Use of melon landraces in integrated breeding through the application of traditional and biotechnological methods

Abstract

Background: In Armenia, melon (Cucumis melo L.) is traditionally cultivated, including both modern cultivars and traditional landrace forms. Increasing demand, changing market conditions, and climate change underscore the need to develop new genotypes. Local landraces represent a valuable genetic resource for breeding due to their genetic diversity, superior taste and quality traits, adaptation to local conditions, and resilience to environmental stresses. These characteristics highlight the potential of modern breeding approaches to accelerate the generation of diverse genotypic material and expand breeding programs.

Objective: Development and evaluation of new promising regenerant melon lines with enhanced yield, improved quality traits, and high adaptability to local soil and climatic conditions, using the landrace melon Meghrashaghik as a valuable genetic resource and combining conventional breeding methods with biotechnological approaches.

Methods: The study was conducted at the Laboratory of Plant Biotechnology, Phytopathology, and Biochemistry and at the experimental plots of SCVIC ME of RA during 2023-2025. The landrace melon Meghrashaghik was used as the starting material. To obtain regenerant lines, in vitro tissue culture was performed on Murashige and Skoog (MS) medium supplemented with phytohormones, depending on the stage of cultivation (callus induction, regeneration, rooting, etc.). Phenological traits and yield were recorded under field conditions throughout the growing season. The biochemical composition of fruits – total sugars and ascorbic acid content – was determined spectrophotometrically, while dry matter content was measured using a refractometer. Statistical analysis was performed using analysis of variance (ANOVA) at p ≤ 0.05, and mean comparisons were conducted using the least significant difference (LSD) test.

Results: In vitro cultivation produced proliferating and regenerating callus, with a regeneration frequency of 60.1% and rooting of 88.1% in regenerant plants. Somaclonal variation was observed in shoot morphology, growth rate, and leaf coloration, indicating induced genetic variability. Field evaluation of 26 regenerant lines identified five promising lines, with R4-4 and R5-5 showing the strongest overall performance. These lines flowered earlier than the control, showed superior biometric traits, and achieved the highest yields, reaching 287.2–287.3 cwt·ha⁻¹, or 9.3–9.4% above the control. Several regenerants also showed increased sugar and vitamin C content, with the highest values recorded in R4-4. Based on agronomic and biochemical traits, lines R4-4 and R5-5 were selected as the most promising for further breeding.

Novelty of the study: This study is the first to apply an integrated biotechnological approach based on in vitro tissue culture to obtain regenerant lines of the landrace melon Meghrashaghik, followed by field selection of promising genotypes. The use of callus culture and induced morphogenesis enabled the observation of somaclonal variation as a source of genetic diversity, accelerating the generation of new variants with improved biometric traits, higher yield, and enhanced fruit quality. The promising lines R4-4 and R5-5 represent a valuable genetic resource and can serve as starting material for the rapid breeding of high-yielding melon cultivars and hybrids.

Conclusion: The results demonstrate the potential of combining biotechnological and conventional breeding methods in melon selection to accelerate the generation of genetically diverse material and to expand breeding programs. 

Keywords: melon, landrace lines, somaclonal variation, regenerant lines, biotechnology, yield, fruit quality, breeding