二倍体杂交种棱果沙棘双向杂交起源及其母本主要来源于中国沙棘的分子证据

Molecular Evidence for Bidirectional Hybrid Origin and Hippophae rhamnoides ssp. sinensis as the Mainly Maternal Plant of the Diploid Hybrid H. goniocarpa(Elaeagnaceae)

棱果沙棘为同域分布的中国沙棘和肋果沙棘同倍化自然杂交形成的。本文利用母系遗传的cpDNA trnS-G序列检测青海祁连棱果沙棘及其亲本中国沙棘和肋果沙棘同域分布的两个地区(拱北湾、八宝河滩)共93个个体的遗传关系。结果表明棱果沙棘及其亲本在拱北湾和八宝河滩分别有12个和7个单倍型,两地区的棱果沙棘都与其亲本共享单倍型,其中拱北湾棱果沙棘共36个个体中有28个与中国沙棘共享3个单倍型(H2,H4,H5),有2个个体与肋果沙棘共享单倍型(H11),八宝河滩的棱果沙棘共10个个体中有7个与中国沙棘共享一个单倍型(H4),3个与肋果沙棘共享单倍型(H7)。应用最大简约法(MP)分别对两地区的棱果沙棘及其亲本trnS-G序列构建的系统发育树中棱果沙棘的大部分个体都与中国沙棘聚在一起,另外,棱果沙棘4种特有单倍型(H3、H7、H8、H9)的6个个体在系统树上也与中国沙棘聚为一支。以上结果进一步证明了二倍体自然杂交种棱果沙棘为双向杂交起源,但其主要母本来源应为中国沙棘。

Hippophae goniocarpa is a natural hybrid species through homoploid hybridization between H. rhamnoides ssp. sinensis and H. neurocarpa distributed sympatrically. Maternally inherited cpDNA trnS-G sequence was used to detect the genetic relationship among 93 individuals of H. goniocarpa and its parent species which distributed sympatrically in Gongbeiwan and river land of Babao of Qilian, Qinghai. The results showed that H. goniocarpa and its parent species in the Gongbeiwan and river land of Babao had 12 and 7 haplotypes, respectively. H. goniocarpa shared common haplotypes with both H. rhamnoides ssp. sinensis and H. neurocarpa in the two places. Twenty-eight out of 36 individuals of H. goniocarpa shared common haplotypes with H. rhamnoides ssp. sinensis（ H2, H4, H5）, only two individuals shared common haplotypes with H. neurocarpa at Gongbeiwan. Seven out of 10 individuals of H. goniocarpa shared common haplotypes with H. rhamnoides ssp. sinensis（H4）, 3 out of 10 individuals of H. goniocarpa shared common haplotypes with H. neurocarpa （H7） at river land of Babao. Phylogenetic tree of H. goniocarpa and its parent species from two regions was constructed by Maximum Parsimony （MP）, and the results showed together with H. rhamnoides ssp. sinensis. In addition, 6 （H3, H7, H8 and H9） were also clustered with H. that most individuals of H. goniocarpa were clustered individuals of H. goniocarpa with 4 typical haplotypes rhamnoides ssp. sinensis. The bidirectional hybrid origin of H. goniocarpa is further proved here and H. rhamnoides ssp. sinensis is found to be the main maternal Sotlrce.