Morphologic and physiologic effects on polyploidy induction in Citrus ourantifolia

Citrus fruit has high nutritious، medical and economical values. Seediness is considered as a weakness in selecting high quality citrus fruits. Among polyploids، triploids produce seedless fruits. In order to produce triploid fruits، there must be a tetraploid plant، therefore، in this research; the production of tetraploid plant was highlighted in Citrus ourantifolia using a chemical material named colchicine through dropping method. 60 days after treatment by 0. 2، 0. 6، 1. 0 and 1. 4% concentrations of colchicines، the flow cytometric investigation on treatment plants were conducted. The morphological and anatomical characteristics of tetraploid plants were investigated. Comparison of the leaves of tetraploid with diploid plants indicated that the leaves of tetraploid plants in length and width were smaller than the diploid ones. The height of tetraploid plants was reduced significantly compared with that of the diploid ones. Comparison of the density and the size of stomata and secretory sacs showed that the density of stomata and secretory sacs in tetraploid plants decreased but، the size of stomata and secretory sacs increased، significantly، compared with the diploid ones. The amounts of chlorophyll a، chlorophyll b، total chlorophyll and carotenoids in treatment plants showed no significant increase in tetraploid and diploid plants.