六倍体小黑麦与普通小麦杂交细胞遗传的研究

STUDY ON CYTOGENETICS OF CROSSING HEAXPLOID WITH TRITICUM AESTIVUM

本文报道了六倍体小黑麦与普通小麦杂交的性状与细胞遗传.共配制25个杂交组合,观察到以六倍体小黑麦为母本杂交当代结实率平均为36.17%,种子发芽率为80.14%,以普通小麦为母本杂交当代结实率平均为72.60%,幼胚在组织培养条件下出苗率为20.1%,F_1减数分裂中期有13.37个二价体和15.01个单价体,与理论数值接近.F_1的结实率正反交组合均很低,平均为2.98%,种子发芽率平均为32.38%.F_2的性状分离极其复杂,有三个主要类型即亲本类型与中间型,减数分裂中期二价体数变动在14-20间、单价体数变动在0-14间;根尖细胞用Giemsa染色进行C带分析.看到多有3-4对R组染色体,其中5R、6R、7R较多.F_1与亲本回交性状与染色体组型迅速恢复为亲本类型.在F_3及以后世代看到D、R组染色体混合类型是稳定的,可以从中选出多种类型的代换系.这种杂种方式对六倍体小黑麦性状的改进是有效的.

<ABSTRACT>It is reported that the characters and cytogenetics of crossing hexaploid triticale with triticum aestivum. Making 25 cross combinations, rate of observed mean seedset of hexaploid triticales were used as female parent is 36.17%, rate of seed emergence is 80.14%; rate of mean seed-setof the triticalum aestivum were used as female parent is 72.60%, rate of emergence in cuiture is 20.1%. The chromosome configuration have 13.37 bivalents and 15.01 univalents at metaphase of meiosis in F_1, approximate to theory value. The seed-set rate of reciprocal cross combination is 2.98%, rate of mean seed emergence is 32.38%. The characters of F_2 have very complex segregation and have three species of parent or middle, bivalent number from 14 to 20 and univalent number from 0 to 14 at metaphase of meiosis in F_2; cells of root tip were analysed by Giemsa C-banding, the result showed that no few 3 to 4 pairs R chromosomes and 5R, 6R, 7R chromosomes are majority.The characters and genome type of brackcrossing F1 hybrids with parent were expected restorer to parent type. The result showed blend type of D&R chromosomes are stable and were selected variety of chromosomse substitution line in F_3 and their offsprings. The crossing manner has effects in improving characters of hexaploid triticale.