The Survey of diversity in leaf and fruit morphological characters of Celtis australis in various geographical conditions.

As Celtis sites in North of Iran are degrading, it is necessary to determine genetic variation and recognize ecological requirements for better conservation and management. For investigating geographical variation of Celtis australis based on leaf and fruit morphology, three plant populations of the species were sampled. Ten trees with at least 100 meters interval distance were selected from each population, and leaf samples were collected from middle crown early October. Leaves were mixed together and 5 leaves were selected randomly for detail studies. Results indicated that petiole length, tip width, number of serration, fruit weight and peduncle length were significantly different among the populations. Leaf width, leaf width at 0.1 of its length, leaf length in first component and fruit dimensions (length, diameter, weight and fruits thickness) in second component, tip length, stomata width and stomata width at 0.9 in third component showed the major role in the observed variance based on principal components analysis. First five components justified 81.9% of total observed variance. Leaf weight, leaf tip length and leaf width showed the highest plasticity value while fruit dimensions, number of serration and length of stomata showed the lowest plasticity value. Geographical variation especially in leaf morphological traits of Celtis australis is concluded based on these results. Also since petiole length, leaf tip width and number of serration are less affected by environmental factors, they may be used as distinctive traits in identifying Celtis species.