Study On Relationship Between Microspore Abortion Of CMS Lines Associated With The Abnormal Degradation Of Tapetal Of Anther In Wheat (triticum Aestivum L.)

The aim of the experiments is tantamount to study the relationship between tapetumdegradation, which leads to calcium distribution and nutrient metabolism abnormal in anther,and pollen abortion in CMS of wheat.Wheat (S)-1376was test materials. The development stage of pollens’ nucleus attricellular was surveyed by DAPI dyed, and the starch accumulated in pollens stained by KI-I2.Tapetum degradation was investigated by paraffin sections. Potassium pyroantimonateprecipitation method was used to survey calcium distribution. Ca2+-ATPase was located bylead nitrate. Semi-thin sectioning was utilized to observe nutrients accumulation.Results:(1) The data demonstrated that the pollens were complete abortion and were no starchstored at trinucleate that were dyed by DAPI and KI-I2at tricellular. The result of paraffinsections showed that the tapetum cells in advance degradation at the tetrad stage in (S)-1376.(2) The results of TEM and potassium proportionate precipitation showed that during thetetrad stage, calcium precipitates were found a few on the cell wall of the outer tangentialmembrane of the tapetal cells and microspore mother cells in1376and (S)-1376. At earlyuninucleate stage, a large amount of calcium precipitates were observed on in advancedegraded tapetum，however，little was found in Ubisch bodies in (S)-1376. At that stage, in1376calcium precipitates hardly were discovered in tapetum and microspore. At lateuninucleate stage, calcium precipitates reduced in the tapetum of (S)-1376. But in1376, alarge number of calcium precipitates accumulated in the tapetum, Ubisch bodies and the outerwall of the microspore. At bicellular stage, there was hardly found calcium precipitates onanther sections in (S)-1376. Nonetheless, in1376, a large number of calcium precipitates stillaccumulated in upcoming completely degraded tapetum, Ubisch bodies and the outer wall ofthe microspore. Based on this study, we found that abnormal degraded tapetum secretedabnormal ubisch bodies cannot transport calcium to the pollen. (3) The results of TEM and lead nitrate showed that the density and presence of Ca2+-ATPase were noticeably different in the pollen wall and tapetum in1376and (S)-1376.During tetrad stage, in1376some of Ca2+-ATPase distributed on the pollen mothercell.Comparatively, the less Ca2+-ATPase distributed in anther sections in (S)-1376.Fromearly uninucleate stage to late uninucleate stage, a few Ca2+-ATPase distributed on the antherchamber in (S)-1376, but abundant Ca2+-ATPase allocated on the tapetum, Ubisch bodiesand the outer wall of the microspore. Thus, abnormal degraded tapetum secreted abnormalubisch bodies were dysfunction of Ca2+-ATPase, it may be the main causes of abnormaldistribution and transport of calcium in (S)-1376.(4) we got the following results from experiments that observed the distribution ofnutrients in wheat during anther development. Polysaccharides content in pollens and tapetumcells was lower than the maintainer line in the whole development except the tetrad stage.Lipids content in pollens and tapetum cells also was lower than the maintainer line in theentire development. Proteins content in microspores was very superior mother cells at thetetrad stage in (S)-1376. It was significantly reduced at the late uninucleate. Proteins contentin tapetum in the early uninucleate was considerably lower than1376.Conclusion:Tapetum of (S)-1376degraded earlier than (A)-1376that caused abnormal Ubischbodies without Ca2+-ATPase detected.It might result in that Ubisch bodies cannot transportthe calcium and nutrients to the outward wall of the pollens. Ultimately, the pollens of (S)-1376CMS were aborted directly.