远缘杂种孤雌生殖系Giemsa C-带的遗传稳定性分析  

Genetic Stability Analyses in Inbred Lines Derived from Distant Hybrid Parthenocarpy with Giemsa C-banding Markers

作　　者：颜春洪[1] 宋运淳[1] 谷明光[2] 何锶洁[2] 

机构地区：[1]武汉大学生命科学院 [2]中国科学院遗传研究所

出　　处：《Acta Genetica Sinica》1997年第2期170-177,共8页

摘　　要：利用ＧｉｅｍｓａＣ－显带方法发现在玉米自交系自３３０和二倍体多年生类玉米远缘杂交孤雌生殖后代中出现广泛的Ｃ－带结构异染色质变异，表现为Ｃ－带数目和分布位置的变化以及异配型Ｃ－带的出现。这种变异不仅存在于表型不稳定的早代孤雌系中，而且还存在于表型稳定的高代系中。造成这种变异的原因可能是因为远缘种质的引入影响到遗传平衡进而引起染色体发生结构重排并引起染色质的变化，这种变化与玉米染色体组中非同源染色体间存在的同源片段和因此造成的减数分裂过程中非同源染色体配对有着直接的关系。这些研究对于认识孤雌生殖育种的理论基础和应用价值具有重要意义。Giemsa C-banding patterns of 6 inbred lines derived from the parthenocarpic progenies of a backcrossed distant hybrid [(Zi-330×DP)BC1] and their parents were investigated in this paperThe results indicated that great variations (including changes of C-bands' number and distribution in the genome,and/or C-bands heterozygosity) existed in the patterns of C-banding constitutive heterochromatin of these 6 linesThe variations were found not only in 3 inbred lines with unstable characters but also in 3 inbred lines with stable charactersThis may be due to that germplasm introgression of diploperennial teosinte(DP),one of the distant cross parents,affected the genetic balance and then this brought about chromosomal structure arrangement and/or chromatin constituent changesThese changes were directly correlated with abnormal pairing in meiosis between duplicated chromosome segments presented abundantly in maize genomeThe authors proposed that heterochromatin change(s) in genome might play an important role in balancing the germplasms between maize and its distant relative after cross and parthenocarpyObservation in this paper may be beneficial for understanding the basis in plant parthenogenesis and its values in maize breeding

关 键 词：遗传稳定性 玉米 远缘杂交 孤雌生殖系 C带 

分 类 号：S513.035.1[农业科学—作物学]