Fertility Alternation Regularity And Sterility Mechanism In Thermo-Photo-Sensitive Genic Male Sterile (TGMS) Wheat (Triticum Aestivum L.)

Hybrid wheat has not been used widespread in production after being studied for more than forty years, so it is necessary to apply new technology and new methods to breed better sterile lines and better hybrids. The thermo-photo-sensitive genic male sterility (TGMS) in wheat discovered in Chongqing in recent years represents a novel type of male sterile line in wheat. Two-line system based on TGMS wheat is considered to be the third major system for hybrid seed production in wheat, following the three-line system based on cytoplasmic male sterility (CMS) and the chemical hybridization agent (CHA) system. The basic theoretical studies about this novel germplasm resource are very fewer by now. The regularity of the fertility alternation, the cytology of pollen abortion, the relationship between fertility alternation and plant hormones and the expression of APRT gene are studied in this paper in order to provide theoretical basis and technology support to two-line hybrid wheat.1 The regularity of fertility alternation of TGMS WheatThe sowing date tests conducted for many years indicate that TGMS lines C49S, C050S, C010S, C338S, C412S and C404S all showed fertility alternation phenomenon in the pattern of completely sterility to semi-sterility and to normal fertility by adjusting the sowing date to change the environmental temperature and photoperiod conditions at the formation and development stages of the male sexual cells. Sowed before October 30 in Chongqing, about 10 to 15 days earlier than the normal sowing date, the TGMS lines showed completely sterility or highly sterility; Sowed during the dates from November 10 to November 30, the TGMS lines showed semi-sterility; Sowed after December 10, about 20 to 30 days later than the normal sowing date, the TGMS lines showed normal fertility. The seed setting of the tillers developed later were higher than that of the main shoot and the tillers developed earlier in TGMS wheat. The frequencies of the fertile pollen grains and the fertile florets in the spikelets of the lower part of spikes were higher than that in the middle part of spikes, and that in the upper part of...