Growth and physiology of maize plants subjected to water deficit and to different brassinosteroid and azospirillum concentrations

Abstract

Work that demonstrates the use of brassinosteroid and azospirillum bacteria to attenuate the harmful effect of lack of water in corn is incipient. Therefore, the search for an answer that helps to understand the attenuating effect of the use of brassinosteroid and azospirillum bacteria on the physiological characteristics and growth of corn is relevant, since the water demand of the crop is high and the search for alternatives is necessary viable ways to reduce the harmful effects of water deficit. The objective of this study was to evaluate the influence of brassinosteroid and Azospirillum brasilence on the growth and physiology of corn plants submitted to water stress conditions. The experiment was carried out in a vegetable house with a hybrid K9606 VIP3 corn. The experiment was carried out in a vegetable house, using corn plants, the hybrid K9606 VIP3. The experimental design used was completely randomized, in a 2x2x3 factorial scheme, with six replications, totaling 72 experimental units. The first factor corresponds to two water regimes (presence and absence of water deficit). The second factor corresponds to inoculation via seed (at the time of sowing) of Azospirillum brasilense and absence of inoculation. And the third factor corresponds to the application of three concentrations of brassinosteroids (0, 0.3 and 0.6 μM Br). Plant height, stem diameter, number of leaves, root dry weight, leaf and stem, relative water content, chlorophyll a, b, carotenoids, sucrose, starch and total soluble carbohydrates in the leaves and roots were determined. Chlorophyll a levels were highest in water-deficient, inoculated plants with 0.3 μM brassinosteroids. In water-deficient, inoculated plants, the carbohydrate levels were higher in plants with 0.3 and 0.6 μM brassinosteroids. Among plants that were water-deficient and inoculated, plants treated with 0.6 μM brassinosteroids had the highest relative water content. Thus, it is recommended the inoculation of seeds and application of 0.6 μM of brassinosteroids together with Azospirillum brasilense in water-deficient maize plants.