PROPAGATION OF UZBEKISTAN WATERMELONS IN VITRO AND COMPARISON OF DIRECT-SEEDED AND TRANSPLANTED WATERMELONS

Abstract

A rapid protocol using bud tip explants for micropropagation of Uzbekistan watermelon [Citrullus lanatus (Th unb.) Matsum. & Nakai] species were reached in Shirin, Shirin and Karakish. Shoots from 5-day-old in vitro germinated seedlings were grown in shoot regeneration medium for 3 weeks. The effects of different concentrations of benzyl adenine (BA) and carbohydrate species on shoot growth were studied. The results confirmed that the range of 0.5-1.0 mg/L BA was almost equally effective in increasing the shoot length of cultures of the 3 genotypes. Sucrose, in the presence of BA, was superior to other carbohydrates in the 3 studied genotypes in terms of increased shoot number and average length obtained. For 3 genotypes, the highest percentage of rooting was achieved when medium supplemented with 1.0 mg/L indole-3-butyric acid (IBA) was used. The highest frequency of acclimatized plants for the 3 genotypes was 85%, 85% and 90% in sterile compost, respectively, when Shirin, Karakish and Shirin shoots rooted in the rooting treatment with IBA. Shirin genotype gave significantly higher yield and average fruit weight than Shirin and Karakish genotypes in direct-seeded and transplanted watermelons. The major soluble sugars of the experimental species were separated, identified and quantified using high performance liquid chromatography (HPLC). Fructose was found to be the most abundant sugar and was found to be higher in Beyazkiş for seeded watermelon and Karakiş for transplanted watermelon. This shows that in vitro propagation can be used to obtain high-quality diploid Uzbek watermelons for use in breeding lines.