Sixteen melon genotypes were collected from different places by the help of principle project for vegetables improving and hybrids production. These melon genotypes were planted in complete randomized block design at El-Kassasien Horticultural Research Station, Ismaelai Governorate, to discover some information about genetic relationships among these materials under the artificial infection with Fusarium wilt pathogens and detect some molecular markers related to the biotic stress. The obtained results could be summarized in the following:-
1. A wide variation was found among melon genotypes by the analysis of variance.
2. Data revealed that, melon genotypes with the green flesh color were related to each other and melon genotypes with orange flesh color were also, related to each other, under healthy conditions.
3. Under infection condition, the gene expression had changed for all melon genotypes, and genetic distances were decreased.
4. The genetic distance between Galia, Ideal, Rafegal, Regal, Polidor, and Marsmatrouh was small, mean while the plant introduction PI 140471and PI 266935 had a large genetic distance with the other melon genotypes .
5. The genetic distance between Hale’s Best, PI 124111, Cinco, Honeydew orange flesh and Charantaize was small, while the genetic distance between Ismaelawi and all melon genotypes was very large distance, under infection condition.
6. The melon genotypes with Charantaize types, Honeydew orange flesh, Cinco , Charantaize , PI 124111, Hale’s Best, were more divergent than plant introductions PI 140471 and PI 266935, which recorded (6.093), (6.570), (6.175), (4.931) and (5.328) genetic distance, respectively
7. The genetic distance between PI 140471 and PI 266935 was very small, which was (0.894). This means that the two plant introduction were similar under infection condition, in the same time the genetic distance between PI 183227 and PI 140471 was most large (10.235).
8. Data declared that, the maximum inter-cluster distance was observed between cluster VII and cluster VI , which recorded (4.546) genetic distance, meanwhile, the minimum inter-cluster distance was observed between cluster IV and cluster I , also, between cluster IV and cluster III (0.571) , indicating close relationship among the included genotypes, under healthy condition.
9. Under infection condition, the maximum inter-cluster distance (2.966) was observed between cluster VII and cluster III, meanwhile, the minimum inter-cluster distance (0.259) was observed between cluster V and cluster I .
10. For the intra - cluster genetic distance, data declared that, the maximum intra-cluster distance (4.546) was observed between the genotypes of cluster VI under healthy condition, meanwhile, the minimum intra-cluster genetic distance between genotypes was observed for cluster I (0.091) .
11. Data of cluster analysis indicated that, the sixteen melon genotypes were grouped into seven clusters. These cluster grouping were mainly due to differences in their biological performance under healthy and infection conditions.
12. Under healthy condition, Hale’s Best, and Charantaize grouped together in cluster I, PI 140471 and PI 266935 grouped together in cluster VI, while Honeydew green flesh and Ideal were grouped tighter in cluster IV .Also, Galia, Regal, Polidor, Marsmatrouh grouped together in cluster III, meanwhile, PI 124111 alone in cluster II and Ismaelawi alone in cluster VII.
13. Under infection conditions, the grouping pattern had changed into Galia, Rafegal and Marsmatrouh in cluster I; Regal, Polidor, Hales best, Pi 124111 and Charantaize grouped together in cluster II. ; PI 140471 and PI 266935 grouped together in cluster III; Honeydew green alone in cluster IV; Cinco and honeydew orange flesh grouped together in cluster V; while ideal grouped alone in cluster VI and PI 183227 and Ismaelawi were grouped together in cluster VII.
14. For molecular markers related to Fusarium wilt disease, data revealed that, total number of DNA fragments were forty eight bands, the plant introduction PI 140471 gave alone forty one bands, followed by Galia (inbred line) thirty six bands, while the least genotype amplifying DNA fragments was PI 266935, under infection condition.
15. For similarity coefficient, data revealed that PI 140471 was related to Galia, Rafegal , Regal and Polidor which the similarity coefficient was (0.813), (0.833), (0.854) and (0.833), respectively . Honeydew orange flesh , was related to Galia , Rafegal , Regal , Polidor and PI 183227 , meanwhile Charantaize Variety was related to Galia , Rafegal , Polidor and close related to honeydew orange flesh in their resistance to Fusarium wilt disease .
16. The dendogram produced from genetic distances between melon genotypes, demonstrated that, the twelve melon genotype were grouped into five clusters. Every cluster had two melon genotypes, while the rest melon genotypes Galia and Ideal were alone.
17. Data revealed that, under infection condition the best cluster for the highest yield was the cluster II which included Honeydew orange flesh and Cinco, while cluster II exhibited a great men for earliness, total soluble solids and leaf area. The member of cluster V, Honeydew orange flesh and Cinco should form the basis of selection against Fusarium wilt, also the PI 140471 and PI 266935.
|
