Genetic Divergence Analysis in Cucumber (Cucurmis sativus L.) by RAPD Marker

Cucumber (Cucurmis sativus L.) is a widely cultivated plant in the gourd family Cucurbitaceae and is one of the economically important vegetables in the world because it can be consumed fresh and can be grown in all countries and throughout the year. Two cucumber populations, one containing 29 accessions resistant to downy mildew and one containing 18 susceptible to downy mildew collected by Lampang Agricultural Research and Training Centre at Rajamangala Institute of Technology Lanna, Lampang province, Thailand were analyzed using 17 Random Amplified Polymorphic DNA (RAPD).  Clustering analysis using Jaccard’s distance coefficients with an unweighted pair-group method using an arithmetic averages (UPGMA) algorithm was performed. The polymorphic information content (PIC) average at 0.24 and ranged from 0 to 0.5. The OPB-5 primer recorded the highest polymorphism (95.06%) while the OPB-1 showed the least (4.16%). Total PCR products of 101 bands were observed and 97 bands were polymorphic bands. These RAPD markers will be useful for genetic identification of cucumber cultivars in relation to its downy mildew resistance.