Assessment of Cowpea (Vigna unguiculata (L.) Walp.) Mutant Lines for Drought Tolerance

Abstract

Cowpea provides the cheapest source of protein with an average range of protein content of 23–30%. However, cowpea growth, development, and yield are greatly affected by drought during flowering and pod filling in the sub-Sahelian areas. The best way to cope with this situation is to develop drought-tolerant cowpea varieties. The objective of this study was therefore to evaluate cowpea lines developed through mutagenesis using gamma radiation to assess their reaction under optimal and water-stressed conditions. The response of ten mutants-irradiated Moussa local was then evaluated in pots arranged in a split plot design in a screen house. Two conditions were applied with optimum and water-stressed conditions. The stress was applied for two weeks at flowering. Two cowpea varieties Gorom local (drought-tolerant) and Moussa local (susceptible) nonirradiated were used as checks. Thereafter, field trials under two different sowing dates were conducted to identify the best tolerant mutant line(s) using agromorphological and tolerance indicators. The results indicated that mutant lines (MoussaM51-4P10 and MoussaM43-20P14) exhibited better stress tolerance and produced higher yield under water stress conditions. Stress Tolerance Index (STI) was better to select cowpea mutant tolerant with higher yielding under moderate stress (SI = 35%). The study confirmed that water stress has a negative effect on cowpea seeds production and on leaf chlorophyll content. The high temperature during experiment increased water stress effect mainly on non-irradiated checks (Gorom local and Moussa local).

Development of Novel Blackgram (Vigna mungo (L.) Hepper) Mutants and Deciphering Genotype × Environment Interaction for Yield-Related Traits of Mutants

“…This suggested that gamma rays showed high mutagenic efficacy that leads to the creation of heterogeneous populations in the background of the three parental cultivars. Similar results were found by Senapati and Misra [42] and Kuralarasan et al [43] in blackgram, Das and Baisakh [44] in mungbean, and Gnankambary et al [45] in cowpea. The yield-related traits contribute reasonably to total genetic variation among the mutagenized population revealed by loading plot values in PCs.…”

The Reaction of Some Cowpea Genotypes to the Thermohydric Conditions From the Area of Sandy Soils in the South of Oltenia

“…Temperatures above 35 0 C, which were recorded at the foliar level, intensified the thermohydric stress, the cowpea varieties reacting by reducing the photosynthesis process and intensifying the sweating process. Compared to 2020, in 2021, when higher temperatures were recorded in the air, the daily accumulation rate of CO2 through the photosynthesis process was lower by 6.91 µmol CO2/m 2 /s, and water losses through sweating were also lower by 0.72 mmol H2O/m 2 /s due to stomatal closure Due to the plant's biological properties, increased drought resistance and low soil fertility requirements, cowpea can be a good alternative to bean and soybean crops, which are very sensitive to stressors in areas with excessive drought (Drăghici, 2018, Gnankambary et. al., 2020.…”

Variation in seed protein, selected minerals, phytic acid, and potential mineral bioavailability of cowpea [Vigna unguiculata (L.) Walp] mutants and accessions

“…Mutagenesis is one of the popular techniques for increasing genetic diversity for crop development. Gamma‐ray mutation has been employed to improve the genetic diversity of cowpea in Burkina Faso (Gnankambary et al., 2020) and Namibia (Horn et al., 2016).…”