Morphological and molecular identification of Macrophomina phaseolina in the pool of pathogens of sugar beet (Beta vulgaris) root rot: Screening of fungicides for its control

摘要

Currently, the main biotic factor responsible for the loss of sugar beet yield is root rot. The early detection and accurate identification of the causative agents of this disease introduce oneself to be a prerequisite for optimizing its control. In recent years, the importance of Macrophomina phaseolina, a cosmopolitan fungus that causes coal rot of plants on all continents, has grown in importance. This study was carried out in the biolaboratory of JSC “Shchelkovo Agrokhim” (Shchelkovo, Moscow Region, 141101, Russia) from 2018 to 2020 to evaluate several drugs from plant protection products manufacturers in order to optimize control over Macrophomina phaeseolina. The fungus was isolated from sugar beet root crops in the Belgorod region. The disease manifested itself as black-brown root rot with characteristic cavities in the tissues of the root crop. The samples sent differed from each other in the degree of damage to root crops and leaves. The pathogen was identified both by traditional taxonomy methods and by real-time polymerase chain reaction (RT-PCR). In the same study, M. phaseolina isolate was insensitive to the active substances propiconazole, diphenoconazole and flutriafol. The active ingredients carbendazim, azoxystrobin, and tebuconazole have been shown to be the most effective in controlling M. phaseolina.