Watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] is one of the economically most important fruit crops of the Cucurbitaceae family. Among different watermelon traits, disease resistance and fruit quality are the important traits for growers and consumers. The single nucleotide polymorphism (SNP) markers similar to those traits can potentially and cost-effectively distinguish the genetic variations among these traits. Consequently, we developed 33 SNP makers linked to different watermelon traits associated with fruit quality and disease resistance, and validated in the genetic resources of watermelon and F1 breeding lines using ‘Fluidigm SNP Genotyping’ assay. Most of the SNP markers distinguished the alleles into three different types such as reference allele, alternative allele and heterozygous from watermelon genotypes for various traits. The SNP markers ‘ZymFL-T81P’ (ZYMV- resistance), ‘FON1-U161’ and ‘FON1-S075’ (Fusarium wilt-resistance), ‘Pmr21-Cla831’ (PM-resistance), and ‘ClGBS-J168’ and ‘GBS-GC230’ (GSB-resistance) can successfully differentiate resistant (R), susceptible (S) and heterozygous watermelon genotypes. Similarly, the SNP marker associated with sugar content, citrulline content, arginine content, rind hardness, flesh firmness, fruit shape, rind strip pattern of watermelon fruit and seed coat colour can successfully distinguished the watermelon genetic resources and F1 breeding lines as reference allele (A) type, alternative allele (B) type and heterozygous (H). These SNP markers could be utilized for marker assisted selection as well as screening of a large number of watermelon germplasm for fruit quality and disease resistance. However, further validation like artificial inoculation of pathogens for the traits related to disease resistance is required in watermelon crops.

Powdery mildew (PM), caused by the biotrophic fungus Podosphaera xanthii, drastically reduces the yield and quality of melon (Cucumis melo L.). Knowledge of the genetic control and high throughput molecular markers linked with resistance against this disease are essential for breeding programs. The bioassay study of the F1 and F2 populations derived from the parents, ‘PMR 5’ (♂) and ‘SCNU1154’ (♀) revealed a monogenic dominant nature of resistance to the devastating race, race 5. Besides, we developed three SNP based high resolution melting markers, PMm-HRM-1, PMm-HRM-2, and PMm-HRM-3, based on the previously identified SNPs on chromosome 12 and validated them using 8 melon lines and 137 F2 populations. Among these, the SNP of marker PMm-HRM-1 causes a missense mutation in the LRR region of MELO3C002393 and we were able to distinguish the resistant vs susceptible genotypes from eight diverse melon accessions and the segregating F2 population with more than 90% genotyping efficiency. The other two markers were based on intergenic SNPs and had more than 80% genotyping efficiency in F2 population. These markers will be helpful to melon breeders to develop melon cultivars resistant to P. xanthii race 5 via marker assisted breeding programs.

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• Developing DNA Markers based on Male-Specific Chromosomal Regions for Selecting Male Plants in Hop (Humulus lupulus)
  Tae hyun Ha, Jae Il Lyu, So Young Yi, Si-Yong Kang
  Plant Breeding and Biotechnology.2024;[Epub]     CrossRef
• Identification of Gene Responsible for Conferring Resistance against Race KN2 of Podosphaera xanthii in Melon
  Sopheak Kheng, San-Ha Choe, Nihar Sahu, Jong-In Park, Hoy-Taek Kim
  International Journal of Molecular Sciences.2024; 25(2): 1134.     CrossRef

Squash (Cucurbita moschata D.) is an economically important vegetable of the Cucurbitaceae family. The genetic purity of commercial hybrid seed is crucial for the success of hybrid seed production. The molecular markers like single nucleotide polymorphism (SNP) can efficiently and cost-effectively distinguish the genetic differences among F₁ hybrid cultivars. Therefore, in this study, we used ‘Fluidigm SNP Genotyping’ assay using 27 SNPs to distinguish and purity analysis of registered commercial F₁ hybrid cultivars and F₁ breeding lines of squash. Of these, eight SNP markers, including CMo-A01, CMo-A02, CMo-A04, CMo-A05, CMo-A12, CMo-A16, CMo-A20 and CMo-A25 can successfully identified heterozygotes from the registered commercial F₁ hybrid squash cultivars with 100% accuracy and partial contamination was detected for F₁ hybrid squash breeding lines which resulted due to outcrossing. Moreover, the HRM analysis of a registered commercial F₁ hybrid cultivar ‘Parangsae’ with CMo-A03 SNP marker showed 96.30-100% purity of the cultivar. Our results suggest that the ‘Fluidigm SNP Genotyping’ technology could be a rapid and cost-effective method for cultivar differentiation and genetic purity analysis of F₁ hybrids and squash cultivars.

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• Unlocking the Potential of Cucurbitaceae Seed Oils: A Narrative Review on Phytochemical, Pharmacological, and Biotechnological Applications
  Boniface Anthony Ale, Peter Chinedu Agu, Patrick Maduabuchi Aja
  Natural Product Communications.2026;[Epub]     CrossRef