Molecular differentiation and diversity of cassava (Manihot esculenta) taken from 162 locations across Puerto Rico and assessed with microsatellite markers
Molecular differentiation and diversity of cassava (Manihot esculenta) taken from 162 locations across Puerto Rico and assessed with microsatellite markers
复制标题
DOI：
10.1093/aobpla/plr010
复制
发表时间：
2011-01-01
期刊：
影响因子：
2.9
通讯作者：
Siritunga, Dimuth
中科院分区：
文献类型：
--
作者：
Montero-Rojas, Maria;Correa, Ana Maria;Siritunga, Dimuth
背景和目标 种质多样性及其遗传特征的知识是作物改良和保护策略的宝贵资产。尽管自 15 世纪起木薯就已成为加勒比地区的重要作物，但人们对当今加勒比地区木薯的起源却知之甚少。在研究木薯时，遗传变异性和较长的生长周期带来了一系列独特的挑战，部分由于这些挑战，人们对波多黎各木薯的遗传多样性知之甚少。 方法 为了评估波多黎各木薯的遗传多样性，从该岛的不同乡镇收集了 162 个遗传背景未知的样本，并通过 33 个单序列重复标记进行了分析。出于比较目的，还对波多黎各木薯种质资源库的 23 个种质进行了评估。 主要结果 我们的结果表明，未知木薯样品的遗传多样性 (HE) (0.7174) 略高于当前波多黎各木薯资源库 (0.6996)。与未知样本相比，波多黎各木薯收藏中观察到的杂合子 (HO) 比例较高。算术平均分析的未加权配对方法表明，大多数样品与波多黎各木薯收藏品聚集在一起。然而，只有一组未知的木薯样品，并且没有波多黎各收集的材料。该簇的成员很可能共享集合中的种质所未代表的等位基因。结论这项广泛的研究表明未知样本中存在高水平的遗传多样性。传统做法，特别是间作和自生苗合并，导致了重组基因型对栽培种群的贡献。这项研究表明，波多黎各当地木薯很有潜力成为未来遗传改良计划的有用组成部分。
Background and aims Knowledge of germplasm diversity and its genetic characterization is an invaluable asset in crop improvement as well as conservation strategies. Although an important crop and present in the Caribbean since the 15th century, the origins of today's cassava in the Caribbean are poorly understood. Genetic variability and long growing cycles provide a unique set of challenges when researching cassava, and it is in part due to these challenges that little knowledge regarding the genetic diversity of cassava in Puerto Rico exists.Methodology In order to evaluate the genetic diversity of cassava in Puerto Rico, 162 samples with unknown genetic background were collected from different townships of the island and were analysed by 33 single sequence repeat markers. For comparative purposes, 23 accessions of the Puerto Rican cassava germplasm collection were also evaluated.Principal results Our results show that the genetic diversity (HE) of unknown cassava samples (0.7174) is slightly higher than in the current Puerto Rican cassava collection (0.6996). The observed proportion of heterozygotes (HO) was higher in the Puerto Rican cassava collection compared with the unknown samples. An unweighted pair-group method with arithmetic averaging analysis showed that most of the samples clustered with the accessions of the Puerto Rican cassava collection. However, there was one cluster of only unknown cassava samples and no accessions of the Puerto Rican collection. Members of this cluster most likely share alleles which are not represented by the accessions in the collection.Conclusion This broad study shows the presence of high levels of genetic diversity in the unknown samples. Traditional practices, especially intercropping and incorporation of volunteer seedlings, have led to the contribution of recombinant genotypes to cultivated stocks. This study revealed a high potential for local Puerto Rican cassava to be a useful part of future genetic improvement programmes.