East Timor as an important source of cashew ( Anacardium occidentale L.) genetic diversity

PeerJ

article

Lara Guterres¹  João Barnabé²  André Barros⁵  Alberto Bento Charrua¹  Maria Cristina Duarte⁴  Maria M. Romeiras²  Filipa Monteiro² 

[1] Nova School of Business and Economics, Campus de Carcavelos, Universidade Nova de Lisboa;LEAF—Linking Landscape, Environment, Agriculture and Food Research Center, Associated Laboratory TERRA, School of Agriculture ,(ISA), University of Lisbon;Universidade Nacional Timor Lorosa’e;cE3c—Centre for Ecology, Evolution and Environmental Changes & CHANGE—Global Change and Sustainability Institute, Faculty of Sciences, University of Lisbon;Innate Immunity and Inflammation Laboratory, Instituto Gulbenkian de Ciência;Department of Earth Sciences and Environment, Faculty of Science and Technology, Licungo University

关键词: Genetic diversity;    SSRs;    Population structuring;    Southeast Asia;    Diversity hotspots;   

DOI  :  10.7717/peerj.14894

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundCashew (Anacardium occidentale L.) is a crop currently grown in several tropical countries because of the economic importance of cashew nuts. Despite its enormous economic worth, limited research has been conducted on the molecular diversity of cashew genetic resources. In this study, a wide comprehensive assessment of the genetic diversity of cashew trees in East Timor was performed using microsatellites (SSRs) to evaluate intraspecific diversity and population structuring.MethodsA total of 207 individual cashew trees, including trees from East Timor (11), and outgroup populations from Indonesia (one) and Mozambique (two), were analyzed with 16 cashew-specific SSRs. A comprehensive sampling of cashew trees within East Timor was performed, covering the distribution of cashew orchards in the country. Genetic diversity indices were calculated, and population structuring was determined using three different approaches: genetic distances (UPGMA and NJ), AMOVA, and individual-based clustering methods through Bayesian (STRUCTURE) and multivariate (DAPC) analyses.ResultsThe population structuring analysis revealed that the genetic diversity of cashew populations in East Timor was higher in this study than previously reported for cashew trees. A higher allelic richness was found within cashew populations in East Timor compared with the outgroup populations (Mozambique and Indonesia), reinforced by the presence of private alleles. Moreover, our study showed that cashew populations in East Timor are grouped into two dissimilar genetic groups, which may suggest multiple cashew introductions over time. These new cashew genetic resources could be explored for future crop improvement.ConclusionsCrop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Therefore, this study provides useful information regarding genetic diversity and population structure that can be harnessed to improve cashew production in East Timor. This data is also important to creating a country-specific genetic cashew signature to increase cashew market value.

【 授权许可】

CC BY