Genomic Designing for Climate-Smart Pea

Abstract

Pea (Pisum sativum L.), a diploid (2n = 2x = 14) annual cool-season legume crop adapted to a wide range of climates and altitudes, plays a very important role for sustainable agriculture as rotation and cash crops for food, vegetable, fodder, manure, etc. The genome size of a pea is estimated at 4.45 Gb comprising large amount of repetitive sequences with high complexity, so that the complete reference genome sequence of pea has not been published yet, which hindered the development of genome-assisted breeding in pea. This chapter discussed the challenges, priorities, and prospects of pea as climate-smart (CS) crop, in food, nutrition, energy, and environment security, effects on global warming and climate change to the industry and breeding of pea. For details, studies on CS agronomic traits of peas like flowering time, root characters, nutrient-use efficiency, water use efficiency, carbon and nitrogen sequestration, greenhouse gas emission, genome plasticity, as well as specific traits for vegetable purposes, were reviewed; CS stress tolerance/resistance traits studies of peas, like cold tolerance, drought tolerance, salinity tolerance, disease resistance, insect resistance were also reviewed. Pea-hosted biological nitrogen fixation (BNF) and soil resources, rhizobium for nodulation, characterization for rhizobium, interaction between pea and its anchored rhizobium, interaction between rhizobium and soil, optimized operation for rhizobium fertilization were illustrated. Utilizations of primary gene pool, secondary gene pool, tertiary gene pool, artificially induced/incorporated traits/genes in CS pea genetic development were reviewed. Of CS pea studies, classical mapping efforts, classical breeding achievements (yield, quality, stress resistance, etc.), limitations of traditional breeding and rationale for molecular breeding, genetic diversity analysis of Pisum genus using various means, such as association mapping studies between important traits and markers, molecular mapping of CS genes and QTLs, marker-assisted breeding for CS traits, genomic-aided breeding for CS traits, were all reviewed. Social, political, and regulatory issues concerning CS peas, for concerns and compliances, patent and IPR issues, disclosure of sources of GRs, access and benefit sharing, famers’ rights, traditional knowledge, treaties and conventions, participatory breeding, in China and elsewhere were discussed. Peas, especially green pea production dramatically expanded and became increasingly important from the beginning of this century. Achievements on pea studies will lead to genomics, phenomics, and genome editing exploration to assist CS pea breeding purpose in the future.