Analysis of Genetic Diversity and Population Structure in Bitter Gourd (Momordica charantia L.) Using Morphological and SSR Markers.

Ahmad Alhariri,Tusar Kanti Behera,Mayanglambam Bilashini Devi,Nada F Hemeda,Ayaat A Teleb,G Boopalakrishnan,Gograj Singh Jat,Ahmed Elkordy,E Ismail

doi:10.3390/plants10091860

Abstract

The present investigation was carried out using 51 diverse bitter gourd accessions as material for studying genetic diversity and relatedness using morphological and SSR markers. A wide variation was observed for morphological traits like the number of days to the first female flower anthesis (37.33–60.67), the number of days to the first fruit harvest (47.67–72.00), the number of fruits/plant (12.00–46.67), fruit length (5.00–22.23 cm), fruit diameter (1.05–6.38 cm), average fruit weight (20.71–77.67 g) and yield per plant (513.3–1976 g). Cluster analysis for 10 quantitative traits grouped the 51 accessions into 6 clusters. Out of 61 SSR primers screened, 30 were polymorphic and highly informative as a means to differentiate these accessions. Based on genotyping, a high level of genetic diversity was observed, with a total of 99 alleles. The polymorphic information content (PIC) values ranged from 0.038 for marker BG_SSR-8 to 0.721 for S-24, with an average of 0.429. The numbers of alleles ranged from 2 to 5, with an average of 3.3 alleles per locus. Gene diversity ranged from 0.04 for BG_SSR-8 to 0.76 for S-24, showing a wide variation among 51 accessions. The UPGMA cluster analysis grouped these accessions into 3 major clusters. Cluster I comprised 4 small, fruited accessions that are commercially cultivated in central and eastern India. Cluster II comprised 35 medium- to long-sized fruited accessions, which made up an abundant and diverse group. Cluster III comprised 11 long and extra-long fruited accessions. The polymorphic SSR markers of the study will be highly useful in genetic fingerprinting and mapping, and for association analysis in Momordica regarding several economic traits.

Highlights

Based on the ∆K method, the results suggest that the 51 bitter gourd accessions can be grouped into three sub-groups
The results are based on ten important quantitative traits to assess the potentiality of bitter gourd gynoecious lines regarding yield and earliness; the genetically divergent accessions identified in the present experiment will be useful in future breeding programs for enhancing the productivity of bitter gourd
This study analyzed the pattern of genetic divergence existing in 51 bitter gourd accessions; these constituted the bitter gourd diversity group for future association mapping

Summary

Introduction

It is highly valuable for its nutritional content, providing carbohydrates, proteins, vitamins, minerals, and ascorbic acid [1], and for numerous medicinal uses [2]. The primary center of origin for bitter gourd is probably India, with China as a secondary center of diversity [6,7]. India is richly endowed with bitter gourd genetic resources, as Indian bitter gourd germplasms are diverse in phenotypic characteristics, i.e., sex expression [8], growth habit, maturity, fruit shape, size, color and surface texture [9,10,11,12,13,14]. Indian bitter gourd accessions exhibit valuable genes that are as yet unexplored [15].

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Results

Discussion

Conclusion