甘草属种间杂交种叶绿体DNA父系遗传的发现及分析

Inheritance analysis and discovery of chloroplast paternal inheritance in interspecific crossing of Glycyrrhiza

关键词:  甘草属,种间杂交, ITS, 叶绿体DNA, 父系遗传

Key words:  Glycyrrhiza, interspecific crossing, ITS, chloroplast DNA, paternal inheritance

摘要:

通过对甘草属乌拉尔甘草(Glycyrrhiza uralensis)、光果甘草(G. glabra)、胀果甘草(G. inflata)及其人工杂交种组合G. uralensis♀ × G. glabra♂、G. glabra♀ × G. uralensis♂、G. uralensis♀ × G. inflata♂、G. inflata♀ × G. uralensis♂共68份材料的核基因ITS序列、叶绿体rbcL、matK、trnH-psbA基因的序列分析,探讨了甘草属叶绿体DNA遗传方式。结果表明:(1)亲本种和人工杂交种ITS序列长度均为614 bp,其中34份人工杂交种ITS序列存在4处变异位点,且人工杂交种均检测出来自父本、母本ITS序列相同位点碱基的叠加,检测率为100%。(2)亲本种与人工杂交种的叶绿体基因rbcL、matK、trnH-psbA序列长度相同,共有4处变异位点,人工杂交种在变异位点处的碱基与其相对应的父本碱基一致率高达97.1%。以上结果说明,该研究获得34份人工杂交种为100%杂交成功的F₁子代,核基因ITS序列可用于甘草属杂交种的遗传鉴定; 甘草属叶绿体rbcL、matK、trnH-psbA基因具有父系遗传特性,推测甘草属质体的遗传方式主要表现为父系遗传,这种质体遗传方式的发现为甘草属杂交种和遗传多样性研究提供了新的认识,也为杂交种的亲本鉴定提供分子依据。

Abstract:

The goal of this paper was to have a better understanding of chloroplast inheritance patterns and identify the hybrid parent in Glycyrrhiza. A total of 68 individuals of Glycyrrhiza were selected including 34 parental species, G. uralensis, G. glabra, G. inflata and 34 artificial interspecific crosses, G. uralensis♀ × G. glabra♂, G. glabra♀ × G. uralensis♂, G. uralensis♀ × G. inflata♂ and G. inflata♀ × G. uralensis♂. Thirty-four artificial interspecific crosses were performed and the sequence polymorphisms of chloroplast DNA(cpDNA)and internal transcribed spacer(ITS)of nuclear gene of parents and progenies were studied. Sequence analysis showed that ITS sequences of parents and progenies had the same length of 614 bp and altogether four variable sites, with three genotypes. Two different ITS sequence copies at four variable sites were found in each individual of F₁ hybrids, one from the paternal and the other from the female parent, about which the detection ratio was 100%. It suggested that 34 artificial interspecific crosses produced successful F₁ hybrids in this research and genetic trait of ITS could infer parents of Glycyrrhiza. Sequence analysis showed that the cpDNA rbcL, matK and trnH-psbA sequences of parents and artificial interspecific crosses had the same length, within a total of four variable sites and six genotypes. Two different cpDNA haplotypes were found in Glycyrrhiza. The cpDNA haplotypes of F₁ hybrids matched those of the male parents and that ratio was up to 97.1%, indicating that the genetic trait was mainly inherited from the paternal parent. This result demonstrated that the chloroplast inheritance pattern of Glycyrrhiza was mostly paternal inheritance, which provides new insights into the use of cpDNA markers in studies of natural hybrids and genetic polymorphism in Glycyrrhiza.