Rice False Smut: An Increasing Threat to Grain Yield and Quality

Abstract

Rice false smut (RFS) is the most important grain disease in rice production worldwide. Its epidemics not only lead to yield loss but also reduce grain quality because of multiple mycotoxins generated by the causative pathogen, Villosiclava virens (anamorph: Ustilaginoidea virens). The pathogen infects developing spikelets and specifically converts individual grain into a RFS ball that is established from mycelia covered with powdery chlamydospores, sometimes generating sclerotia. RFS balls seem to be randomly formed in some grains on a panicle of a plant in the paddy field. However, epidemics differ largely among varieties, fields, and seasons. This chapter introduces current understanding on the disease, mycotoxins, the biology of the pathogen, pathogenesis of RFS, rice resistance, the disease cycle, the disease control, and assay.

Morpho‐molecular and mating‐type locus diversity ofUstilaginoidea virens: an incitant of false smut of rice from Southern parts of India

“…False smut of paddy caused by Ustilaginoidea virens (Cook) Takahashi (Telomorph: Villosiclava virens) is an emerging grain infecting disease wherein infected grains transformed into yellow to black coloured smut balls. The pathogen causes economic losses in both quantity (reducing the grain yield) and quality (by contamination of grains with toxins) (Dodan and Singh 1996;Muniraju et al 2017aMuniraju et al , 2017bWang et al 2019). The disease was first reported from Tamil Nadu, a Southern state of India (Cooke 1878), and later, it spreads to more than 40 countries in the world and caused many outbreaks sporadically (Akai 1974;Rush et al 2000;Atia 2004;Mahmud 2019).…”

High-resolution mapping of the quantitative trait locus (QTLs) conferring resistance to false smut disease in rice

“…Breeding rice cultivars with a high level of resistance to false smut is one of the effective, environment-friendly, economic, and sustainable approaches to control this disease (Wang et al 2019). In the last few decades, several reports were published on screening and identi cation of rice germplasm Ten false smut resistance quantitative trait loci were mapped from Lemont, and four of them showed larger and consistent effect across two seasons (Zhou et al 2014).…”

Mapping quantitative trait loci for disease resistance to false smut of rice

“…Because of economic importance, the disease has been extensively studied in different aspects including disease occurrence, pathogen detection, mycotoxin isolation and identification, infection process, resistance evaluation of germplasms, and disease control in recent years (Tang et al 2013;Wang et al 2019;Sun et al 2020). Rapid detection and quantification of U. virens from soils and seeds provide practicable techniques for predicting epidemic risks and assessing U. virens distribution in the fields (Chen et al 2014;Yang et al 2018).…”