The response of cowpea genotypes (Vigna unguiculata (L.) Walp) toward drought stress Dwi Setyo Rini* and Hartati Saman*
*Research Centre for Genetic Engineering,
National Research and Innovation Agency (BRIN) Indonesia
Jalan Raya Jakarta Bogor KM 46 Cibinong, West Java, 16911 Indonesia
Abstract
Drought is a major environmental constraint for agriculture affecting the growth and development of plants. Due to its effect, drought can be drastically altered the agricultural production in the world. This research was conducted to study the response of cowpea (Vigna unguiculata (L.) Walp) as a legume plant having a high nutritional value related to its protein and fiber contents. Our previous research has identified cowpea genotypes, namely Carolina and Pinu Pahar, as drought-sensitive and tolerant genotypes to drought stress, respectively. In this study, the results at the pod filling stage indicated that the relative ratio of root : shoot DW (dry weight) of Caroline and Pinu Pahar genotypes watered in every seven days, showed 1.04-fold and 2.5-fold inductions, respectively as compared to their control conditions. The data of leaf dehydration assay after 20 minutes presented that the leaves of Caroline genotype lost 60.9% of total leaf weight, whereas Pinu Pahar genotype only decreased by 27.8% of leaf weight. The expression of CPRD12 (Cowpea Clones Responsive to Dehydration12) was analyzed in this study. In the dry conditions for 15 days, the transcript level of CPRD12 (Cowpea Clones Responsive to Dehydration12) gene more increased in drought-sensitive cowpea genotype as compared to drought-tolerant genotype.
Keywords: cowpea, CPRD12, drought stress, water loss
