AUTHOR=Chiteri Kevin O. , Jubery Talukder Zaki , Dutta Somak , Ganapathysubramanian Baskar , Cannon Steven , Singh Arti 

TITLE=Dissecting the Root Phenotypic and Genotypic Variability of the Iowa Mung Bean Diversity Panel

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.808001

DOI=10.3389/fpls.2021.808001

ISSN=1664-462X

ABSTRACT=Mung bean (Vigna radiata (L.) Wilczek) is a drought-tolerant, short-duration crop, and a rich source of protein, and other valuable minerals, vitamins, and antioxidants. The main objectives of this research were (1) to study the root traits related with the phenotypic and genetic diversity of 375 mung bean genotypes of the Iowa (IA) diversity panel, and (2) conduct genome wide association studies of root related traits using the Automated Root Image Analysis (ARIA) software. We collected over 9000 digital images at three-time points (days 12, 15, 18 after germination). Broad sense heritability for days 15 (0.22-0.73) and 18 (0.23 - 0.87) was higher than those for day 12 (0.24 - 0.51). We also report root ideotype classification; PI425425 (India), PI425045 (Philippines), PI425551 (Korea), PI264686 (Philippines), PI425085 (Sri Lanka) emerged as the top five in the topsoil foraging category, while PI425594 (Unknown origin), PI425599 (Thailand), PI425610 (Afghanistan), PI425485 (India), AVMU0201 (Taiwan) were top five in the drought tolerant and nutrient uptake “steep, cheap, and deep” ideotype. We identify promising genotypes that can help diversify the gene pool of mung bean breeding stocks and will be useful for further field testing. Using association studies, we identified markers showing significant associations with lateral root angle (LRA) on chromosomes 2, 6, 7 and 11, length distribution (LED) on chromosome 8, total root length – growth rate (TRL_GR), volume (VOL), and total dry weight (TDW) on chromosomes 3 and 5. We discuss potential candidate genes from these regions. We report beta-galactosidase 3 associated with lateral root angle (LRA), which has previously been implicated in the adventitious root development via transcriptomic studies in mung bean. Results from this work on phenotypic characterization, root based ideotype categories, and significant molecular markers associated with important traits will be useful for marker-assisted selection and mung bean improvement through breeding.