Muskmelon, which is an important cucurbit of the tropical and subtropical region of the world, shows great diversity, with six different botanical or horticultural groups and fifteen varietal groups. In this study, a total of fifty (50) simple sequence repeat (SSR) markers were used to investigate the genetic diversity and population structure of 46 muskmelon accessions of different horticultural or varietal groups. Thirty-eight (38) of the fifty SSR markers were highly polymorphic. A total of 99 alleles were generated by the polymorphic markers, with an average of 2.06 alleles per loci. Heterozygosity among accessions for individual loci varied from 0.00 to 0.21, with the highest (0.21) reported for the CMCTN71 marker. The gene diversity and polymorphism information content (PIC) values varied between 0.08 to 0.72 and 0.07 to 0.67, with an average of 0.47 and 0.38, respectively. The primer that showed the highest gene diversity and PIC values was DM0913. The unweighted pair-group method for arithmetic average (UPGMA)-based dendrogram classified all the 46 accessions into two major clusters. Population structure analysis classified 46 muskmelon accessions into 2 subpopulations. The subpopulation I contained 29 accessions from the cantalupensis group, and subpopulation II contained 17 accessions from momordica, inodorus and conomon groups, respectively. Analysis of variance indicated that 18 and 68% of variance was due to subpopulations and differences among individuals, respectively. The present study supports the existence of sufficient variation among musk melon genetic resources in India, and their classification based on molecular markers will be helpful to accelerate the breeding programme for specific traits.

Control of cucurbit pests, such as striped cucumber beetle (Acalymma vittatum), spotted cucumber beetle (Diabrotica undecimpunctata howardi) and squash bug (Anasa tristis), in organic systems is difficult due to a lack of effective insecticide options. This has led to the development of many integrated pest management techniques, such as use of row covers, crop rotation and cover crops. This study explored the novel use of strip tillage and row covers to reduce pest pressure in summer squash (Cucurbita pepe) and muskmelon (Cucumis melo) production systems. Results showed that although strip tillage reduced striped cucumber beetle and squash bug numbers, there was a yield reduction in both crops compared with the plasticulture system. Row cover increased marketable yield in both systems, with the highest yield being in the plasticulture system. Unmarketable fruit directly attributed to insect damage was higher in the plasticulture systems, but was not significantly different when compared with the strip tillage system. Although there are many documented positive attributes of strip tillage, results from this study indicate that a combination of plasticulture and row cover may be a superior system for organic cucurbit production.

A five-point drought stress screening methodology for muskmelon based on visual observation has been standardized by modifying an earlier field screening method. The scale (1 to 5), were categorized into five groups, namely, highly drought tolerant (1), drought tolerant (2), average drought tolerant (3), drought susceptible (4) and highly drought susceptible (5). To validate and standardized the technique, 48 genotypes of muskmelon were evaluated for two successive years. Important physiological parameters, i.e.: relative water content (RWC), electrolyte leakage, photosynthetic efficiency (Fv/Fm), chlorophyll concentration index (CCI), root and shoot length were measured and correlated to make screening results more reliable. Drought tolerance efficiency of genotypes was calculated based on yield, and drought-tolerant genotypes were identified with better yield efficiency and ranking on visual scale. Whereas, yield efficiency of some drought-tolerant genotypes were less, althouth they came under drought-tolerant scale. Being a tolerant genotype, these may not be economical for commercial cultivation. Under water-deficit condition a significant positive correlation was observed between drought tolerance efficiency, and RWC, Fv/Fm, CCI and root length. Out of 48 genotypes, 14 genotypes were came under highly drought-tolerant category based on 5 point scale.