Recovery of Germinability of Aged Conidia of Botrytis cinerea Pers. by Several Saccharides

Abstract

Generally, the ability of germination of aged conidia of Botrytis cinerea Pers. in distilled water is almost lost, when they were incubated at 20°C for more than 6 days. However, when mono-, oligo-, or polysaccharide was added to the suspension, aged conidia regained the ability of germination, appressorium formation, growth of germ tubes, and the infectivity. This recovery effect of sugars on conidia aged by incubation at 20°C for 40 days, was recognized in 10-2-10-3M solution, but not in 10-5M solution.The recovery effect of monosaccharide, e.g., glucose and fructose, on the germinability of conidia was remarkably increased in 10-2-10-3M solution, and the growth of germ tubes, appressorium formation and infectivity were also promoted as well as the germination. However, effect of mannose, galactose, and xylose was not recognized in 10-210-3M solution. Although arabinose stimulated the germination of aged conidia in 10-2M solution, the appressorium formation was not effected.In oligosaccharide solution aged conidia also regained the germinability, growth of germ tubes, appressorium formation and infectivity in descending order of sucrose, maltose, and lactose. In polysaccharide solution this effect was also recognized in descending order of dextrin, inulin, and starch, but they were less effective than in mono- and oligosaccharide solutions. Generally, the growth of germ tubes was more vigorous in 10-2M solution than in 10-3M solution, and the appressorim formation and infectivity were also promoted more in 10-3M solution than in 10-2 and 10-5M solutions.