Ameliorative Effects of Brassinosteroids on Growth and Productivity of Snap Beans Grown Under High Temperature

摘要

The effect of brassinosteroids (BRs) was tested, in order to assess the possibility of alleviation of the adverse effects of high temperature stress on snap bean plants during delayed summer cultivation. Therefore, two field experiments were carried out in successive seasons, 2010 and 2011, with two bean cultivars 'Paulesta' and 'Oxzi-ra', spraying with BRs of the following concentrations 0 (control), 25, 50 and 100 ppm. Plant growth, yield and pods quality of beans were studied. Spraying bean plantswith BRs at a concentration of 25 and 50 ppm increased vegetative growth, total yield and quality of pods with no significant difference between both treatments. Using BRs at 25 ppm increased the total free amino acids (FAA) in leaves and total phenolicacids in the pod in comparison to control-treatment. 'Oxzira' cultivar resulted in the highest number of leaves, number of branches, dry weight of whole plant, total yield, total FAA in leaves and total phenolic acids in pod. Whereas, 'Paulesta' cultivar had the highest of plant length and total FAA in pods.