八倍体小偃麦与六倍体小偃麦杂交的细胞遗传学研究

Cytogenetic Study on Crosses Between Octoploid Trititrigia and Hexaploid Trititrigia

利用来源于中间偃麦草（Ｅｌｙｔｒｉｇｉａｉｎｔｅｒｍｅｄｉｕｍ）的八倍体小偃麦远中２和来源于四倍体长穗偃麦草（Ｅｌｙｔｒｉｇｉａｅｌｏｎｇａｔｕｍ）的六倍体小偃麦８８０１（ＡＡＢＢＥＥ）杂交，结果表明正反交间结实率、Ｆ１出苗率均存在显著差异；Ｆ１植株多表现高度不育。通过Ｆ１花粉母细胞减数分裂染色体行为分析，发现杂种Ｆ１中染色体组主要构型为１４Ⅱ＋２１Ⅰ（占观察细胞的４０％左右），也有其他类型的构型，平均构型为：０．８９Ⅲ＋１２．５３Ⅱ（８．５６Ⅱ＋３．９７Ⅱ）＋２１．０７Ⅰ，从而确认远中２染色体组中不含有偃麦草的Ｅ组染色体。并初步认为远中２染体组型为ＡＡＢＢＤＤＸＸ。

The reciprocal crosses between Yuanzhong 2(AABBDDFF), an octoploidy Triticum seet Trititrigia derived from Elytrigia intermedium and 8801(AABBEE), a line of hexaploidy Triticum seet Trititrigia derived from Elytrigia elongatum (4X) were conducted. The result showed that seedsetting percentage and seedling percentage of the crosses in F 1 generation were different significantly, and the F 1 plants were highly sterile. Based on the analysis of meiosis behavior of pollen mother cell of F 1 plant, the main chromsome pairing configuration was 14Ⅱ+2Ⅰ(taking up about 40% of observed cells). The maximum number of bivalent chromosome was only 14. The average chromsome pairing configuration was 0.89Ⅲ+12.53Ⅱ(8.56Ⅱ+3.97Ⅱ)+21.07Ⅰ.Thereby, we can confirm that the genome of Yuanzhong 2 excludes E genome derived from Elytrigia intermedium. We can preliminarily conclude the chromosome pattern of Yuanzhong 2 is AABBDDXX.