Poster

         Crops and Wild Relatives

Discovering the Genetic Basis of Rice Grain Shape

Presenting Author
UZEZI OKINEDO
Description
Breeding for high-quality rice can be accelerated by high-throughput phenotyping, leading to the identification and assessment of the genetic basis of rice grain structure. In this study, we used a recently described phenotyping pipeline to analyze rice grain size and shape, which are essential components of rice quality, in the diverse USDA rice mini-core collection. We measured nine grain phenotypes and identified significant differences among the five sub-populations represented in the mini core only for solidity, with aus sub-populations exhibiting substantially lower solidity values. Solidity measures the ratio of grain area to the area of a convex hull surrounding the grain. These ratios vary from 0–1, where values closer to one indicate rounder seeds and smaller values signify curved or abnormal shapes. We identified genome-wide associations for variation in solidity on chromosomes 3, 7, 8, and 9, with 913 candidate genes within 1 MB upstream and downstream of these associated loci. Seven of these candidate genes have known functions in seed-related traits and 38 genes have no known function. These candidate genes for solidity may provide novel insight into the genetic control of rice grain shape and assist future breeding efforts. Our ongoing work focuses on characterizing haplotype diversity at these loci across rice varieties.