Tolerance of NS-sunflower genotypes to charcoal rot

Abstract

The most limiting factors in sunflowers production are weather conditions and plant diseases. Charcoal rot of sunflower is disease caused by soil-borne fungus Macrophomina phaseolina (Tassi) Goid. that gains importance in temperate regions. Control of charcoal rot is complicated due to pathogens long persistence in form of microsclerotia in the soil, often-delayed appearance of visible symptoms in plants and large number of host-plants. Due to that, development and use of resistant or tolerant sunflower genotypes is one of the most effective methods for charcoal rot management. The aim of this study was to determine variability of NS-sunflower inbred lines and hybrids in response to M. phaseolina infection and to detect tolerance within selected genotypes. Totally, 24 NS-sunflower commercial hybrids and 70 inbred lines were tested for tolerance to pathogen M. phaseolina at Rimski Šančevi, Novi Sad, during 2010 and 2011. For artificial inoculation two methods were used - Unwounded Stem Based Inoculation (USBI) which is close to natural infestation process and Toothpick Method which considers infestation by microslerotia through wound in plants.