Evaluation of genetic variability of six Iranian landraces of onion (Allium cepa L.) for seed yield and yield components

In this research, the factors affecting seed production of six landraces (Sefid-e-Ghom, Germez-e-Azarshahr, Dorcheh-e-Isfahan, Tarom, Germez-e-Kazeroon, Sefid-e-Abarkooh) and a foreign cultivar (Yellow Sweet Spanish as a control) were evaluated in a randomized complete block design experiment with three replications. Results indicated significant differences between genotypes regarding some of the traits. Seed stalks were emerged in Tarom and Yellow Sweet Spanish earlier than other landraces. Flowering of Germez-e-Kazeroon and Tarom were the first and last, respectively. Also, ripening of seed in Germez-e-Kazeroon and Yellow Sweet Spanish was earlier and later than other landraces, respectively. The number of seed stalks/plant and seed yield/ha were increased while increasing in bulb size from 5 to 7 cm. Among the landraces, Sefid-e-Ghom and Germez-e-Azarshahr showed the highest and lowest number of seed stalks/plant, respectively. Sefid-e-Ghom, also, showed the highest seed yield/inflorescence, /plant and/ha. Although the differences were not significant statistically. Relationships between traits showed that seed yield/plant and /ha was a positively correlated with the number of seed stalks/plant. Genotypes were grouped in three clusters using Ward method.