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...
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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 |
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