اثر گرده افشاني بر كميت و كيفيت بذر ده رقم پياز انتخاب شده در اصفهان

EFFECT OF POLLINATION ON SEED QUANTITY AND QUALITY OF TEN SELECTED ONION (ALLIUM CEPA L.) CULTIVARS IN ISFAHAN

In spite of the advantages of native onion (Allium cepa L.) cultivars, commercial seed production of these cultivars has its own difficulties in our country. Therefore, every year large amount of seed is imported. One of the main problems in seed production of onion is pollination and fertilization of their flowers. Insects including honeybees are the main pollinators of onion flowers. In order to study the effects of insects, especially honeybees on onion seed yield and quality, a split plot experiment in a complete randomized block design with three replications was used. Main plots consisted of ten onion cultivars and sub-plots consisted of open pollination and non-pollination in cages. Results showed that seed yield per inflorescence in the presence of pollinators, was 2.4 times of non-pollinated inflorescences (in cages and without pollinator presence). Pollination effect on weight of 1000 seeds was negligible. Germination percentage of seeds produced in open pollinated plots was 7% higher than those of non-pollinated plots. Germination mean hours for seeds of pollinated plots was 10.6 hr less than seeds of non-pollinated plots. Seedling dry weight from pollinated plots was higher than non-pollinated plots. There was a significant difference between cultivars regarding seed yield per seed stalk. `Ghomʹ and `Horandʹ cultivars produced highest and lowest seed yield, respectively. Due to interaction between pollination and cultivars, effect of pollination varied among cultivars. Also there were significant differences between cultivars regarding weight of 1000 seeds, germination percentage, germination rate of seeds and seedling dry weight.