Investigation of drought tolerance mechanism in melon genetic resources by molecular and physiological methods

In recent years beside global climate change, environmental factors such as drought are limiting the efficiency of melon yield. Finding material having high drought tolerance is proboble in Turkey due to its position and having rich genetic diversity. In this research a total of 192 melon genotypes which belong to the Cucurbitacea genetic resources of Cukurova University Department of Horticulture, collected from different regions of Turkey and wild species obtained from foreign countries were used.Two differnt screening were done in climate controlled greenhouse and in climate controlled growth chamber, the tolerance level of melon genotypes were determined, and Kav 248 was selected as the most tolerant and Kav 20 was selected as most susceptible. Leaf and root samples were taken at 0, 4. 8. 12. 24. 48. and 72 hours from the control group and the drought stressed group in the experiment with selected genotypes. RNA was isolated from leaves and roots of genotypes, mRNA was isolated from total RNA and after cDNA synthesis was realized. Expressed genes were identified by cDNA-AFLP method in case of drought stress. Selective PCR reactions were realized using a total of 77 AFLP primar combinations after preamplification. As a result of the cDNA-AFLP analyzes carried out within the scope of our research, 24 DNA strand profiles were DNA sequenced. As a result of BLAST analysis of the DNA sequences, 10 DNA sequences showed homology with the melon genome. Four pathways were identified using the KEGG database in order to determine the pathways of the identified genes. Validation of the obtained data was performed by real-time PCR analysis.