Molecular Analysis of the Genetic Diversity of Chinese Hami Melon and Its Relationship to the Melon Germplasm from Central and South Asia

Abstract

Chinese Hami melon consists of the varieties cassaba, chandalak, ameri, and zard. To show their genetic diversity, 120 melon accessions, including 24 accessions of Hami melon, were analyzed using molecular markers of nuclear and cytoplasmic genomes. All Hami melon accessions were classified as the large-seed type with seed length longer than 9 mm, like US and Spanish Inodorus melon. Conomon accessions grown in east China were all the smallseed type. Both large-and small-seed types were in landraces from Iran, Afghanistan, Pakistan, and Central Asia. Analysis of an SNP in the PS-ID region (Rpl16-Rpl14) and size polymorphism of ccSSR7 showed that the melon accessions consisted of three chloroplast genome types, that is, maternal lineages. Hami melon accessions were T/338 bp type, which differed from Spanish melon and US Honey Dew (T/333 bp type), indicating a different maternal lineage within group Inodorus. The gene diversity (D), calculated from random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) polymorphism, was 0.476 in 120 melon accessions; the largest diversity was in Central Asian accessions (D = 0.377) but was low for Hami melon accessions (D = 0.243), even though Hami melon has diverse morphological traits, earliness, and shelf life. Reflecting such small genetic diversity, Hami melon accessions of vars. ameri and zard were grouped into cluster II, except for one accession, by the unweighted pair group method and the arithmetic mean (UPGMA) cluster analysis. Variety chandalak with distinct characters, such as early maturing and poor shelf life, was assigned to clusters IV and VI, indicating inter-varietal genetic differentiation within Hami melon. Three accessions from Turkmenistan and Afghanistan, with large seeds and T/338 bp type of chloroplast genome, were classified as cluster II with Hami melon accessions of vars. ameri and zard. We therefore concluded that Hami melon may have been transmitted from the west. The small-seed type melon of group Conomon grown in east China may have been introduced into China independently of Hami melon, because it had the A/338 bp type of the chloroplast genome and was clustered distantly from Hami melon according to nuclear genome analysis.

Genetic diversity among melon accessions (Cucumis melo) from Turkey based on SSR markers

“…The authors speculated that their results were attributed to using a different germplasm or to the discrimination power of the marker type. Genetic differences depending on the marker system were also reported by Staub et al (2000), Nakata et al (2005) and Aierken et al (2011), indicating that the ability of SSR markers to discriminate was better than that of RAPD markers.…”

Morphological and Molecular Characterization of Turkish Landraces of <i>Cucumis melo</i> L.</span>

“…In the present study, the accessions of flexuosus group were discriminated from the sweet ones, but the accession of momordica group was clustered with the sweet ones. It has been stated that genetic diversity could vary based on the marker methods (Staub et al, 2000;Aierken et al, 2011). By virtue of their uniqueness, SSRs are most valuable for studying intra-and inter-specific relationships.…”

Drying characteristics and solar convective drying kinetics of China Hami melon slice

“…Two hundred years ago, muskmelon was called Hami melon [1] . Hami melon have been seen as an important local characteristic cash crops in Xinjiang where has gross product of 1.1 million tons and planting area of 41,000 ha [2] . They contain numerous health functional constituents, such as ascorbic acid and flavonoids.…”