Genomics Aided Breeding Strategies For Biotic Stress In Grain Legumes

This contributed volume explores the latest breakthroughs in genetic and genomic resources for enhancing biotic stress responses in grain legumes – including minor ones. It covers the advances made to date, including gene identification, transcriptomics, proteomics, transgenics, genome editing, genomic selection, epigenetic breeding, and speed breeding related to different biotic stresses. Authored by crop-specific experts, the chapters in this book are essential resources for those directly involved in improving grain legume crops. Legumes play a vital role in ensuring food and nutritional security, enhancing soil quality, and promoting environmental sustainability. Rich in protein, they are essential in preventing hunger and malnutrition while adding to dietary diversity. However, as these crops are commonly grown in marginal lands with poor inputs, they are highly susceptible to biotic stresses such as diseases and pests, which can cause significant yield losses. This book consolidates all available knowledge about genetic and genomic aspects of biotic stress responses in various grain legumes. It is a must-have resource for all stakeholders involved in grain legume improvement. Whether you are a breeder, pathologist, biotechnologist, seed production specialist, market manager, graduate or post-graduate student, or any other industry professional, this book serves as an excellent guide to help you stay at the forefront of grain legume improvement.

Legumes (family Fabaceae) comprise a diverse range of crops grown worldwide, which are important constituents of sustainable agriculture and harbour a role in improving human and livestock health. Legumes serve as a rich source of plant-based proteins, rank second in nutrition value after cereals, and are ideal to supplement a protein-deficient cereal-based human diet. Legumes also provide other essential services to agriculture through their ability to fix atmospheric nitrogen, recycle nutrients, enhance soil carbon content, and diversify cropping systems. Legume production and seed quality are affected by a range of biotic (pests, insect diseases, and weeds) and abiotic stresses (drought, heat, frost, and salinity). In addition to this, rapidly changing climate, shrinking arable land, erratic rainfalls, and depleting water and other natural resources impact legume production and threaten food and nutrition security worldwide. Persistent demand for legume crops is existing to fulfil the food requirements of an ever-growing human population. Therefore, legume breeders and geneticists have employed different conventional and modern breeding strategies to improve yield, resistance to biotic and abiotic stresses, grain quality, and nutritional and nutraceutical properties. Conventional breeding strategies are laborious, time consuming, expensive, and inefficient to achieve the desired goals. However, advanced breeding techniques such as alien gene introgression, genomics-assisted breeding, transgenic technology, speed breeding, association and mapping studies, genome editing, and omics will contribute to sustainable agriculture and food security.

This book examines the development of innovative modern methodologies towards augmenting conventional plant breeding, in individual crops, for the production of new crop varieties under the increasingly limiting environmental and cultivation factors to achieve sustainable agricultural production, enhanced food security, in addition to providing raw materials for innovative industrial products and pharmaceuticals. This is Vol 7, subtitled Legumes, focuses on advances in breeding strategies using both traditional and modern approaches for the improvement of individual legume crops. Included in this volume are Adzuki bean, Black gram, Chickpea Cluster bean, Common bean, Cowpea, Faba bean, Hyacinth bean, Lentil, Mung bean, Pigeonpea and Soybean. This volume is contributed by 57 internationally reputable scientists from 9 countries. Each chapter comprehensively reviews the modern literature on the subject and reflects the authors own experience.

Biotic stresses cause yield loss of 31-42% in crops in addition to 6-20% during post-harvest stage. Understanding interaction of crop plants to the biotic stresses caused by insects, bacteria, fungi, viruses, and oomycetes, etc. is important to develop resistant crop varieties. Knowledge on the advanced genetic and genomic crop improvement strategies including molecular breeding, transgenics, genomic-assisted breeding and the recently emerging genome editing for developing resistant varieties in pulse crops is imperative for addressing FPNEE (food, health, nutrition. energy and environment) security. Whole genome sequencing of these crops followed by genotyping-by-sequencing have facilitated precise information about the genes conferring resistance useful for gene discovery, allele mining and shuttle breeding which in turn opened up the scope for 'designing' crop genomes with resistance to biotic stresses. The nine chapters each dedicated to a pulse crop in this volume elucidate on different types of biotic stress agents and their effects on and interaction with the crop plants; enumerate on the available genetic diversity with regard to biotic stress resistance among available cultivars; illuminate on the potential gene pools for utilization in interspecific gene transfer; present brief on the classical genetics of stress resistance and traditional breeding for transferring them to their cultivated counterparts; depict the success stories of genetic engineering for developing biotic stress resistant varieties; discuss on molecular mapping of genes and QTLs underlying biotic stress resistance and their marker-assisted introgression into elite varieties; enunciate on different emerging genomics-aided techniques including genomic selection, allele mining, gene discovery and gene pyramiding for developing resistant crop varieties with higher quantity and quality of yields; and also elaborate some case studies on genome editing focusing on specific genes for generating disease and insect resistant crops.

Grain legumes mainly consisting of common bean, pea, chickpea, faba bean, cowpea, lentil, pigeon pea, peanut, Asian Vigna species, grass pea and horsegram are under cultivation in a considerable area worldwide. With their higher protein content and symbiotic nitrogen-fixing bacteria in root nodules enabling them to fix their own nitrogen, reducing the fertilizer use in agriculture has become very important for the production systems. For most of these important grain legumes, a large number of germplasm accessions were characterized and evaluated for various agro-morphological traits, including biotic, abiotic and quality parameters. Core and mini-core collections have also been developed for the majority of grain legumes; they were further evaluated for different parameters. From these genetic resources, potential donors of desirable traits have been selected after evaluation and characterization and have been utilized in the genetic improvement of cultivars. Current available genomic resources and technologies can facilitate allele mining for novel traits of interest and incorporation from wild relatives into elite domestic genetic backgrounds.

Pea is an important temperate region pulse, with feed, fodder and vegetable uses. It originated and was domesticated in Middle East and Mediterranean regions, and formed important dietary components of early civilizations. Although Pisum is a very small genus with two or three species, it is diverse and structured, reflecting taxonomy, ecogeography and breeding gene pools. This diversity has been preserved in collections totalling about 90,000 accessions. Core collections have been formed, facilitating phenotypic and agronomic evaluations. However, only 3% of ex situ collections are wild Pisum sp., with substantially larger diversity. The genomic resources allow initiation of association mapping, linking genetic diversity with trait manifestation. So far, only a small part of wild gene pools have been exploited in breeding for biotic and abiotic stresses. Current genomic knowledge and technologies can facilitate allele mining for novel traits and incorporation from wild Pisum sp. into elite domestic genetic backgrounds.

Faba bean was first domesticated in the Near East about 10,000 BC. It is now grown worldwide on 2.56 million ha with a yield of 4.56 million tons. The traditional landraces are affected by the different biotic and abiotic stresses. Replacement of these low-yielding landraces by improved cultivars has resulted in a yield increase of 15.4kg/ha/year over the last 40 years. A reduction of the planted area from 7.5 million ha in 1961 to 2.56 million ha in 2010 and cultivation of improved cultivars are the major causes of genetic erosion. Gene banks around the world conserved more than 36,000 accessions. Diversity studies showed limited variation among currently grown cultivars, but high variation among different botanical groups has been recorded. The International Center for Agricultural Research in the Dry Areas has undertaken desirable selection and breeding efforts to identify different sources of resistance and to develop improved varieties in collaboration with national agricultural research systems. A molecular approach was used in advanced research institutes to tag major genes/quantitative trait loci with molecular markers. However, more efforts are needed to saturate the genetic maps to facilitate marker-assisted breeding.

Cool season grain legumes including pea, faba bean, lentil, chickpea, and grass pea are extensively grown in many parts of the world. They are a primary source of proteins in human diet. This volume deals with the most recent advances in genetics, genomics, and breeding of these crops. The "state of the art" for the individual crops differs; howeve