فهرست مطالب a.m. bakhshandeh

This research was aimed to investigate the foliar application of Plant Growth Regulators (PGRs) on growth parameters, yield, some morphophysiological traits, and alkaloids of rosea periwinkle (Catharanthus roseus L. (G. Don) under drought stress conditions. The field study was conducted based on split-plot factorial in the randomized complete block design (RCBD) with three replications at the research farms of Shahid Chamran University in Ahwaz city in 2016-17. The experimental treatments included drought stress as the main factor at three levels of 40% (control), 60% and 80% of maximum allowable depletion (MAD) and foliar application of jasmonic acid (JA) at two levels (0 and 10 µM) and salicylic acid (SA) at three levels (0, 0.1, 1, and 10 mM) as subplots. Based on the results of the mean comparison of main effects, drought stress (80% MAD) reduced 36.6% of fresh weight and 25.4% of the dry weight of the plant compared to the control. The treatment 10 mM SA resulted in 13.4, 125.5, and 59.6% increases in plant height, leaf area and flower dry weight, respectively, compared to the control. The foliar application of JA increased flower dry weight and plant fresh weight by 16.3 and 8.6%, respectively. The results showed that the foliar application of SA in concentrations of 1 and 10 mM caused the highest content of vincristine and vinblastine, respectively. The interaction of both PGRs and drought stress showed the highest alkaloids content. The highest vinblastine and vincristine under severe drought stress were obtained in foliar application of 1 mM SA+10µM JA and 10 mM SA+10µM JA, respectively.

The influence of Nitrogen (N) rates on mineral nutrient uptake in stem and seeds, proline and carbohydrate in flag leaves of Wheat (Triticum aestivum L . Var Chamran) under saline conditions was studied in a field experiment in 2003 and 2004. The experiment was conducted using a split plot design with three replications. The treatments comprised five levels of salinity: 1.5, 5, 10, 15 and 20 ds/m in main plot and three nitrogen levels: 50 , 100 and 150 kg N/ha in sub plot. Salinity treatments were applied in a clay–loam soil by water with NaCl and CaCl2 (5:1 by wt ). The results showed, the nutrient uptake was influenced by both salinity and N treatments. With the Exception of magnesium in seed, salinity increased nitrogen, calcium and magnesium concentrations in seed and stem in both years. By increasing salinity levels, the concentration of potassium in stem and seed decreased and Sodium concentration increased. In the stem the concentration of Sodium in the 20 ds/m was about 17 and 22 times more in the first and second year, respectively. In these experiments, by increasing salinity and nitrogen treatments, proline concentration in flag leaves increased in the two stages (flowering and milky stages) in both years. Salinity had similar effect on carbohydrate accumulation in both stages, but nitrogen treatment had two different effects on carohydrate concentration. In flowering stage, by increasing nitrogen application, carohydrate concentration increased but in milky stage decreased.