小麦BNS雄性不育的显性不育和非等位显性恢复特性观察

BNS is a new type of thermo-sensitive wheat male-sterility line, and is of important value in the application of wheat heterosis. In order to detect the sterile mechanism of the line, a total of 53 wheat varieties were crossed with BNS, and some F1 then were helf-crossed and backcrossed with parents to produce F2 and BC1. Then, in these generation, the sterile distribution and segregation under the sterile condition were obersivated and analysed. The results showed that the distribution of self-seedset rates in F1 was continuous from 0~77.57%, but not a normal one, average self-seedset rate being 33.16%. The percentages of higher infertility combinations which self-seed rate was less than 5% and high recovery combinations which self-seed rate was more than 60% were 11.32% and 15.09% respectively, the rest were part infertility. Further analysis indicated that the average self-seedset rate of F2 were similar to that of F1 in all F1-F2 combinations, and the plant numbers of completely sterile was increase greatly along with the decrease of average self-seedset rate. When some combinations that had different self-seedset rate were crossed reciprocal, their self-seedset rates in F1 in each pair of combinatuon were difference between cross and reciprocal cross, but in high sterile combination, the self-seedset rate level could not be restored as father parant's, being still highly infertile. These results suggested that the sterility of BNS should be nuclear genic character, and had dominant characteristic in the concept of cytogenetics. The restored genes should be non-allelic genes of the sterile gene. Based on the self-seedset rate distribution in F1 and segregation in F2, it was presumed that the number of sterle gene may be one pair, and the restored gene may be two pairs that had different recovery ability to the sterility, which formed BNS' sterile and recovery genetic system by the way of gene interaction of dominant sterility and dominant inhibiting. The pattern of this presumption was preliminary validated by the test of expectant segregation in six F2 combinations and three pairs of backcrosses combinations.