Dr. Rod Wing: Using nature variation across the Genus Oryza to feed the world

PSLA Lecture Series: Dr. Rod Wing

Figure 1: G-PhoCS estimated demographic model for Asian rice complex. Arrows are labeled with median and 95% HPD for the total migration rate estimates. From (Jae young Choi et al., 2017)

March 13, 2017

On Thursday, March 9th, Dr. Rod Wing presented his work to the Department of Plant Science and Landscape Architecture at the University of Maryland. His research investigates breeding new rice varieties with 2-3 times yield with less water, fertilizer, pesticides and land using genomic selection to. Dr. Wing is a professor at University of Arizona and is also involved with the International Rice Research Institute (IRRI), which enables him to collect rice genomic data globally. To feed the increasing population effectively, Dr. Wing focuses on modern molecular breeding technology, which aims at understanding the differences in genome structure, combined with phenotyping observations, gene expression, and other information. So far, IRRI has sequenced more than 3000 rice genomes globally and identified about 20 million rice single nucleotide polymorphisms (SNPs) by aligning read (Zwickl et al., 2014). Dr. Wing initiated a project called the Oryza Map Alignment (OMAP) and Oryza Genome Evolution (OGE) projects. Co-operating with other scientists, he developed 18 bacterial artificial chromosome (BAC) libraries representing all Oryza genome types and 6 reference genomes; then they realized that a single reference genome sequence for the Oryza is not sufficient to capture the allelic diversity in the genus.

So far, based on sequence data from 11 Oryza species and outgroup Leersia perrieri, they present a comprehensive repeat database: the Rice Transposable Element database (RITE), transcriptome datasets, methylation data sets. Especially, when studying the origin of rice, they found that there were multiple origins, but single domestication of Asian rice [Fig 1.]. However, African rice is an entirely different species. He draws our attention to the importance of sequencing the wild species of rice as they contain high resistance to pathogens and environmental stresses. In the future, by studying the wild species rice genomes and using phenotypic and genetic data for a better selection process, scientists and breeders can drastically shorten the time it takes to produce new varieties.

Reference:

1. Zwickl D J, Stein J C, Wing R A, et al. Disentangling methodological and biological sources of gene tree discordance on Oryza (Poaceae) chromosome 3[J]. Systematic biology, 2014, 63(5): 645-659.

2. Choi J Y, Platts A E, Fuller D Q, et al. The rice paradox: Multiple origins but single domestication in Asian rice[J]. Molecular Biology and Evolution, 2017: msx049.