Carbohydrate content of some potato virus Y-diseased solanaceous plants

Different carbohydrate components, viz. total soluble reducing and non reducing sugars and starch were compared in leaves of four solanaceous plants namely Lycopersicon esculentum cv. Money maker [susceptible tomato]; Lycopersicon pimpinellifolium L. [resistant tomato]; Capsicum annuum cv. "California Wonder" [pepper] and Solanum nigrum var. judaicum [Enab El-Deeb] at different intervals after inoculation with an isolate belonging to Y° group of the common strain of potato virus Y [PVY] studies indicate that: i - In susceptible tomato: virus infection lowered significantly the total carbohydrate content and starch content and decreased also the monosaccharide content but increased sucrose concentration. ii- In resistant tomato: virus infection decreased significantly all carbohydrate fractions except only the monosaccharides. iii- In pepper: virus infection lowered the total carbohydrate content as a result of decreased monosaccharides, sucrose and starch components .iv- In Enab El-Deeb: virus infection also decreased the total carbohydrate as well as the starch and total soluble sugars

Nitrogenous components in healthy and potato virus Y-infected solanum and pepper leaves

Solanum nigrum var. judaicum and Capsicum annum cv. California wonder plants at the 4-6 and 5-7 leaf stage, respectively, were artificially infected with potato virus Y, then examined at 5, 10, 15, 20 and 40 days postinfection. Considerable differences were observed in the concentration of the various nitrogenous components of the two hosts. Investigations showed that solanum leaves affected by PVY had a higher total nitrogen content than the leaves of the healthy plants as a result of increasing amino acids, ammonia, amide, total soluble nitrogen and total insoluble protein content. PVY lowered total nitrogen content compared with healthy leaves resulting from a drop in all nitrogenous components, but amide and total insoluble proteins increased