Inheritance of Fertility Restoration of Photoperiod-sensitive Male Sterility with D~ 2 Cytoplasm in Wheat ( Triticum aestivum )

Using the nuclear cytoplasm hybrids NC2134 and Jian26 (both with the cytoplasm of Aegilops crassa 6x) as the cytoplasm donors and 69 spring wheat cultivars (lines) as nuclear donors, the backcrosses were made, with the purpose of screening fertility restoring lines and male sterile lines. Male fertility of their F 1, BC 1, BC 2 and F 2 were observed under long day condition (≥15 h) by later sowing (later than March 25) in spring season in Beijing or in greenhouse by light supplement. The results indicated that about 28% of the cultivars carrying the restoring gene to photoperiod sensitive male sterility with D 2 cytoplasm and 35% of the cultivars could be bred as male sterility lines by transferring the nuclear into the D 2 cytoplasm. Fertility frequency of some F 2 populations was investigated and the results showed that the restoration of photoperiod sensitive male sterility with D 2 cytoplasm was controlled by 1~2 of major restoration genes and modified by some minor genes. Nuclear cytoplasm hybrid NC2134 carrying 2 major restoration genes and Jian26 may be only 1. The inheritance model of the restoration of photoperiod sensitive male sterility with D 2 cytoplasm and its complex nature were discussed.