Genetic diversity, population structure, and resistance to Phytophthora capsici of a worldwide collection of eggplant germplasm.

Rachel P Naegele,Rachel P Naegele,Samantha Boyle,Lina M Quesada-Ocampo,Samantha Boyle,Mary K Hausbeck,Boris Alexander Vinatzer

doi:10.1371/journal.pone.0095930

Rachel P Naegele, Rachel P Naegele + Show 5 more

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https://doi.org/10.1371/journal.pone.0095930

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Abstract

Eggplant (Solanum melongena L.) is an important solanaceous crop with high phenotypic diversity and moderate genotypic diversity. Ninety-nine genotypes of eggplant germplasm (species (S. melongena, S. incanum, S. linnaeanum and S. gilo), landraces and heirloom cultivars) from 32 countries and five continents were evaluated for genetic diversity, population structure, fruit shape, and disease resistance to Phytophthora fruit rot. Fruits from each line were measured for fruit shape and evaluated for resistance to two Phytophthora capsici isolates seven days post inoculation. Only one accession (PI 413784) was completely resistant to both isolates evaluated. Partial resistance to Phytophthora fruit rot was found in accessions from all four eggplant species evaluated in this study. Genetic diversity and population structure were assessed using 22 polymorphic simple sequence repeats (SSRs). The polymorphism information content (PIC) for the population was moderate (0.49) in the population. Genetic analyses using the program STRUCTURE indicated the existence of four genetic clusters within the eggplant collection. Population structure was detected when eggplant lines were grouped by species, continent of origin, country of origin, fruit shape and disease resistance.

Highlights

Cultivated eggplant, Solanum melongena L., is a high-value vegetable commodity in Europe and Asia
We evaluated the fruit shape index, Phytophthora fruit rot resistance, genetic diversity and population structure of a diverse collection of eggplant germplasm using 22 simple sequence repeats (SSRs)
Our objectives were to evaluate a worldwide collection of eggplants for population structure and genetic diversity, and to determine if the population structure is associated with fruit shape or resistance to Phytophthora capsici

Summary

Introduction

Cultivated eggplant, Solanum melongena L., is a high-value vegetable commodity in Europe and Asia. Unlike most other cultivated solanaceous crops (tomatoes, peppers, and potatoes), eggplants are an Old World species. Studies have indicated that the progenitors of domesticated eggplant (S. melongena) originated in Africa and were derived from the closely related Solanum incanum (part of the eggplant complex) [6] and Solanum linnaeanum [5]. Both S. incanum and S. linnaeanum can form partially fertile hybrids with S. melongena making them potential sources for desirable traits such as abiotic and biotic disease resistance [7,8,9]. Domesticated heirloom varieties and landrace accessions may harbor resistance, and are often more similar to modern cultivated varieties than wild species, making them a good source for desirable traits [16,17]

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