Efeito de estresses combinados salino e de altas temperaturas em Vigna unguiculata (L.) Walp: abordagens fisiológicas e anatômicas

Abstract

Salinity and high temperatures are factors that negatively affect the production of plant species of socioeconomic importance in arid and semi-arid waters. At present, major reactions from plant technicians are covered and information on environmental conditions is included. Cowpea (Vigna unguiculata (L.) Walp) is one of the most important crops of the region. In addition, it is a moderately resistant strategy to drought and salt stress, stressing principles that limit the productivity of this crop. The present work had as physiological and anatomical objective of the rope bean on the effect of saline stresses and high temperatures. The experiments were conducted at UFRPE-UAG / CENLAG. Seeds of cowpea cultivar IPA 206 were seeded on filter paper moistened in distilled water or 100 mM NaCl solution (saline stress condition) and placed in a germination chamber with 12-hour photoperiod at temperatures of 30, 35 and 40°C for 7 days . The measures of the flexible ones were cut and their length was measured in relation to the analytical balance. For a physiological characterization, as were submitted to germination tests, IVG, analysis of root and shoot root length and dry mass, and anatomical analysis from histological sections of hypocotyls. The results were: the interaction between salinity and high temperatures decreased the seed germination potential of V. unguiculata and the sampling rate was 40°C. Saline stress (100 mM NaCl) in the hot, diseased air (40°C) inhibited the growth, growth and dry mass of V. unguiculata seedlings. Saline stress associated with high temperatures caused disarrangement in the arrangement of xylem and phloem bundles in cowpea seedlings. Thus, the combined stresses potentiate the effects of saline and thermal stress alone.