油菜种间杂种的配子竞争力与染色体数变异规律研究  

Variation of Chromosome Number and Fertilization Fitness in Gametes of Interspecific Hybrids between Brassica napus × Brassica campestris

作　　者：卢长明[1,2] 加藤正弘[1,2] 

机构地区：[1]江西农业大学农学院 [2]爱媛大学农学部

出　　处：《江西农业大学学报》1999年第1期17-21,共5页Acta Agriculturae Universitatis Jiangxiensis

摘　　要：用甘蓝型油菜与白菜进行种间杂交（简称甘白交），研究其杂种配子的受精能力差异和后代染色体数目变异规律，结果表明：（１）甘白交Ｆ１代体细胞染色体数为２ｎ＝２９，并发现有２５％２ｎ＝２４～３１条染色体的异数体以及２ｎ＝３９的个体。（２）甘白交Ｆ１配子染色体数为ｎ＝１０～１９，平均为ｎ＝１３．６８。不同染色体数配子出现频率不同。成对分离的配子中（１４／１５，１３／１６，１２／１７，１１／１８，１０／１９）往往染色体数较少的一种频率较高。（３）各种染色体数的配子均可形成可育的配子并参与受精形成种子，但它们参与受精并产生后代的竞争力（适合度）具有明显差异。ｎ＝１０和ｎ＝１９的配子竞争力最强，ｎ＝１１，ｎ＝１８和ｎ＝１２的配子在非整倍体配子中竞争力较强，ｎ＝１４，ｎ＝１５和ｎ＝１６的配子竞争力最差。（４）ｎ＝１０的配子每增加一条染色体和ｎ＝１９的配子每减少一条染色体配子适合度都相应降低。因此，ｎ＝１４和ｎ＝１５的配子适合度最低。（５）以甘白交Ｆ１杂种为母本可提高ｎ＝１０～１３配子频率和降低ｎ＝１７～１９配子频率，而以甘白交Ｆ１杂种为父本则能提高ｎ＝１７～１９配子频率和降低ｎ＝１０～１３配子频率。因此，在以选育２ｎ＝２２为?Studies were carried out on the variation of chromosome number and fertilization fitness in gametes of interspecific hybrids between Brassica napus and Brassica campestris. Results showed that (1) number of somatic chromosomes in F 1 generation varied with individual plants, with 75% being 2n=29 and 25% being others including 2n=24 to 2n=28, 2n=30 to 2n=31, and 2n=39. Greater variation was observed in the crose of artificial B. napus ×B. campestris than cross of natural B. napus ×B. campestris; (2) Chromosome number of gametes produced by F1 hybrids(AAC) ranged from 10 to 19, with the average of n=13. 68. Gametes at different number of chromosome differed in frequency. Gametes of n=10,11,12,13,14 were more frequent than those of n=19,18,17,16,15, respectively, although they form in pairs by chromosome disjunction into two poles during anaphase Ⅰ of meiosis. (3) Gametes at any chromosome number within this range might be viable and form into offsprings, but they differed in competitional ability of fertilisation (or in fitness). The strongest competitors of gametes were those of n=10, and secondly those of n=19. Among the aneuploid gametes, those of n=11, n=18 and then n=12 were more competitive. The worst copetitors were those of n=14,15, and 16. (4) Fitness weakened with every increased chromosome upon n=10 and every decreased chromosome from n=19. Thus, gametes of n=14 and n=15 are weakest in fit ness. (5) The accumulated frequency of n=10～13 got higher and that of n=17～19 got lower when hybrids were used as maternal parent in backcross. Therefore, it is better to use sesquidipoid (AAC) as maternal parent in the breeding progrom aiming at aneuploids of 2n=22 and 2n=24, and as paternal parent in the progrom aiming at B.napus. (6) The sesquidiploid with high pollen fertility produces more frequent n=10～12 and n=17～19 gametes and less frequent n=14～16 gametes. (7) Fertility of gametes in sesquidiploids is predominantly dependent upon their A genomes in that different A genome differs in the ability

关 键 词：甘蓝型油菜 白菜 种间杂交 染色体数 配子育性 

分 类 号：S634.301[农业科学—蔬菜学] S634.101[农业科学—园艺学]