Evaluation of four Mozambican cowpea landraces for drought tolerance

Abstract

The southern part of Mozambique is vulnerable to drought, affecting the country’s food production, and thus requires more drought-tolerant crops. Four local cowpea landraces, Massava nhassenje, Timbawene moteado, Namarua and Tete-2, which are currently widely used by local Mozambican farmers, were evaluated for their drought tolerance with the aim to identify the most drought-tolerant landrace and also a phenotypic marker easily applicable for drought-tolerance selection under local Mozambican conditions. Above- and below-ground plant characteristics, including biomass, protein content, proteolytic activity, symbiotic nitrogen fixation and nodule number, were measured in a greenhouse under well-watered and drought conditions using vermiculite as the plant growth medium. The key finding was that variability exists among the landraces for growth under drought with Timbawene moteado displaying significantly higher leaf dry biomass, leaf and nodule protein content, and symbiotic nitrogen fixation and the lowest increase in proteolytic activity compared to all other landraces. Timbawene moteado might be suitable for inclusion into a future cowpea breeding program in Mozambique and might also be tested in other areas in Mozambique experiencing drought stress. Furthermore, leaf dry biomass might be selected as a simple and informative marker for future screening of the Mozambican cowpea germplasm for drought tolerance.

Keywords: cowpea performance, nodule performance, performance marker, protein content, proteolytic activity

South African Journal of Plant and Soil 2014, 31(2): 87–91