Karim Arab Salmani; Yousef Hakimi
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 ...
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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.
Forouzandeh Soltani; Moien Shajari; Giti Sadat Mirbehbahani; Mohammad Reza Bihamta
Abstract
Understanding genetic diversity and germplasm classification are the keys for selection of right parents for breeding purposes. In the present study, the genetic diversity and classification of 45 Iranian and 15 foreign melons were evaluated. A greenhouse experiment was laid out as a randomized completely ...
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Understanding genetic diversity and germplasm classification are the keys for selection of right parents for breeding purposes. In the present study, the genetic diversity and classification of 45 Iranian and 15 foreign melons were evaluated. A greenhouse experiment was laid out as a randomized completely block design with three replications and five plants in each replicates. Fruit number had a positive correlation with female flower numbers, fruit number, and fruit yield. The fruit number, however, correlated negatively with the leaf area. Genotypes with monoicous flowering habit produced female flowers in lower nodes and formed longer fruit. The number of the female flower, fruit number, yield, high total soluble solids (TSS), leaf area, the first node of female appearance, and flesh firmness were amongst the high weighted and more coefficient in the component analysis. For the breeding purpose, all accessions of cluster 4 were andromonoecious and obtained high TSS, leaf area, and flesh firmness. From the first three clusters, 11 accessions were monoecious, which belonged to TN-93-5, TN 92100, TN 921071, TN 922025 (Cluster1), FLTM 27, and FLTM35 (Cluster2), TN921026, TN-94-21, TN- 94-44, TN-94-28, and TN-94-3 (Cluster3). The characteristic of cluster 3 included melons with high female flower and fruit number and fewer number of the first node of female flower. In conclusion, good genetic resources and foreign types for selection are available for improving the breeding of melons based on the evaluated traits.
