Srivastava Rakesh K, Yadav O P, Kaliamoorthy Sivasakthi, Gupta S K, Serba Desalegn D, Choudhary Sunita, Govindaraj Mahalingam, Kholová Jana, Murugesan Tharanya, Satyavathi C Tara, Gumma Murali Krishna, Singh Ram B, Bollam Srikanth, Gupta Rajeev, Varshney Rajeev K
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India.
Indian Council of Agricultural Research-Central Arid Zone Research Institute, Jodhpur, India.
Front Plant Sci. 2022 Apr 7;13:781524. doi: 10.3389/fpls.2022.781524. eCollection 2022.
Pearl millet [ (L.) R. Br.] is a C crop cultivated for its grain and stover in crop-livestock-based rain-fed farming systems of tropics and subtropics in the Indian subcontinent and sub-Saharan Africa. The intensity of drought is predicted to further exacerbate because of looming climate change, necessitating greater focus on pearl millet breeding for drought tolerance. The nature of drought in different target populations of pearl millet-growing environments (TPEs) is highly variable in its timing, intensity, and duration. Pearl millet response to drought in various growth stages has been studied comprehensively. Dissection of drought tolerance physiology and phenology has helped in understanding the yield formation process under drought conditions. The overall understanding of TPEs and differential sensitivity of various growth stages to water stress helped to identify target traits for manipulation through breeding for drought tolerance. Recent advancement in high-throughput phenotyping platforms has made it more realistic to screen large populations/germplasm for drought-adaptive traits. The role of adapted germplasm has been emphasized for drought breeding, as the measured performance under drought stress is largely an outcome of adaptation to stress environments. Hybridization of adapted landraces with selected elite genetic material has been stated to amalgamate adaptation and productivity. Substantial progress has been made in the development of genomic resources that have been used to explore genetic diversity, linkage mapping (QTLs), marker-trait association (MTA), and genomic selection (GS) in pearl millet. High-throughput genotyping (HTPG) platforms are now available at a low cost, offering enormous opportunities to apply markers assisted selection (MAS) in conventional breeding programs targeting drought tolerance. Next-generation sequencing (NGS) technology, micro-environmental modeling, and pearl millet whole genome re-sequence information covering circa 1,000 wild and cultivated accessions have helped to greater understand germplasm, genomes, candidate genes, and markers. Their application in molecular breeding would lead to the development of high-yielding and drought-tolerant pearl millet cultivars. This review examines how the strategic use of genetic resources, modern genomics, molecular biology, and shuttle breeding can further enhance the development and delivery of drought-tolerant cultivars.
珍珠粟[ (L.) R. Br.]是一种C4作物，在印度次大陆和撒哈拉以南非洲的热带和亚热带地区以作物-畜牧为主的雨养农业系统中种植，用于获取其籽粒和秸秆。由于迫在眉睫的气候变化，干旱强度预计将进一步加剧，因此有必要更加关注珍珠粟的耐旱育种。在不同的珍珠粟种植环境目标群体（TPEs）中，干旱的性质在时间、强度和持续时间上差异很大。已经全面研究了珍珠粟在各个生长阶段对干旱的反应。对耐旱生理和物候的剖析有助于理解干旱条件下的产量形成过程。对TPEs的总体了解以及各个生长阶段对水分胁迫的不同敏感性有助于确定通过耐旱育种进行操控的目标性状。高通量表型分析平台的最新进展使得筛选大量群体/种质的耐旱适应性性状变得更加现实。适应种质在耐旱育种中的作用得到了强调，因为在干旱胁迫下测得的表现很大程度上是适应胁迫环境的结果。有人指出，将适应的地方品种与选定的优良遗传材料杂交可以融合适应性和生产力。在基因组资源开发方面已经取得了重大进展，这些资源已被用于探索珍珠粟的遗传多样性、连锁图谱构建（QTLs）、标记-性状关联（MTA）和基因组选择（GS）。现在高通量基因分型（HTPG）平台成本低廉，为在以耐旱为目标的常规育种计划中应用标记辅助选择（MAS）提供了巨大机会。下一代测序（NGS）技术、微环境建模以及涵盖约1000份野生和栽培种质的珍珠粟全基因组重测序信息有助于更深入地了解种质、基因组、候选基因和标记。它们在分子育种中的应用将导致高产耐旱珍珠粟品种的培育。本综述探讨了如何战略性地利用遗传资源、现代基因组学、分子生物学和穿梭育种来进一步加强耐旱品种的开发和推广。
