Genetic Diversity and Population Structure of Brachiaria Species and Breeding Populations
Genetic Diversity and Population Structure of Brachiaria Species and Breeding Populations
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DOI：
10.2135/cropsci2017.01.0045
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发表时间：
2017-09-01
期刊：
影响因子：
2.3
通讯作者：
Worthington, Margaret
中科院分区：
文献类型：
--
作者：
Jimena Trivino, Narda;Guillermo Perez, Juan;Worthington, Margaret
几种无分裂的腕足菌（Trin.）Griseb。（syn. Urochloa P. Beauv.）是一种具有重要商业价值的热带牧草，但对该属的种间多样性和种群结构了解甚少。先前发表的属级腕鱼系统发育研究采用了很少的基因型，与已建立的形态学证据和已证实的brizantha （Hochst）种间生育能力相矛盾。A.里奇。Stapf。B. decumbens Stapf。ruziziensis (R. Germ；[C.M.埃弗拉]。本研究对14种腕鱼属和1种大头蛇属261个基因型的遗传多样性和群体结构进行了分析。利用39条简单序列重复引物，共701条多态性带进行群外分析。小组中包括的基因型包括种质资源、商业品种和有性繁殖的育种群体。结构、邻域连接、算术平均的非加权对群法和多重对应分析结果证实了三种重要商业种brizantha、B. decumbens和B. ruziziensis的亲缘性。与ruziziensis亲缘关系最为密切，雌雄二倍体和四倍体无染色体体的becachiaria decumbens种群形成两个亲缘关系密切但又不同的类群。humidicola (Rendle) Schweick与dictyoneura （Figari）的亲缘关系。和德·诺特·斯塔夫。这些结果也证实了单有性繁殖的湿芽孢杆菌的独特基因组成。我们的研究结果在很大程度上支持了基于形态的腕鱼分类分组，并表明包含来自每个物种的许多多态性标记和多个基因型使属水平的系统发育更加稳健。
Several apomictic Brachiaria (Trin.) Griseb. (syn. Urochloa P. Beauv.) species are commercially important tropical forage grasses, but little is known about the interspecific diversity and population structure within this genus. Previously published genus-level Brachiaria phylogenies were conducted with few genotypes and contradicted well-established morphological evidence and proven interspecific fertility in the B. brizantha (Hochst. ex A. Rich.) Stapf., B. decumbens Stapf., and B. ruziziensis (R. Germ. & C.M. Evrard) agamic complex. In this study, we characterized the genetic diversity and population structure of 261 genotypes from 14 Brachiaria species and a Panicum maximum Jacq. outgroup using 39 simple sequence repeat primers with 701 polymorphic bands. The genotypes included in the panel included germplasm accessions, commercial cultivars, and sexually reproducing breeding populations. Results of STRUCTURE, neighbor joining, unweighted pair group method with arithmetic mean, and multiple correspondence analyses confirmed the relatedness of the important commercial species B. brizantha, B. decumbens, and B. ruziziensis. Brachiaria decumbens was most closely related to B. ruziziensis, and the diploid sexual and tetraploid apomict B. decumbens accessions formed into two related but distinct groups. The close relationship between B. humidicola (Rendle) Schweick and B. dictyoneura (Figari. and De Not) Stapf. and the unique genetic makeup of the lone sexually reproducing B. humidicola accession were also corroborated by these results. Our findings largely supported morphology-based taxonomic groupings in Brachiaria and indicated that genus-level phylogenies are made more robust by the inclusion of many polymorphic markers and multiple genotypes from each species.