Study On Yield Response And Application Potential Of Cytoplasmic Male Sterile Lines In Maize

Stability about male sterility and restorer of S male sterile line were researched, and combining ability of two cytoplasmic male sterile lines was estimated. Increase yield mechanism and methods of using male sterile line were analysed. The main conclusions can be summarized as follows.1. S male sterile line ST001 , ST029 were stable across testing seasons and locations, with more than 98% sterile plant as 0 degree. 12 inbred lines in different heterosis groups used in testing fertility restoration of the two male sterile lines exhibit that restoration rates of ST001 combined with Qi319, Dail8, 9226 and H₂₁ I is 100% as high as that of ST029 with Qi319, Dai19 and 9226. Restoration of the two male sterile lines is mostlyâ…  to â…¢ degree in combinations with the 12 inbred lines although different combination has considerable discrepancy .Thus, restoration rates of the two male sterile lines must be effected by other cytoplasm genes, also maintenance line and restoring line of S male sterile line can be fined in nature.2. Analysis in combining ability of 9 inbred lines and S male sterile line ST001, ST029 indicated that ST001, ST029 have higher combining ability than other inbred lines, general combining ability of the two lines are high relatively while that of ST001 is positive effect expect spike row number same as ST029 in plant height, ear height, spike row number, 100-kernel weight, single-plant yield. So, these advantages of ST001 and ST029 are directly correlated to sterility, the two lines have high value in utilizing for their high inheritance of most traits.3. Means of using male-sterile single-hybrids were studied and the results showed that kernel number per ear and 100-kernel weight were effected considerable in different methods. LAI are similar in early period between different treatments while significant difference in days from gag topollen, because nutrient in sterile plant was transferred to ear instead to tassel. Study on mix proportion and pattern indicated that treatment in 1:3 has highest yield, because it not only offering enough pollens but also. Furthermore this pattern using fertile and sterile hybrids contenting different cytoplasm can resist racial specificity infection.4. Methods of utilizing cytoplasmic male sterile line were researched. The result shows that castrate increased yield of inbred line and male sterile line, restorative male-sterile single-hybrids and sterility male-sterile single-hybrids both increase yield through even ears. So, male sterile and castrate both can improve yield.