Use of the fluorchrome vital dye acridine orange to determine viability and germination of Tilletia indica teliospores in soil

Abstract

A vital staining method using the fluorochrome acridine orange (AO) was developed for staining teliospores and primary sporidia (basidiospores) of Tilletia indica the causal agent of Karnal bunt of wheat. This procedure allows determination of the viability of teliospores in soil. Also the method makes it possible to monitor germination of teliospores in different soil types under different soil moisture levels. The primary sporidia produced from germinated teliospores could be easily detected in small soil samples (10 g). This is the first report on evaluation of germination of viable teliospores directly in different soil types. This method makes it possible qualitatively to determine the germination of teliospores in nonsterile soil taken directly from the field. The AO procedure, as a supplement to the quarantine inspection of seed lots, could be used for routine testing of the viability of teliospores of T. indica extracted from seed lots.