Effect of EMS-Based Mutagenesis on Growth and Yield Response in Tepary Bean (Phaseolus acutifolius)

Tepary bean is an important food legume cultivated in semi-arid areas in many parts of the world, including sub-Saharan Africa. This crop is highly tolerant to drought and pests, but it is also generally low yielding. Similar to many other legumes, the genetic improvement of the tepary bean is also limited by its narrow genetic base. Techniques, such as mutation breeding, particularly chemical mutagenesis with ethyl methanesulfonate (EMS) have been successfully tested to induce genetic variability in this crop. As part of the few reports of chemical mutagenesis in tepary bean, this paper evaluated the seedling performance of the M1 EMS mutagenised plants and adult plant performance of the subsequent generations of tepary bean under different conditions. Based on the results, EMS induced some dominant mutations that were detectable in the M1 generation. These effects were further extended to the early mutagenised generations (M2 to M4) of the tepary bean under field conditions, revealing novel information regarding the response of tepary bean to chemical mutagenesis at both the seedling and adult plant stages.

Keywords: Ethyl methane sulfonate, growth, mutagenesis, tepary bean, yields.