مجله علوم باغبانی ایران
سال چهل و چهارم شماره 1 (بهار 1392)

Vegetative propagation of Persian walnut encounters a major problem in Iran growing conditions. This experiment was carried out to study the physiological effects of rootstock as regards herbaceousness or woodiness, and with respect to the presence of leaf on it or not on minigrafting success. Throughout the study, 1.5-2.5 cm length Persian walnut scions were minigrafted on herbaceous vs. softwood (with or without leaf) walnut rootstocks grown for a few weeks in controlled conditions. Results indicated that the existence of leaf on the rootstock had negative effects on the success of minigrafting in either leafy or leafless rootstocks (48 and 56 percent, respectively). A significant difference was observed between herbaceous and softwood rootstocks. Softwood rootstocks benefited from 56% success as compared with 46% in herbaceous ones. Interaction effect was also observed between kind of rootstock and leaf existence as the existing leaf increased grafting success in herbaceous rootstocks while decreasing it in softwood ones. The negative effect of leaf on minigrafting of softwood rootstocks was in so far as it decreased grafting success from 73% in leafless rootstocks to 43% in leaf bearing ones. Leaf had no significant effect on the time needed for the graft to take, yet it enhanced the graft success on herbaceous rootstocks more than it did on softwood ones. The soluble sugar content at the grafting point of leaf bearing softwood rootstock was more than that for the leafless ones, however grafting success was not dependent upon sugar content. This difference came maybe from substances made through either young or older leaves in either herbaceous or softwood rootstocks that were transported to the grafting union point and subsequently affecting the graft success and scion growth. The grafted plants had desirable survival and growth rates till one year past the experiments.

To evaluate the genetic diversity of native populations of Crown Imperial (Fritillaria imperialis L.) in Zagross region, ISSR molecular along with 32 morphological traits were employed. A number of 160 samples corresponding to eight Zagross populations distributed in six provinces were collected and assessed. Using six primers, 57 bands were totally produced from which 49 were polymorphic. Mean percentage of polymorphism was 85.6% and mean number of polymorphic bands per assay unit was equal to 8.17%. Mean Polymorphism Information Content (PIC) was 0.31. In dendrogram produced as based on Jacard Similarity Coefficients and UPGMA grouping method, all the populations were organized into distinct clusters denoting efficiency of the employed primers in production of suitable fragments along the genome. Analysis of Molecular Variance (AMOVA) and its partitioning among and within populations were analyzed for eight populations of F.imperialis either with or without regional structures. Variations among and within populations were 44.05% and 55.95% of the total variations, respectively. Regional grouping couldnt cover any part of total variance. Morphological dendrogram didn’t show an obvious pattern regarding a distinction of populations from each other. Correlation between morphological and molecular similarity matrixes wasn’t observed as significant (r= 0.25).

The present research was carried out to evaluate the response of seven selected Persian leek accessions to in vitro gynogenesis. The experimental design was a factorial one based upon a completely randomized design of three culture media treatments B2D0 (2 mgl-1 BA), B2D2 (2 mgl-1 BA and 2 mgl-1 2, 4-D), and B2D4 (2 mgl-1 BA and 4 mgl-1 2, 4-D) along with seven Persian leek accessions (Gorgan, Neishabur, Hamedan, Mianeh, Kangavar, Varamin and Kerman) carried out in three replications. Traits of embryo rate, regeneration rate, survival rates, callus formation and vitrified flowers were evaluated. Out of a total of 18,900 flower buds cultured, 459 embryos (2.43%) were all successfully regenerated into complete plants. Gorgan and Mianeh accessions ended up with the highest embryo and regeneration rates (25%) in the culture medium of B2D2 (2 mgl-1 BA and 2 mgl-1 2, 4-D). Results finally indicated that unpollinated flower culture is an effective method of in vitro gynogenesis of Persian leek.