野生二粒小麦与二倍体野燕麦远缘杂交后代的核型分析及进化关系

对野生二粒小麦与二倍体野燕麦远缘杂交后代进行染色体核型分析。结果表明：杂交后代084株系的核型公式为2n=6x=42=36m(4SAT)+6sm，核型为1A，为极对称核型，属于原始类型；野生二粒小麦、二倍体野燕麦及084株系的进化指数分别为1、4和1，表明084株系的进化程度与野生二粒小麦一致，低于二倍体野燕麦；084株系的染色体相对长度较亲本大，且其平均臂比、核型不对称系数及臂比大于1.7的染色体比例均在野生二粒小麦与二倍体野燕麦之间，说明远缘杂交在一定程度上对加速小麦属的进化有重要意义；084株系染色体臂比与母本的相近，且存在4对染色体与父本的相对长度和臂比极为相近，核型分析结果从一定程度上证明了野生二粒小麦与二倍体野燕麦杂交后代的真实性。

Karyotype of the progeny of a wide cross between Triticum dicoccoidesand diploid wild oat and their evolutional relationship

Abstract: The karyotype of the progeny of a wide cross between Triticum dicoccoides and diploid wild oat was analyzed. The result showed that the karyotype formula of the hybrid progeny line 084 was 2n=6x=42=36m (4SAT)+6sm. The karyotype belonged to type 1A, which is an original and extremely symmetrical type. The evolution index of the Triticum dicoccoides, the diploid wild oat and the line 084 were 1, 4 and 1, respectively, indicating the degree of the evolution of the line 084 was consistent with the Triticum dicoccoides, and lower than the diploid wild oat. The chromosome length ratio of the line 084 was larger than the parents. And the average arm ratio, the asymmetry ratio, and the quantity ratio of the chromosomes with arm ratio >1.7 were all between corresponding ratios of Triticum dicoccoides and the diploid wild oat, suggesting that wide cross had certain significance in accelerating wheat evolution. The chromosome arm ratios between the progeny and the Triticum dicoccoides were very similar, and the lengths and arm ratios of four pairs of chromosomes of the line 084 were very similar to those in the diploid wild oat, indicating that the line 084 was true intergeneric hybrid.