Determination of chilling and heat requirements of grape cuttings and changes in carbohydrates and hormones during chilling period Evaluation of drought resistance and turf quality in some selected Tall fescue collected from different places of IRAN
Saeed Eshghi, Mehdi Garazhian, Iman Rohollahi, Mohsen Kafi, Azam Khoshkholghsima, Abdolmajid Liaghat
Iranian Journal of Horticultural Science
This research was carried out to determine the chilling and heat requirements of grapevine cultivars (Rotabi, Siah Shiraz and Yaguti) and carbohydrate and hormones changes in chilled cuttings. Uniform cuttings of above mentioned cultivars were harvested when leaves were abscised in autumn, and then transferred to refrigerator (2˚C). Cuttingswere subjected to 0 (unchilled control), 100, 200, 300, 400, 500 chilling hours, then cuttings were put in distilled water at room temperature and continues
... light conditions. Results indicated that the highest bud break percent of 'Siah Shiraz', 'Rotaby' and 'Yaguti' were obtained from 500, 400 and 400 h respectively. The shortest time (29d) to 50% bud break of 'Siah Shiraz' was in 500 h(29 d), in 'Rotabi' and 'Yaguti' were in 400 h (20 and 16d) chilling. Rate of starch content in all cultivars were decreased when chilling exposed hours increased, while soluble carbohydrate content in cuttings increased with increasing chilling hours. Also, with increasing chilling exposed hours, GA, Cytokinin and Auxin contents increased whereas ABA decreased. In conclusion, chilling requirement of 'Yaguti', 'Rotabi' and'Siah Shiraz'cultivars were 400, 400, 500 hours and heat requirements were 4320, 5472 and 8064 GDH, respectively. ABSTRACT In order to identify low maintenance turfgrass, turf quality of selected entries of germination stage under drought stress were evaluated by Digital Image Analysis methods in the field conditions. The first greenhouse study examined the interaction of four different levels of soil water contents (40, 60, 80 % and 100% field capacity) on 14 Festuca arundinacea entries. We determined the effects of low soil moisture (80%, 60% and 40 % field capacity) on the emergence and early establishment using 14 wild F. arundinacea populations collected from various regions of Iran and two commercial turf cultivars. Based on results, the highest final emergence (100%) was exhibited by Isfahan accession, at 40% FC, but it was 6.7% in Quchan accession. Finally, in the last experiment, turfgrass quality and coverage in selected entry of second experiment were evaluated in the field for one year. Gonabad entry showed very good turfgrass coverage at first evaluation after mowing. However, Isfahan accession showed the best turfgrass coverage in the end of experiment. Cultivar Barvado showed the highest turf colour index. These results suggest that collected entries from Iran specifically Isfahan and Brojen entries could be used for plant breeding programs and improvement of low maintenance turfgrass in Iran.