Conventional Breeding Techniques Research Articles

Recent Advancements in Mitigating Abiotic Stresses in Crops

In recent years, the progressive escalation of climate change scenarios has emerged as a significant global concern. The threat to global food security posed by abiotic stresses such as drought, salinity, waterlogging, temperature stress (heat stress, freezing, and chilling), and high heavy metal accumulation is substantial. The implementation of any of these stresses on agricultural land induces modifications in the morphological, biochemical, and physiological processes of plants, leading to diminished rates of germination, growth, photosynthesis, respiration, hormone and enzyme activity disruption, heightened oxidative stress, and ultimately, a reduction in crop productivity. It is anticipated that the frequency of these stresses will progressively escalate in the future as a result of a rise in climate change events. Therefore, it is crucial to develop productive strategies to mitigate the adverse effects of these challenges on the agriculture industry and improve crop resilience and yield. Diverse strategies have been implemented, including the development of cultivars that are resistant to climate change through the application of both conventional and modern breeding techniques. An additional application of the prospective and emerging technology of speed breeding is the acceleration of tolerance cultivar development. Additionally, plant growth regulators, osmoprotectants, nutrient and water management, planting time, seed priming, microbial seed treatment, and arbuscular mycorrhiza are regarded as effective methods for mitigating abiotic stresses. The application of biochar, kaolin, chitosan, superabsorbent, yeast extract, and seaweed extract are examples of promising and environmentally benign agronomic techniques that have been shown to mitigate the effects of abiotic stresses on crops; however, their exact mechanisms are still not yet fully understood. Hence, collaboration among researchers should be intensified to fully elucidate the mechanisms involved in the action of the emerging technologies. This review provides a comprehensive and current compilation of scientific information on emerging and current trends, along with innovative strategies to enhance agricultural productivity under abiotic stress conditions.

Generation of major glutelin-deficient (GluA, GluB, and GluC) semi-dwarf Koshihikari rice line.

We generated a new Koshihikari rice line with a drastically reduced content of glutelin proteins and higher lodging resistance by using new and conventional plant breeding techniques. Using CRISPR/Cas9-mediated genome editing, we generated mutant rice with drastically decreased contents of major glutelins. A Koshihikari rice mutant line, a123, lacking four glutelins (GluA1, GluA2, GluB4, and GluB5) was used as a host, and another five major glutelin genes (GluA3, GluB1a, GluB1b, GluB2, and GluC) were knocked out through two iterations of Agrobacterium-mediated transformation. Mutant seeds were deficient in the GluA family, GluB family, and GluC, and the line obtained was named GluABC KO. Glutelin content was much lower in GluABC KO than in the existing low-glutelin rice mutant LGC-1. A null segregant of GluABC KO was selected using new-generation sequencing and backcrossing, and the sd-1 allele for the semi-dwarf trait was introduced to increase lodging resistance.

Breeding approaches for improvement of temperate fruit crops and nuts - a review

Fruit breeding is an ancient technology with dynamic current technology and an exciting future (Janick and Moore, 1975, 1996).  In its broadest sense, fruit breeding refers to the purposeful genetic improvement of fruit crops through various techniques including selection, hybridization, mutation induction, and molecular techniques. Its origins trace to the domestication process in prehistory and antiquity, where useful species were chosen and cultivated, and improved by continuous selection (Janick, 2005, 2011). Much of the world fruit industry is still based on grower selection from chance seedlings as well as mutations (sports) and as a result many fruit species are characterized by a narrow germplasm base. Spontaneous hybridization between wild plants and cultivated clones was critical to the early domestication of fruits. The lengthy juvenile period and the large field space required to grow temperate fruits have imposed major limitations on conventional breeding and various molecular biological techniques have been employed to make fruit breeding easier. (Igarashi et al.2016). Marker-assisted selection (MAS) uses DNA markers to provide an early DNA-based evaluation of genetic performance potential of seedlings, with the aim of improving cost and/or genetic efficiency of seedling selection (Ru, et al., 2015). Transgenic technology has facilitated the development of fruit trees with resistance to fungal or bacterial diseases, improved fruit quality, or root stocks with better rooting or dwarfing ability. In recent years, new technologies for genetic improvement, such as transgrafting, and genome-editing, have emerged. (Mudge, et al. 2009; Jia and Wang 2014). Using these techniques, no foreign genes are present in the final product, and some of them show considerable promise for application to apple breeding. Furthermore, genome editing, by which only the target gene can be accurately modified, is emerging as a novel breeding technology. These new technologies will undoubtedly facilitate fruit breeding, and yield novel and attractive fruit cultivars.

Phenotyping, genetics, and "-omics" approaches to unravel and introgress enhanced resistance against apple scab (Venturia inaequalis) in apple cultivars (Malus × domestica).

Apple scab disease, caused by the fungus Venturia inaequalis, endangers commercial apple production globally. It is predominantly managed by frequent fungicide sprays that can harm the environment and promote the development of fungicide-resistant strains. Cultivation of scab-resistant cultivars harboring diverse qualitative Rvi resistance loci and quantitative trait loci associated with scab resistance could reduce the chemical footprint. A comprehensive understanding of the host-pathogen interaction is, however, needed to efficiently breed cultivars with enhanced resistance against a variety of pathogenic strains. Breeding efforts should not only encompass pyramiding of Rvi loci and their corresponding resistance alleles that directly or indirectly recognize pathogen effectors, but should also integrate genes that contribute to effective downstream defense mechanisms. This review provides an overview of the phenotypic and genetic aspects of apple scab resistance, and currently known corresponding defense mechanisms. Implementation of recent "-omics" approaches has provided insights into the complex network of physiological, molecular, and signaling processes that occur before and upon scab infection, thereby revealing the importance of both constitutive and induced defense mechanisms. Based on the current knowledge, we outline advances toward more efficient introgression of enhanced scab resistance into novel apple cultivars by conventional breeding or genetic modification techniques. However, additional studies integrating different "-omics" approaches combined with functional studies will be necessary to unravel effective defense mechanisms as well as key regulatory genes underpinning scab resistance in apple. This crucial information will set the stage for successful knowledge-based breeding for enhanced scab resistance.

EXPLORING THE RESPONSE MECHANISMS OF RICE TO SALINITY STRESS

The world's agricultural productivity has been on the decline due to salinity, which is a significant abiotic element. To find a solution to this problem, researchers have been concentrating their efforts on the enzymes and biochemical pathways involved in salt tolerance. The ultimate objective is to develop crops that are resistant to salt. Developments in molecular biology have facilitated the production of salt-tolerant cultivars by conventional breeding techniques. A significant amount of salt can inhibit the growth of rice (Oryza sativa L.), a major food crop in many nations. This is especially true during the early stages of plant development. Rice's physiological, molecular, and biochemical reactions to excessive salinity have been the subject of significant exploration and investigation. The possible applications and implications of salinity tolerance are also discussed in this article, as well as the approaches that can be used to locate plants that are tolerant of salt.

Genetic Databases and Gene Editing Tools for Enhancing Crop Resistance against Abiotic Stress.

Abiotic stresses extensively reduce agricultural crop production globally. Traditional breeding technology has been the fundamental approach used to cope with abiotic stresses. The development of gene editing technology for modifying genes responsible for the stresses and the related genetic networks has established the foundation for sustainable agriculture against environmental stress. Integrated approaches based on functional genomics and transcriptomics are now expanding the opportunities to elucidate the molecular mechanisms underlying abiotic stress responses. This review summarizes some of the features and weblinks of plant genome databases related to abiotic stress genes utilized for improving crops. The gene-editing tool based on clustered, regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) has revolutionized stress tolerance research due to its simplicity, versatility, adaptability, flexibility, and broader applications. However, off-target and low cleavage efficiency hinder the successful application of CRISPR/Cas systems. Computational tools have been developed for designing highly competent gRNA with better cleavage efficiency. This powerful genome editing tool offers tremendous crop improvement opportunities, overcoming conventional breeding techniques' shortcomings. Furthermore, we also discuss the mechanistic insights of the CRISPR/Cas9-based genome editing technology. This review focused on the current advances in understanding plant species' abiotic stress response mechanism and applying the CRISPR/Cas system genome editing technology to develop crop resilience against drought, salinity, temperature, heavy metals, and herbicides.

Engineering Drought Tolerance in Crops Using CRISPR Cas systems

Drought stress is one of the most considerable threats to global agricultural food security, causing yield losses worldwide. Therefore, the search for effective genetic and molecular methods for developing cultivars that are tolerant or resistant to harsh environments has been more intensive over the last decades. Apart from time-consuming conventional breeding techniques, biotechnologists are now investigating modern genome editing tools for engineering tolerance and resistance to various biotic and abiotic stresses in crops. Various genetic engineering techniques such as zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) were developed based on the discovery of the DNA structure. However, these methods have limitations, with ZFNs being prone to errors due to their limited base pair recognition, and TALENs requiring a complex protein engineering process and struggling to cleave methylated DNA. In recent years, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) and its alternatives have gained popularity in plant biotechnology. Out of the genome editing techniques mentioned earlier, CRISPR/Cas9 is becoming more popular because it's faster and easier to use. Given that drought is now a significant threat to global agriculture due to the drying of arable lands, this review focuses on how we can use CRISPR genome editing to enhance crop tolerance to drought stress and explores its future potential.

Fatty acid composition and genome-wide associations of a chickpea (Cicer arietinum L.) diversity panel for biofortification efforts

Chickpea is a nutritionally dense pulse crop with high levels of protein, carbohydrates, micronutrients and low levels of fats. Chickpea fatty acids are associated with a reduced risk of obesity, blood cholesterol, and cardiovascular diseases in humans. We measured four primary chickpea fatty acids; palmitic acid (PA), linoleic acid (LA), alpha-linolenic acid (ALA), and oleic acid (OA), which are crucial for human health and plant stress responses in a chickpea diversity panel with 256 accessions (Kabuli and desi types). A wide concentration range was found for PA (450.7–912.6 mg/100 g), LA (1605.7–3459.9 mg/100 g), ALA (416.4–864.5 mg/100 g), and OA (1035.5–1907.2 mg/100 g). The percent recommended daily allowances also varied for PA (3.3–6.8%), LA (21.4–46.1%), ALA (34.7–72%), and OA (4.3–7.9%). Weak correlations were found among fatty acids. Genome-wide association studies (GWAS) were conducted using genotyping-by-sequencing data. Five significant single nucleotide polymorphisms (SNPs) were identified for PA. Admixture population structure analysis revealed seven subpopulations based on ancestral diversity in this panel. This is the first reported study to characterize fatty acid profiles across a chickpea diversity panel and perform GWAS to detect associations between genetic markers and concentrations of selected fatty acids. These findings demonstrate biofortification of chickpea fatty acids is possible using conventional and genomic breeding techniques, to develop superior cultivars with better fatty acid profiles for improved human health and plant stress responses.

Profiling Genetic Breeding Progress in Bagrid Catfishes

The Bagridae fish family holds significant economic value and enjoys a high demand in the commercial market due to its desirable characteristics, such as delicious meat, fewer muscle spines, and a pleasing flavor. In recent years, the Bagridae has experienced rapid development in the seed industry in response to industry demands. Researchers have conducted extensive studies on genetic breeding in the Bagridae, employing a comprehensive breeding approach that combines conventional breeding techniques with innovative new technologies and cooperative efforts. In this review, we present an overview of the market situation and discuss various breeding processes applied to the Bagridae, including selective breeding, genetic engineering breeding, cell engineering breeding, molecular marker-assisted breeding, and hybrid breeding. Additionally, we focus on introducing the cultivation methods for two new Bagridae varieties. Furthermore, we explore and summarize the breeding conditions, genetic background, heterosis, comprehensive breeding technology, stress resistance, and metabolic nutrition of hybrid Bagridae catfishes. Overall, noticeable heterosis has been observed in the breeding of the hybrid yellow catfish “Huangyou-1”, which exhibits promising market prospects and economic benefits for aquaculture. Our study aims to underscore the importance of harnessing the heterosis of catfish, particularly the Pelteobagrus and Bagridae species. Consequently, this review provides an update on the current available information regarding the seed industry of the Bagridae fish family.

Co-expression of multi-gene in cotton promotes the aggregation of multi-resistance and yield traits

Given the diminishing availability of cultivable lands and environmental degration, it has become imperative to develop cotton varieties that possess resistance against diverse abiotic and biotic stresses, and improved yields. However, conventional breeding techniques such as crossbreeding has proven to be inefficient and time-consuming for generating novel varieties. Transgenic breeding technology offers advantages such as shortened breeding cycle, overcoming reproductive isolation, and precise integration of single or multiple genes into host plants. In this study, we incorporated six genes including the apoptosis inhibitors p35 and IAP, high yield related gene Bn-cs RRM2, drought resistance gene HDG11, glyphosate resistance gene EPSPS, and insect resistance gene Cry1AC into the pBI121 vector, which was then transformed into cotton plants via Agrobacterium-mediated transformation. The overexpression of these genes significantly enhanced plant tolerance to Verticillium wilt, drought, glyphosate, and cotton bollworm, along with high yields in field conditions. Our results suggested that the integration of multiple genes in cotton is a potential strategy for breeding cotton varieties with broad resistance traits.

Molecular insights on the origin and development of waxy genotypes in major crop plants

Abstract Starch is a significant ingredient of the seed endosperm with commercial importance in food and industry. Crop varieties with glutinous (waxy) grain characteristics, i.e. starch with high amylopectin and low amylose, hold longstanding cultural importance in some world regions and unique properties for industrial manufacture. The waxy character in many crop species is regulated by a single gene known as GBSSI (or waxy), which encodes the enzyme Granule Bound Starch Synthase1 with null or reduced activity. Several allelic variants of the waxy gene that contribute to varying levels of amylose content have been reported in different crop plants. Phylogenetic analysis of protein sequences and the genomic DNA encoding GBSSI of major cereals and recently sequenced millets and pseudo-cereals have shown that GBSSI orthologs form distinct clusters, each representing a separate crop lineage. With the rapidly increasing demand for waxy starch in food and non-food applications, conventional crop breeding techniques and modern crop improvement technologies such as gene silencing and genome editing have been deployed to develop new waxy crop cultivars. The advances in research on waxy alleles across different crops have unveiled new possibilities for modifying the synthesis of amylose and amylopectin starch, leading to the potential creation of customized crops in the future. This article presents molecular lines of evidence on the emergence of waxy genes in various crops, including their genesis and evolution, molecular structure, comparative analysis and breeding innovations.

Recent Developments in CRISPR/Cas9 Genome-Editing Technology Related to Plant Disease Resistance and Abiotic Stress Tolerance.

The revolutionary CRISPR/Cas9 genome-editing technology has emerged as a powerful tool for plant improvement, offering unprecedented precision and efficiency in making targeted gene modifications. This powerful and practical approach to genome editing offers tremendous opportunities for crop improvement, surpassing the capabilities of conventional breeding techniques. This article provides an overview of recent advancements and challenges associated with the application of CRISPR/Cas9 in plant improvement. The potential of CRISPR/Cas9 in terms of developing crops with enhanced resistance to biotic and abiotic stresses is highlighted, with examples of genes edited to confer disease resistance, drought tolerance, salt tolerance, and cold tolerance. Here, we also discuss the importance of off-target effects and the efforts made to mitigate them, including the use of shorter single-guide RNAs and dual Cas9 nickases. Furthermore, alternative delivery methods, such as protein- and RNA-based approaches, are explored, and they could potentially avoid the integration of foreign DNA into the plant genome, thus alleviating concerns related to genetically modified organisms (GMOs). We emphasize the significance of CRISPR/Cas9 in accelerating crop breeding processes, reducing editing time and costs, and enabling the introduction of desired traits at the nucleotide level. As the field of genome editing continues to evolve, it is anticipated that CRISPR/Cas9 will remain a prominent tool for crop improvement, disease resistance, and adaptation to challenging environmental conditions.

BARKAT: A NEW HIGH FODDER YIELDING OAT (AVENA SATIVA L.) VARIETY WITH BETTER NUTRITIONAL VALUE

Oats are utilized primarily as feed for domestic animals and is also fourth most important cereal crop of the world. The Fodder Research Center, Sargodha, used conventional breeding techniques to generate the general cultivar "Barkat" of oat (Avena sativa L.). It will be launched in 2021. The "FRI-01" commercial cultivar is a highly uniform off spring of the crosses between parental accessions (No. 970 and No. 288) and subsequent selections in multiple segregating populations (F2 through F6) using pedigree procedures. The cultivar outperformed the commercial check "Sargodha-Oat 2011" by 10% and 12.76% in forage yield during 2014-2015 and 2015-2016 station trials, respectively, and by 13.32% in fodder yield during 2016-17 at the zonal level. It is a late-maturing green cultivar that produces light brown seed and has a tall, multi-tillering plant form. It gave 7.13% higher fodder yield during 2017-18 and 22.38% increase over check variety during 2018-19 in national trials. Forage qualities include high palatability (85%), protein content (10.6%), and tolerance to biotic and abiotic stresses. The flowers bloom roughly ten days after the reference variety. Barkat (FRI-01) sown on 1st October and 15th October gave highest fodder yield in comparison with other tested sowing dates while maximum green fodder yield 87 ton ha-1 at 80 kg per ha seed rate and 30 cm row spacing. Barkat (FRI-01) will be extremely valuable cultivars in both irrigated and desert region of Punjab Province due to its high yield, great palatability, higher protein contents than standard check, and tolerance to biotic and abiotic stress. Also, the cultivar can serve as a parental line in future efforts to enhance oat genetics.

Moth bean (Vigna aconitifolia): a minor legume with major potential to address global agricultural challenges.

Moth bean (Vigna aconitifolia) is an orphan legume of Vigna genus, exhibiting wide adaptability and has the potential to grow well in arid and semi-arid areas, predominantly across different eco-geographical regions of Asia, particularly the Indian subcontinent. The inherent adaptive attributes of this crop have made it more tolerant towards a diverse array of abiotic and biotic stresses that commonly restrain yield among other Vigna species. Additionally, the legume is recognized for its superior nutritional quality owing to its high protein content as well as amino acid, mineral and vitamin profile and is utilized as both food and fodder. Moth bean can play a vital role in sustaining food grain production, enhancing nutritional security as well as provide a source of income to resource-poor farmers amid rise in global temperatures and frequent drought occurrences, particularly in rain-fed cropping systems which accounts for about 80% of the world's cultivated land. However, this minor legume has remained underutilized due to over-exploitation of major staple crops. With the exception of a few studies involving conventional breeding techniques, crop improvement in moth bean for traits such as late maturity, indeterminate growth habit, shattering and anti-nutritional factors has not garnered a lot of attention. Recent advances in sequencing technologies, modern breeding approaches and precision phenotyping tools, in combination with the available crop gene pool diversity in gene banks, can accelerate crop improvement in moth bean and lead to the development of improved cultivars. Considering the recent surge in awareness about the development of climate-smart crops for sustainable agricultural future, collective effort towards effective utilization of this hardy, neglected legume is the need of the hour.

Application progress of CRISPR/Cas9 genome-editing technology in edible fungi.

Edible fungi are not only delicious but are also rich in nutritional and medicinal value, which is highly sought after by consumers. As the edible fungi industry continues to rapidly advance worldwide, particularly in China, the cultivation of superior and innovative edible fungi strains has become increasingly pivotal. Nevertheless, conventional breeding techniques for edible fungi can be arduous and time-consuming. CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9) is a powerful tool for molecular breeding due to its ability to mediate high-efficiency and high-precision genome modification, which has been successfully applied to many kinds of edible fungi. In this review, we briefly summarized the working mechanism of the CRISPR/Cas9 system and highlighted the application progress of CRISPR/Cas9-mediated genome-editing technology in edible fungi, including Agaricus bisporus, Ganoderma lucidum, Flammulina filiformis, Ustilago maydis, Pleurotus eryngii, Pleurotus ostreatus, Coprinopsis cinerea, Schizophyllum commune, Cordyceps militaris, and Shiraia bambusicola. Additionally, we discussed the limitations and challenges encountered using CRISPR/Cas9 technology in edible fungi and provided potential solutions. Finally, the applications of CRISPR/Cas9 system for molecular breeding of edible fungi in the future are explored.

Molecular and biochemical characterization of rice developed through conventional integration of nDart1-0 transposon gene

Mutations, the genetic variations in genomic sequences, play an important role in molecular biology and biotechnology. During DNA replication or meiosis, one of the mutations is transposons or jumping genes. An indigenous transposon nDart1-0 was successfully introduced into local indica cultivar Basmati-370 from transposon-tagged line viz., GR-7895 (japonica genotype) through conventional breeding technique, successive backcrossing. Plants from segregating populationsshowed variegated phenotypes were tagged as BM-37 mutants. Blast analysis of the sequence data revealed that the GTP-binding protein, located on the BAC clone OJ1781_H11 of chromosome 5, contained an insertion of DNA transposon nDart1-0. The nDart1-0 has “A” at position 254 bp, whereas nDart1 homologs have “G”, which efficiently distinguishes nDart1-0 from its homologs. The histological analysis revealed that the chloroplast of mesophyll cells in BM-37 was disrupted with reduction in size of starch granules and higher number of osmophillic plastoglobuli, which resulted in decreased chlorophyll contents and carotenoids, gas exchange parameters (Pn, g, E, Ci), and reduced expression level of genes associated with chlorophyll biosynthesis, photosynthesis and chloroplast development. Along with the rise of GTP protein, the salicylic acid (SA) and gibberellic acid (GA) and antioxidant contents(SOD) and MDA levels significantly enhanced, while, the cytokinins (CK), ascorbate peroxidase (APX), catalase (CAT), total flavanoid contents (TFC) and total phenolic contents (TPC) significantly reduced in BM-37 mutant plants as compared with WT plants. These results support the notion that GTP-binding proteins influence the process underlying chloroplast formation. Therefore, it is anticipated that to combat biotic or abiotic stress conditions, the nDart1-0 tagged mutant (BM-37) of Basmati-370 would be beneficial.

Intelligent reprogramming of wheat for enhancement of fungal and nematode disease resistance using advanced molecular techniques.

Wheat (Triticum aestivum L.) diseases are major factors responsible for substantial yield losses worldwide, which affect global food security. For a long time, plant breeders have been struggling to improve wheat resistance against major diseases by selection and conventional breeding techniques. Therefore, this review was conducted to shed light on various gaps in the available literature and to reveal the most promising criteria for disease resistance in wheat. However, novel techniques for molecular breeding in the past few decades have been very fruitful for developing broad-spectrum disease resistance and other important traits in wheat. Many types of molecular markers such as SCAR, RAPD, SSR, SSLP, RFLP, SNP, and DArT, etc., have been reported for resistance against wheat pathogens. This article summarizes various insightful molecular markers involved in wheat improvement for resistance to major diseases through diverse breeding programs. Moreover, this review highlights the applications of marker assisted selection (MAS), quantitative trait loci (QTL), genome wide association studies (GWAS) and the CRISPR/Cas-9 system for developing disease resistance against most important wheat diseases. We also reviewed all reported mapped QTLs for bunts, rusts, smuts, and nematode diseases of wheat. Furthermore, we have also proposed how the CRISPR/Cas-9 system and GWAS can assist breeders in the future for the genetic improvement of wheat. If these molecular approaches are used successfully in the future, they can be a significant step toward expanding food production in wheat crops.

Transgene-Free Genome Editing for Biotic and Abiotic Stress Resistance in Sugarcane: Prospects and Challenges

Sugarcane (Saccharum spp.) is one of the most valuable food and industrial crops. Its production is constrained due to major biotic (fungi, bacteria, viruses and insect pests) and abiotic (drought, salt, cold/heat, water logging and heavy metals) stresses. The ever-increasing demand for sugar and biofuel and the rise of new pest and disease variants call for the use of innovative technologies to speed up the sugarcane genetic improvement process. Developing new cultivars through conventional breeding techniques requires much time and resources. The advent of CRISPR/Cas genome editing technology enables the creation of new cultivars with improved resistance/tolerance to various biotic and abiotic stresses. The presence of genome editing cassette inside the genome of genome-edited plants hinders commercial exploitation due to regulatory issues. However, this limitation can be overcome by using transgene-free genome editing techniques. Transgene-free genome editing approaches, such as delivery of the RNPs through biolistics or protoplast fusion, virus-induced genome editing (VIGE), transient expression of CRISPR/Cas reagents through Agrobacterium-mediated transformation and other approaches, are discussed. A well-established PCR-based assay and advanced screening systems such as visual marker system and Transgene killer CRISPR system (TKC) rapidly identify transgene-free genome edits. These advancements in CRISPR/Cas technology speed up the creation of genome-edited climate-smart cultivars that combat various biotic and abiotic stresses and produce good yields under ever-changing conditions.

Breeding Approaches for Quality Improvement in Fruit Crops: Strategies and Achievements

As we know that fruit plays important role in the daily human diet for healthy living and is also a commercial commodity in trade and processing industries. The primary factor that customers use to determine whether or not a fruit is acceptable is its quality like appearance, shape, size, colour and taste, etc. Success in a breeding program depends upon the overall acceptability of fruit quality because most of the developed varieties having desired traits like resistance to biotic and abiotic stresses could not be commercialized and are not in commercial cultivation owing to their poor-quality traits. Therefore, the development of cultivars with desirable quality attributes in fruit crops is challenging. Quality improvement in fruit crops is restricted by several factors such as long juvenility, tall stature, environmental stress and high heterozygosity. Quality traits in fruit crops are polygenic and governed by many genes which makesit difficult to improve particular desirable traits. Many attempts have been made to enhance the qualitative characteristics of annual crops, although perennial fruit crops neatly overlook this issue. Accordingly, the use of both combined conventional and modern breeding techniques could in overcoming these problems. Biotechnological and molecular approaches like marker-assisted selection, transgenics, genomic editing, genomics cis-genics and candidate gene offer precision and reliability to reduce the breeding cycle and are also advantageous when dealing with tedious fruit crops. The challenges with fruit breeding and the state of various breeding techniques for enhancing fruit quality in fruit trees will be the main topics of this review.

Plant breeding advancements with "CRISPR-Cas" genome editing technologies will assist future food security.

Genome editing techniques are being used to modify plant breeding, which might increase food production sustainably by 2050. A product made feasible by genome editing is becoming better known, because of looser regulation and widespread acceptance. The world's population and food supply would never have increased proportionally under current farming practices. The development of plants and food production has been greatly impacted by global warming and climate change. Therefore, minimizing these effects is crucial for agricultural production that is sustainable. Crops are becoming more resilient to abiotic stress because of sophisticated agricultural practices and a better understanding of the abiotic stress response mechanism. Both conventional and molecular breeding techniques have been used to create viable crop types both processes are time-consuming. Recently, plant breeders have shown an interest in genome editing approaches for genetic manipulation that use clustered regularly interspaced short palindromic repeats (CRISPR/Cas9). To ensure the security of the food supply in the future, plant kinds with desired traits must be developed. A completely new era in plant breeding has begun because of the revolution in genome editing techniques based on the CRISPR/CRISPR-associated nuclease (Cas9) systems. All plants may effectively target a particular gene or group of loci using Cas9 and single-guide RNA (sgRNA). CRISPR/Cas9 can thereby save time and labor compared to conventional breeding methods. An easy, quick, and efficient method for directly altering the genetic sequences in cells is with the CRISPR and Cas9 systems. The CRISPR-Cas9 system, which was developed from components of the earliest known bacterial immune system, allows for targeted gene breakage and gene editing in a variety of cells/RNA sequences to guide endonuclease cleavage specificity in the CRISPR-Cas9 system. Editing can be directed to practically any genomic site by altering the guide RNA (gRNA) sequence and delivering it to a target cell along with the Cas9 endonuclease. We summarize recent CRISPR/Cas9 plant research findings, investigate potential applications in plant breeding, and make predictions about likely future breakthroughs and approaches to food security through 2050.