majid pourrahimi; Seyed Ahmad Sadat Noori; fatemeh amini; Hossein Ramshini
Abstract
To evaluate the gene effect, heritability and correlations of ajowan (Carum capticum L.) morphological traits ten parents were chosen from a genetically broad-based population and polycrossed to produce half-sib families. The evaluated traits were number of days to flowering, plant height, number of ...
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To evaluate the gene effect, heritability and correlations of ajowan (Carum capticum L.) morphological traits ten parents were chosen from a genetically broad-based population and polycrossed to produce half-sib families. The evaluated traits were number of days to flowering, plant height, number of fertile branches, number of umbrellas per plant, number of seed per umbel, seed yield per plant, harvest index, essential oil percentage, essential oil yield. Parents and polycross progenies seeds were grown in a randomized complete block design with three replications in the University of Tehran research field, during 2015-2017. The results showed that in parents and their progenies broad-sense heritability ranged from 0.64 to 0.96. Narrow-sense heritability based on regression of progenies on the parents (h2po) and analyses of progenies (h2n) suggested that additive genes control these traits. Correlation of seed yield with plant height, number of fertile branches, number of umbrellas per plant and number of seed per umbel were positive and significant. The results indicated that there were significant negative correlation between thymol and γ- terpinene both in parents and half-sib families. We concluded that there were significant variation and high heritability for most of the evaluated traits in the ajowan populations to improve seed yield and essential oil yield.
Yousef Hakimi; Karim Arab Salmani
Abstract
Genetic variability in a crop population is essential for successful plant breeding. Fifteen cucumber (Cucumis sativus L.) genotypes were evaluated in the greenhouse under the warm condition to estimate the magnitude of their genetic variability and heritability as also morphological and pomological ...
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Genetic variability in a crop population is essential for successful plant breeding. Fifteen cucumber (Cucumis sativus L.) genotypes were evaluated in the greenhouse under the warm condition to estimate the magnitude of their genetic variability and heritability as also morphological and pomological characteristics. Genotypes were also classified in to five groups based on the performance and determination of the highest discriminating characteristic that accounted for more significant variability using cluster analysis and principal component analysis (PCA). The measured characteristics were cucurbit chlorotic yellows virus and fungal severity, off-type plant, stem, internode, leaf, petiole, fruit and fruit trail length, leaf width, male flower percentage, fruit color and groove, fruit diameter, fruit fresh weight, fruit dry matter and ash percentage, fruit pH, EC and TSS, fruit yield, and total fruit number. The IR4 and IR5 genotypes showed the highest fruit yield (460.85 and 425.86 kg/plot) and number (108.72 and 84.22 fruit/plant). IR11 had the highest fruit length of 16.60 cm. High broad-sense heritability was associated with all the traits except for cucurbit chlorotic yellows virus and fungal severity, fruit pH, and total fruit yield. Cluster analysis and its comparison of means showed that IR4 and IR5 from the fifth cluster expressed the best agronomic traits and yield potentials in the warm condition (40°C/32°Cday/night). Hence, selection for any characteristic would favor genotypes in these clusters. The PCA involved fruit dry matter and TSS as the most discriminating trait that accounted for more significant cucumber variability, which should be considered in cucumber improvement programs.
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.
