关键词: 普通小麦（Triticum aestivum L.）, 温光敏雄性不育, 内源激素

Abstract:

【Objective】 In order to provide more information about pollen fertility regulation in thermo-photo-sensitive genic male sterile (TGMS) wheat BNS and BNS366, the relationship between male sterility and the changes of endogenous hormones during microsporogenesis was analyzed.【Method】BNS and BNS366 were used as experimental materials, and Aikang58 and Zhengmai366 (Near-isogenic line of BNS366) were used as controls, respectively. Four different types of wheats were sowed at October 10^th (normal sowing) and December 2^nd (late sowing). I₂-KI method was used to measure the frequency of fertile pollen grains. National and international methods were used to determine self-seeds rate. Indirect enzyme-linked immunosorbent assays (ELISA) method was used to detect 6 kinds of endogenous hormone contents in leaves from the pistil and stamen differentiation stage to the trinuclear stage, young panicles from the pistil and stamen differentiation stage to the tetrad stage and anthers from the uninucleate stage with small-vacuole to the trinuclear stage.【Result】Under normal sowing conditions, the frequency of fertile pollen grains, the national and international rate of self-seeds in both BNS and BNS366 wheats were zero that were completely male sterility, while under late sowing conditions, the three indexes were 34.74%, 43.12% and 48.48% in BNS that was partial male sterility, as well as 92.63%, 55.37 % and 67.94% in BNS366 that was normal fertility. However, the three indexes in Aikang58 and Zhengmai366 wheats under normal and late sowing conditions were 82.56%-94.00%, 73.90%-82.31% and 96.54%-139.26%, respectively, that were normal fertility and no significant difference were found between the two sowing conditions. Moreover, the increased frequency of fertile pollen grains-∆ [(frequency under normal conditions-frequency under late sowing conditions)×100%/ frequency under late sowing conditions] in BNS and BNS366 were lower than those in Aikang58 and Zhengmai366. Multiple comparisons of the hormone’s levels were carried out in the two experiment groups, respectively. We found that the increased hormones levels [(hormones levels under normal conditions - hormones levels under late sowing conditions)×100%/hormones levels under late sowing conditions] differed in all four different varieties. The correlation analytic method was carried on the statistical analysis to the endogenous hormone content and the frequency of fertile pollen grains, and to the endogenous hormone content-∆ and the frequency of fertile pollen grains-∆. For both of BNS and BNS366, there were common characters in dynamic changes of endogenous hormone contents during developmental stages of wheat young panicles in sterile lines. The IAA (indole-3-acetic acid) contents were insufficient in the leaves of the tetrad (BNS) and the pistil primordia differentiation stage (BNS366), and insufficient in the anthers of the uninucleate stage with small-vacuole (BNS) and the uninucleate stage with big-vacuole (BNS366), too, but sufficient in the anthers of the binucleate stage. The gibberellic acid (GA) contents were insufficient in young panicles of the tetrad stage and in anthers of the uninucleate stage with small-vacuole. There were no differences of the zeatin riboside (ZR) contents among the materials. The abscisic acid (ABA) contents tilted towards short supply (BNS) and that was inadequate really (BNS366) in young panicles of the tetrad stage. There were also no differences among the materials in the brassinosteroid (BR) contents. The methyl jasmonate (MeJA) contents were generally insufficient in leaves of the pistil and stamen differentiation stage, the tetrad stage, the uninucleate stage with small-vacuole or the uninucleate stage with big-vacuole, and the trinucleate stage, and in young panicles at the pistil and stamen differentiation stage (BNS) or at the tetrad stage (BNS366), respectively, and in anthers at the uninucleate stage with big-vacuole.【Conclusion】Under normal sowing conditions,the lack of IAA, GA, ABA, especially MeJA before the uninucleate stage with big-vacuole in BNS and BNS366 might promote the occurrence of male-sterility.

Key words: common wheat (Triticum aestivum L.), thermo-photo-sensitive genic male sterile (TGMS), endogenous hormones