Registration of the sorghum multi-parent advanced generation intercross (MAGIC) B-line population ‘MBL’: A source of seed parent genetic diversity

Authors: Kumar, Neeraj; BOATWRIGHT, LUCAS - Clemson University; BRENTON, ZACHARY - Carolina Seed Systems, Inc; COX, ALEX - Clemson University; MCCALLA, KATHLEEN - Clemson University; KRESOVICH, STEPHEN - Clemson University; BOYLES, RICHARD - Pee Dee Research & Education Center

Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sorghum is a major source of human food, animal feed and bioenergy production. Improving the grain yield of sorghum is crucial for feeding the world population in future. Grain yield is a complex trait and regulated by many genes with small effects. We created a set of sorghum plants named ‘MAGIC’ (multiparent advanced generation intercross) B-line (MBL) population that was strategically designed for precisely determining the location of genes controlling complex traits like grain yield in grain sorghum. MBL was derived from four diverse parental lines of grain sorghum using multiple cycles of cross pollination. We identified several novel connections between various yield influencing traits and DNA markers in MBL population. We were able to identify the precise locations of the genes controlling yield and its component traits using the MBL. The precision with which the location of genes could be determined using the MBL was up to 15 times higher than what could be achieved using a population derived from a cross between just two parental lines. The entire MBL is publicly available in the germplasm collection. The MBL population will serve as a unique genetic and genomic resource by the entire sorghum research community to identify superior traits related to grain yield and its components for sorghum improvement. In addition, we selected a set of high yielding progenies from the MBL that could serve as female parents in hybrid seed production in public and private breeding programs for improving grain yield in sorghum.

Technical Abstract: Multi-parent populations are capable to dissect complex quantitative traits by capturing multiallelic variation compared to biparental populations. MAGIC B-line (MBL) population is a multiparent advanced generation intercross (MAGIC) population developed at Clemson University using four diverse accessions of grain sorghum [Sorghum bicolor (L.) Moench] that are known to not restore fertility in A1 cytoplasm. A set of 708 F7 recombinant inbred lines (RILs) (Reg. no. MPx, NSL 546930 MAP) were derived from the founders SC630 (PI533937), SC605 (PI534096), BTx642 (PI656029), and BTxARG-1 (PI561072) using repeated cycles of intercrossing. Each founder was carefully chosen to represent the four prominent sorghum races (kafir, guinea, durra, and caudatum) and capture important traits to segregate in the progeny, including stay-green, plant height, waxy endosperm, and plant/pericarp color. MBL and their founders were phenotypically characterized for plant/pericarp color and plant height, flowering, panicle type, grain yield and several yield components. The entire population and their founders were genotyped using Diversity Array Technology sequencing (DArTseq) to generate 3,751 quality-filtered SNPs. Genetic mapping of the MBL led to the discovery of novel marker-trait associations (MTAs) in addition to confirming several known genes. During elucidation of MTAs, there were novel genomic loci that demonstrated pleiotropic effects for agronomic, grain yield, and yield-related traits. With all founders are maintainers (B-lines) of cytoplasmic male sterility, progeny lines serve as genetic resources to improve B-line diversity, which can be limited due to a restricted number of non-restorers in Sorghum bicolor. This population can be further exploited to identify superior alleles to enrich seed parent gene pool.