Effect of Salinity on Germination and Seeding Parameters of Forage Cowpea Seed

Objective: To investigate the effects of osmotic stress on performance forage cowpea varieties at critical stage of germination to salinity stress. Methodology: A study was conducted at the Seed Technology Laboratory of Mansoura University, Egypt during April and May 2014. Two forage cowpea cultivars (Buff and Baladi) were evaluated in the salinity concentrations 0, 2, 4, 6, 8, 10, 12, 14 and 16 dS mG 1 NaCl. Results: The results exposed that germination parameters namely final germination percentage, germination index and seedling vigor index were estimated. Seedling characters namely shoot and root length, shoot and root foliage weight, shoot and root dry weight and chlorophyll content were measured. Forage cowpea cultivars significantly diverse in means of final germination percentage, germination index, seedling vigor index, shoot and root lengths, shoot and root fresh weights, shoot and root dry weights and chlorophyll content. Increasing salinity levels from 0-16 dS mG 1 significantly diminished germination percentage, germination index, seedling vigor index, shoot and root lengths, shoot and root fresh weights, shoot and root dry weights and chlorophyll content and the control treatment recorded the highest averages of these characters. Thus, the lowest averages of these characters were recorded with highest salinity levels i.e., 16 dS mG 1 . Conclusion: Results clearly displayed that germination index, seedling vigor index, shoot and root lengths, shoot and root fresh weights, shoot and root dry weights and chlorophyll content significantly affected by the interaction between forage cowpea cultivars and salinity concentrations. It could be determined that Buff cultivar was more tolerant to salinity stress and produced highest germination and seedling parameters which must be put in breeding program of forage cowpea under salinity conditions.