Sarao, Navraj KaurJaideep Kaur2019-01-132019-01-132018http://krishikosh.egranth.ac.in/handle/1/5810090145Muskmelon is an important vegetable crop of the Cucurbitaceae family grown in temperate and tropical regions of the world. Fusarium wilt is one of the major constraints for melon production around the world. Yield losses were reported as high as 100%. It primarily infects the roots resulting in blockage of uptake of water and nutrients, thus killing the plant. Various resistance genes (Fom-1, Fom-2, Fom-3 and Fom-4) specific for specific races have been reported so far. In order to readdress the production bottlenecks in melon within reasonable time frame, deployment of genomic tools such as marker assisted breeding is urgently required. Therefore, this study is frame worked to map the fusarium wilt resistance gene using SSR markers. Two genetically diverse parents “Punjab Sunehri” and “KP4HM15” were crossed and F1 was selfed to generate a F2 mapping population of 154 plants. Phenotypic evaluation on F2:3 families indicated that resistance to fusarium wilt is controlled by single dominant gene, which might be of race 0, 1 or 0, 2. For molecular analysis, a total of 527 simple sequence repeat (SSR) primer pairs were screened for parental polymorphism following bulk segregant analysis (BSA). Linkage analysis indicated that four SSR markers CMCTN35, DM0096, CSWCTT02 and ECM181 were linked to the Fom gene. Marker DM0096 was closest to the gene at 17.6cM distance and the marker CSWCTT02 was mapped at 22.7cM distance from the gene. The four markers were mapped on melon chromosome 5. There is a need to design more flanking SSR markers between DM0096 and CSWCT02 region in order to minimize the distance from the Fom gene and its transfer into the elite cultivar (Punjab Sunehri) for providing durable resistance against fusarium wilt disease. The markers provide further perspectives for fine mapping and map based cloning of the Fom gene.ennullThesis