Hossein Astaraki; Hossein Ramshini; Mahmoud Lotfi; Ali Izadi Darbandi
Abstract
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 ...
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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).
Majid Esmaeili; Forouzandeh Soltani; Mohammad Reza Bihamta; Mohammad Javan Nikkhah
Abstract
The purpose of this study was to estimate heritability, general and specific combining ability and the relationship between traits. Investigated traits were fruit number per plant, total yield per plant, average fruit weight, flesh thickness, flesh firmness, seed cavity size, total soluble solid, fruit ...
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The purpose of this study was to estimate heritability, general and specific combining ability and the relationship between traits. Investigated traits were fruit number per plant, total yield per plant, average fruit weight, flesh thickness, flesh firmness, seed cavity size, total soluble solid, fruit length in melon. A complete diallel design was conducted for this purpose five parental genotypes were crossed and the hybrids were evaluated in a randomized complete block design with three replications. Analysis of variance of traits showed a significant differences between hybrids, therefore the first Griffing method was used to analyze the combining ability. The general combining ability effects were significant for all parents in the evaluated traits. The specific combining ability of yield per plant was higher than the general combining ability, which indicates the dominance and non-additive actions of genes. High narrow-sense heritability for yield per plant, flesh firmness and the number of fruit per plant (0.86, 0.72 and 0.70, respectively) indicated low environmental effect for these traits and the greater role of additive effects. The highest narrow-sense heritability was estimated for yield per plant (0.86). The role of non-additive effects of genes in controlling yield and flesh firmness traits was greater than additive effects. Therefore, the preparation of superior hybrids using breeding methods based on progeny tests will be effective in improving the mentioned traits in melon.
