MORPHOLOGICAL AND GENETICAL DIVERSITY OF MANGO (Mangifera indica L.) CULTIVARS IN SHENDI AREA

Abstract

ABSTRACT This study was performed to identify mango cultivars in Sudan based on their morphology and genetic. Leaves and fruits were collected in triplicate representing 30 cultivars. Sixteen cultivars were grafted genotypes of Indian or Egyptian origin, Eleven cultivars were grown directly from seeds (Balady) and 3 cultivars imported recently from South Africa. IPGRI (2006) descriptors were used in the study. Comparisons between means were made by least significant differences (LSD). The result showed a high diversity of mango genotypes and cultivars. There were great variations in leaf length, Width and petiole length with significant (P > 0.05) differences between the genotypes and cultivars in each genotype. Seedling cultivars showed longer leaves ( < 20cm) compared to the South African and grafted cultivars which showed a wide range of leaf length. Leaf width followed the same trend as the leaf length. Petiole length showed significant differences (P > 0.05) between the three genotypes but not between cultivars in each of them. Leaf margin and texture vary greatly between cultivars with no dominant shape among any of the three genotypes. The inflorescence lengths vary significantly (P > 0.05) between genotypes and cultivars with averages of 34.6, 24.2 and 23.3 cm for the seedling, Grafted and South African cultivars respectively. The color, shape, density and floral leaves of the inflorescence of mango cultivars vary greatly. Mango fruits showed significant (P < 0.05) differences in size, weight and circumferences depending on the cultivar. The length ranged between 7.9 to 20.1 cm, the width 6.1 to 11.6 cm, the weight between 195.7 to 1154.4 gm and 19.6 to 36.9 cm for the circumference. The fruit shape, apex shape and slope of shoulder were also variety characteristics. No significant differences were observed between cultivars regarding fruit beak type and sinus type. The fruit skin weight percentage vary greatly between cultivars

ranging between 9.6 and 19.7 % with yellow or green colors. The weight texture and color of the pulp was genotypes dependant. The pulp fiber content showed great variations in quantity and quality of mango cultivars with a range of 7.0 to 45% fiber weight percentage. The seed length, width, thickness and weight percentage vary between cultivars and were proportional to those of the fruit. Mango varieties were amplified using 4 different Operon RAPD primers. The primers were OPC9, OPL18, OPR10 and OPY14.The 4 RAPD primers used in this study were found to be poly morphic with mango cultivars tested. A total of 175 fragments were detected for the eleven samples representing 24 different loci with 91.7% polymorphism. Variety Ras maktoul and Sinaria produced no fragment with primer OPR10 where as Bizeret Shendi and Shabala produced no fragments with OPY 14 and OPL 18 respectivly. - The Similarity indices were calculated using Jaccard‟s coefficient.- The most relative varieties were Kutchineer and Taiba with 87% similarity; while the most distant were Bet bady and Wad srear with similarity percentage of 4% . According to the similarity indices, the 11 samples were grouped into four clusters. Among these, variety Bet bady and variety Shabala were each grouped in separate clusters (clusters 3 and 4), varieties Bizrt shendi and Ras maktoul were grouped together in Cluster 2 while all of the other varieties were included in Cluster