ارزیابی ارقام تجارتی سیب ‭(Malus domestica Borkh) ‬بومی و خارجی موجود در کلکسیون های کشور

To avoid genetic erosion of existing apple cultivars we gained preliminary information on the locations where small and bigger collections were spread around the country. So, the scions were taken from the native and imported apple trees, found in horticultural research stations principally in Khorassan Razavi province, Semnan, Isfahan, and other collections like apple collection of Tehran University (Karaj) in addition to many modern private orchards in Damavand and Isfahan. In order to create more uniform conditions for doing future researches on cultivar evaluation, in the new collection we used clonal MM111 as a vigorous hardy rootstock with more persistant life. In a multipurpose effort different clonal MM106, M26, M9, B9 and MM111 rooted cuttings were obtained and a new propagation field was established in Karaj nursery under mist conditions to help them grow easier in low humid climate characterized with full sunny days, high temperatures and long growth season. At least, 9 trees had to be propagated 6 on MM111 to be distributed to the principal collection of Karaj and 3 on MM106 for support collection of Mashhad (Khorassan Razavi). Some private nurseries helped us furnishing field and rootstock considering high number of trees needed. At the end of project the old collection with three old trees grafted on seed rootstocks composed of 91 cultivars and promising genotypes was modified into a new collection of 153 cultivars grafted on MM111 with 6 trees for each cultivar established based on augment experimental design in Karaj. All the collected cultivars were contemporaneously propagated and transferred to Mashhad. The spring cold tolerant cultivars and drought tolerant ones were successfully selected in two natural stresses occurred in 2003 and 2005 respectively. Other observations showed the high genetic variability of the cultivars in resistance against Zeuzera spp. and other wood insects. We could make a classification of apple cultivars based on their resistance to fire blight using USDA system, making field observations from 2004 to 2008. At the same time we could cluster the cultivars studying many vegetative traits and also yield per tree, total fruit fall and fall frequencies from fruit set to ripening time as genetic potential of cultivar productivity. Precocity of the cultivars was recorded in the new collection and phonology of flowering was studied. Old collection was conserved by annual replant of dried trees.

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سیب ها ، ارقام ، پلاسم زایشی ، تنش سرمایی ، مجموعه ها