Investigation on growth and physiological characteristics of Populus euphratica Oliv. Provenances at Garmsar Desert Station

Populus euphratica is a native tree species of Iran and ecologically has a wide distribution. Its tolerance to high level of air temperature and soil salinity is one of its important characteristics. For this reason, it has a high potential for afforestation in dry lands and deserts. The aim of the study was to evaluate the growth, morphological and physiological characteristics of different provenances of this species, in order to introduce the best ones for plantation on arid and saline lands. Among the provenances which have been tested during 2011 at Garmsar Desert Station, based on a randomized complete blocks design with three replications, 16 provenances were selected for the trial. Leaf sampling from the selected provenances was made in order to measure proline, sugar, chlorophyll, carotenoides and total proteins. Growth parameters, including stem collar diameter, total height, special leaf area and dry leaf weight were also measured. Analysis of variance of the physiological characteristics showed that there were significant differences between the provenances in respect to their chlorophyll, carotenoides, sugar, proline and total protein. According to the Duncan classification, most of the provenances ranked in one group for their average proline content. The provenances of Golestan, Khojir, Kerman, Zabol, Kashan and Dezful achieved the widest stem diameter (1.15-1.95 cm.), total height (1.15-1.51 m.) and statistically ranked in one group. Soil salinity had negative effect on height growth. The outstanding provenances were introduced for plantation in sites, ecologically similar to Garmsar condition.