Assessment of genetic relationships among Cucumis spp. by SSR and RAPD marker analysis

Abstract

The first successful production of a sterile interspecific hybrid obtained from a cross between Cucumis hystrix Chakr. (2n = 2x = 24) and Cucumis sativus var. sativus L. (2n =2x = 14), and its subsequent fertility restoration through chromosome doubling provide an effective means for investigating genetic relationships among Cucumis spp. In this study, random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers were used to investigate relationships among C. s. var. sativus L., C. s. var. hardwickii (R.) Alef., C hystrix, C. hytivus Chen & Kirkbride (the amphidiploid species from chromosome doubling of the C. sativus x C. hystrix interspecific hybrid, 2n = 38), C. melo (2n =2x = 24) and C. metuliferus Meyer and Naudin (2n =2x= 24). A total of 109 SSR bands and 398 RAPD primed sites were used to calculate Jaccard's distance coefficients for cluster analysis using a unweighted pair‐group method using an arithmetic averaging (UPGMA) algorithm. The genetic relationships identified using SSR and RAPDmarkers were highly concordant, such that the correlation between SSR and RAPDgenetic distance (GD) estimates was r = 0.94. SSR and RAPDanalysis of 22 accessions allowed for their grouping into two distinct groups designated as CS and CM. While group CS consisted of 11 C. sativus genotypes, and the C. hytivus and C. hystrix accessions, group CM included six C. melo genotypes and C. metuliferus. The GD values between C. hystrix and C. sativus ascribed by SSR and RAPD matrices were 0.59 and 0.57, respectively. These GDs were smaller than those detected between C. hystrix and C melo (0.87 and 0.70 derived from SSR and RAPD markers, respectively).

Cucurbits (Cucurbitaceae; Cucumis spp., Cucurbita spp., Citrullus spp.)

“…In terms of coefficients of variation (CV) per band, RAPDs exhibited lower CVs than did either isozymes or SSRs in Cucumis with moderate congruence between results generated by each marker class. In contrast, Zhuang et al (2004) reported a high degree of congruence between genetic relationships revealed by RAPDs and SSRs among Cucumis taxa.…”

“…(2n=2x=24; Chinese origin) (Kirkbride 1993;Chen et al 1997b). Molecular-marker analyses have recently confirmed that these two species form a coherent group in relation to subgenus Melo (Zhuang et al 2004). This is also reflected in the development of a stable amphidiploid hybrid, C. X hytivus Chen & Kirkbride, derived from the artificial hybridization of these two species (Chen and Kirkbride 2000).…”

Genetic Diversity Cucumber Using Inter Simple Sequence Repeats (ISSR)

“…The development of genetic markers associated with cucumber has a narrow genetic base Staub et al, [9] which limits development of new cucumber cultivars. To date, the degree of genetic diversity in cucumber has been assessed with a number of DNA markers Zhuang et al, [10] which provide useful information for cucumber cross breeding. Molecular markers such as RAPD and SSRs have been employed for determination of genetic diversity in African cucumber (Cucumis sativus L.) Ahmad Mliki et al, [11].…”

Assessment of genetic diversity of cucumber cultivars in China based on simple sequence repeats and fruit traits

“…These markers have been used to assess genetic diversity and relationships among cucumber cultivars, as they are not influenced by environmental conditions. Although some studies made use of one or more DNA markers (Danin-Poleg et al, 2001;Zhuang et al, 2004;Staub et al, 2005;Sikdar et al, 2010), few reports have examined the correlation between genetic diversity and agronomic traits, especially fruit traits.…”