Salinity tolerance at the germination stage of Senegalese varieties of peanut, cowpea, millet and sorghum

Abstract

Salinization continues to increase in semi-arid areas like Senegal where it limits seed germination, a crucial phase in a plant's cycle. Adaptation to salinization, one of the great challenges of modern agriculture, is possible through the use of halotolerant varieties which could be selected early during seed germination. The general objective of this study is to evaluate the effect of salinity on the germination of peanut, cowpea, millet and sorghum. The effect of NaCl (0, 40, 80 and 120 mM) was tested on seed germination for one week at 30°C in a culture chamber. The parameters evaluated are: the final percentage of germination (FG), the germination vigor index (GVI), the coefficient of velocity of germination (CVG), the percentage reduction in germination compared to the control (PRG) and the daily average germination (DAG). The FG, GVI and CVG of millet, cowpea, sorghum and peanut show significant differences (p<0.01) for each NaCl concentration. On the other hand, DAG and PRG give significant differences only at 80 mM and/or 120 mM NaCl. FG, CVG, DAG and GVI decreased with increasing salinity for all varieties unlike PRG. Cowpea (V4) are less sensitive to salinity than peanut (V3), which tolerate NaCl better than cereals. Millet (V5) is more resistant than sorghum (V7). The increase in NaCl led to a significant difference in germination. Cowpea (V4) would be more osmotolerant than peanut (V3) which is more tolerant than cereals such as millet (V5) and sorghum (V7) to salinity. These varieties would be the most recommended for successful cultivation in a saline environment.