yield stability of melon genotypes under drought stress conditions

Development of cultivars with high yield under normal conditions and maintaining their yield under abiotic stresses is the main purpose of plant breeding programs in arid and semi-arid areas. the present study aimed to evaluate the yield stability of a collection of commercial melon varieties under drought stress. the trial was conducted in a field under normal conditions (plants were irrigated after 50 mm evaporation of a class a evaporation pan) and drought stress conditions (irrigation was carried out after 100 mm evaporation of a class a evaporation pan). in average, 3.32 kg fruit/plant and 2.76 kg fruit/plant were obtained under normal and drought stress conditions, respectively. the highest reduction in yield as the consequence of drought exposure was recorded for ’mazandarani’ (52%) and ’samsoori’ (48%). the most drought-tolerant genotypes were ’mamaghani’, ’nahavandi’, ’shadegan’, ’crenshaw’ and ’suski-e-sabz’ as they had constant yield under both growing conditions. on the other hand, ’samsoori’ and ’saveh’ were the most sensitive genotypes to drought. for most of the measured traits, the values of broad-sense heritability were over 0.50 i.e. there was a large genetic diversity among melon genotypes. this variation can be utilized for selecting high potential fruit yield and drought-tolerant genotypes. total soluble solids (tss) (ºbrix) was 15.2% for ’honey-dew’. tss (ºbrix) was obtained 10.7, 10.09, and 9.2% for iranian genotypes of ’khatooni’, ’samsoori’, and ’saveh’, respectively. in conclusion, although some iranian melon genotypes were recognized as drought tolerant, they need to be improved for tss (ºbrix).