Review: Rice Blast Disease

Abstract

Rice blast caused by Magnaporthe grisea is the major damaging disease in nearly all rice growing nations. Economically relevance with 60 percent of total population of world depending on rice as the main source of calories, may have destructive effects of the disease, however, this pathogen has developed into a pioneering model system for researching host-pathogen interactions. The disease outbreak depends on the weather and climatic conditions of the various regions. The disease's occurrence and symptoms vary from country to country. Susceptible cultivars cause huge rice production loss in yield. The principal cause of resistance breakdown in rice against rice blast disease is pathogenic variability. During sexual hybridization, pathogenic changes may provide evidence of pathogenic variation found at the asexual stage of the fungus. The virulent pathotypes cause severe disease incidence. Only through pathogenicity research the pathotypes can be determined using a collection of different rice varieties that are usually different carrying various resistance genes. Rice breeders now have a number of resistant genes however, most of the breeding programs emphasized upon monogenic resistance. Genetic heterogeneity of M. grisea should be taken into account when screening blast resistant rice genotypes through morphological analysis, pathogenicity and molecular characterization. Knowledge on the virulence of the rice blast and host resistant is essential for managing the disease. Cultivation of resistant varieties with chemical control is highly effective against blast pathogens.

Rice Blast Prevalence in Smallholder Rice Farmlands in Uganda

“…Comparable to a study reported by Asfaha, Selvaraj, and Woldeab (2015), at higher altitude blast incidence and severity were lower probably due to low relative humidity that hinders the development of the disease, while at a lower altitude, the temperatures were high and therefore not favorable for spore germination. Reports have also shown that the incidence of rice blast is positively correlated with rainfall and relative humidity, but negatively correlated with temperature (Shahriar, Imtiaz, Hossain, Husna, & Eaty, 2020;Shafaullah, M. A. Khan, N. A. Khan, & Ysir, 2011).…”

Molecular virulence determinants of Magnaporthe oryzae: disease pathogenesis and recent interventions for disease management in rice plant

“…The disease spreads frequently under moist conditions with relative humidity ranging from 80%-100% and temperatures ranging from 25 to 30°C (Talbot 2003). Significant harvest losses have been reported in many rice-growing countries of the South-east Asia (China, Sri Lanka, Indonesia, Bangladesh, India) (Wilson and Talbot 2009;Suprapta and Khalimi 2012;Kumar and Kalita 2017) and also in other regions like South America, Australia, Korea and Philippines (Greer and Webster 2001;Pena et al 2007;Shahriar et al 2020) (Figure 1). In an outbreak of rice blast disease in Malaysia, yield loss caused by panicle blast was as high as 50-70% (Ashkani et al 2015;Zakaria and Misman 2018).…”

Identification of Pyruvate Dehydrogenase E1 as a Potential Target against Magnaporthe oryzae through Experimental and Theoretical Investigation

“…Rice blast, caused by Magnaporthe oryzae , is arguably the most destructive fungal disease of rice [ 2 ]. M. oryzae infects plants at almost all growth stages and reduces rice yield by 10–35% [ 3 ]. It is estimated that the amount of rice destroyed by rice blast disease each year is enough to feed 60 million people [ 4 ].…”