Genetic analysis of vegetative branching in sorghum

• Published in: Theoretical and applied genetics Vol. 127; no. 11; pp. 2387 - 2403
• Main Authors: Kong, Wenqian, Guo, Hui, Goff, Valorie H, Lee, Tae-Ho, Kim, Changsoo, Paterson, Andrew H
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.11.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Agriculture; Analysis; Biochemistry; Biomass; biomass production; Biomedical and Life Sciences; Biotechnology; branches; branching; Breeding; Chromosome Mapping; Chromosomes; Chromosomes, Plant; Corn; Gene-Environment Interaction; genes; Genes, Plant; Genetic aspects; Genetic Association Studies; genetic techniques and protocols; Genomes; Genotype; inbred lines; inflorescences; Life Sciences; meristems; Morphology; Original Paper; Oryza sativa; parents; Phenotype; Physiological aspects; physiological state; Physiology; plant architecture; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Stems - anatomy & histology; Polymorphism, Single Nucleotide; Quantitative genetics; Quantitative Trait Loci; Rice; Single nucleotide polymorphisms; Sorghum; Sorghum - anatomy & histology; Sorghum - genetics; Sorghum bicolor; tillers; Sorghum; Recombinant Inbred Line Population; Tertiary Branch; Plant Architecture; Recombinant Inbred Line
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-014-2384-x

KEY MESSAGE : We identified quantitative trait loci influencing plant architecture that may be valuable in breeding of optimized genotypes for sustainable food and/or cellulosic biomass production, and advancing resilience to changing climates. We describe a 3-year study to identify quantitative trait loci (QTLs) for vegetative branching of sorghum in a recombinant inbred line population of 161 genotypes derived from two morphologically distinct parents, S. bicolor × S. propinquum. We quantify vegetative branching based on morphological position and physiological status. Different sets of QTLs for different levels of branching were identified. QTLs discovered on chromosomes 1, 3, 7 and 8 affect multiple vegetative branching variables, suggesting that these regions may contain genes that control general axillary meristem initiation. Other regions that only influence one vegetative branching trait could contain genes that influence developmental processes contributing to divergent patterns of plant architecture. We investigate the relationship between vegetative branching patterns and dry biomass, and conclude that tillers with mature panicles and immature secondary branches each show consistent positive correlation with dry biomass. Among 19 branching-related genes from rice, eight sorghum homologs of seven rice genes are in syntenic blocks within branching-related QTL likelihood intervals. Five of these eight genes are within 700 kb of SNPs significantly associated with differences in branching in genome-wide association study of a diversity panel of 377 sorghum accessions, and three contain striking allelic variations between S. bicolor and S. propinquum that are likely to impact gene functions. Unraveling genetic determinants for vegetative branching may contribute to deterministic breeding of optimized genotypes for sustainable food and cellulosic biomass production in both optimal and marginal conditions, which are resilient to future climates that are more volatile and more stressful.