Efficiency of Mass Selection and Selection Indices on Improving Growth, Yield and Quality of Cantaloupe (Cucumis melo, L.).

Abstract

Present investigation was carried out during three successive seasons, in years 2021 and 2022.Two cycles of inbreeding and mass selection program were applied, using the methods of selection indices, on 6 strains of melon (cantaloupe) under the green houses of Sabahya Horticulture Research station, Alexandria. Original population (S0),first and second selection generation (S1 and S2) and Boshra 411 as a check cultivar were sown in experimental evaluation in early summer season in first March of year 2022 to test the progress in the traits under studies in a factorial experiment with two factors (genotypes and selection cycle) in randomized complete block design with three replicates (RCBD) in private farm at Al-Mahmudiyah area in Al-Buhaira governorate. Analysis of variance over all mean performances, estimation of genetic parameters like, heritability; genetic advance (GA) and inbreeding depression (ID)were estimated, for vegetative, flowering and fruiting, yield, and its components characteristics.The most important results are summarized as follows: There were significant and highly significant differences between all genotypes in all traits with exception to fruit shape index trait. Differences between original population and selection cycles, were significant and highly significant for all traits under study. By comparing the inbred strains to each other (G, M, Q, S, W and X) it can be noted that line S was superior to other strains in most characteristics. By comparing the same strains with the control variety (Boshra 411), it can be noted that there was a clear superiority of the control variety in all traits under study. First and second selection generations (S1 and S2) had the highest values for traits like flesh thickness %, netting degree (1-10), placenta hardness (1-10) and dray matter%. The highest estimates of heritability in broad sense (> 75%) were observed for dray matter % (93.28%); total soluble solids % (90.67%); total number of fruits / plant (82.94%); placenta hardness (1-10) (77.26%) and flesh thickness % (76.34%). This was consistent with the close values of GCA and PCV and highest values of Genetic advance (GA) for the same traits. Estimates of inbreeding depression were positive in traits, plant length, total number of nodes / plants; fruit set percentage %; total number of fruits / plants; total yield / plant (KG) and fruit shape index. The largest inbreeding depression were in traits total number of fruits/ plant and fruit set percentages % (19.91 and 18.13 % respectively).