Fakhradin Looregipoor - Department of Horticultural Science, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
Najmeh Hadi - Medicinal Plants and By-products Research Division, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
Abdolali Shojaeiyan - Department of Horticultural Science, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran

Bitter cucumber (Momordica charantia L., fam. Cucurbitaceae) is a good source of carbohydrates, proteins, vitamins, and minerals with the highest nutritional-medicinal value among gourds. The present study aimed at investigating the morphological and biochemical traits of some bitter cucumber genotypes. The results showed that all morphological traits except lobe width, length to lobe width ratio, and number of nodes to the first male flower, photosynthetic pigments of leaf (carotenoids only) and fruit, qualitative traits of fruit (except total acidity), and biochemical traits of leaf or fruit (except phenols) were significantly affected by genotype. The genotype “Bankok orange” had the lowest number of days until the appearance of the first male or female flowers or fruit. The first four components in the principal component analysis showed the total data diversity. The PC۱ emphasized on the morphological traits, PC۲ the leaf photosynthetic pigments, fruit flavonoids, and fruit dry weight percentage, PC۳ on the fruit quality and phenology, and PC۴ on the fruit photosynthetic pigments and leaf biochemical traits. Based on the results of traits correlation, internode length on main stem had a high correlation with stem thickness, leaf length, and lobe depth. Fruit weight also had a significant negative correlation with fruit dry weight percentage, leaf chlorophyll-b, total leaf chlorophyll, and fruit flavonoids. The results of genetic estimation of traits showed that fruit length, fruit peduncle length, fruit carotenoids, and leaf phenols had the highest coefficient of phenotypic and genetic changes, respectively, and had the highest diversity compared to the other traits. Also, fruit chlorophyll-b had the highest heritability (۹۹%). Examining the hydroalcoholic extracts of the plant showed that this plant contains significant amounts of phenolics, especially total flavonoids, which confirms its medicinal value. It could be suggested to extract the species phytochemicals and examine their biological and pharmacological properties.

Biochemical traits, genetic parameters, germplasm diversity, Momordica charantia L, Morphology