Translational Genomics in Crop Breeding for Biotic Stress Resistance: An Introduction

Abstract

Biotic stresses pose a m ajor threat to crop productivity. Crops are challenged by a plethora of biotic stresses, but only a limited num ber o f key pests and diseases cause the vast majority of economic losses in a particular crop. Plant protection measures such as application of pesticides and deployment of resistant gene(s)/quantitative trait loci (QTLs) into cultivars have so far been quite successful in curtailing the losses; however, these measures have also led to the constant evolution of new biotypes/pathotypes/strains/races o f pest and disease organisms. Hence, there is a continuous need to identify genomic regions that can impart resistance against these variants. The availability of large-scale genomic resources in many crop species has enhanced our understanding on the path to developing host-plant resistance. As a result, numerous race-specific gene(s) and QTLs have now been identified and cloned with the help o f molecular markers. It is quite exciting that these genomic regions are being introgressed into breeding programs of many crops. The objective of this book is to critically review the current availability and utilization of genomic tools for major biotic stresses in important cereals, legumes, vegetables, and tuber and oilseed crop. The book also summarizes the success stories achieved through application of genomics-assisted breeding (GAB), as well as the scope for deployment o f modem breeding methods such as marker-assisted backcrossing (MABC) and genomic selection in the era o f next-generation sequencing (NGS) technologies, which have the potential to advance the genetic gains for enhancing resilience against biotic stress. This chapter summarizes highlights of different chapters included in the book that is expected to be a resource for young researchers, GAB practitioners, and policy makers for employing better strategies toward achieving food security.

Identification of marker-trait associations for morphological descriptors and yield component traits in sugarcane

“…The conventional marker-assisted breeding approaches require markers that are able to tag alleles explaining a major proportion of trait variations, e.g., disease resistance genes, etc. Since, yield and quality characteristics are complex, it requires a more comprehensive tailoring and coverage during investigations for marker-trait associations (Varshney and Tuberosa 2013).…”

Pea Breeding for Resistance to Rhizospheric Pathogens

“…Genomic selection can be used to identify multiple traits to improve pea rhizosphere disease-resistance mechanisms through genomic-assisted breeding [ 283 ]. Hence, these genetic tools and procedures improve the capacity of breeders for the uptake of biotechnology and reduce the gap between genomics, molecular and conventional breeding strategies [ 245 , 284 ]. For instance, the post-genome reverse genetics technique of gene silencing (RNAi) and ‘targeted induced local lesions IN genomes’ (TILLING) for gene deletion and point mutation can confirm gene function to accelerate a selection of desirable traits [ 4 , 285 ].…”

Proteomics and Metabolomics: Two Emerging Areas for Legume Improvement

“…and biotic stresses (e.g., anthracnose, bean rust, bacterial blight, Fusarium wilt etc. ), thus limiting their productivity (Dita et al, 2006 ; Varshney and Tuberosa, 2013 ; Rodziewicz et al, 2014 ). Moreover, these environmental conditions severely affect rhizobia-legume symbiosis, which contributes to ~45% of nitrogen required for agriculture (Karmakar et al, 2015 ).…”