Conventional Plant Breeding Research Articles

Evaluation of yield and agronomic components by triallel cross and selection of high essential oil yielding hybrids in Basil

The basil (genus Ocimum) is a medicinal and fragrant herb or shrub with a wide range of applications as an ornamental plant, culinary ingredient, flavoring agent, and bioactive fragrance ingredient in foods cosmetics, and household items. Basil essential oil is in high demand, especially for novel high-quality oils with distinct aromas and chemical properties. The objectives of this study were, i) to increase the essential oil yield of better quality by gathering different genes responsible for the above economic characters scattered among different genotypes belonging to the same species or in other species of basil, and ii) the estimation of nature and amount of different genetic parameters. In the Ocimum, the single crosses and their corresponding three-way crosses/hybrids developed during the cropping season 2017–18 (single crosses) and 2018–2019 (three-way crosses). The three-way crosses/hybrids were evaluated in the field experimental trials during the 2019–20 at the CSIR-CIMAP, Lucknow (India) research farm. The analysis of variance (ANOVA) worked out for general and specific line effects for the eleven traits, and they were found highly significant for all the eleven traits. All the three-way crosses exhibited high variations for oil yield and yield contributing characters. For all eleven attributes, the additive genetic components of variance (σ2A) were higher than the dominant genetic components of variance (σ2 D), indicating that selection is simple for these attributes. For all the traits in the study, additive × dominance (σ2AD) gene action was higher than additive × additive (σ2AA), and dominance × dominance (σ2 DD), indicating that epistasis component of variance was present. Based on the genetic components of variance and mean performance of oil yield, only two tri-hybrids, C46.1 and C35.1, for the high oil yield and linalool (%), tri-hybrids C14.5 and C24.3 (47.13%), were found better. One tri-hybrid rich in Chavibetol, C26.1 (14.58%), is also selected for the extensive area cultivation in the North Indian plain. In addition, the three-way cross can combine desirable features from three genotypes into a single genotype. In conventional plant breeding, by a three-way cross design, the hybrids can be improved by crossing between an F1 (single cross) (A×B) as a female parent and a genotype (C) as the male parent. The essential oil of promising Ocimum tri-hybrids indicates aromatic compounds, such as methyl chavicol, linalool, β-ocimene, Chavibetol, and camphor content are present in adequate amounts. It is the first report using a triallel mating design in the basil. These tri-hybrids can be recommended for cultivation on a large scale.

Biofortified Crops – Boon for Nutritional Security

Micronutrient deficiencies of iron, zinc, and vitamin-A are such serious global health issues, that it affects one out of every three people worldwide. The intensity of this “hidden hunger” compels us to acknowledge global nutritional security issues. Plant based food are the most popular and trending choices for people of all rungs of the social ladder. Biofortification is a sustainable and promising process of improving nutrition in plant based food through different agronomic approaches, conventional plant breeding and genetic engineering. Biofortified crops have been developed with high iron, high zinc, vitamin-A, with other nutritional quality enhancements and these crops have already proved to be a ‘boon for nutritional security’. This review highlights some selected Biofortified crops with special reference to rice (Oryza sativa), as 50% of the global population relies on it.

Development and Adoption of Genetically Engineered Plants for Virus Resistance: Advances, Opportunities and Challenges.

Plant viruses cause yield losses to crops of agronomic and economic significance and are a challenge to the achievement of global food security. Although conventional plant breeding has played an important role in managing plant viral diseases, it will unlikely meet the challenges posed by the frequent emergence of novel and more virulent viral species or viral strains. Hence there is an urgent need to seek alternative strategies of virus control that can be more readily deployed to contain viral diseases. The discovery in the late 1980s that viral genes can be introduced into plants to engineer resistance to the cognate virus provided a new avenue for virus disease control. Subsequent advances in genomics and biotechnology have led to the refinement and expansion of genetic engineering (GE) strategies in crop improvement. Importantly, many of the drawbacks of conventional breeding, such as long lead times, inability or difficulty to cross fertilize, loss of desirable plant traits, are overcome by GE. Unfortunately, public skepticism towards genetically modified (GM) crops and other factors have dampened the early promise of GE efforts. These concerns are principally about the possible negative effects of transgenes to humans and animals, as well as to the environment. However, with regards to engineering for virus resistance, these risks are overstated given that most virus resistance engineering strategies involve transfer of viral genes or genomic segments to plants. These viral genomes are found in infected plant cells and have not been associated with any adverse effects in humans or animals. Thus, integrating antiviral genes of virus origin into plant genomes is hardly unnatural as suggested by GM crop skeptics. Moreover, advances in deep sequencing have resulted in the sequencing of large numbers of plant genomes and the revelation of widespread endogenization of viral genomes into plant genomes. This has raised the possibility that viral genome endogenization is part of an antiviral defense mechanism deployed by the plant during its evolutionary past. Thus, GM crops engineered for viral resistance would likely be acceptable to the public if regulatory policies were product-based (the North America regulatory model), as opposed to process-based. This review discusses some of the benefits to be gained from adopting GE for virus resistance, as well as the challenges that must be overcome to leverage this technology. Furthermore, regulatory policies impacting virus-resistant GM crops and some success cases of virus-resistant GM crops approved so far for cultivation are discussed.

Genetics and Genomics of Fusarium Wilt of Chilies: A Review

Hot pepper (Capsicum annum L.) is a major spice crop and is used worldwide for its nutritional value. In the field, its plant is susceptible to various fungal diseases, including fusarium wilt, caused by soil-borne fungus Fusarium oxysporum f. sp. capsici, which can survive in the soil for several years. The infected plant can be recognized by the yellowing of older leaves and downward curling of apical shoots, followed by plant wilting and ultimately the death of the plant. The resistance mechanism in plants is controlled by a single dominant gene, and conventional plant breeding techniques are used to develop a wilt-resistant germplasm. Non-conventional techniques such as gene pyramiding and expression enhancement of antifungal genes could be used to shorten the time to develop resistance against fusarium wilt in hot peppers. In this review, we discuss different aspects of the disease and the molecular basis of resistance in chili/hot pepper plants. Furthermore, this review covers the scope of conventional and non-conventional breeding strategies and different management approaches used to tackle the disease.

The molecular biology of grafting: Recent research may provide new applications for a millennia-old agricultural technology.

Plant biologists have begun to unravel the molecular mechanisms behind grafting, yielding insights into plant evolution and expanding the scope of this technique.

Current Status and Perspectives on the Application of CRISPR/Cas9 Gene-Editing System to Develop a Low-Gluten, Non-Transgenic Wheat Variety.

Wheat gluten contains epitopes that trigger celiac disease (CD). A life-long strict gluten-free diet is the only treatment accepted for CD. However, very low-gluten wheat may provide an alternative treatment to CD. Conventional plant breeding methods have not been sufficient to produce celiac-safe wheat. RNA interference technology, to some extent, has succeeded in the development of safer wheat varieties. However, these varieties have multiple challenges in terms of their implementation. Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease 9 (CRISPR/Cas9) is a versatile gene-editing tool that has the ability to edit immunogenic gluten genes. So far, only a few studies have applied CRISPR/Cas9 to modify the wheat genome. In this article, we reviewed the published literature that applied CRISPR/Cas9 in wheat genome editing to investigate the current status of the CRISPR/Cas9 system to produce a low-immunogenic wheat variety. We found that in recent years, the CRISPR/Cas9 system has been continuously improved to edit the complex hexaploid wheat genome. Although some reduced immunogenic wheat varieties have been reported, CRISPR/Cas9 has still not been fully explored in terms of editing the wheat genome. We conclude that further studies are required to apply the CRISPR/Cas9 gene-editing system efficiently for the development of a celiac-safe wheat variety and to establish it as a “tool to celiac safe wheat”.

Genomic Selection: Current Status, Opportunities and Challenges

Now a days, Genomic Selection (GS) became a preferable choice for selection of appropriate candidate for animal and plant breeding research. Various studies related to GS has been done recently where it has shown potential benefits and advantages over traditional and conventional plant breeding methods. GS has been successfully implemented in various animal and plant breeding programs. It reduces the total costs by selecting the animals at early stage hence shorten the generation interval. Genomic selection is the future of livestock and plant breeding as it improves the genetic gain by decreasing genetic interval and improving reliability. Although there is a need of further investigation to improve the accuracy of genomic estimated breeding value and manage long-term genetic gain. This article provides a brief review what we have achieved through GS till yet and what is future scope and perspective in the GS research.

Genetic techniques for plant breeding

Genetic techniques for plant breeding

Data-driven decentralized breeding increases prediction accuracy in a challenging crop production environment

Crop breeding must embrace the broad diversity of smallholder agricultural systems to ensure food security to the hundreds of millions of people living in challenging production environments. This need can be addressed by combining genomics, farmers’ knowledge, and environmental analysis into a data-driven decentralized approach (3D-breeding). We tested this idea as a proof-of-concept by comparing a durum wheat (Triticum durum Desf.) decentralized trial distributed as incomplete blocks in 1,165 farmer-managed fields across the Ethiopian highlands with a benchmark representing genomic prediction applied to conventional breeding. We found that 3D-breeding could double the prediction accuracy of the benchmark. 3D-breeding could identify genotypes with enhanced local adaptation providing superior productive performance across seasons. We propose this decentralized approach to leverage the diversity in farmer fields and complement conventional plant breeding to enhance local adaptation in challenging crop production environments.

Genomic-Assisted Marker Development Suitable for CsCvy-1 Selection in Cucumber Breeding.

Cucumber is a widely grown vegetable crop plant and a host to many different plant pathogens. Cucumber vein yellowing virus (CVYV) causes economic losses on cucumber crops in Mediterranean countries and in some part of India such as West Bengal and in African countries such as Sudan. CVYV is an RNA potyvirus transmitted mechanically and by whitefly (Bemisia tabaci) in a semipersistent manner. Control of this virus is heavily dependent on the management of the insect vector and breeding virus-resistant lines. DNA markers have been used widely in conventional plant breeding programs via marker-assisted selection (MAS). However, very few resistance sources against CVYV in cucumber exist, and also the lack of tightly linked molecular markers to these sources restricts the rapid generation of resistant lines. In this work, we used genomics coupled with the bulked segregant analysis method and generated the MAS-friendly Kompetitive allele specific PCR (KASP) markers suitable for CsCvy-1 selection in cucumber breeding using a segregating F2 mapping population and commercial plant lines. Variant analysis was performed to generate single-nucleotide polymorphism (SNP)-based markers for mapping the population and genotyping the commercial lines. We fine-mapped the region by generating new markers down to 101 kb with eight genes. We provided SNP data for this interval, which could be useful for breeding programs and cloning the candidate genes.

Phenotypic Evaluation of Grain Zinc Enhanced Wheat Lines for Agronomic and Quality Traits

Background: Biofortification of wheat (Triticum aestivum) with increased micronutrients via conventional plant breeding is a potential mechanism for alleviating micronutrient deficiencies. As the quantitative inheritance for zinc concentration adds towards greater G x E interactions, the study for significant genotype x location interactions for zinc is an important target towards the production of biofortified wheat. Methods: The present study was conducted to evaluate a set of promising zinc elevated wheat backcross lines containing introgressions from T. monococcum and T. boeoticum for grain zinc (ppm) and iron concentration (ppm), protein content (%) and other agronomic and quality traits. Eighteen promising wheat backcross derivatives (BC1F5 and BC2F5) were evaluated along with donor and recipient parents in a randomized complete block design with three replications at two different locations i.e. Ludhiana and Gurdaspur (Punjab) during 2016-17. Result: Pooled analysis of variance revealed genotype x location interactions were non significant for grain zinc (P greater than 0.05) and protein (P greater than 0.05) which indicated ranking of lines for these traits did not change with location and hence the increase for these traits in wheat lines were stable and not influenced by the environment. The data also indicated a BC2F5 derivative belonging to cross PBW703/BF14//2*PBW703 possessed significantly higher grain zinc concentration at both the locations exhibiting 18% and 16% zinc enhancement over check variety PBW725 at Ludhiana and Gurdaspur, respectively.

Comprehensive nutritional evaluation of popular rice varieties of Assam, Northeast India

High-yielding varieties (HYVs) of rice have benefited farmers and the public by increasing yields and reducing the cost to consumers. Yet the nutritive value, a pivotal trait of HYVs remains grossly under-investigated. In this work, efforts have been specifically focused on nutrients profiling of 20 popular HYVs from Assam as brown rice and its milled counterparts. The study has revealed several varieties that are a reasonably good source of either protein, or fat, or zinc, or calcium. Substantial nutrient variability was observed in the 20 HYVs brown rice with the largest variation observed in pyridoxine (49%cv), followed by pantothenic acid (36%cv), iron (24%cv), protein (14%cv), and fat (13%cv). At 5 % milling substantial reduction of all nutrients occurred (40–58%) which was further exacerbated at 10 % milling. Compared to 10 % milled rice, brown rice has a far better nutrient profile and even limiting to 5 % milling can marginally increase rice nutrient content. A change in consumption pattern from white rice to brown rice or even 5% milled rice will be nutritionally beneficial. The rice nutrient data can also help in improving nutrient intakes through the use of nutritious cultivars and in conventional plant breeding to develop superior nutrient varieties.

Studies on Heterosis, Residual Heterosis and Inbreeding Depression for Yield and Related Traits in Sorghum (Sorghum bicolor L.)

Background: Selection of genotypically superior parents is most challenging task for the development of potential hybrids. In conventional plant breeding, magnitude of heterosis and inbreeding depression has been proved very effective in identifying vigorous parental combinations. Methods: The present investigation was carried out to study the heterosis, residual heterosis and inbreeding depression of forty sorghum crosses (F1s and F2s) obtained by crossing of eight restorer lines with five cytoplasmic male sterile lines in Line x Tester mating design in 2013 and 2014. Observations were recorded on morphological traits viz. days to 50% flowering, days to maturity, plant height, flag leaf length, flag leaf width, panicle length, panicle width, panicle weight,1000 seed weight and grain yield per plant. Result: Among all crosses, ICSA467 x UPC2 and MR750A2 x UPC2 were found to be best for most of the characters. Inbreeding depression was recorded as significantly positive for plant height for most of the crosses indicates the occurrence of transgressive segregants in F2 generation.

Carotenoid Extraction from Locally and Organically Produced Cereals Using Saponification Method

Carotenoids are important phytochemicals contributing nutritional health benefits in the human diet, with a significant contribution from cereals as one of the major food component around the world. Different methods have been described and adopted for the extraction and isolation of carotenoid compounds. Saponification can be seen as an option for carotenoid extraction from cereals as it converts retinol esters to retinol and removes other abundant compounds such as triglycerides. Extraction of carotenoids content of locally adapted and organic cereals have been limitedly investigated and was, therefore, evaluated in the present study, with a specific aim to understand genotypic and local cultivation effects and interactions. Therefore, 17 diverse cereal genotypes of local origin were grown organically in four localities and evaluated for carotenoid content and composition by HPLC. The results showed a large variation in content and composition of carotenoids in locally adapted and organically grown cereal genotypes, with lutein as the dominating type in wheat and rye, while zeaxanthin was the dominating type in barley. High-level genotypes showed values (9.9 mg/kg of total carotenoids) similar to the highest values previously reported in specific types of wheat. The barley genotypes showed relatively high stability in carotenoids content within and between cultivation locations, while large interactions were found with the cultivation location for the rest of the genotypes, indicating their local adaptation. The local adaptation of the cereal genotypes evaluated contributes large opportunities for local production of high value, highly nutritious food products, while the direct value of these genotypes for conventional plant breeding for varieties performing similar over broad environmental ranges, are more limited.

Maize breeding for abiotic stress tolerance: An alternative to face climate changes

Maize breeding faces several challenges when the matter is abiotic stresses. For many years, the focus was to develop genotypes adapted to optimal environmental conditions, however, the need to ensure yields under unsuitable and unstable conditions of a climate-changing world is undeniable. Therefore, this review is addressed to the main abiotic stresses that jeopardize maize production worldwide, presenting an overview regarding losses and impacts imposed by them, stating what has been achieved through conventional and molecular plant breeding techniques, and the future prospects on this subject. The conventional breeding added to molecular techniques bring great expectations for developing abiotic stresses tolerant maize genotypes. Universities and research companies worldwide have contributed to expand and spread basic and essential knowledge, however, the entrance of large multinational companies might revolutionize the field. Genetic modified hybrids and projects of continental coverage will introduce many innovations and alternatives to ensure food security for the increasingly growing world population.

State-of-the-Art in CRISPR Technology and Engineering Drought, Salinity, and Thermo-tolerant crop plants.

Our review has described principles and functional importance of CRISPR-Cas9 with emphasis on the recent advancements, such as CRISPR-Cpf1, base editing (BE), prime editing (PE), epigenome editing, tissue-specific (CRISPR-TSKO), and inducible genome editing and their potential applications in generating stress-tolerant plants. Improved agricultural practices and enhanced food crop production using innovative crop breeding technology is essential for increasing access to nutritious foods across the planet. The crop plants play a pivotal role in energy and nutrient supply to humans. The abiotic stress factors, such as drought, heat, and salinity cause a substantial yield loss in crop plants and threaten food security. The most sustainable and eco-friendly way to overcome these challenges are the breeding of crop cultivars with improved tolerance against abiotic stress factors. The conventional plant breeding methods have been highly successful in developing abiotic stress-tolerant crop varieties, but usually cumbersome and time-consuming. Alternatively, the CRISPR/Cas genome editing has emerged as a revolutionary tool for making efficient and precise genetic manipulations in plant genomes. Here, we provide a comprehensive review of the CRISPR/Cas genome editing (GE) technology with an emphasis on recent advances in the plant genome editing, including base editing (BE), prime editing (PE), epigenome editing, tissue-specific (CRISPR-TSKO), and inducible genome editing (CRISPR-IGE), which can be used for obtaining cultivars with enhanced tolerance to various abiotic stress factors. We also describe tissue culture-free, DNA-free GE technology, and some of the CRISPR-based tools that can be modified for their use in crop plants.

MICROPROPAGATION OF MATURE TERMINALIA CATAPPA VARIETIES

Micropropogation is used to multiply plants such as those that been genetically conventional plant breeding with the multiplying progeny plants. Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation. The success of Plant tissue culture in recent years approaches have been used as an efcient tool for micropropagation of trees in short time. [1][2]. Propagation of woody trees through tissue culture has many advantages over conventional propagation with different methods like fast growing, season independent of production of the plant, germ plasm conservation and facilitating their growth. This review provides an overview of the success achieved on in vivo work done for a number of important forest trees.Rapid culturing of producing clonal plants this review states that invitro work has been done for no of important forest trees [3]. Both the varieties were subjected, nodal explants were subjected with MS Media and Growth hormones with the dilution of kinetin with 1-1.5 mg/ml and with the mixture of both Kinetin, BAP with the dilution of 1-3 mg/ml with an increase of time for 3-5 weeks the growth was 3-6 cm length. The study of micropropagation in both the varieties, all the values of the work are Mean of at least 3 independent experiment. The MEAN±SEM and the extract number of experiments are given in legends. The Signicance of difference between control and each trial treatment was analysed using ANOVA showed statistical results as and ANOVA is p≤0.05*is signicant

Scaling Up Delivery of Biofortified Staple Food Crops Globally: Paths to Nourishing Millions.

Background:Micronutrient deficiencies affect over one quarter of the world’s population. Biofortification is an evidence-based nutrition strategy that addresses some of the most common and preventable global micronutrient gaps and can help improve the health of millions of people. Since 2013, HarvestPlus and a consortium of collaborators have made impressive progress in the enrichment of staple crops with essential micronutrients through conventional plant breeding.Objective:To review and highlight lessons learned from multiple large-scale delivery strategies used by HarvestPlus to scale up biofortification across different country and crop contexts.Results:India has strong public and private sector pearl millet breeding programs and a robust commercial seed sector. To scale-up pearl millet, HarvestPlus established partnerships with public and private seed companies, which facilitated the rapid commercialization of products and engagement of farmers in delivery activities. In Nigeria, HarvestPlus stimulated the initial acceptance and popularization of vitamin A cassava using a host of creative approaches, including “crowding in” delivery partners, innovative promotional programs, and development of intermediate raw material for industry and novel food products. In Uganda, orange sweet potato (OSP) is a traditional subsistence crop. Due to this, and the lack of formal seed systems and markets, HarvestPlus established a network of partnerships with community-based nongovernmental organizations and vine multipliers to popularize and scale-up delivery of OSP.Conclusions:Impact of biofortification ultimately depends on the development of sustainable markets for biofortified seeds and products. Results illustrate the need for context-specific, innovative solutions to promote widespread adoption.

Swedish consumers´ attitudes and values to genetic modification and conventional plant breeding – The case of fruit and vegetables

ABSTRACT This study examined public attitudes to genetic modification (GM) and conventional plant breeding and explored general differences in attitudes to these two types of breeding concepts, including the effect of individual personal characteristics such as gender and age. It also sought to identify the influence of personal values linked to attitudes to GM crops and conventional plant breeding, following Schwartz value theory. Relations between specific values and attitudes to GM organisms (GMOs) have been studied previously, but not gender- and age-specific relations between specific values and attitudes to conventional plant breeding. Data were collected in this study using a questionnaire completed on-line by 1500 Swedish consumers in 2019. The questionnaire covered three different aspects: 1) sociodemographic data, including gender and age; 2) attitudes to GMO/conventional plant breeding; and 3) values, measured using the human values scale. It was found that consumers expressed more positive attitudes to conventional plant breeding than to GMO, men expressed more positive attitudes to both conventional plant breeding and GMO than women did, and younger consumers expressed more positive attitudes to GMO than older consumers did. A negative correlation between attitudes to conventional plant breeding and the value ‘tradition’, but no correlation to ‘universalism’, ‘benevolence’, ‘power’ or ‘achievement’, was identified for men. For women, correlations between attitudes to conventional plant breeding and ‘benevolence’ (neg.) and ‘achievement’ (pos.) were found. For both men and women, attitudes to GMO were negatively influenced by ‘universalism’ and ‘benevolence’, and positively influenced by ‘power’ and ‘achievement’. The implications of these results are discussed.

A short review: Comparisons of high-throughput phenotyping methods for detecting drought tolerance

Drought is a major threat worldwide for crop production, especially due to the rapid climate changes. Current drought solutions involve improving irrigation system, rainwater harvesting, damming, cloud seeding, and changes of cultivation methods. Despite effective, each solution has economic, environmental, and temporal drawbacks. Among all solutions, the most effective, inexpensive and manageable method is the use of drought-tolerant cultivars via plant breeding. However, conventional plant breeding is a time-consuming and laborious task, especially for phenotypic data acquisition of target traits of numerous progenies. High-throughput phenotyping (HTP) is a recently developed method and has potential to overcome the mentioned issues. HTP offers massive, accurate, rapid, and automatic data acquisition in the breeding procedure and can be a breakthrough for developing drought resistant/tolerant cultivars. This study introduces various methods of HTP to detect drought stress, which can accelerate the breeding processes of drought-tolerant cultivars to provide helpful guidelines for breeders and researchers to choose appropriate methods.