Abstract
Salt stress is a major stress influencing wheat seedling establishment. A laboratory experiment was conducted to evaluate the response of 20 cultivars of wheat to two levels of salinity (8 and 16 dS/m NaCl), at the College of Agriculture, Shiraz University, Shiraz, Iran in 2008. Maximum root length was obtained in Dabira (5.73 mm) at 16dS/m salinity level. In control, durum wheat cultivars including D81-17, Yavaros, D82-16, D79-15 and Taro3 had the maximum root length compared to bread wheat, however, with increasing salinity level to 16dS/m, minimum root length was observed in D82-16 (0.3 mm). In all cultivars, with increasing salinity level, shoot length was decreased and minimum shoot length was observed in D82-16 and D79-15. Under control conditions, Taro 3 cultivar had maximum seedling dry weight (108.6 mm), however, at 8 and 16 dS/m salinity levels, seedling dry weight of this cultivar was decreased to 92.33 and 78.43 mg, respectively. All seeds (100%) were germinated in D82-16, Taro3, Bolani Cross, and Chamran cultivars under 16 dS/m but in Marvdasht cultivar, seed germination percentage under 8 and 16 dS/m reached to 65 and 50%, respectively. Shiraz (10.8 seeds/day), Adl Cross(10 seeds/day), and Bolani Cross (9.1 seeds/day) had maximum germination rate under 16 dS/m salinity level. Differences among wheat cultivars also found in germination stress index (germination rate under stress divided by germination rate under control) and Shiraz, Adl Cross and Bolani Cross had maximum germination stress index, while Yavaros and D82-16 had minimum germination stress index. Furthermore, with increasing salinity level, different responses were observed among wheat cultivars in root and shoot length, germination rate and germination stress index which demonstrated the genetic diversity among wheat cultivars. It appeared that durum wheat cultivars, compared to bread wheat cultivars, had lower germination stress index and germination rate. Among what cultivars, Bolani Cross, Shiraz and Adl Cross appeared to be more tolerant and Marvdasht, Yavaros and Karkheh more sensitive to salt stress at seedling stage which is worthy of attention by farms growing wheat in saline soils. did not suitable cultivars for salt areas.
Keywords: Bread and durum wheat cultivars, Salt tolerance, Germination stress index, Germination rate |
