The sterility segregation and its genetic patterns of indica P(T)GMS rice were analyzed mainly based on the investigation of bagged seed set of individuals in reciprocal F\-2 population from the crosses between P(T)GM...The sterility segregation and its genetic patterns of indica P(T)GMS rice were analyzed mainly based on the investigation of bagged seed set of individuals in reciprocal F\-2 population from the crosses between P(T)GMS lines of different origin and typical indica conventional varieties of different ecotype under long day length and high temperature condition by using the software of the maximum likelihood method. The results showed that the sterility of Annong S 1,Hengnong S 1,and W6154S,of which the sterility alteration was mainly induced by temperature fluctuation,was controlled by one major recessive gene. But the sterility of W7415S was controlled by more than two major recessive genes. Apart from the major recessive gene,there was a group of polygenes in controlling of the sterility segregation in F\-2 population. Moreover,the polygenic variance was different from line to line. It implied that the polygenes of W6154S or W7415S was far more complicated than that of Annong S 1 and Hengnong S 1 according to the maximum likelihood method. All the conventional indica varieties of different ecotypes possessed the major dominant fertility genes. Meanwhile,the genetic background in different ecotype conventional varieties,the essentiality of which lies in the existence of polygenes,was different and influenced the major gene expression deeply. It was also indicated that genetic background of middle season variety Nanjing 11 was more complicated than that of early season variety Erjiuqing and late season variety GER 1 as well. Finally,the differences of drift in critical temperature inducing male sterility of P(T)GMS lines (for short term DCT) and the stratgey of breeding practically usable P(T)GMS line with slighter DCT were discussed in the paper.展开更多
The hybrid growth of rapeseed now has reached to 4.7×106hm2,accounting for 70 % of total rapeseed growth area in China. Over the last 40 years,the researches and utilizations of hybrid rapeseed in China have sign...The hybrid growth of rapeseed now has reached to 4.7×106hm2,accounting for 70 % of total rapeseed growth area in China. Over the last 40 years,the researches and utilizations of hybrid rapeseed in China have significantly contributed to the development of rapeseed industry in China. The production of hybrid rapeseed mainly utilizes cytoplasmic male sterility(CMS),combined at the same time with nuclear male sterility and other pollinating-control systems in China. The hybrid rapeseed studies in China are also characterized by the improvement of quality and oil content in hybrid breeding. Future studies to enhance the heterosis of rapeseed will be focused on several important issues,including the combination of heterosis and ideotype breeding,further increase of oil content in hybrids,utilization of sub-genomic heterosis and resistance improvement. The paper will discuss the following perspectives in hybrid rapeseed studies:relationships among heterosis,quality and disease traits,solutions for excessive source and pool in hybrids compared with open-pollinated cultivars,and the importance of increasing harvest index of hybrids to achieve a better yield in hybrids.展开更多
文摘The sterility segregation and its genetic patterns of indica P(T)GMS rice were analyzed mainly based on the investigation of bagged seed set of individuals in reciprocal F\-2 population from the crosses between P(T)GMS lines of different origin and typical indica conventional varieties of different ecotype under long day length and high temperature condition by using the software of the maximum likelihood method. The results showed that the sterility of Annong S 1,Hengnong S 1,and W6154S,of which the sterility alteration was mainly induced by temperature fluctuation,was controlled by one major recessive gene. But the sterility of W7415S was controlled by more than two major recessive genes. Apart from the major recessive gene,there was a group of polygenes in controlling of the sterility segregation in F\-2 population. Moreover,the polygenic variance was different from line to line. It implied that the polygenes of W6154S or W7415S was far more complicated than that of Annong S 1 and Hengnong S 1 according to the maximum likelihood method. All the conventional indica varieties of different ecotypes possessed the major dominant fertility genes. Meanwhile,the genetic background in different ecotype conventional varieties,the essentiality of which lies in the existence of polygenes,was different and influenced the major gene expression deeply. It was also indicated that genetic background of middle season variety Nanjing 11 was more complicated than that of early season variety Erjiuqing and late season variety GER 1 as well. Finally,the differences of drift in critical temperature inducing male sterility of P(T)GMS lines (for short term DCT) and the stratgey of breeding practically usable P(T)GMS line with slighter DCT were discussed in the paper.
文摘The hybrid growth of rapeseed now has reached to 4.7×106hm2,accounting for 70 % of total rapeseed growth area in China. Over the last 40 years,the researches and utilizations of hybrid rapeseed in China have significantly contributed to the development of rapeseed industry in China. The production of hybrid rapeseed mainly utilizes cytoplasmic male sterility(CMS),combined at the same time with nuclear male sterility and other pollinating-control systems in China. The hybrid rapeseed studies in China are also characterized by the improvement of quality and oil content in hybrid breeding. Future studies to enhance the heterosis of rapeseed will be focused on several important issues,including the combination of heterosis and ideotype breeding,further increase of oil content in hybrids,utilization of sub-genomic heterosis and resistance improvement. The paper will discuss the following perspectives in hybrid rapeseed studies:relationships among heterosis,quality and disease traits,solutions for excessive source and pool in hybrids compared with open-pollinated cultivars,and the importance of increasing harvest index of hybrids to achieve a better yield in hybrids.
