Determinação quantitativa de proteína, prolina e pigmentos fotossintéticos em três variedades de feijão nhemba [Vigna unguiculata (L.) Walp.] durante o crescimento vegetativo em condições de strees hídrico

Abstract

Effects of water stress on protein, proline and photosynthetic pigments parameters were evaluated in three varieties of cowpea (Vigna unguiculata) during vegetative growth between the months of June and October 2008. The plants were allowed to grow in the greenhouse of the Department of Sciences Biological in plastic pots and under controlled water regime conditions. Plants subjected to water stress were watered with about 20% of the field capacity while those subjected to optimal irrigation conditions were watered with about 80% of the field capacity. Under stress conditions, the Namarrua variety showed the highest levels of proline and protein. The Massava-Nhassenje variety did not present very large intervals between the stress and control values ​​in these two parameters, while the IT82D-812 registered lower values ​​in terms of protein concentration. Regarding the concentration of photosinetic pigments under stress conditions, the IT82D-812 variety showed higher concentrations of chlorophyll a and b and pheophytin a, while the varieties Namarrua and Massava-Nhassenje showed higher concentrations of carotenoids and pheophytin b, respectively. The three variants registered, in stress, a decrease in all parameters evaluated compared to the control, underlining the hypothesis that the stress imposed by the water deficit during the vegetative growth affects the metabolic processes such as photosynthesis and protein synthesis, which in certain cases conditions the accumulation of osmotic solutes such as proline. (TRADUÇÃO NOSSA)