Wednesday, November 7, 2007 - 9:30 AM
260-1
Growth Responses of Wheat Plants (Triticum aestivum L.) and (Triticum monococcum L.) to Drought and Salinity Stresses.
Dr. Hayat Touchan1, Mohammad Pessarakli2, Dr. Ramin Yadegari2, and Dr. Karen S. Schumaker2. (1) Aleppo University, Department of Field Crops, Faculty of Agriculture, Aleppo, Syria, (2) University of Arizona, Department of Plant Sciences, Forbes Bldg., Room 303, Tucson, AZ 85721
Growth responses of two different wheat plants (Triticum aestivum, turgidum L.), cv. “Durum” and (Triticum monococcum L.), cv. "DV92"in terms of shoot and root lengths and fresh and dry matter (DM) weights were evaluated under drought and salinity stresses, in a greenhouse via hydroponics system, using one-half strength Hoagland solution No. 1. Plants were grown under normal (non-stress) condition for 56 days (8 weeks) prior to exposure to stresses. Then, the plants were imposed to various levels of drought and salinity stresses [osmotic potentials (OP) of 0, -2, -4, -6, and -8 dS/m induced by either polyethylene glycol (PEG) or sodium chloride (NaCl)]. Four replications of each treatment were used in a randomized complete block (RCB) design experiment. Plants were grown under these conditions for 42 days (6 weeks). During this period, two plants from each treatment were harvested weekly for shoot and root fresh and DM weights. The fresh weights of the harvested materials were measured. Then, the harvested materials were oven-dried at 60°C and DM weights determined and recorded. Prior to each harvest, both shoot and root lengths were measured and recorded. The results showed growth of both wheat plants were adversely affected by either drought or salinity stress. Both shoot and root fresh and DM weights were more severely affected than shoot and root lengths by either stresses. Plant succulence (Fresh weight/Dry weight ratio) of Triticum aestivum slightly increased under salinity stress, but that of Triticum monoccocum significantly decreased. However, under drought stress there was no significant differences found in plant succulence of either cultivars compared with the controls. All the study parameters showed that the effect of drought was more pronounced than the salinity on both cultivars. Also, the effects of either stresses were more pronounced on Triticum monoccocum compared with Triticum aestivum.