In breeding for disease resistance, the magnitude of the genetic response is difficult to appreciate because of environmental stresses that interact with the plant genotype. We discuss herein the fundamental problems in breeding for disease resistance with the aim being to better understand the interactions between plant, pathogen, and spatial patterns. The goal of this study is to fine tune br...

It is known that many soil fungí synthesize brown, large aromatic polymers (fungal melanins), chemically related to soil humic acids (Martin and Haider, 1971; Schnitzer and Neyroud, 1975). Since the chemical constituents (or at least, their degradation products) and the physicochemical properties of fungal melanins are comparable to those of humic acids, it is possible that fungal metabolism ma...

Soil-borne pathogens such as Verticillium species, invade into the roots of many herbaceous and woody hosts. The xylem environment supplies these with a continuous flow nitrogen-rich nutrition. Detailed quantitative increases in amino acids stems, petioles, leaflets young tomato plants infected Verticillium. albo-atrum causal agent wilt disease, are described this paper for first time. Results ...