Role of putrescine on growth, regulation of stomatal aperture, ionic contents and yield by two wheat cultivars under salinity stress

Amelioration of salinity stress at different levels [0.0, 2000, 4000, 8000 and 12000 mg/l] in two wheat cultivars Giza 168 and Gimeza 9 was investigated. Foliar application of diamine putrescine at different concentrations [1.25, 2.5 and 5mM] in pot experiments was conducted during two successive seasons [2001 and 2002]. Exogenous application of putrescine on salt stressed plants considerably increased shoot growth [number of tillers, number of leaves, area of leaves, fresh and dry weight] and grain yield/plant. Foliar application of putrescine also induced a potent effect in reducing the stomatal aperture and slightly increased the stomatal number on both leaf surface in the two cultivars. Furthermore putrescine treatment decreased degradation of chlorophyll and increased soluble sugar contents. Application of putrescine inhibited Na and Cl uptake and accelerated the accumulation of K, Ca, Mg and P in the shoots of salt stressed plants. Moreover, a higher solute concentration contributing to osmotic adjustment was observed in shoots of salinity treated Gimeza 9 than in those of Giza 168. This response together with the higher accumulation of inorganic solutes in Gimeza 9 and organic solutes [soluble sugars] in Giza 168 indicated different salt tolerance mechanisms operating in the two cultivars

Growth Parameters, photosynthetic pigments and mineral ions content of vicia faba plants treated with uniconazole

Growth parameters [viz. stem length, number of branches and leaves, fresh and dry weight of the shoot system as well as the water content of the shoot and its percentage], photosynthetic pigments [viz. chlorophyl a, chlorophyl b and carotenoids] and the mineral ions content [viz. K, Ca and Mg] of bean [Vicia faba cv. Giza 402] plants sprayed twice [after 4 and 6 weeks from sowing] with solutions of uniconazole [at the concentrations 0, 5, 10, 20 or 40 ppm] and collected after 5 and 7 weeks, were studied. The treatments decreased most of the studied growth parameters at the 2 investigated ages, the decrements were almost directly proportional with the concentration used of the growth regulator and it was sometimes significant at 1% or 5% levels of probability. Increases in photosynthetic pigments and mineral ions content occurred due to the treatments, the increments were in a linear relationship with the concentration used, these increments were often significant at 1% or 5% levels of probability and they were more pronounced at the 1st investigated age

Growth flowering and productivity of vicia faba plants treated with uniconazole

A pot experiment was carried out during the growth season 1991/92 and repeated during the growth season 1992/93 to study the effect of spraying bean plants twice, during vegetative growth, with solutions of uniconazole [at concentrations of 0, 5, 10, 20 or 40 ppm] on the growth parameters [plant height, rate of stem elongation as well as number of branches and leaves], flowering, yield components [number and weight of pods and number and weight of seeds, all per plant, as well as the weight of 100 seeds] and the chemical composition of the harvested seeds. The treatments significantly decreased plant height and inhibited the rate of stem elongation, especially during the 2 or 3 weeks [according to the concentration used] following the treatment, the decrements were in a linear relationship with the concentration used. The average number of branches leaves [all per plant] and days required for the appearance of the first flower were increased due to the treatments. The increments were only significant with the first criterion after the second application of uniconazole. All the concentrations used [except that of 40 ppm] caused significant increases in the yield components, the best results were obtained with 20 ppm

Growth parameters, photosynthetic pigments and mineral ions content of bean [vicia faba cv Giza 402] plants raised from pre-sowing uniconazole soaked seeds

Growth parameters [represented by stem length, number of branches and leaves, fresh and dry weight of shoot system as well as the water content and its percentage in the shoot], photosynthetic pigments content [viz. chlor. a, chlor. b and carotenoids] and the mineral ions content [viz. K, Ca and Mg] of Vicia faba [cv. Giza 402] plants raised from pre-sowing soaked seeds in the following concentrations of uniconazole 0, 5, 10, 20 or 40 ppm and collected after five and nine weeks from sowing were studied. The treatments reduced all the studied growth parameters at the two ages investigated. The decrement was often directly proportional with the concentration used of uniconazole and it was almost significant at 1% level of probability. The only exception of this was that at the second studied age, increase in the average number of branches and levels was observed with the treatments and it was sometimes significant at 5% level of probability. The treatments caused increase in the photosynthetic pigments which was more obvious after five weeks from sowing while after nine weeks from sowing the increment in this criterion was restricted to the two higher concentrations used [20, 40 ppm]. Mineral ions contents [viz. Ca, K and Mg] of bean shoots were increased in comparison with control plants, the increase were directly proportional with the concentration used of uniconazole and it was almost significant at 1% level of probability