INVESTIGATOR: Comai, L., Groover, A.
INSTITUTION: University of California, Davis and US Forest Service, Davis
NON-TECHNICAL SUMMARY: The overall goal of the proposed research is to provide new genomic tools for plant breeders to rapidly identify poplar germplasms with unique genotypes with increased biomass yields. The proposed research will take advantage of advances in DNA sequencing technology to identify trees from traditional breeding programs that carry additional chromosomal regions. Such properties can confer faster growth, as has been shown in other plant species. Techniques for creating poplar hybrids with unique combinations of chromosomal regions at high frequency will also be developed. The project addresses the specific challenge posed by the long generation time of trees and aims at generating and analyzing diversity through fast and cost-effective non-transgenic genetic manipulation. The development of high yielding bioenergy poplar will decrease the acreage required for biomass production, minimize food vs. biofuels land use trade-offs, and the cost of biomass per dry ton, while increasing biofuels carbon balance and sustainability.
OBJECTIVES: 1. Characterize ploidy changes, deletions and possible rearrangements in existing Populus hybrids, correlate these data with biomass properties. 2. Produce germplasm with enriched genotypic and chromosomal dosage variation compared to traditional Populus hybrids and test the contribution of smaller chromosomal regions to interesting traits. This germplasm will serve as a testbed for exploring correlations between the dosage of specific chromosomal segments and growth traits, and to identify commercially-relevant genomic combinations. 3. Compare these dosage variants to parents and other hybrids and correlate gene expression with biomass-related traits.
APPROACH: The project will explore fundamental features of ploidy changes, dosage and heterosis underlying Populus hybrids and their phenotypes. Previous research has shown that commercial F1 hybrids can be triploid or aneuploid, and can have transgressive phenotypes desirable for biomass production. Unfortunately the chromosomal composition and genetic features of these individuals are poorly characterized, and have not yet been examined by genomics research or effectively manipulated in breeding programs. Next generation sequencing-based approaches will be used to characterize parental species and multiple hybrids. γ−irradiation of pollen will be used to induce deletions of varying size. Selected individuals with interesting genomic characteristics will be subjected to RNA-seq for comparison to other hybrid and parental species.
Name: Comai, L.