Population genetics of invasive Citrullus lanatus, Citrullus colocynthis and Cucumis myriocarpus (Cucurbitaceae) in Australia: inferences based on chloroplast and nuclear gene sequencing

Genetic Differentiation of Citrullus colocynthis L. Populations Depending on Allozyme Diversity

“…In all populations the values of H o were higher than H e reflecting excess in heterozygosity that was also confirmed by negative inbreeding coefficient (F) values for polymorphic loci. These results conflicted the hypothesis of Biles et al (1989) and Levi et al (2001a) that the genus Citrullus had a narrow genetic basis, but they were in consistent with Mujaju & Nybom (2011) and Shaik et al (2015) who found that the diversity was higher in the wild species C. colocynthis than C. lanatus. This outcome confirmed the hypothesis that the species widely distributed, as C. colocynthis, have a higher genetic diversity percentage (H e ) than geographically limited species (Hamrick et al, 1992).…”

Citrullus colocynthis (L.) Schrad. (colocynth): Biotechnological perspectives

“…RAPD was also used, alongside ISSR, to confirm the genetic stability of in vitro regenerants (Verma et al, 2013). Shaik et al (2015) used two gene regions, the nuclear G3pdh gene and the chloroplast ycf6-psbM intergenic spacer region, to differentiate three Citrullus species (C. colocynthis, C. lanatus (camel melon), and C. myriocarpus (prickly paddy melon)) invasive to Australia, discovering that a western and an eastern introduction of C. colocynthis may have taken place. Mary et al (2016) used DNA barcoding with the trnH-psbA intergenic spacer to characterize C. colocynthis relative to other curcubit genera, placing it as a distinct phylum.…”

Understanding invasion history and predicting invasive niches using genetic sequencing technology in Australia: case studies from Cucurbitaceae and Boraginaceae

“…The results of extensive sampling across Australia showed that C. lanatus and C. myriocarpus were each represented by a single genotype and haplotype, indicating that the populations present were derived from a single introduction event or multiple introduction events of a single genotype (and subsequently selfing). Moderate levels of genetic diversity were present among Australian C. colocynthis , and this species sorted geographically into separate haplotypes found in eastern and western regions, suggesting at least two separate introductions from two different source populations ( Shaik et al ., 2015 ). These findings suggested that the two gene regions described above can be used to identify the invasives in question as C. myriocarpus subsp.…”

“…citroides for camel melon, previously described in the literature as the Australian wild melon C. lanatus var . lanatus ( Shaik et al ., 2011 , 2012 , 2015 ).…”

“…Scientific Reports , under review; Zhu et al ., 2016 ). The Cucurbitaceae model compares three related melons that appear to have been introduced to Australia via camel trading routes established in the 1800s, with genetic diversity among the three largely selfing species varying from existing as a single in genotype in Australia for prickly paddy melon ( Cucumis myriocarpus ) and camel melon ( Citrullus lanatus ) to the more heterogeneous populations of Citrullus colocynthis composed of two major introduced genotypes in Australia ( Shaik et al ., 2015 ). Two of the melon species ( C. myriocarpus ) and ( C. lanatus ) are annuals, whereas C. colocynthis is perennial.…”