Rice production needs to be sustained in the coming decades, as the changeable climatic conditions are becoming more conducive to disease outbreaks. The majority of rice diseases cause enormous economic damage and yield instability. Among them, rice blast caused by Magnaportheoryzae is a serious fungal disease and is considered one of the major threats to world rice production. This pathogen can infect the above-ground tissues of rice plants at any growth stage and causes complete crop failure under favorable conditions. Therefore, management of blast disease is essentially required to sustain global food production. When looking at the drawback of chemical management strategy, the development of durable, resistant varieties is one of the most sustainable, economic, and environment-friendly approaches to counter the outbreaks of rice blasts. Interestingly, several blast-resistant rice cultivars have been developed with the help of breeding and biotechnological methods. In addition, 146 R genes have been identified, and 37 among them have been molecularly characterized to date. Further, more than 500 loci have been identified for blast resistance which enhances the resources for developing blast resistance through marker-assisted selection (MAS), marker-assisted backcross breeding (MABB), and genome editing tools. Apart from these, a better understanding of rice blast pathogens, the infection process of the pathogen, and the genetics of the immune response of the host plant are very important for the effective management of the blast disease. Further, high throughput phenotyping and disease screening protocols have played significant roles in easy comprehension of the mechanism of disease spread. The present review critically emphasizes the pathogenesis, pathogenomics, screening techniques, traditional and molecular breeding approaches, and transgenic and genome editing tools to develop a broad spectrum and durable resistance against blast disease in rice. The updated and comprehensive information presented in this review would be definitely helpful for the researchers, breeders, and students in the planning and execution of a resistance breeding program in rice against this pathogen.

Mutation breeding is a simple and effective technique for generating genetic variation within crops. Mutagens such as Gamma radiation induce changes in their DNA that could lead to the development of new traits, such as improved yield or disease resistance. In the present study, Gamma ray mutagenesis was performed on three traditional rice varieties (Gudma dhan, Dawar dhan, and Lohandi dhan) to identify potentially beneficial mutants with desirable agro-morphological agricultural characteristics. The major constraints to address were their tall statures and weak culms, fewer panicles and tillers, and late maturity. Using a fixed dose of 300 Gy, 35 mutants were identified in Dawar dhan, 33 in Gudma dhan, and 21 in Lohandi dhan. The selected mutants showed an average reduction in plant height that ranged from 42.69% to 33.11%, as compared to their respective landraces. Also, a substantial reduction (ranging from 3.08%-10.55%) in days to 50% flowering was observed. Importantly, these mutants showed an increase in yield of 38.11% (Dawar dhan), 32.63% (Gudma dhan), and 7.0% (Lohandi dhan). These findings demonstrate the utility of mutation breeding through Gamma radiation in alleviating the key constraints inherent to traditional rice landraces.

Chia (Salvia hispanica L.) is an immensely valuable crop with high market value and countless healthy properties. Despite of being a super food crop only a few studies have been carried out for understanding the genetic factors and inheritance pattern in this crop. Therefore, the ongoing experiment was conducted to study genetic divergence and heritability for seed yield, oil content and other ancillary traits in chia with 26 genotypes. Analysis of variance acknowledged noteworthy variations for all the traits under investigation, except for days to maturity. High heritability_(bs) along with high genetic advance for number of inflorescence per plant, oil content and seed yield per plant implied that these characters were highly heritable. The study of genetic divergence provided a quantitative measure of diversity and grouped the genotypes into six clusters. Traits like number of inflorescence per plant, seed yield per plant and test weight were amongst the highest contributors in the vicinity of genetic divergence while maximum inter and intra cluster distance was present between cluster IV and VI, and in cluster II, respectively.