and it is easier to take advantage of inter-subspecies heterosis by introducing wide-compatibility genes. However, the fertility changes of photothermosensitive genic male sterile lines are affected by light and temperature conditions, especially temperature conditions. Therefore, safe seed production and good seed reproduction of sterile lines are a pair of contradictions. Seed production is safer but multiplication is more difficult. The low-temperature-sensitive CMS lines currently selected for production have a long sterility period and relatively safe seed production due to their low sterility critical value, but they are difficult to breed under natural conditions. kind. This increases the cost of seed production on the one hand, and is also limited by cold water resources on the other hand. In addition, in the breeding of low-temperature-sensitive male sterile lines, because such breeding materials cannot be fertile under local conditions, the addition and selection of breeding materials are restricted by conditions, which affects the breeding scale and progress, and hinders the breeding process .

The first object of the present invention is to select and breed rice photothermosensitive genic male sterile lines with low critical light temperature values that have obvious regulating effect on fertility by plant age, and use the seed plants with low sterile light temperature critical value to grow in larger Ecological space and ecological period for safe seed production, and the characteristics of the greatly increased sterility critical value of regenerated plants at old plant ages can be used for breeding in the same ecological space and time period for safe seed production of seed plants, thereby solving the problem of local seed production and The contradiction that breeding and breeding cannot coexist avoids the trouble of breeding in different places or breeding under cold irrigation conditions, and finds a new way of low cost and good effect for practical photothermosensitive male sterile line breeding. The second is that through hybridization and selection, the genes regulating plant age and fertility can be gathered in the new photothermosensitive genic male sterile line, and the breeding target of the sterile light temperature critical value of the new male sterile line can be set lower, so that The new CMS seed production is safer and more practical. At the same time, the old plant-age regenerated plants can be used for in-situ breeding and additional generation during the selection and breeding process, so that the breeding work can make full use of local favorable conditions to speed up the breeding process.

The present invention stems from our research and found that some rice varieties (lines) and rice photothermosensitive genic male sterile lines have plant age regulation fertility genes. In addition to regulation, it is also affected by plant age. Older regenerated plants have a higher sterile light-temperature critical value than seed plants, and the seed plants grown from the seeds received for propagation on regenerated plants return to the original low sterile light-temperature critical value. It can be inherited very stably, and studies have found that this characteristic is controlled by multiple genes.

The present invention is realized in the following way: firstly, different germplasms with plant age regulating fertility genes are screened out from rice varieties (lines) and photothermosensitive genic male sterile lines of different genotypes. The method for screening rice varieties (lines) with plant age-regulating fertility genes is to use rice varieties (lines) to hybridize with rice photothermo-sensitive genic male sterile lines that do not have plant-age-regulating fertility genes, and then from the hybrid progeny F2 population The selected photothermosensitive genic male sterile plants are identified whether they have the plant age regulation fertility characteristic, and if they have this characteristic, then it is determined that the rice variety (line) has the plant age regulation fertility gene. The method for screening rice photothermo-sensitive genic male sterile lines with plant age-regulated fertility genes is to compare whether there is a difference in the sterility light-temperature critical value of the seed plant and the regenerated plant of the old plant age in the same ecological environment, if the old plant age The sterility light-temperature critical value of the regenerated plants was significantly higher than that of the seeded plants, so it was determined that the photo-temperature-sensitive genic male sterile line of rice had plant age-regulated fertility genes. Thereafter, select the germplasm that has been screened to have a plant-age-regulating fertility gene and hybridize with rice varieties (lines) or photothermo-sensitive genic male sterile lines of different genotypes. The hybridization method includes: (1) selecting a plant-age-regulating fertility gene Genetic rice varieties (lines) are crossed with photothermosensitive male sterile lines. (2) Hybridization of rice photothermosensitive genic male sterile lines with rice varieties (lines) with plant-age-regulating fertility genes, and then using rice varieties (lines) with plant-age-regulating fertility genes as recurrent parents for backcrossing breeding. (3) Select different genotypes of rice photothermosensitive male sterile lines with plant age regulation fertility genes to cross each other (including multiple crosses). (4) Selecting a rice photothermosensitive genic male sterile line with a plant age-regulated fertility gene to cross (including multiple crosses) with a rice variety (line) with a plant age-regulated fertility gene. After crossing, through the separation and recombination of genes, select the photothermosensitive genic sterile individual plants with obvious plant age regulation fertility characteristics from the offspring. In the selection of each generation, the sterile plants with low phototemperature critical value are selected as the seedlings. For the object, the regenerated plants of the old plant age are the fruit-bearing plants with high light and temperature critical value as the object. The selected individual plants continue to be selected for continuous multi-generation single-line selection until a homozygous and stable rice photothermo-sensitive genic male sterile line with plant-age-regulated fertility characteristics is selected, and then the artificial climate chamber and natural ecological environment are used to control the genetic male sterile line. Identify the critical value of light and temperature for sterility in seed plants, identify the critical value of light and temperature for fertile regenerated plants at old plant ages, and determine the critical value of light and temperature for sterility and The critical value of light and temperature for fertile old plant regenerated plants. The bred rice variety can be named as a rice photothermosensitive genic male sterile line that regulates fertility by plant age.

The main feature of the present invention is that the general photothermosensitive genic male sterile line of rice only has the photothermosensitive genic male sterile gene, while the rice photothermosensitive genic male sterile line that regulates fertility by plant age does not have the photothermosensitive genic male sterile gene. In addition to the age-regulating fertility gene, it also has the age-regulating fertility gene, and emphasizes the strength of the age-regulating fertility characteristics. It is more practical to regulate the fertility gene so that the intensity of this characteristic is greater, and the sterility threshold value of plants of different ages varies greatly.

Advantages and effects of the present invention: Since the light-temperature critical value of the sterile light-temperature critical value of the light-temperature-sensitive male sterile line with the characteristic of regulating the fertility of the plant age has the characteristics of being regulated by the plant age, it is possible to use the seedlings with a low critical value of the sterile light-temperature temperature It can be used for safe seed production, and the old plant-aged regenerated strains with high critical value of sterile light and temperature can be used for high-yield seed propagation. It solves the contradiction that the same practical male sterile line cannot be produced and multiplied at the same time at the same time or that it is difficult to reproduce the seed if the seed production is safe, and the contradiction that the seed production is not safe enough if the multiplied seed is easy, and eliminates the need for off-site breeding or Restrictions and troubles of cold irrigation breeding. In the process of breeding new sterile lines, the gap between the sterility critical value of the seed plant and the old regenerated strain can be selected to reduce the breeding target of the sterility critical value of light and temperature of the seed plant to a lower level, and more It is conducive to safe seed production, and at the same time, in the process of selection and breeding, the seeds can be multiplied and added on the spot, so as to speed up the breeding process. Therefore, through the utilization of this invention, the risk of breeding seeds of two-line hybrid rice can be reduced and the manpower and material costs of breeding a large number of seeds and new sterile lines can be saved.

Example 1: From the recross combination W7415S/C71140//Qishanzhan, a rice temperature-photosensitive GMMS line N9S with obvious plant age-regulated fertility characteristics was bred. W7415S is an indica rice photothermosensitive genic male sterile line from Hubei Academy of Agricultural Sciences, which has been screened out from more than 20 rice photothermosensitive genic male sterile lines and determined to have plant age-regulated fertility genes. The sterility threshold temperature of the seedlings was about 1°C higher than that of the seedlings. C71140 is an indica rice variety originating from Taiwan that is screened from more than 100 rice varieties (lines) and identified to have a plant-age-regulating fertility gene. Qishanzhan is an indica rice variety bred by Guangdong Academy of Agricultural Sciences. Three parents of W7415S, C71140 and Qishanzhan were used for compound crossing to select sterile seedlings with low critical value of light and temperature for sterility from the F2 generation, and old plants with high critical value of sterile light and temperature were selected after regeneration of Hetou As for the regenerated strain, a stable homozygous strain with good comprehensive traits was bred after 8 consecutive generations of single strain selection, named N9S. The seed plants and old regenerated plants of N9S were placed in the artificial climate box at the same time for different light and temperature combinations, and the annual fertility observation was carried out in the natural environment. Seeds can be produced safely in Guangzhou in the morning and evening seasons. The sterility temperature critical value of N9S old plant regenerated plants is 25-26°C, and seeds can be reproduced in Guangzhou in the morning and evening seasons. It shows that N9S has more plant age-regulated fertility genes, and it is a rice temperature-photosensitive genic male sterile line with obvious plant-age-regulated fertility characteristics.

Example 2: From the W7415S/C71140 hybrid combination, a rice low-temperature-sensitive GMMS line N26S was bred with obvious plant age-regulated fertility characteristics. W7415S is an indica rice photothermosensitive genic male sterile line from Hubei Academy of Agricultural Sciences, which has been screened out from more than 20 rice photothermosensitive genic male sterile lines and determined to have plant age-regulated fertility genes. The sterility threshold temperature of the seedlings was about 1°C higher than that of the seedlings. C71140 is an indica rice variety originating from Taiwan that is screened from more than 100 rice varieties (lines) and identified to have a plant-age-regulating fertility gene. Using W7415S to cross with C71140, select sterile seedlings with low sterile light-temperature critical value from the F2 generation, and select old plant-age regenerated plants with high sterile light-temperature critical value after keeping the grass head for regeneration. After line selection, a stable homozygous line with good comprehensive traits was selected and named N26S. The seed plants and old regenerated plants of N26S were placed in the artificial climate box at the same time for different light and temperature combinations, and the annual fertility observation was carried out in the natural environment. Seeds can be safely produced in Guangzhou in the morning and evening seasons. The critical value of the sterility temperature of old N26S regenerated plants is about 25°C, and seeds can be reproduced in Guangzhou in the morning and evening seasons. It shows that N26S has more plant age-regulated fertility genes, and it is a rice low-temperature-sensitive genic male sterile line with obvious plant-age-regulated fertility characteristics.

Claims (6)

1. the photo-thermo sensitive male nuclear sterile rice line selection of strain regulatory fertility in age, it is characterized in that filtering out different germplasms rice varieties (being) and the photo-thermo-sensitive genic male sterile line from different genotype with strain regulatory fertility in age gene, use then through screening and have the germplasm of strain regulatory fertility in age gene and the rice varieties (being) or the photo-thermo-sensitive genic male sterile line mutual cross mutually of different genotype, the hybridization back is by the separation reorganization of gene, from the offspring, the photoperiod-temperature sensitive genie male-sterile line individual plant with obvious strain regulatory fertility in age characteristic is selected, in the selection in per generation, the strain of growing directly from seeds is an object with the low sterile strain of light temperature critical value, old strain regeneration strain in age is an object with the high solid strain of light temperature critical value, selected individual plant is proceeded the choosing of continuous multi-generation individual plant system, after selecting the stable photo-thermo sensitive male nuclear sterile rice line that isozygotys with strain regulatory fertility in age characteristic, by climatic cabinate and natural ecological environment the strain of growing directly from seeds is done the evaluation of sterile light temperature critical value again, old strain regeneration strain in age is done to educate the evaluation of light temperature critical value, determine the sterile light temperature critical value of its strain of growing directly from seeds of photo-thermo sensitive male nuclear sterile rice line of breeding and the warm critical value of educated light of old strain regeneration strain in age, but the photo-thermo sensitive male nuclear sterile rice line of the rice varieties called after strain regulatory fertility in age that brings out.

2, according to the photo-thermo sensitive male nuclear sterile rice line selection of the said strain of claim regulatory fertility in age, it is characterized in that said rice varieties (being) screening technique with strain regulatory fertility in age gene, be by hybridizing with rice varieties (being) and the photo-thermo sensitive male nuclear sterile rice line that does not have strain regulatory fertility in age gene, from filial generation F2 colony, select the photoperiod-temperature sensitive genie male-sterile line strain to differentiate again and whether have strain regulatory fertility in age characteristic, as have this characteristic, determine that then this rice varieties (being) has strain regulatory fertility in age gene.

3, according to the photo-thermo sensitive male nuclear sterile rice line selection of the said strain of claim regulatory fertility in age, it is characterized in that said photo-thermo sensitive male nuclear sterile rice line screening technique with strain regulatory fertility in age gene, be whether variant with the sterile light temperature critical value of old strain regeneration strain in age by the strain of under same ecotope, relatively growing directly from seeds, if the sterile light temperature critical value of old strain regeneration strain in age, determines then that this photo-thermo sensitive male nuclear sterile rice line has strain regulatory fertility in age gene obviously than the plant height that grows directly from seeds.

4, it is characterized in that saidly having the germplasm of strain regulatory fertility in age gene and the rice varieties (being) of different genotype or the cross method of photo-thermo-sensitive genic male sterile line through screening and having according to the photo-thermo sensitive male nuclear sterile rice line selection of the said strain of claim regulatory fertility in age: (1) selects the rice varieties (being) and photo-thermo-sensitive genic male sterile line hybridization with strain regulatory fertility in age gene for use; (2) with photo-thermo sensitive male nuclear sterile rice line and rice varieties (being) hybridization, make recurrent parent with rice varieties (being) then, carry out back cross breeding with strain regulatory fertility in age gene with strain regulatory fertility in age gene; (3) select different genotype photo-thermo sensitive male nuclear sterile rice line phase mutual cross (comprise and reestablishing diplomatic relations) for use with strain regulatory fertility in age gene; (4) select photo-thermo sensitive male nuclear sterile rice line with strain regulatory fertility in age gene and rice varieties (being) hybridization (comprise and reestablishing diplomatic relations) for use with strain regulatory fertility in age gene.

5, according to the selection of the described tool strain of claim regulatory fertility in age characteristic water rice photo-thermo-sensitive nucleic male sterile line, the seed selection that it is characterized in that the paddy rice temperature Photosensitive caryon sterile line .N9S of said tool strain regulatory fertility in age characteristic is: rice variety seven mountains that utilize tool strain regulatory fertility in age gene to be bred in the rice variety C71140 and the academy of agricultural sciences, China Guangdong Province in China Taiwan by the photo-thermo sensitive male nuclear sterile rice line W7415S and tool strain regulatory fertility in the age gene source of the academy of agricultural sciences's seed selection of China Hubei account for and are the parent, come out by the method seed selection of multiple cross.

6, according to the selection of the described tool strain of claim regulatory fertility in age characteristic water rice photo-thermo-sensitive nucleic male sterile line, the seed selection that it is characterized in that the paddy rice low thermo-sensitive type caryon sterile line N26S of said tool strain regulatory fertility in age characteristic is: utilizing tool strain regulatory fertility in age gene is the parent by the photo-thermo sensitive male nuclear sterile rice line W7415S and the rice variety C71140 of tool strain regulatory fertility in age gene source in China Taiwan of the academy of agricultural sciences's seed selection of China Hubei, comes out by the method seed selection of single cross.