College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.
Ministry of Education Key Laboratory of Grassland Resources, Hohhot, China.
PeerJ. 2022 Nov 30;10:e14442. doi: 10.7717/peerj.14442. eCollection 2022.
Russian wildrye, (Fisch.) Nevski, is widely distributed in the high latitude areas of Eurasia. It plays an important role in grassland ecosystem maintenance, as well as being a valuable palatable forage species for livestock and wildlife. Russian wildrye germplasm has rich phenotypic and genetic diversity and has potential for improvement through crossbreeding. In this study, fifteen Russian wildrye hybrid combinations were produced and one F1 population with 123 putative hybrids was obtained by crossing two individual plants with significant differences in nutritional characteristics and reproductive tiller number. Twelve phenotypic traits of the F1 population were measured for three consecutive years, and ten of the twelve traits were in line with the genetic characteristics of quantitative traits. Hybrid superiority was revealed among F1 hybrids in both nutritional and reproductive traits. One non-recurrent parent plant with the highest PCA-synthesis score was selected and used to make a backcross with the 'BOZOISKY SELECT' male parent, and 143 putative BC1 hybrids were obtained. Sixteen pairs of EST-SSR primers were randomly selected from polymorphic primers derived from different expressed tiller trait related genes. Three primer pairs that amplified both the paternal and maternal characteristic band were used to assess the purity of the F1 population, and three primer pairs (with one shared primer pair) were used to identify the BC1 population. The hybrid purity was 96.75% for the F1 population and 95.80% for the BC1 population, and the results were confirmed by self-fertility test through bagging isolation. The genetic similarity coefficients between the F1 progeny and the male parent ranged from 0.500 to 0.895, and those between the BC1 progeny and the male parent ranged from 0.667 to 0.939. A subset of individuals in the BC1 population had closer genetic distance to the recurrent parent, and genetic variation within the BC1 population decreased compared to the F1 population.
俄罗斯冰草（Fisch.）Nevski 广泛分布于欧亚大陆高纬度地区。它在草原生态系统维护中起着重要作用，同时也是家畜和野生动物有价值的美味饲料。俄罗斯冰草种质资源具有丰富的表型和遗传多样性，通过杂交可以进行改良。本研究通过杂交 2 个营养特性和生殖分蘗数差异显著的个体，产生了 15 个俄罗斯冰草杂交组合，并获得了一个包含 123 个可能杂种的 F1 群体。连续 3 年对 F1 群体的 12 个表型性状进行了测量，其中 10 个性状符合数量性状的遗传特征。F1 杂种在营养和生殖性状上均表现出杂种优势。选择一个 PCA 综合得分最高的非轮回亲本与“BOZOISKY SELECT”雄性亲本回交，获得了 143 个可能的 BC1 杂种。从不同表达的生殖特性相关基因中筛选出多态性引物，随机选取 16 对 EST-SSR 引物。使用扩增出父本和母本特征带的 3 对引物评估 F1 群体的纯度，使用 3 对引物（其中 1 对引物共用）鉴定 BC1 群体。F1 群体的杂种纯度为 96.75%，BC1 群体的杂种纯度为 95.80%，通过套袋隔离自交结实试验进行验证。F1 后代与雄性亲本的遗传相似系数为 0.500-0.895，BC1 后代与雄性亲本的遗传相似系数为 0.667-0.939。BC1 群体中的一部分个体与轮回亲本的遗传距离更近，与 F1 群体相比，BC1 群体的遗传变异减少。
