Micropropagation of Diyarbakır watermelon (Citrullus lanatus cv."Sürme")

Xll SUMMARY PhD. Thesis Micropropagation of Diyarbakır Watermelon {Citrullus lanatus ev. Sürme) Vedat PÎRİNÇ Dicle University Graduated School of Natural and Applied Science Department of Biology 2004, Page: 141 The aim of this study was to develop an in vitro micropropagation methods used in breeding and propagation for diploid "Sürme" variety of Diyarbakır watermelon that has the highest growing potential in the region. Methods were also developed for tetraploid formation used in breeding and production of triploid watermelon in future. An effective surface sterilisation of seed used as a main explant source was to soak in 3% commercial NaOCI solution for 5 minutes. Explants consisted of two cotyledons from 5- days-old seedlings were the best explant type. For all in vitro shoot proliferation studies, a modified Murashige and Skoog (MS) basal medium supplemented with 30 g l"1 sucrose and 7 g M was the best medium. 5.8 degree was found the best pH degree of the medium. BA of 0.5 mg l"1 was the best cytokine type and concentration to propagate the most shoots. 0.5 mg l"1 BA gave 8.46 shoot/explant with 2.21 cm shoot length. 1 382 400 plants could be produced from initial culture beginning with 100 explants, during 6 months. The best auxin type and concentration is NAA of 1 mg 1"', for rooting of regenerated shoots. The maximum rooting rate was 87% obtained from the cultures keeping in dark for 7 days. The yield of shoots and rooting rate is obtained better than expecting rate from all subculture numbers.Xlll The tetraploid formation was occurred when the seed and the plant apical top treated with 0.02% and 0.2 % colchicines for 24 hours respectively. The ploidy level of plant was estimated by counting the numbers of chloroplast per guard cell pair at the lower epidermis. The mean number of chloroplast, for plant and the seed, treated with colchicine was 19.47 and 16.95 respectively. This finding was proof for tetraploid formation. The ploidy level of diploid "Sürme" variety was obtained by counting the chloroplast. Average 10.70 chloroplast was counted from this variety. Using the micropropagation protocol developed for Diyarbakır watermelon "Sürme" variety growers' income will be increased because yield and quality of crops will be rise as a result of obtaining the seedlings from the same seed or seeds. The result of this study can also be used as a reference for the studies propagation new varieties, transgenic plants and mutant species in future. KEYWORDS: Watermelon, tissue culture, micropropagation