Breeding method and application of a low-temperature-sensitive genic male sterile line of rice with high and low temperature-resistant sterility critical temperature

Abstract

The invention provides a method for breeding low-temperature-sensitive genic male sterile line of rice with high temperature-resistant sterility and high critical temperature, comprising the following steps: using rice low-temperature-sensitive genic male sterile line to hybridize with high-temperature-resistant rice varieties, and screening pollen The high-temperature-resistant low-temperature-sensitive genic sterile plants with high sterility critical temperature and qualified self-seed setting rate at high temperature are crossed with low-temperature-tolerant rice varieties, and the plants with qualified outcrossing seed-setting rate at low temperature are screened out. The method overcomes the defects of high risk of hybrid seed production due to unstable fertility of the current photothermo-sensitive genetic male sterile line, and low yield of seed production caused by hybrid seed production under high temperature conditions. The invention also discloses the application of the rice low-temperature-sensitive genic male sterile line obtained by the method in breeding sterile line seeds and hybrid seed production. The hybrid seed production is safe, the hybrid seed quality is high, and the sterile line has strong high temperature resistance. The reproductive yield of sterile line seeds is high.

Description

technical field [0001] The invention belongs to the technical field of rice breeding, and in particular relates to a breeding method and application of a high-low temperature-resistant rice low-temperature-sensitive genic male sterile line with a high sterility critical temperature. Background technique [0002] In 1970, Yuan Longping, Li Bihu and others discovered a cytoplasmic male sterile plant in Hainan wild rice. In 1973, the technical system of hybrid seed breeding of sterile line and maintainer line and hybrid seed breeding of sterile line and restorer line was successfully researched, that is, three-line matching. With the large-scale promotion of three-line hybrid rice, it has made great contributions to my country's food security. However, because the cytoplasmic male sterility used by the three-line method is restricted by the restoration relationship, it is difficult to breed new sterile lines and new restorer lines, and the utilization rate of rice resources is...

AI Technical Summary

Problems solved by technology

However, there are two major technical defects in the photothermosensitive genic male sterile line: first, even in the midsummer high temperature season, the hybrid seed production will fail due to the short-term midsummer low temperature that induces the photothermosensitive genic male sterile line to restore fertility , causing huge economic losses. For example, in 1993, 1996, 1999, 2004, 2008, 2012 and 2014, a large area of ​​photothermosensitive GMS line seed production failed

Second, in the midsummer high temperature season, hybrid seed production often has a high temperature climate with a maximum temperature above 35°C and an average daily temperature above 30°C. The female parent's stigma activity is low and the male parent's pollen activity is low, resulting in low yield of hybrid seed production, for example The temperature-sensitive genic male sterile line Guangzhan 63S has had many times over the years due to the high temperature in the flowering period, resulting in a seed setting rate of hybrid seed production lower than 30%. In addition, the pollen viability of male parents such as 9311 was reduced under high temperature conditions, resulting in low yield of hybrid seed production. The fundamental reason why the average yield of large-scale seed production of photothermosensitive GMS lines is difficult to break through 400 catties / mu

However, this type of sterile line has not been widely used in production. There are three reasons: first, the pollen critical sterility temperature is lower than 27°C, the safety of hybrid seed production is not high, and it is susceptible to high temperature induced sterility The pollen of the male sterile line is fertile, which leads to the failure of hybrid seed production; second, the high temperature resistance of the sterile line is not strong. When the natural daily average temperature reaches 32°C, the pollen fertility rate of the sterile line is lower than 40%, and the seed setting rate is lower than 30%. The third is that these CMS lines are sensitive to low temperature below 21°C, and are vulnerable to low temperature damage, resulting in a decrease in the seed setting rate of hybrid seed production

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