تهیه و نگارش فلور تیره افرا ‭(Aceraceae)‬

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 modem 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 MM' " as a vigorous hardy rootstock with more persistant life. In a multipurpose effort different clonal MM'. 7, Mi7, Mq, Bq and MM' , , 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, q trees had to be propagated 7 on MM' " to be distributed to the principal collection of Karaj and l' on MM' .7 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 q, cultivars and promising genotypes was modified into a new collection of '01' cultivars grafted on MM'" with 7 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 i.. l' and i.. 0 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 i. . f to i.. A. 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.

Keywords:

افراییان , گیاگان , گونه ها , مجموعه ها , پوشش گیاهی