石斛兰杂交后代iPBS标记鉴定及遗传分析

Identification of iPBS markers and genetic analysis of Dendrobium hybrid progeny

为获取性状优良的子代单株用于后续新品种培育和优质亲本的选配,采用iPBS与形态学双标记鉴定方法,对‘粉条纹’石斛(母本)与‘丹绒之星’石斛(父本)杂交组合进行遗传鉴定研究。结果表明:iPBS标记鉴定36个子代植株均为真杂种,在遗传距离0.71处,亲本及36个子代可分为3大类群,子代先与父本聚为一类再与母本聚合,两亲本与子代的遗传相似系数父本(0.6861)>母本(0.5105);形态学鉴定显示两亲本在各个性状上均存在较大差异,子代假鳞茎高度均值为25.48 cm,假鳞茎直径1.14 cm,叶片长度14.17 cm,叶片宽度3.45 cm,子代株型与叶型大小主要介于双亲间;子代花横径均值为4.96 cm,花纵径均值为5.75 cm,两者优于双亲的比例分别为16.67%和2.78%,多数子代植株花型较父母本偏小;在花部性状中,上萼宽、侧萼长宽和侧瓣长4个性状表现出一定超亲优势,唇瓣长和花梗数2个性状展现出较强的中亲优势,其余性状均呈现出不同程度的衰退趋势;子代在花色遗传上以父本的白紫色系为主,并在双亲花色色谱基础上展现梯度变化。综上,iPBS分子标记可有效提高鉴定石斛兰杂种的效率,形态学标记鉴定有助于高效选育性状优良的子代个体,2种标记方法均可有效缩短石斛兰杂交育种进程。

In order to obtain progeny with excellent traits for subsequent breeding of new varieties and selection of high-quality parents,using iPBS and morphological double marker identification to investigate the genetic identification of the hybrid combination of Dendrobium Fancy Pink Stripe(male parent)and Den.parishii‘Damrong Star’3lip(female parent).The combination was genetically identified.The results showed that:The 36 progeny were identified true hybrids with iPBS markers.At the genetic distance of 0.71,the parents and 36 progeny could be divided into three groups,and the progeny were clustered with the male parents first and then aggregated with the female parent and the coefficients of genetic similarity between the parents and the progeny were male parent(0.6861)>female parent(0.5105).Morphological identification showed significant differences in various traits between the two parents.The mean values of pseudobulb height,pseudobulb diameter,leaf length and leaf width in the hybrids generation were 25.48 cm,1.14 cm,14.17 cm and 3.45 cm,respectively.The size of plant and leaf type of the hybrid was mainly between the two parents;The mean values of transverse diameter and longitudinal diameter of the flower were 4.96 cm,and 5.75 cm respectively.The proportions of the two superior to their parents were 16.67%and 2.78%,respectively.And the majority of the hybrid plants had a smaller flower type than that of their parents.Among the floral traits,four traits(upper calyx width,lateral calyx length and lateral petal length)showed some supra-parental dominance,and two traits,labellum length and pedicel number,showed strong meso-parental dominance,while the rest of the traits showed different degrees of decline;The hybrid was dominated by the white-purple line of the parents in terms of the genetic inheritance of the floral colours,and showed gradient variations in the floral colours on the basis of the chromatograms of the two parents.In summary,iPBS molecular markers can effectively improve the efficiency of identifying Den.hybrids,and the morphological markers assists to efficiently select the hybrid individuals with excellent traits,and it can effectively shorten the breeding process of Den.crossbreeding by using these two types of marker.