Sheath blight caused by necrotrophic fungus Rhizoctonia solani Kühn is one of the most serious diseases of rice. Use of high yielding semi dwarf cultivars with dense planting and high dose of nitrogenous fertilizers accentuates the incidence of sheath blight in rice. Its diverse host range and ability to remain dormant under unfavorable conditions make the pathogen more difficult to manage. As there are no sources of complete resistance, management through chemical control has been the most adopted method for sheath blight management. In this review, we provide an up-to-date comprehensive description of host-pathogen interactions, various control measures such as cultural, chemical, and biological as well as utilizing host plant resistance. The section on utilizing host plant resistance includes identification of resistant sources, mapping QTLs and their validation, identification of candidate gene(s) and their introgression through marker-assisted selection. Advances and prospects of sheath blight management through biotechnological approaches such as overexpression of genes and gene silencing for transgenic development against R. solani are also discussed.

How dreadful a virus may be -this has been well understood across the globe during the COVID-19 pandemic. Viruses pose a serious threat not only to mankind but also to agriculture by infecting several economically important crops such as rice, wheat, corn, cotton, and vegetables. Conventional methods will not be able to control these quickly evolving and emerging plant viruses. Present-day genome-editing techniques have emerged as promising tools to introduce desirable traits in target crop plant. The two major antiviral strategies, RNA silencing and genome editing have been vividly discussed in this review article. RNA silencing strategy has been utilized in antiviral breeding for more than three decades. Many crops engineered to stably express small RNAs targeting various viruses have been approved for commercial release. Among these technologies, the CRISPR/Cas9 system has gained more popularity by virtue of its simplicity, efficiency and reproducibility. CRISPR/Cas9 have been exploited to engineer plant virus resistance, either by directly targeting and cleaving the viral genome, or by modifying the host plant genome to introduce viral immunity. Here, we describe the biology of the CRISPR/Cas9 system and plant viruses, and how this genome engineering tool has been used to target the devastating plant viruses.

Using traditional methods and methodologies, plant breeding has been very effective in producing improved varieties. Nowadays, the availability of genomic tools and resources leads to a new plant breeding revolution as they promote the study of the genotype and its relationship with the phenotype, particularly for complex traits. Genomics (coined in 1986 by Tom Roderick) is an interdisciplinary research field that focuses on the study of any organism's genome. Genomics field revolves around gene analysis and gene working. It is generally classified as structural genomics, functional genomics, comparative genomics, epigenomics, translational genomics and pharmacogenomics. Functional genomics links the organism's genome to its function and phenotype. It could be further subdivided into proteomics, transcriptomics and metabolomics and could be studied by reverse genomic techniques like RNAi and mutagenesis. Genomics or decoding the plant genome sequence using high throughput techniques will allow scientific community to access agronomically important genes and will speed up the breeding programs for the development of superior varieties with higher yield and stress tolerance.

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