Physiological Alterations in Sphenostylis stenocarpa due to Telfairia mosaic virus

Interaction between plant and virus induces significant alterations in the physiology of the plant affecting its performance. African yam bean (AYB) is a high yielding legume with the potential of solving the food security need of the nation. Alterations in basic physiological parameters due to Telfairia mosaic virus (TeMV) infection of AYB ( Sphenostylis stenocarpa (Hochst ex. A. Rich) Harms) were studied. Infected AYB exhibited symptoms of severe mosaic, leaf distortion and malformation. Results analyses revealed that the virus engendered significant ( P ≤ 0.05) reduction in chlorophyll a , ratio of chlorophyll a / b with increase in peroxidase (POD), polyphenol oxidase (PPO), and glucose-6-phosphate dehydrogenase (G6PdH) enzymes activity. The virus caused insignificant reduction in relative water content (RWC), chlorophyll b , carotenoids with increase in 6-phosphogluconate dehydrogenase (6PGdH) activity. Alterations induced by TeMV on S. stenocarpa physiological components did not differ statistically at initial period but significant at prolonged infection. Telfairia mosaic virus caused percentage reduction of 34.2% for chlorophyll a at 120 days after inoculation (DAI) and 31.1% for ratio of chlorophyll a / b at 30 DAI. The virus induced increase in activity of –61.2% (POD), –65.5% (PPO) and –126.9% for G6PdH an enzyme of the oxidative pentose phosphate pathway (OPPP) at 90 DAI. All enzymes activity declined at 120 DAI except G6PdH activity. Telfairia mosaic virus significantly altered some physiological parameters with attendant effect on growth and yield of S. stenocarpa .