The Relationshop On Anther Tapetum, Sporopolleninand Specific Expression Of RAFTIN1 In Physiological Male Sterile Wheat

SQ-1 is a new proprietary wheat gametocide solely developed by Chinese scientists. A proper dose can achieve 95% -100% of the male sterility at appropriate spraying times, and the saturation pollination rate can reach 85% or higher. So far, it has been already playing an increasingly important role in research and practice of hybrid wheat.By now, a great number of scholars have researched into mechanism of physiologically male sterility induced by SQ-1, mostly focusing on metabolism, energy metabolism, endogenous hormones, etc. Among these, the researches into the abnormal changes of specific tissues and organs in the process of wheat pollen abortion prove to be inadequate, particularly far fewer into the changes of cell microstructure and genes of specific structures.Based on the comparative experiments, it studies the correlation between physiological ly male sterility of tapetum , sporopollenin and the expression of the gene RAFTIN1, further stduy into the pollen abortion-related submicroscopic structure of cell structure and also its gene expression of specific structure, and eventually the revelation of the mechanism of wheat physiologocally male sterility. Materials are ms (Kots)-90-110 of genetically male sterility, physiologically male sterility which is fertile of BC5F1 corresponding as ms (Kots)-90-110 induced by SQ-1, the normal development of BC5F1. this research attempts to analyze the morphological changes of the Anther tapetum on the microspores at different stages, the accumulation of sporopollenin and the gene RAFTINI expresssion by performing paraffin section, cell staining and fluorescence quantitative PCR.The important results obtained are as follows:(1)At different stages, the two groups in comparisons are different in degradation rates. At the stage of the prophase microsporocyte, they have no obvious differences in two male sterility lines. At mononuclear stage, tapetum begins to degenerate into irregular shapes, while the physiologically and genetically male sterility degenerate much faster, only part of the unfinished vestigial residual visible. Anaphase mononuclear tapetum degradates worse, while two sterile anther tapetum almost finish the vestige. When coming to the binucleate and trinuclear stages, the tapetum of physiologically and genetically male sterility degradates completely, same as the normal tapetum compared. The results show that degradation in advance of the prophase mononuclear tapetum develops a close relation to the anaphase pollen abortion.(2) During the development of wheat microspore, the accumulation of sporopollenin makes a difference between the objects compared. The average optical density of normal microspores rises as it grows, which comes consistent with its pollen wall. While the number of sporopollenin for two male sterile lines is not significantly changed. It can be concluded that degradation of tapetum ahead of time which causes less sporopollenin and obstructs the formation of its pollen wall, leading to the pollen abortion(3) By comparison with normal mononucleate, and the performance of fluorescence quantitative PCR, the research obtains relative expression of gene RAFTIN1. The statistical analysis shows by DPS7.05 software that the expression of the gene RAFTIN1 at the binucleate stage tops among three stages. The expression of this gene, in two sterile lines, differentiates greatly between at the mononucleate and binucleate stages, and greater at the trinucleate stage.By comparison, the conclusion can be arrived that at the mononucleate stage, the relative expression of the gene RAFTIN1 in both physiological and genetic sterile lines is significantly higher than that in fertile lines, but at the binucleate stage, that in the fertile lines is much higher than that of physiologically male sterility, while no significant difference with the genetically sterile line.