八倍体小偃麦远中2染色体组构成的研究

STUDIES ON THE GENOME OF YUANZHONG2-AN OCTOPLOID TRITITRIGIA

利用来源于四倍长穗偃麦草（Ｅｌｙｔｒｉｇｉａｅｌｏｎｇａｔｕｍ４Ｘ）的六倍体小偃麦８８０１（ＡＡＢＢＥＥ）与八倍体小偃麦远中２杂交，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），平均构型为：０．８９ＩＩ＋１２．５３Ｉ＋２１．０７Ｉ，从而确认亲本八倍体小偃麦远中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。染色体荧光原位杂交（ＦｌｕｏｒｅｓｃｅｎｃｅＩｎＳｉｔｕＨｙｂｒｉｄｉｚａｔｉｏｎ，ＦＩＳＨ）技术检测结果表明：远中２的染色构成是由４４条普通小麦染色体、１０条中间偃麦草染色体和一对小麦／中间偃麦易位染色体共同组成。并分析了这种组型产生的原因及遗传上的稳定性。

he reciprocal crosses between Yuanzhong 2,an octoploid Trititrigia derived from Elytrigia intermedium and 8801(AABBEE),a line of hexaploid Trititrigia derived from Elytrigia elongatum (4X) were conducted.Based on the analysis of meiosis behavior of pollen mother cell of F1 plant,the main chromsome pairing configuration is 14Ⅱ+2Ⅰ(taking up about 40% of observed cells).The maximum number of bivalent chromosome is only 14.The averagen chromsome pairing configuration is 0.89Ⅲ+12.53Ⅱ+21.07Ⅰ.Thereby,we can confirm that the genome of Yuanzhong 2 exclude E genome derived from Elytrigia intermedium.We can preliminarily concluded the chromosome patten of Yuanzhong 2 is AABBDDXX.The technic of fluorescence in situ hubridization(FISH) was employed to detect the chromosome of Yuanzhong 2.The result indicated that the genome of Yuanzhong 2 is composed of 44 chromosomes from Triticum aestivum,10 chromosomes from Elytrigia intermedium and a pair of translocated chromosomes of triticum aestivum/Elytrigia intermedium.