Increases in rice productivity are significantly hampered because of the increase in the occurrence of abiotic stresses, including drought, salinity, and submergence. Developing a rice variety with inherent tolerance against these major abiotic stresses will help achieve a sustained increase in rice production under unfavorable conditions. The present study was conducted to develop abiotic stress-tolerant rice genotypes in the genetic background of the popular rice variety Improved White Ponni (IWP) by introgressing major effect quantitative trait loci (QTLs) conferring tolerance against drought (qDTY 1.1 , qDTY 2.1), salinity (Saltol), and submergence (Sub1) through a marker assisted backcross breeding approach. Genotyping of early generation backcrossed inbred lines (BILs) resulted in the identification of three progenies, 3-11-9-2, 3-11-11-1, and 3-11-11-2, possessing all four target QTLs and maximum recovery of the recurrent parent genome (88.46%). BILs exhibited consistent agronomic and grain quality characters compared to those of IWP and enhanced performance against dehydration, salinity, and submergence stress compared with the recurrent parent IWP. BILs exhibited enhanced tolerance against salinity during germination and increased shoot length, root length, and vigor index compared to those of IWP. All three BILs exhibited reduced symptoms of injury because of salinity (NaCl) and dehydration (PEG) than did IWP. At 12 days of submergence stress, BILs exhibited enhanced survival and greater recovery, whereas IWP failed completely. BILs were found to exhibit on par grain and cooking quality characteristics with their parents. Results of this study clearly demonstrated the effects of the target QTLs in reducing damage caused by drought, salinity, and submergence and lead to the development of a triple stress tolerant version of IWP.

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Horticultural crops produce a wide range of useful goods for humans. There has been an increase in research focus on horticulture crop enhancement, particularly in terms of production and quality. The use of genome editing to enhance horticulture crops has seen a sharp rise in recent years due to the advancement and benefits of genome-editing technology. Here, we provide a brief overview of the various genome-editing techniques applied in horticulture research, with a particular emphasis on CRISPR/CRISPR-associated 9 (Cas9)-mediated genome editing. We also provide an overview of recent developments in the use of genome editing to enhance horticulture crops. Breeding and the rapidly growing field of genome editing will significantly boost the quantity and quality of horticulture crops.

Rice is one of the major cereal food crops whose production has to be doubled to achieve the projected demand [1] and current yield trends are not sufficient to meet the projected growth in production. Increasing the rice production by 30% during 2030 needs overcoming challenges viz., yield plateau, declining land, water and labor resources and predicted effects of global climate change. Development of high performance rice genotypes with enhanced yield potential and resilience to climate change will help in sustained increase in rice production. Deployment of genomic technologies can accelerate development and delivery of improved germplasm with enhanced resilience and adaptability [2,3]. In this context, the present study was undertaken with an aim of developing rice genotypes pyramided with QTLs/genes controlling tolerance against various biotic and abiotic stresses viz., bacterial leaf blight (xa13, Xa21), blast (Pi9), Gall midge (Gm4), drought (qDTY1.1 qDTY2.1), submergence (Sub1) and salinity (Saltol)). CBMAS14065 an elite culture harboring QTLs controlling tolerance against drought, salinity and submergence was crossed with a donor harboring BLB, Blast and Gall midge resistant genes. True F 1 s were backcrossed with CBMAS14065 and BC 1 F 1 progenies were subjected to foreground selection using markers linked to the target traits. Superior plants (18) of BC 1 F 1 generation were subjected to background selection which revealed 71.42 -86.90% recurrent parent (CBMAS14065) genome recovery. Selected BC 1 F 1 plants were advanced to BC 2 F 1 generation backcrossing with CBMAS14065. In BC 2 F 1 generation, through foreground selection 6-8 QTL/gene positive plants have been selected and advanced for further evaluation. The superior lines with desired QTLs/genes will be subjected to rigorous phenotypic evaluation against target stresses and advanced further.