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开展花生种间杂交与杂种遗传研究对于探明种间亲缘关系、创制新种质和培育新品种具有重要意义。本研究利用花生栽培品种白沙1016(2n=4X=40,AABB)与二倍体野生种A.macedoi(2n=2X=20)进行种间杂交,通过胚拯救获得种间杂种F_1植株,进而对F_1进行了分子标记鉴定、有丝分裂与减数分裂观察和基因组荧光原位杂交(GISH)分析。结果显示,杂种F_1有30条染色体,其中既有来自母本白沙1016的染色质,又有来自父本A.macedoi的染色质;A.macedoi染色体经DAPI染色显示出明亮着丝粒带且包含一对“小染色体”;白沙1016的A染色体组也显示出A.macedoi基因组标记探针的杂交信号;F_1减数分裂终变期染色体平均构型为0.6 III+8.27 II+11.6 I,减数分裂I期后、末期表现为不均等分裂。以上结果表明本研究获得了新的种间杂种F_1材料,所涉及的A.macedoi可能为A染色体组物种;A.macedoi染色体与花生A染色体组发生交换产生补偿性易位的几率比较大;减数分裂后、末期染色体的不均等分裂和非四分体形成,是杂种F_1表现高度不育的重要原因之一。
Carrying out the research on inter-peanut crossbreeding and hybrid inheritance is of great significance for identifying kinship, creating new germplasm and cultivating new varieties. In this study, interspecific hybridization was conducted between peanut cultivars Baisha 1016 (2n = 4X = 40, AABB) and diploid wild A.macedoi (2n = 2X = 20) F_1 was identified by molecular markers, mitosis and meiosis observation and genome fluorescence in situ hybridization (GISH) analysis. The results showed that hybrid F_1 has 30 chromosomes, of which there are both chromatin from parent Paksha 1016 and chromatin from A. macedoi. A.macedoi chromosomes show bright centromere by DAPI and contain A pair of “small chromosomes”; white sand 1016 A chromosome group also shows A.macedoi genome marker probe hybridization signal; F_1 meiotic metaphase chromosome average configuration of 0.6 III +8.27 II +11.6 I, Meiosis after I, the end showed uneven split. The above results showed that the new interspecific hybrid F1 was obtained in this study. The A.macedoi involved may be the A-chromosome species. The probability that the A.macedoi chromosome will exchange with the peanut A-genome will produce a compensatory translocation. After splitting, the heterozygous division and non-tetrad formation of terminal chromosomes are one of the important reasons for the high sterility of F1 hybrids.