Comparison of Populus caspica growth behavior and their progenies

Degradation of natural habitats and decreasing of genetic diversity of Populus caspica led to vast reduction of its regeneration and growth potential in north of Iran. Hence, the growth potential of mass-produced seedlings was compared with their parents. For this purpose, the ramets of three selected seedlings from 17 parent trees belonging to north of Iran, along with ramets of their parent trees, totally 1020 ramets, were planted as a randomized complete block design with three replicates. During growing season of 2013, height growths of the seedlings were measured for 6 time periods. Results showed significant differences in height growth among the time periods, progenies, parental trees, and their interactions. Seedlings of Mazandaran 5, Gilan 3 & 4 and Golestan 3, revealed the best results. In the other hand, Mazandaran 4, Golestan 5 & 6 revealed the worst results. July and August showed highest height growth. During all of the time periods, progeny height growth was more than that of their parents, so that mean height growth of progenies and parents were 285.1 and 250.4 cm, respectively. In addition, mean diameter of progenies, 20.9 mm, was significantly more than that of their parents with a value of 18.2 mm. As the main result of this research, high performance of seedborn seedlings of P. caspica progenies (due to superiority of sexual reproduced seedlings compared to asexual reproduced ones) can be used for reforestation in degraded forests in northern part of Iran.