三倍体罗汉果及其亲本的同工酶比较研究

Comparative study on triploid Siraitia grosvenorii and their parents by isozymes analysis

关键词:  三倍体罗汉果  亲本  同工酶  遗传距离

Key words:  triploid Siraitia grosvenorii  parents  isozymes  genetic distance

摘要:

为了加快三倍体罗汉果育种的进程和效率,进一步提高其亲本选择性,该文对F1代3x罗汉果与其4x和2x亲本的过氧化物酶(POD)同工酶和酯酶(EST)同工酶进行了比较。结果表明:F1代3x罗汉果与其4x和2x亲本的POD和EST同工酶均有一定差异,3x和4x的POD和EST同工酶不同迁移率的平均酶带数目较2x多,酶带活性也较强; 4x 的POD同工酶数目较3x的多,但EST同工酶两者差异较小; F1代3x罗汉果的同工酶均出现了与其4x和2x亲本不同的新酶带,预示着其可能具有的杂种优势; 聚类分析结果显示,F1代3x罗汉果与其4x母本的遗传距离更近,并且当4x母本间亲缘遗传关系较近时,其F1代3x在亲缘遗传上也相聚较近,说明F1代3x在亲缘遗传上更倾向于其4x母本。由于三倍体罗汉果育种亲本间存在杂种优势,且更倾向于其母本遗传,因此通过该研究可以初步总结出三倍体罗汉果及其父本、母本的遗传规律,并提出罗汉果三倍体良种选育的建议,即在3x罗汉果育种时需要更加关注4x母本的优良性状表现,并以亲本的遗传背景为基础,选择遗传差异较为显著的父本和母本。

Abstract:

In order to accelerate the process and efficiency of breeding triploid Siraitia grosvenorii by artificial method, and further improve the correctness in parents' selection, in this article the triploid S. grosvenorii of F1 generation was studied and compared with its tetraploid and diploid by Peroxidase Isozyme and Esterase Isozyme analysis. The results showed that there were certain variations in Peroxidase Isozyme and Esterase Isozyme in different ploidy S. grosvenorii. Compared with the diploid, triploid and tetraploid had the more different mobility isozyme band and more active isozyme band in Peroxidase Isozyme and Esterase Isozyme. Tetraploid had more different mobility isozyme bands than triploid in Peroxidase Isozyme, but they had little difference in isozyme band of Esterase Isozyme. The genetic distance of triploid descendant of F1 generation was closer to its female parent and at the same time, the genetic distance of different triploid descendants of F1 generation were closer to each other when their female tetraploid parents were closer as revealed through sample clustering analysis based on euclidean square distance index according to the data of peroxidase isozyme and esterase isozyme,so that the triploid descendant of F1 generation was genetically closer to its tetraploid female parent. Because it had heterosis in the parents of triploid S. grosvenorii and was genetically closer to female parent, based on this genetic law we could propose the following suggestions about the breeding of improved varieties in triploid S. grosvenorii. The suggestion was that we needed to pay more attention on the excellent character performance of tetraploid female parent in the breeding of triploid S. grosvenorii, and selected the genetic distance was more remarkable between the male and female parent based on the genetic background.