Heat stress tolerance in peas (Pisum sativum L.): Current status and way forward

In the era of climate change, the overall productivity of pea (Pisum sativum L.) is being threatened by several abiotic stresses including heat stress (HS). HS causes severe yield losses by adversely affecting several traits in peas. A reduction in pod yield has been reported from 11.1% to 17.5% when mean daily temperature increase from 1.4 to 2.2°C. High-temperature stress (30.5-33°C) especially during reproductive phase is known to drastically reduce both seed yield and germination. HS during germination and early vegetative stage resulted in poor emergence and stunted plant growth along with detrimental effects on physiological functions of the pea plant. To combat HS and continue its life cycle, plants use various defense strategies including heat escape, avoidance or tolerance mechanisms. Ironically, the threshold temperatures for pea plant and its responses are inconsistent and not yet clearly identified. Trait discovery through traditional breeding such as semi leaflessness (afila), upright growing habit, lodging tolerance, lower canopy temperature and small seeded nature has highlighted their utility for greater adaptation under HS in pea. Screening of crop gene pool and landraces for HS tolerance in a targeted environment is a simple approach to identify HS tolerant genotypes. Thus, precise phenotyping using modern phenomics tools could lead to increased breeding efficiency. The NGS (next generation sequencing) data can be associated to find the candidate genes responsible for the HS tolerance in pea. In addition, genomic selection, genome wide association studies (GWAS) and marker assisted selection (MAS) can be used for the development of HS tolerant pea genotypes. Additionally, development of transgenics could be an alternative strategy for the development of HS tolerant pea genotypes. This review comprehensively covers the various aspects of HS tolerance mechanisms in the pea plant, screening protocols, omic advances, and future challenges for the development of HS tolerant genotypes

Metabolomics-Driven Mining of Metabolite Resources:Applications and Prospects for Improving Vegetable Crops

Vegetable crops possess a prominent nutri-metabolite pool that not only contributes to the crop performance in the fields, but also offers nutritional security for humans. In the pursuit of identifying, quantifying and functionally characterizing the cellular metabolome pool, biomolecule separation technologies, data acquisition platforms, chemical libraries, bioinformatics tools, databases and visualization techniques have come to play significant role. High-throughput metabolomics unravels structurally diverse nutrition-rich metabolites and their entangled interactions in vegetable plants. It has helped to link identified phytometabolites with unique phenotypic traits, nutri-functional characters, defense mechanisms and crop productivity. In this study, we explore mining diverse metabolites, localizing cellular metabolic pathways, classifying functional biomolecules and establishing linkages between metabolic fluxes and genomic regulations, using comprehensive metabolomics deciphers of the plant’s performance in the environment. We discuss exemplary reports covering the implications of metabolomics, addressing metabolic changes in vegetable plants during crop domestication, stage-dependent growth, fruit development, nutri-metabolic capabilities, climatic impacts, plant-microbe-pest interactions and anthropogenic activities. Efforts leading to identify biomarker metabolites, candidate proteins and the genes responsible for plant health, defense mechanisms and nutri-rich crop produce are documented. With the insights on metabolite-QTL (mQTL) driven genetic architecture, molecular breeding in vegetable crops can be revolutionized for developing better nutritional capabilities, improved tolerance against diseases/pests and enhanced climate resilience in plants

Vegetable peas (Pisum sativum L.) diversity: An analysis of available elite germplasm resources with relevance to crop improvement

Aim of study: To determine the amount of diversity in pea breeding materials with the objective to classify a set of potential parents carrying novel/economic variations that could be used in future breed pea varieties. Area of study: ICAR–Indian Institute of Vegetable Research, Varanasi. Material and methods: A total of 45 pea accessions were analysed for phenotypic and molecular diversity using 17 agro-morphological traits and 52 SSR markers. Main results: All traits under investigation showed considerable genetic variation. The genotypes exhibited 6.7, 2.7 and 12-fold variation for traits viz., pods/plant, 10-pod weight and yield/plant, respectively. Among 52 SSR markers, 22 were found to be polymorphic. A total of 90 allelic variants were detected, with an average of 2.7 alleles/locus. PIC and D-values for markers AA135 (0.79 and 0.81) and PSMPSAD51 (0.7 and 0.74) were the highest, while AB40 (0.19 and 0.2) had the lowest. Two principal components PC1 and PC2 explained 46.96 and 23.96% of total variation, respectively. The clustering based on agro-morphological traits differentiated 45 individuals into three mega clusters, while SSR markers-based clustering classified these accessions into four groups. Research highlights: Based on their uniqueness, we identified a set of genotypes (VRPD-2, VRPD-3, PC-531, ‘Kashi Nandini’, ‘Kashi Udai’, ‘Kashi Mukti’, ‘Arkel’, VRPE-101, ‘Azad Pea-3’, EC865944, VRPM-901 and VRP-500) harbouring genes for various economic traits. The findings presented here will be extremely useful to breeders who are working on improvement of peas through selective introgression breeding

Gene-Based Resistance to <i>Erysiphe</i> Species Causing Powdery Mildew Disease in Peas (<i>Pisum sativum</i> L.)

Globally powdery mildew (PM) is one of the major diseases of the pea caused by Erysiphe pisi. Besides, two other species viz. Erysiphe trifolii and Erysiphe baeumleri have also been identified to infect the pea plant. To date, three resistant genes, namely er1, er2 and Er3 located on linkage groups VI, III and IV respectively were identified. Studies have shown the er1 gene to be a Pisum sativum Mildew resistance Locus ‘O’ homologue and subsequent analysis has identified eleven alleles namely er1–1 to er1–11. Despite reports mentioning the breakdown of er1 gene-mediated PM resistance by E. pisi and E. trifolii, it is still the most widely deployed gene in PM resistance breeding programmes across the world. Several linked DNA markers have been reported in different mapping populations with varying linkage distances and effectiveness, which were used by breeders to develop PM-resistant pea cultivars through marker assisted selection. This review summarizes the genetics of PM resistance and its mechanism, allelic variations of the er gene, marker linkage and future strategies to exploit this information for targeted PM resistance breeding in Pisum

Gene-Based Resistance to Erysiphe Species Causing Powdery Mildew Disease in Peas (Pisum sativum L.)

Not AvailableGlobally powdery mildew (PM) is one of the major diseases of the pea caused by Erysiphe pisi. Besides, two other species viz. Erysiphe trifolii and Erysiphe baeumleri have also been identified to infect the pea plant. To date, three resistant genes, namely er1, er2 and Er3 located on linkage groups VI, III and IV respectively were identified. Studies have shown the er1 gene to be a Pisum sativum Mildew resistance Locus ‘O’ homologue and subsequent analysis has identified eleven alleles namely er1–1 to er1–11. Despite reports mentioning the breakdown of er1 gene-mediated PM resistance by E. pisi and E. trifolii, it is still the most widely deployed gene in PM resistance breeding programmes across the world. Several linked DNA markers have been reported in different mapping populations with varying linkage distances and effectiveness, which were used by breeders to develop PM-resistant pea cultivars through marker assisted selection. This review summarizes the genetics of PM resistance and its mechanism, allelic variations of the er gene, marker linkage and future strategies to exploit this information for targeted PM resistance breeding in Pisum.Not Availabl

Tissue Culture, Genetic Engineering, and Nanotechnology in Bitter Gourd

Bitter gourd (Momordica charantia L.) belongs to the genus Momordica that includes 45 species. It is cultivated extensively in tropical, subtropical, and rarely under temperate climates. The plant is valued in various disciplines of life and natural sciences. It is extensively used for culinary purposes. Its extracts are important for the treatment of a number of diseases and ailments in traditional and modern medicinal systems because of the abundance of insulin-like peptides, a mixture of steroidal sapogenins and alkaloids. It is rarely used as an ornamental plant. There are very few reports on systematic research on agronomic, breeding, and biotechnological aspects that curtail the improvement of this crop plant. This chapter reviews available information on biotechnology in a bitter gourd that will help understand the current scenario and help in making plans for improvement of bitter gourd