Relation between Leaf Spot (Myrothedum Roridum) Intensity and Physio-Biochemical Changes in Mulberry (Moms Spp.)

摘要

Leaf spot caused by Myrothedum roridum is a severe disease to mulberry (Moms spp.) in West Bengal. Disease intensity reduces quality of mulberry leaves and in turn quality of silk produced. Knowledge on disease intensity and it's impact on the quality of mulberry leaves are pre requisite to take disease management measures in proper time. In view of this, changes in important physiological characters and biochemical constituents at various disease intensity levels (1-5, 6-15, 16-30, 31-50 and > 50% leaf area infected with disease were studied and compared with healthy (no disease) leaves. Biochemical characters such as, total chlorophyll and total soluble protein reduced significantly in infected leaves while total soluble sugar and phenol content increased. Physiological characters such as photosynthetic rate, stomatal conductance, physiological water use efficiency (pWUE) and moisture (%) were decreased significantly (P > 0.05) in infected leaves, while stomatal resistance increased and transpiration was not effected. Simple correlation (r) and regression analysis between the physio-biochemical characters and the disease intensity level revealed a significant correlation between increase or decrease in physiological activities and biochemical constituents with the disease intensity levels.