小黑麦杂交F_1代真假杂种的ISSR标记鉴定及遗传多样性分析

为了给ISSR标记技术应用于小黑麦杂种鉴定提供参考,利用ISSR标记对小黑麦品系P1和P_2有性杂交得到的F_1代群体进行分子鉴定,同时结合田间表型调查结果对F_1代群体进行遗传多样性分析。结果表明,66个杂交F_1代单株中,52个为真杂种,其中,5个单株无主茎、未结实,1个生长后期死亡。14条ISSR引物对46个正常结实真杂种扩增的多态性条带百分率为61.19%,其中,UBC822的多态性条带百分率为100%,UBC808和UBC815的多态性条带百分率均为75%。F_1代群体和父母本的遗传相似系数为0.62~0.94,说明杂交后代产生了丰富的遗传变异。聚类分析将杂交F_1代群体和父母本在阈值0.748处分为3大类群,第1类群包括1份材料(父本,P1),第2类群包括1份材料(母本,P_2),第3类包括46个杂交F_1代单株;杂交F_1代与父母本的遗传距离较远,先与母本聚为一类,之后与父本聚为一类。田间调查结果表明,7个性状中,除株高偏向于父本外,分蘖数、有效分蘖数、穗长、小穗数、穗粒数和穗粒重均偏向于母本,与父本的差距较大,这与ISSR分析结果基本相吻合。

Purity Identification and Genetic Diversity Studies on the F1 Hybrid Generation of Triticale

In order to provide reference for the mutation identification and selection of parents, ISSR markers were used to identify the hybrid F₁ generation of new triticale lines P₁ and P₂.Besides, the genetic diversity of F₁ population was studied based on the field investigation results.The results showed that, among 66 F₁ plants, 52 were true hybrids, and 46 plants were used as the experimental materials in this study because the rest of six plants did not grow normally.The amplification percentage was 61.19% for 46 F₁ hybrid plants while using 14 ISSR primers, among which, amplification percentage was 75% for the primer UBC808 and UBC815, and 100% for the primer UBC822.For 46 F₁ plants and their parents, the genetic similarity coefficient ranged from 0.62 to 0.94, which proved that the hybrid offspring produced abundant genetic variation.Cluster analysis showed that the 46 F₁ plants and their parents were classified into 3 categories, which were male parent, female parent and their F₁ generation, respectively.The F₁ generation was firstly clustered with the female and then with the male, which demonstrated that the F₁ population had closer relationship with the female parent than that with the male parent.The results of field investigation showed that the F₁ population was significantly different from male parent in seven traits, such as the number of tillers and effective tillers, spike length, the number of spikelet and seeds, and grain weight per spike, except plant height, which is consistent with the results of ISSR analysis.