Identfication Of Fertility Of Photo-thermoperiod Sensitive Genic Male Sterile Lines And The Impact Of Typhoon RANANIM, AERE,SONGDA And HAIMA

With the development of the two-line hybrid, there are many fine PTGMS (photo-thermo-sensitive genic male sterile) have been found. Some new developed combinations based on PTGMS have showed a great potential in developing hybrids.However, the fertility of PTGMS lines had been strongly influenced by the environmental conditions during rice growing seasons. PTGMS lines will change from sterile to fertile condition when it meets extremely low temperature during its fertility sensitive stage, and it leads to degradation in purity of hybrid rice seed. So it is very important to research and insight the fertility sensitivity of PTGMS lines.The main contents studied in the current undertaken project are as follows: With the AMMI (additive main effects and multiplicative interaction) analyzing model, the determination of the sensitivity to photoperiod among different PGMS (photo-sensitive genie male sterile) lines was performed, cooperating with the temperature. To assess the genetic differences to long photoperiod stress in the fertility sensitive stage (10d~20d before heading), eight genotypes were grown under the regime natural conditions in Hangzhou, The photoperiod in the fertility sensitive stages involves six levels from <12.9h to >14.2h. When fertility sensitive stage photoperiod were at I, II, III, IV and V, the percentages of fertile pollen vary in the ranges 0.00%, 1.65%, 10.48%, 51.89% and 60.84%, respectively. The critical photoperiod of sterility and fertility in the eight PGMS lines were 13.0h~13.8h. Considering the amounts and directions of main effect and their IPCA1 (interaction principal components analysis) and IPCA2, we can classify the lines and daylengh levels into different groups, and describe the characteristics of genotype × daylengh interaction, offering the information and tools for the development and utility of photo-sensitive male sterile lines. The eight PGMS rice lines with their reproductive sensitivity to long daylengh that can be screened by using the AMMI model may add valuable germplasm the breeding program of hybrid rice.Eleven Oryza saliva thermo-sensitive genic male sterile (TGMS) lines, ZD35S,ZD45S, ZD73S, ZD77S, ZD151S, ZD177S, ZD245S, ZD291S, ZD381S, ZD390S and Peiai64S, were seeded at hangzhou, China 2004. The results of investigations on pollen showed that the impact of Typhoon RANANIM, AERE, SONGDA and HAIMA on some lines were different. Among daily maximum temperature, daily mean temperature and daily minimum temperature, the last one had the most significant correlation with the fertility.