The underground reserve (root) has been an uncharted research territory with its untapped genetic variation yet to be exploited. Identifying ideal traits and breeding new rice varieties with efficient root system architecture (RSA) has great potential to increase resource-use efficiency and grain yield, especially under direct-seeded rice, by adapting to aerobic soil conditions. In this review, we tried to mine the available research information on the direct-seeded rice (DSR) root system to highlight the requirements of different root traits such as root architecture, length, number, density, thickness, diameter, and angle that play a pivotal role in determining the uptake of nutrients and moisture at different stages of plant growth. RSA also faces several stresses, due to excess or deficiency of moisture and nutrients, low or high temperature, or saline conditions. To counteract these hindrances, adaptation in response to stress becomes essential. Candidate genes such as early root growth enhancer PSTOL1, surface rooting QTL qSOR1, deep rooting gene DRO1, and numerous transporters for their respective nutrients and stress-responsive factors have been identified and validated under different circumstances. Identifying the desired QTLs and transporters underlying these traits and then designing an ideal root architecture can help in developing a suitable DSR cultivar and aid in further advancement in this direction.
Phytophagous insects pose a significant threat to global crop yield and food security. The need for increased agricultural output while reducing dependence on harmful synthetic insecticides necessitates the implementation of innovative methods. The utilization of CRISPR-Cas (Clustered regularly interspaced short palindromic repeats) technology to develop insect pest-resistant plants is believed to be a highly effective approach in reducing production expenses and enhancing the profitability of farms. Insect genome research provides vital insights into gene functions, allowing for a better knowledge of insect biology, adaptability, and the development of targeted pest management and disease prevention measures. The CRISPR-Cas gene editing technique has the capability to modify the DNA of insects, either to trigger a gene drive or to overcome their resistance to specific insecticides. The advancements in CRISPR technology and its various applications have shown potential in developing insect-resistant varieties of plants and other strategies for effective pest management through a sustainable approach. This could have significant consequences for ensuring food security. This approach involves using genome editing to create modified insects or crop plants. The article critically analyzed and discussed the potential and challenges associated with exploring and utilizing CRISPR-Cas technology for reducing insect pest pressure in crop plants.
14 September 2022 in International Journal of Environment and Climate Change
Aim: This study aims to find the informative polymorphic Microsatellite (SSR) markers for drought tolerance between the recipient parent (Pratishya) and donor parent (CR Dhan 801) of rice. The drought tolerant QTLs (qDTY1.1, qDTY2.1, and qDTY3.1) from the donor parent were subsequently introgressed into the popular variety Pratikshya via marker-assisted backcross breeding. Place and Duration of Study: The parental polymorphism study was conducted at Molecular Drought Breeding Laboratory, Department of Genetics and Plant Breeding and Central Laboratory, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi; and at Crop Improvement Division, ICAR-NRRI, Cuttack during Rabi 2018-19. Methodology: The parents used for the study were Pratikshya (recurrent parent) and CR Dhan 801 (donor parent). The leaf samples were collected from 20-25 days old seedlings which were used for parental polymorphism survey after DNA extraction. The genomic DNA isolation was done by using CTAB method. A set of 510 SSR markers covering all the 12 chromosomes of rice were used for parental polymorphism survey in the present study. The standard protocol of polymerase chain reaction (PCR) and agarose gel electrophoresis was used. The DNA fragments were documented using gel documentation system. The graphical representation of marker data was obtained with GGT 2.0 software. Results: Out of 510, total 108 SSR primer pairs exhibited polymorphism between recipient parent (Pratikshya) and donor parent (CR Dhan 801) and remaining 392 SSR primers were monomorphic. The highest percentage of parental polymorphism was observed on chromosome 2 (26.53%) and 3 (26.46%) followed by chromosome 1 (23.08%); and least on chromosome number 10 (14.71%). The average per cent of polymorphism on all the 12 chromosomes were 21.28%. Out of 108 polymorphic markers obtained from screening of 510 SSRs, 69 contained dinucleotide repeats, 32 showed trinucleotide repeats and 5 were having tetranucleotide repeats. Conclusion: The screening of markers by parental polymorphism in rice cultivars gives the basis for tagging of the target gene, fine mapping of the gene on the rice chromosome, and subsequent application in Marker Assisted Selection (MAS) programmes. The polymorphic markers identified in this study were be used for genotyping the entire mapping population and for the introgression of the QTLs/genes linked with grain yield during the reproductive stage of drought.
Mungbean is one of the most important grain legumes with high-quality dietary protein in India as well in many other Asian countries. But the crop is severely affected by bruchids (Callosobruchus spp.) from field to storage condition. These storage pests not only affect the yield but also reduce the market value and quality of the crops. The chemical method of bruchid management is not economical and environmentally unsafe. So, the host-plant resistance to bruchids would be the best alternative and most sustainable way to control the bruchid. A very limited number of wild accessions and cultivated genotypes are available for the transfer of bruchid resistance gene through conventional breeding. Thus, insights into the molecular mechanism of resistance will help to find out the resistance genes/QTLs easily with the support of available genome sequence and that can be introgressed to the cultivated varieties through marker-assisted backcross breeding (MABB) approach. Therefore, in this review, we focused on QTL mapping, identification of novel QTLs, marker assisted-selection, genomics and transcriptomics study by using advanced molecular tools which will be very helpful for genomic-assisted breeding in mungbean for bruchid resistance.