利用杀配子染色体 2C诱导中国春-黑麦二体附加系染色体畸变的研究

Study on Chromosomes Aberration in Wheat-rye Disomics Addition Lines Induced by the Gametocidal Chromosome 2C

将中国春 黑麦 (1R 7R)二体附加系与中国春 2C(Aegilopscylindrica)二体附加系杂交 ,获得F1,对F1体细胞染色体进行C分带鉴定和花粉母细胞减数分裂行为的观察与分析 ,发现减数分裂行为异常。对自交获得的 4 30株F2 进行单株染色体C分带和荧光原位分子杂交鉴定 ,检测到易位、缺失、等臂染色体、双着丝点染色体等染色体畸变类型。此外还检测到 2C与小麦 2A、2B、2D染色体的二体或单体自发代换系。杂交F2 染色体畸变的规律与频率如下 :研究共得到含黑麦染色体的变异 2 2株 ,变异频率为 5 1%。其中含黑麦染色体的易位系为 10株 ,占2 3% ;缺失 12株 ,占 2 79% ;黑麦的等臂染色体 3株 ,占 0 7%。易位染色体既有含小麦着丝点的 (大部分 ) ,也含有黑麦着丝点的 (仅 1例 )。黑麦的染色体畸变中 ,发生于不同同祖群的频率不同 ,1R为 5个 ,2R为 3个 ;3R为 1个 ;4R为 3个 ;5R为 6个 ;6R为 4个。易位多为端部易位。共鉴定出小麦的缺失系 5 4株 ,其中A基因组有 2 7个 ,占 6 2 7% ;B基因组有 2 0个 ,占 4 6 5 % ;D基因组有 7个 ,占 1 6 6 %。

In the present study,Chinese Spring-Imperial (1R-7R) wheat-rye disomic addition lines were hybridized with Chinese Spring-2C (derived from Aegilops cylindrica) disomic addition lines.The F_1 hybrids were examined by mitotic and meiotic analysis.There were observed abnormal chromosome configurations.A total of 430 F_2 plants were obtained by self-pollination.Chromosomes aberrations,such as translocation,deletions,isobrachial and dicentromere chromosomes,are identified in F_2 individual plants by C-banding combined with fluorescent in situ hybridization (FISH).Additionally,Chromosome spontaneous substitutions such as 2C substituting for wheat chromosomes 2A,2B and 2D were also observed.The rule and frequency of chromosome aberration in F_2 are the following: 22 out of 430 F_2 plants (5.11%) were found involving aberration rye chromosomes.Among them,10 plants were identified as wheat-rye chromosome translocation lines comprising 2.3%.Rye chromosome deletions comprised 12 of them (2.79%).3 isobrachial aberrations were detected (about 0.7%),too.Most of the translocation lines are with wheat centromere,only one of them is with rye centromere.Rye chromosome aberrations occurred unevenly among homoeologous groups.There were 5 in 1R,3 in 2R,1 in 3R,3 in 4R,6 in 5R and 4 in 6R.The majority of the translocation lines are terminal translocation.54 out of the total 430 progenies are wheat deletions,and 27 are distributed in the A group,20 in the B group and 7 in the D group respectively.Finally,we discussed the possible cause for the uneven chromosome aberration among homoeologous groups in wheat and rye as well as the effect characteristics of 2C on wheat and rye chromosome.