Effects of Yam Mottle Virus Disease on Photosynthesis of Dioscorea opposita ‘Niuwei’ Leaves

Abstract:

In order to understand the effect of mottle virus on the photosynthesis of yam (Dioscorea opposite) ‘Niuwei’, the diurnal changes in chlorophyll and photosynthesis in leaves with different degrees of mottle virus disease were measured. The results showed that the contents of chlorophyll a and total chlorophyll of mildly infected plants were significantly lower than those of healthy plants, and the contents of chlorophyll b and carotenoids of seriously infected plants were also lower than those of healthy plants, but there was no significant difference in chlorophyll b and carotenoids between mildly infected plants and healthy plants. After mottle virus infected yam, the net photosynthetic rate, stomatal conductance and transpiration rate of mildly and seriously infected plants were also lower than those of healthy plants, but the intercellular CO₂ concentration had not significant difference from that of healthy plants. Therefore, it was indicated that the photosynthetic efficiency of yam decreased after infected with mottled virus, thus causing the physiological function to be affected.