Effect Of Area And Sowing Date On Young Panicle Development And Fertility Of Photo-Thermo-Sensitive Male Sterile Wheat

The BS Photo-thermo-sensitive male-sterile lines were bred by the Beijing Engineering Research Center For Hybrid Wheat, and served as tow lines hybrid breeding. The experimentation of planting area and sowing date was based on different latitudes, altitudes and same place different seasons have diversitifed in day length and temperature, this diversity effects fertility and generational course of male sterile wheat. The purpose of this study was to discuss the effect of planting area and sowing date on young panicle development and male fertility of two elite BS-photo-thermo-sensitive male sterile lines (BS366 and BS400) in Shunyi, Beijing; Funan, Anhui province and Lijiang, Yunnan province, and find their appropriate sowing date, feasible breeding and multiplication area for hybrid wheat.The main results are as follows:1 The analysis of agronomic characters and young panicle differentiationThe sterile lines BS366 and BS400 were natural growth, and the result showed that tillering numbers, degenerated spikelet numbers reduced with delayed sowing date, but 3,4 place seed numbers, the numbers with setted seeds and spikelets per panicle increased. Tillering numbers, total spikelet numbers and degenerated spikelet numbers increased with area move to south. The effect of day length and temperature on the date of young panicle differentiation and persist fate, the day length extension,the tempreture increment, young spikes polarization course advanced, experience time reduction.2 The effect of ecological area and sowing date on fertility of sterile lines The fertility of BS366 and BS400 decreased from north to south, but increased with delayed sowing date. The two sterile lines restored fertility highly in high latitudes Shunyi, fertility lowly early sowed in middle and low latitudes Funan and Lijiang, the appropriate sowing date was before October and mid-October. Both ecological area and sowing date affect fertility of sterile lines.3 The effect of day length and temperature on fertility of sterile linesBy correlative analysis on temperature of young panicle differentiation and fertility, the result showed that thermo-sensitive phase of BS366 and BS400 from anther sepera to tetrad. They had lower fertility on short-day and low temperature, and had high fertility on long-day and high temperature, this sterile wheat belongs to short daylengh and low temperature sterile type.4 The study of fertility resumption of sterile linesBy studying fertility regularity of the two steriles wheat on three ecological places and different sowing dates, the results showed that the self-seed rate could be above 80% in Shunyi, it can be used as multiplication area of sterile lines. The sterile lines can reach high sterility or complete sterility in Funan and Lijiang, they showed obvious fertility alteration, this two places can be used as selection area of sterile lines.