Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers

The assessment of genetic diversity and structure of a gene pool is a prerequisite for efficient organization, conservation, and utilization for crop improvement. This study evaluated the genetic diversity and population structure of 24 Tunisian melon accessions, by using 24 phenotypic traits and ei...

Full description

Bibliographic Details
Main Authors: Hela Chikh-Rouhou, Najla Mezghani, Sameh Mnasri, Neila Mezghani, Ana Garcés-Claver
Format: Article
Language:English
Published: MDPI AG 2021-05-01
Series:Agronomy
Subjects:
Online Access:https://www.mdpi.com/2073-4395/11/6/1121
id doaj-43c51749c66248a99fb9b76c09547d4c
record_format Article
spelling doaj-43c51749c66248a99fb9b76c09547d4c2021-06-01T01:46:06ZengMDPI AGAgronomy2073-43952021-05-01111121112110.3390/agronomy11061121Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular MarkersHela Chikh-Rouhou0Najla Mezghani1Sameh Mnasri2Neila Mezghani3Ana Garcés-Claver4Regional Research Centre on Horticulture and Organic Agriculture (CRRHAB/IRESA), LR21AGR03, University of Sousse, 4042 Sousse, TunisiaNational Gene Bank of Tunisia, Boulevard Leader Yasser Arafat, 1080 Tunis, TunisiaNational Gene Bank of Tunisia, Boulevard Leader Yasser Arafat, 1080 Tunis, TunisiaLICEF Research Center, TELUQ University, 5800 Rue Saint-Denis, Quebec, QC H2S3L5, CanadaCentro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto Agroalimentario de Aragón-IA2 (CITA-Universidad de Zaragoza), 50059 Zaragoza, SpainThe assessment of genetic diversity and structure of a gene pool is a prerequisite for efficient organization, conservation, and utilization for crop improvement. This study evaluated the genetic diversity and population structure of 24 Tunisian melon accessions, by using 24 phenotypic traits and eight microsatellite (SSR) markers. A considerable phenotypic diversity among accessions was observed for many characters including those related to agronomical performance. All the microsatellites were polymorphic and detected 30 distinct alleles with a moderate (0.43) polymorphic information content. Shannon’s diversity index (0.82) showed a high degree of polymorphism between melon genotypes. The observed heterozygosity (0.10) was less than the expected heterozygosity (0.12), displaying a deficit in heterozygosity because of selection pressure. Molecular clustering and structure analyses based on SSRs separated melon accessions into fivegroups and showed an intermixed genetic structure between landraces and breeding lines belonging to the different botanical groups. Phenotypic clustering separated the accessions into two main clusters belonging to sweet and non-sweet melon; however, a more precise clustering among <i>inodorus, cantalupensis,</i> and <i>reticulatus</i> subgroups was obtained using combined phenotypic–molecular data. The discordance between phenotypic and molecular data was confirmed by a negative correlation (<i>r</i> = −0.16, <i>p</i> = 0.06) as revealed by the Mantel test. Despite these differences, both markers provided important information about the diversity of the melon germplasm, allowing the correct use of these accessions in future breeding programs. Together they provide a powerful tool for future agricultural and conservation tasks.https://www.mdpi.com/2073-4395/11/6/1121genetic diversitybreeding lineslandracesphenotypic traitsmolecular markers
collection DOAJ
language English
format Article
sources DOAJ
author Hela Chikh-Rouhou
Najla Mezghani
Sameh Mnasri
Neila Mezghani
Ana Garcés-Claver
spellingShingle Hela Chikh-Rouhou
Najla Mezghani
Sameh Mnasri
Neila Mezghani
Ana Garcés-Claver
Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
Agronomy
genetic diversity
breeding lines
landraces
phenotypic traits
molecular markers
author_facet Hela Chikh-Rouhou
Najla Mezghani
Sameh Mnasri
Neila Mezghani
Ana Garcés-Claver
author_sort Hela Chikh-Rouhou
title Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
title_short Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
title_full Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
title_fullStr Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
title_full_unstemmed Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (<i>Cucumis melo</i> L.) Collection Using Phenotypic Traits and SSR Molecular Markers
title_sort assessing the genetic diversity and population structure of a tunisian melon (<i>cucumis melo</i> l.) collection using phenotypic traits and ssr molecular markers
publisher MDPI AG
series Agronomy
issn 2073-4395
publishDate 2021-05-01
description The assessment of genetic diversity and structure of a gene pool is a prerequisite for efficient organization, conservation, and utilization for crop improvement. This study evaluated the genetic diversity and population structure of 24 Tunisian melon accessions, by using 24 phenotypic traits and eight microsatellite (SSR) markers. A considerable phenotypic diversity among accessions was observed for many characters including those related to agronomical performance. All the microsatellites were polymorphic and detected 30 distinct alleles with a moderate (0.43) polymorphic information content. Shannon’s diversity index (0.82) showed a high degree of polymorphism between melon genotypes. The observed heterozygosity (0.10) was less than the expected heterozygosity (0.12), displaying a deficit in heterozygosity because of selection pressure. Molecular clustering and structure analyses based on SSRs separated melon accessions into fivegroups and showed an intermixed genetic structure between landraces and breeding lines belonging to the different botanical groups. Phenotypic clustering separated the accessions into two main clusters belonging to sweet and non-sweet melon; however, a more precise clustering among <i>inodorus, cantalupensis,</i> and <i>reticulatus</i> subgroups was obtained using combined phenotypic–molecular data. The discordance between phenotypic and molecular data was confirmed by a negative correlation (<i>r</i> = −0.16, <i>p</i> = 0.06) as revealed by the Mantel test. Despite these differences, both markers provided important information about the diversity of the melon germplasm, allowing the correct use of these accessions in future breeding programs. Together they provide a powerful tool for future agricultural and conservation tasks.
topic genetic diversity
breeding lines
landraces
phenotypic traits
molecular markers
url https://www.mdpi.com/2073-4395/11/6/1121
work_keys_str_mv AT helachikhrouhou assessingthegeneticdiversityandpopulationstructureofatunisianmelonicucumismeloilcollectionusingphenotypictraitsandssrmolecularmarkers
AT najlamezghani assessingthegeneticdiversityandpopulationstructureofatunisianmelonicucumismeloilcollectionusingphenotypictraitsandssrmolecularmarkers
AT samehmnasri assessingthegeneticdiversityandpopulationstructureofatunisianmelonicucumismeloilcollectionusingphenotypictraitsandssrmolecularmarkers
AT neilamezghani assessingthegeneticdiversityandpopulationstructureofatunisianmelonicucumismeloilcollectionusingphenotypictraitsandssrmolecularmarkers
AT anagarcesclaver assessingthegeneticdiversityandpopulationstructureofatunisianmelonicucumismeloilcollectionusingphenotypictraitsandssrmolecularmarkers
_version_ 1721411567698837504