Abstract
Breeding in the CGIAR Research Program on Roots, Tubers and Bananas (RTB) targets highly diverse biotic and abiotic constraints, whilst meeting complex end-user quality preferences to improve livelihoods of beneficiaries in developing countries. Achieving breeding targets and increasing the rate of genetic gains for these vegetatively propagated crops, with long breeding cycles, and genomes with high heterozygosity and different ploidy levels, is challenging. Cheaper sequencing opens possibilities to apply genomics tools for complex traits, such as yield, climate resilience, and quality traits. Therefore, across the RTB program, genomic resources and approaches, including sequenced draft genomes, SNP discovery, quantitative trait loci (QTL) mapping, genome-wide association studies (GWAS), and genomic selection (GS), are at different stages of development and implementation. For some crops, marker-assisted selection (MAS) is being implemented, and GS has passed the proof-of-concept stage. Depending on the traits being selected for using prediction models, breeding schemes will most likely have to incorporate both GS and phenotyping for other traits into the workflows leading to varietal development.
Highlights
Root, tuber, and banana (RTB) crops—cassava (Manihot esculenta), potatoes (Solanum spp.), sweet potatoes (Ipomoea batatas), yams (Dioscorea spp.), bananas, and plantains (Musa spp.), and tropical and Andean roots and tubers—play a very important role in food security and income, and represent significant agricultural opportunity in tropical areas of sub-Saharan Africa (SSA), Asia, and LatinAmerica, especially for the more than 300 million growers below the poverty line [1,2,3,4]
We review the status of genomic resources being developed by RTB program, and their potential use for genomics-assisted breeding in order to enhance genetic gains for various important traits to address the Sustainable Development Goals of poverty reduction, decreased hunger, and better nutrition
Due to the challenges presented above, developing and applying genomic tools to aid in the selection, especially of complex traits, would both shorten the time required for advancing material, save on expensive and/or very time-consuming phenotyping screens, and significantly reduce the field resources needed to screen material
Summary
Tuber, and banana (RTB) crops—cassava (Manihot esculenta), potatoes (Solanum spp.), sweet potatoes (Ipomoea batatas), yams (Dioscorea spp.), bananas, and plantains (Musa spp.), and tropical and Andean roots and tubers—play a very important role in food security and income, and represent significant agricultural opportunity in tropical areas of sub-Saharan Africa (SSA), Asia, and Latin. Cheaper sequencing has opened many possibilities to apply genomics tools to advance crop-breeding programs for complex traits, such as climate resilience [14] and quality traits [15] This has led to the coining of the term “genomics-assisted breeding” [16], or “whole-genome selection” [17]. Cassava, and yam, and many banana lines, botanical seed numbers are low, requiring larger efforts to produce seed from crosses in a breeding program, and to generate large breeding populations. A Bill and Melinda Gates Foundatin (BMGF)-funded project began in 2018 to tackle the issues of prioritizing quality traits for fresh and major processed RTB products in SSA, and developing high-throughput phenotyping tools for use by breeders to incorporate in their RTB breeding programs (https://www.cirad.fr/en/news/all-news-items/press-releases/2018/rtbfoods).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
