一个小麦-黑麦染色体代换的细胞学鉴定

Identification of a Wheat-rye Chromosome Substitution in Common Wheat

对从六倍体小黑麦与普通小麦的杂种后代中获得的矮秆抗病选系84056-1-36-1进行体细胞C-分带鉴定,结果表明,它的21对染色体中,有1对短臂带型与1R相似的黑麦染色体代换了小麦的1D。观察“中国春”双端二体1A、1B与该选系杂种F_1的花粉母细胞染色体配对,发现分别有82.56%和65.71%的细胞出现异型三价体,所有细胞至少有两个形态不同的单价体;而在“中国春”端二体IDL与84056-1-36-1的杂种中,端体不配对的花粉母细胞占100%,经C-分带后,另外1条单价体显示明显的端带。从上述这些结果推断84056-1-36-1为1R(1D)代换系。

Two C-banding methods, Method Ⅰ and Method Ⅱ, which can recognize all chromosomes of T. aestivum and 5. secale respectively, were used to analyze the somatic chromosomes of a stable selection 84056-1-36-1 derived from a hybrid (hexaploid Triticale X T. aestivum) X T. aenivum. When Method I was used, it was found that the chromosome 1D of 84056-l-36-1 was absent, substituted with a pair of rye chromosomes which showed the banding patterns similar to 1R with Method Ⅱ.When C.S. DDT 1A, DDT IB and DT 1DL were crossed with 84056-1-36-1 respectively, heteromorphic trivalent frequency of PMC was 82.56% in F1 hybrid of (DDT 1A × 84056-1-36-1 and 65.7% in F1 of DDT IB × 84056-1-36-1, two or more univalents appeared at Ml of all the PMCs in the hybrids of these two cross combinations, while 100% of PMCs af MI from E1 of DT 1DL X 84056-1-36-1 has a IDL-telosomic univalent and an univalent which carried te-lomeric band when C-banding was used. All these results suggest that 84056-1-36-1 is a complete substitution with ID beinir replaced, which has comfirmed the conclusion drawn from C-banding analysis of somatic chromosomes.