Genetic diversity, population structure and linkage disequilibrium among watermelons based on peroxidase gene markersby Necip Ocal, Mikail Akbulut, Osman Gulsen, Halit Yetisir, Ilknur Solmaz, Nebahat Sari

Scientia Horticulturae




Scientia Horticulturae 176 (2014) 151–161

Contents lists available at ScienceDirect

Scientia Horticulturae journa l h om epage: www.elsev ier .com/ locate /sc ihor t i

Geneti ka among e m

Necip Oc knu


Department of a r t i c l

Article history:

Received 21 Fe

Received in re

Accepted 1 Jul




Linkage disequilibrium

Turkish watermelons


Population structure ss-re idase (LD) akai] imer e un neighbor-joining (NJ) and principle component analysis (PCA) indicated low level of genetic diversity and few geography-based clustering among the watermelon accessions. Substructuring Bayesian analysis revealed that there were three subpopulations among 258 watermelons. Analysis of molecular variance (AMOVA) indicated that 54% of the molecular variation resided within subpopulations, 39% within geographic origins and 7% among subpopulations. Linkage disequilibrium (LD) analysis indicated presence 1. Introdu

Member humans an melons (W 2001a). Wi and include tus var. lana also known cynthis (L.)

De Winter ( galo, a rela of common some numb

Perennial C and Medite ∗ Correspon

Melikgazi 380

E-mail add http://dx.doi.o 0304-4238/© of LD among POGP loci. Overall, this study concluded that LD existed despite that it was variable among subpopulations, association studies were possible among watermelons, and substructuring analysis was efficient in analyzing population structure among watermelons. This study also indicated that the POGP markers would be useful for clarifying genetic parameters such as population structure and relationships among watermelons. © 2014 Elsevier B.V. All rights reserved. ction s of the genus Citrullus are important for feeding d animals worldwide. It has four species of waterhitaker and Davis, 1962; Jeffrey, 1975; Levi et al., thin this genus, Citrullus lanatus is the most common s two forms: most commercially cultivated C. lanatus and C. lanatus var. citroides [(L. H. Bailey) Mansf.], as citron. The other three species are Citrullus coloSchrad., Citrullus eccirrhosus Cogn. and Citrullus rehmii

De Winter, 1990). Praecitrullus fistulosus (Stocks) Panted species, is found in India and Pakistan. In spite morphological characters it slightly differ in chromoer (2n = 2× = 24) (Robinson and Decker-Walters, 1997). . colocynthis is grown in North Africa, southwest Asia rranean basin. Perennial C. eccirrhosus (Meeuse, 1962) ding author at: Erciyes University, Department of Horticulture, 39, Kayseri, Turkey. Tel.: +90 352 207 6666; fax: +90 352 437 6902. ress: o (O. Gulsen). and annual C. rehmii (De Winter, 1990) are naturally found in

Namibia Desert (Levi et al., 2005). Africa is the center of origin for all Citrullus species and has considerable level of diversity.

The other diversity center of watermelons is Far East. Being in the middle of these two diversity centers, Mediterranean Basin and the Middle East may have potential in hosting diverse range of Citrullus species (Robinson and Decker-Walters, 1997; Wehner, 2008).

Turkey is the second leading producer of watermelon after

China, with about 4.044 million tons of production (FAO, 2012) and almost all regions of Turkey from Mediterranean to Black Sea region and from Hakkari bordering Iran to Edirne neighboring Bulgaria and

Greece produce watermelon. These regions have diverse environmental conditions such as arid and cooler temperatures in central

Anatolia and very humid in Black Sea region. As a result, considerable number of local landraces have emerged which may have important in breeding programs (Huh et al., 2008; Solmaz and Sari, 2009). Genetic studies on watermelons representing Anatolia and the Middle East are scarce.

Various techniques indicated low level of diversity within C. lanatus, but inter-species variation within this genus: EST-SSR rg/10.1016/j.scienta.2014.07.001 2014 Elsevier B.V. All rights reserved.c diversity, population structure and lin watermelons based on peroxidase gen al, Mikail Akbulut, Osman Gulsen ∗, Halit Yetisir, Il


Biology, Erciyes University, Melikgazi 38039, Kayseri, Turkey e i n f o bruary 2014 vised form 24 June 2014 y 2014 a b s t r a c t

Plant peroxidases are a family of stre previously allowed to develop perox structure and linkage disequilibrium lus lanatus (Thunb.) Matsum. and N using 14 peroxidase gene-specific pr of POGP markers was high (98%). Thge disequilibrium arkers r Solmaz, lated proteins possessing highly conserved domains, which gene polymorphism (POGP) markers. Diversity, population based on POGP markers among 256 watermelons [Citrulgenotypes along with two outgroups were evaluated by s and several statistical procedures. Ratio of polymorphism weighted pair-group method arithmetic average (UPGMA), 152 N. Ocal et al. / Scientia Horticulturae 176 (2014) 151–161 (Hwang et al., 2011), RAPD and (Solmaz et al., 2010), SRAP (Solmaz, 2010; Uluturk et al., 2011). Probably this was due to relative recent evolution of watermelon or bottleneck in their history. Estimating genetic diversity is useful for organizing genetic resources, useful for ping of qua populations nomically requires de ulation stru between m causing fals ever popul of waterme 2012).

Plant pe interactions auxin degra plant senes

Amaya et a

Gulsen et a tain heme peroxide (H

Therefore, t heme-bindi tion and th

The level o second low above avera 2001). This primers to (Buchloe da munis) (Gu peroxidase

All indicate ciations be tolerance a melons are enhance div markers m est and like are likely t and distrib

Arabidopsis (2010b) ma them were

Citrus chrom dase genes and multilo ers (Gulsen alternative ons.

Linkage (2007) and random as

This happen events betw between m and LD am study were sity among among and origins, (3) linkage dis ons. 2. Materials and methods 2.1. Plant materials otal s (C. es (Ba cessi grou only alhou f the essio t the ccess cm from −20 plem on 7.00