应用分子原位杂交技术解析小麦-天兰冰草部分双二倍体──远中2号的染色体构成

为分析普通小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）－天兰冰草（Ａｇｒｏｐｙｒｏｎｉｎｔｅｒｍｅｄｉｕｍ）部分双二倍体──远中２号（２ｎ＝５４）的染色体构成，用生物素（ｂｉｏｔｉｎ－１６－ｄＵＴＰ）标记天兰冰草染色体组ＤＮＡ作为探针，以普通小麦品种中国春染色体组ＤＮＡ为封闭ＤＮＡ（ｂｌｏｃｋｉｎｇＤＮＡ），与远中２号的有丝分裂中期染色体ＤＮＡ进行了分子原位杂交。证明远中２号除具有普通小麦的２１对染色体外，附加了１对小麦－天兰冰草易位染色体（即天兰冰草染色体片段易位到小麦染色体的两臂端部）、５对天兰冰草染色体。说明小麦－天兰冰草部分双二倍体在形成过程中染色体行为是比较复杂的，不仅可能产生小麦－天兰冰草染色体间易位，而且小麦染色体也可能与天兰冰草染色体的３种染色休组染色体共同参与组建新的染色体组附加到小麦中去。

Analysis of the Chromosomes Composition of Common Wheat-Agropyronintermedium Partial Amphiploid, Yuan Zhong 2 by in situ hybridization

The chromosome composition of Yuan Zhong 2. a common wheat-Ag. intermedium partial amphiploid (2n = 54), was analyzed with the genomic in situ hybridization (GISH). in which the biotinylated total DNA of Ag. intermedium as the probe and the total DNA of common wheat cv. Chinese Spring as blocking DNA were used to hybridize with the chromosome DNA of Yuan Zhong 2 at mitotic metapbase in root tip cells. The results indicated that Yuan Zhong 2 was formed by adding one pairof wheat-Ag. intermedium translocation chromosome and five pairs of Ag intermedium chromosome in the background of common wheat with 2 1 pairs chromosome. The results suggested that the chromosome behavior in the formation course of wbeat-Ag. intermedium partial amphiploid was relatirely complicated. The chromosome translocations between wheat and Ag intermedium could occur and at the same time, a new extra synthetic genome consisting of some chromosomes from both species could be added tp wheat background .