Inheritance Of Male Sterility And Cytological Characteristics Of Pollen Abortion In Bi-pole-photo-thermo-sensitive Male Sterile Line 337S Of Wheat

Bi-pole-photo-thermo-sensitive Male Sterile Line 337S of Wheat was sensitive not only to short day-length and low temperature but also to long day-length and high temperature . The genetic mechanism of fertility expression by investigation the 337S, 7 different wheat varieties and the F1, F2, BC1 hybrids which were crossed by 337S / 7 wheat varieties was studied in this thesis. The results showed that the Fl generations were fertile. That is to say the fertility inheritance of 337S was controlled by the nuclear and had no relation with cytoplasmic genes . In the majority of varieties tests, the propagation ratio of fertile and sterile plants in the F2 generation of 337S and 5 wheat varieties in short day-length and low temperature was 3:1 . In the other two combinations the ratio is 15:1. That mean the male sterile heredity of 337S was controlled by 2 pairs of recessive genes. Different varieties have different parts of restoring genes :some have 1 pair, some have 2. In long day-length and high temperature, all the propagation ratios of F2 were 15:1, and of BClwere 3:1, These showed the male sterile heredity was controlled by 2 pairs of 1 inked recessi ve genes in the condition. Another 10 main characters studied included; heading date, plant height(cm), ear-length(cm), spikelet number/ear, tiller number/plant, panicles per plot, 1000-grain weight/g and others . All main panicles of the plots were bagged before flowering, and filled spikelets were counted. Correlation analysis between the main trains and fertile traits were made, the results showed that in short day-length and low temperature condition, fertile trait effective tillers with heading date. The correlation of the spikelet number , 1000-kernel weight and the fertile were negative when the environment was long day and high temperature.Anther and pollen abortion in 337S were also investigation. The resultsobtained were summarized as follows : ?Pollen abortion in 337S might occur in various stages . The abnormalities are the abnormal fusion of anther chambers, the disorganization of microspore mother cells with normally developed tapetum. The microspore mother cells fused together to form pesiplasmodium, the disorganized microspore cells transformed into unusual giant cells. (2) Mesospore was often sporadic and disorganized. The same is tapetum cells before microsporogenesis.The left cells delayed disintegration in late stage of abortions. (3) Nucleate stage is the time when most of pollens of 337S degenerated in Short day-length and low temperature. Long day-length and high temperature that happened in microspore mother cells stage. Above all, a conclusion can be drawn that the disorganization of mesospore and tapetum leads to the pollen abortion.