Effects of cowpea aphid-borne mosaic virus infection on the growth and yield parameters of Sesamum indicum plants

Abstract

The potyvirus cowpea aphid-borne mosaic virus (CABMV) is the main viral agent present in crops of Sesamum indicum in several regions of Paraguay. However, information about the effects of CABMV infection in S. indicum plants is scarce and the critical period for virus infection in S. indicum plants is unknown. This study aimed to evaluate the damage caused by CABMV on the development and yield of S. indicum plants experimentally infected at three phenological stages. Mechanical inoculations of CABMV were performed on S. indicum plants at the early vegetative stage, at the beginning of flowering, and during capsule and seed formation. An enzyme-linked immunosorbent Assay (ELISA) test was used to confirm virus infection on the inoculated plants using specific CABMV antisera. Plants inoculated 30 days after emergence (DAE) had severe systemic symptoms, but they were mild in mid and late-infected plants (60 and 90 DAE). Plant aerial dry weight was significantly affected by CABMV infection, reducing up to 71.6% compared to the control. Mid and late-infected plants experienced a lower level of damage, with an average aerial dry weight reduction of 17 and 14.2%, respectively. Furthermore, plants with early, mid, and late CABMV infections showed an average capsule per plant reduction of 97, 33.3, and 13.3%, compared to healthy plants. Seeds per capsule produced by CABMV-infected plants decreased by 93.5%, 21%, and zero, respectively. Viral infections also affected the 1000-seed weight in early infected plants, with a reduction of up to 93.3%. To prevent economic losses, it is crucial to have effective strategies for managing CABMV, particularly during the early stages of the crop.