Research Article

Screening for some physiological mechanisms in some drought tolerant genotypes of cowpea (Vigna unguiculata (L.) Walp)

¹*Kutama AS, ²Hayatu M, ³Binta UB and ⁴Abdullahi IK

¹ Department of Biological Sciences, Federal University Dutse, Jigawa state, nigeria

²Department of Plant Biology, Bayero University, PMB 3011, Kano Nigeria.

³Department of Biological Sciences, College of Arts and Sciences, Kano

⁴ Department of Biotechnology, Lovely Professional University, Jalandhar Punjab, India

* Corresponding Author E-mail: kutamasak@yahoo.com

Accepted 19 May 2014

Abstract

Drought is an abiotic stress that affects the growth of cowpea varieties in sub-Saharan Africa and it is one of the most important constraints threatening the food security in the region. The aim of the present study was screening for some physiological mechanisms in some drought tolerant cowpea genotypes (Vigna ungiculata (L.) Walp).The research was conducted in the screenhouse of International Institute of Tropical Agriculture (IITA) Kano state Nigeria .Nine genotypes of cowpea differing in drought tolerance were evaluated. The experimental layout used was Randomized Complete Block Design (RCBD) with two treatments (unstressed and water stressed) with three replications. The physiological parameters measured include, shoot and root biomass, plant vigor, Leaf Relative Water Content (LRWC) and Chlorophyll content (SPAD). The result showed that water stress reduces biomass and plant vigor. Lowest shoot biomass and vigor were recorded in IT00K-901-5. Increase in Leaf Relative Water Content was recorded in TVU7778 and IT97K-573-1-1. There was general decrease in chlorophyll content (SPAD) in all the varieties after water stress induction. Different rate of drought tolerance was observed among the nine varieties, IT97K-499-35, IT97K-573-1-1 and TVU7778 are drought tolerance based on some physiological mechanisms they exhibited while IT00K-1263 and IT00K-901-5 were susceptible to water stress conditions.

Keyword: Cowpea, Chlorophyll (SPAD) Drought tolerance, Screening