Influence ofIndole-3-Acetic Acid treated Cowpea (Vignaunguiculata L. Walp) Seedson germination, plant development and leaf Chlorophyll Content

Abstract

Plant growth regulators (PGRs) are natural hormones found in plant or their synthetic hormone analogues. Auxin, a type of PGRs that consist of low molecular weight organic phytohormones which influences cell division, plant growth and development. One of the common auxin types is indole-3-acetic acid (IAA) and was the first plant growth regulator to be discovered with characteristics that involved in the control of various plant growth and development.Auxins can be absorbed in tissues and transport to long distances throughout vascular tissueof a plant. Therefore, this study aimed to investigate the influence ofIAA on the treated seeds of cowpea (VignaunguiculataL.Walp) accession TVu-7, TVu-9 and TVu-1945to 50 % seed germination, seedling growth and development, and leaf chlorophyll content.The various IAA concentration used were 0mg/L, 250mg/L, 500mg/L 750mg/L and 1000mg/L. The results of this study showed the relative effect of various concentrations of IAA on seed germination, vegetative structure produced and leaf chlorophyll content. For example, increased IAA concentrations of 1000mg/L further extend the number of days to attend 50 % seed germination in the different cowpea accessions. Also, an increased concentration to 1000mg/L significantly increased the leaf chlorophyll content in the different cowpea accessions.