A gamma rays-induced novel fertile subsessile leaf mutant in cowpea [Vigna unguiculata (L.) Walp]

Protein-rich legumes contribute to nutritional security by complementing cereals-based diets rich in carbohydrates. In cowpea, an arid legume with a narrow genetic base, we attempted to induce ideotype mutations using gamma rays for augmenting productivity and discovered a novel fertile, subsessile leaf mutant ‘PLM211’. Despite the mutant and the parent exhibiting similar individual leaf area and node number, the rudimentary petioles, shortened rachis, little to no branching, and consequently fewer leaves greatly influenced the canopy structure of the mutant. Histological sections of the mutant’s 0.55- 1.01 cm short petioles showed reduced cell size and number as opposed to the parent’s 12.64-14.55 cm long petioles. The potential for uncovering the underlying genes associated with petiole length, leaf morphogenesis, and branching highlights the significance of the mutant as a genetic treasure, opening up avenues for manipulating plant architecture, especially in legumes.