Document Type : Research paper
Authors
1 Greenhouse Research Department, Agricultural and Natural Resources Research and Education Center of Tehran Province (AREEO), Tehran, Iran
2 Seed Breeding Department, Agricultural and Natural Resources Research and Education Center of Tehran Province (AREEO), Tehran, Iran
Abstract
Genetic variability in a crop population is essential for successful plant breeding. Fifteen cucumber genotypes (Cucumis sativus L.) were evaluated in the greenhouse under warm conditions to estimate the magnitude of their genetic variability, trait heritability, morphological features, and pomological characteristics. The genotypes appeared in five categories based on their performance and determination of the most reliable discriminative features that accounted for more significant variability. Cluster Analysis and Principal Component Analysis (PCA) assisted in the classification. The measured characteristics were cucurbit chlorotic yellows virus, fungal severities of infestation, 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 count. 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 value of fruit length (16.60 cm). High broad-sense heritability was associated with all the traits except for cucurbit chlorotic yellows virus and fungal severities of infestation, 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 warm conditions (40 °C/32 °C day/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 can become crucial information in cucumber improvement programs.
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