Implications of Mating Behavior in Watermelon Breeding

Abstract

<jats:p>Understanding the natural mating behavior (self- or cross-pollination) in watermelon is important to the design of a suitable breeding strategy. The objective of this study was to measure the rate of self- and cross-pollination in watermelon [<jats:italic>Citrullus lanatus</jats:italic> (Thunb.) Matsum. &amp; Nakai] using the dominant gene <jats:italic>Sp</jats:italic> (Spotted leaves and fruit) as a marker. The experiment consisted of two studies and was a split plot in a randomized complete block design with 3 years (2009 to 2011) and four locations (Clinton, Kinston, Oxford, Lewiston, NC). For the intercrossing study, whole plots were the two spacings (1.2 × 0.3 m and 1.2 × 0.6 m) with four replications in 2010. For the inbreeding study, whole plots were two equidistant spacings (3 × 3 m and 6 × 6 m) with four replications in 2009 to 2011. Cultivars Allsweet and Mickylee were subplots within each whole plot. In the inbreeding study, spacing and year had a significant effect on the rate of self-pollination, which was moderate (47% and 54%, respectively) when watermelon plants were trained in a spiral and spaced 3 × 3 m or 6 × 6 m apart. Spacing and cultivar did not have a significant effect on cross-pollination in the intercrossing study. Closely spaced watermelon plants (1.2 × 0.3 m and 1.2 × 0.6 m) had low natural outcrossing rate (31% and 35%, respectively) and was not adequate to intercross families. However, breeders should consider the amount of self-pollination in watermelon to calculate the estimates of component of genetic variances.</jats:p>

Flowering Time in Watermelon Is Associated with a Major Quantitative Trait Locus on Chromosome 3

“…Despite being an out-crossing crop, our results indicate oligogenic control of flowering time in domesticated watermelon. However, it should be noted that watermelon has high natural self-pollination rates, as reflected by the lack of inbreeding depression in the species (Kumar et al, 2013;Kumar and Wehner, 2010;Wehner, 2008). Major colocalized QTL were also found to be associated with days to male and female flower development in Cucurbita pepo (Esteras et al, 2012).…”

Response of Some Watermelon Accessions to a Puerto Rico Strain of Zucchini yellow mosaic virus

“…Another possible explanation is that, for a specific accession, the genetic composition of plants tested in our study differs from those in previous studies. Watermelon is assumed to be a highly crosspollinated crop (Kumar et al, 2013). Thus, many accessions in the USDA collection are likely to be a composite of multiple genotypes.…”

Pengembangan Benih Unggul Semangka Citra Jingga Melalui Teknik Kastrasi dan Polinasi di Desa Depokrejo, Purworejo, Jawa Tengah

“…Pembedaan guludan ini bertujuan untuk mempermudah persilangan semangka pada saat kastrasi dan polinasi di tahap berikutnya. Menurut Kumar et al (2013), semangka sebaiknya ditanam di tanah lempung berpasir yang kaya akan bahan organik dengan drainase dan kisaran pH yang baik (6,5-7,5) serta suhu optimal sekitar 24-27 0 C. Penyiangan dilakukan 20-25 hari setelah disemai sedangkan penyiangan selanjutnya dilakukan pada interval satu bulan. Hama semangka tersering dijumpai adalah kumbang pemakan daun yang merusak bunga.…”