AUTHOR=Yan Weikai 

TITLE=A Systematic Narration of Some Key Concepts and Procedures in Plant Breeding

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.724517

DOI=10.3389/fpls.2021.724517

ISSN=1664-462X

ABSTRACT=The goal of a plant breeding program is to develop new cultivars of a crop kind with improved yield and quality for a target region and end-use. Improved yield across locations and years means better adaptation to the climatic, soil, and management conditions in the target region. Improved or maintained quality renders and adds value to the improved yield. Both yield and quality must be considered simultaneously, which constitutes the greatest challenge to successful cultivar development. Cultivar development consists of two stages: the development of a promising breeding population and the selection of the best genotypes out of it. A complete breeder’s equation was presented to cover both stages, which consists of three key parameters for a trait of interest: the population mean (µ), the population variability (σ_G), and the achieved heritability (h^2 or H), under the multi-location, multi-year framework. Population development is to maximize µσ_G and progeny selection is to improve H. Approaches to improve H include identifying and utilizing repeatable genotype by environment interaction (GE) through meg-environment analysis, accommodating unrepeatable GE through adequate testing, and reducing experimental error via spatial analysis. Related concepts and procedures were critically reviewed, including GGE biplot analysis, GGE+GGL biplot analysis, LG biplot analysis, stability analysis, spatial analysis, adequate testing, and optimum replication. Selection on multiple traits includes independent culling and index selection for the latter GYT biplot analysis was recommended. Genotypic selection may provide an alternative and potentially more effective approach in all these aspects. Efforts were made to organize and comment on these concepts and procedures in a systematic manner.