Abstract Detail

Functional Genetics/Genomics

Cobo-Simon, Irene [1], Bennett, Jeremy [2], Fritz, Ava [2], Romero-Severson, Jeanne [3], Reid, Megan [2], Koch, Jennifer [4], Reid, Noah [5], Wegrzyn, Jill [2].

Breeding Resistant Ash for North America: Identifying genetic signatures associated with the lingering phenotype in green ash (Fraxinus pennsylvanica).

Emerald ash borer (EAB) (Agrilus planipennis), a devastating invasive pathogen introduced in 2002 in North America, is impacting nearly all 16 species of native ash (Fraxinus spp) and is rapidly spreading West, affecting all landscapes. EAB can kill a susceptible tree within five years of detection. Prevention, treatment and removal of affected trees is expected to cost billions of dollars. Thus, the development of suitable and efficient management strategies is key to reduce the ecological, economic and social impact of this invasive pest. Fewer than 1% of individuals survive after EAB has come through a stand, and these trees are identified as “lingering”.
Concerted breeding efforts have examined this trait in green ash through the use of an egg bioassay that directly applies larvae to the stem and records larval weight and number of surviving larvae after 8 weeks. Crosses of the best parents have generated a small set of families that are improving in terms of these metrics in subsequent generations. While promising, the nature of tree breeding, outcrossing individuals with long generation times, combined with a time intensive bioassay, is challenged to generate a genetically diverse set of resistant tree stock for outplanting in time.
To complement these breeding efforts, we aim to identify the genetic basis behind the lingering phenotype, with the objective of detecting the variants that contribute to resistance, and ultimately, speed the process of improving ash populations. To accomplish this, we performed a double-digest RAD-Seq across an egg bioassay-phenotyped population of 107 green ash (Fraxinus pennsylvanica) and low-coverage whole-genome shotgun sequencing on 11 parental samples, representing 9 families. Variant detection yielded a total of 30,000 SNPs, which were used for data analysis. A linkage map was also built based on SNP and pedigree information. Finally, QTL analysis was conducted to identify genomic variants associated with the lingering phenotype.
The information obtained here may complement existing successes in breeding, with the objective of obtaining green ash individuals more resistant to EAB.

1 - University Of Connecticut EEB Dept., Ecology & Evolutionary Biology, 75 N Eagleville Rd Unit 3043, Storrs, CT, 06269, United States
2 - University of Connecticut, 75 N Eagleville road, unit 3043, Storrs, CT, 06269, USA
3 - University of Notre Dame, USA
4 - USDA, USA
5 - University of Connecticut, CT, USA

Keywords:
none specified

Presentation Type: Poster
Session: P2, Functional Genetics and Genomics Posters
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 5:00 PM(EDT)
Number: P2CG002
Abstract ID:483
Candidate for Awards:Phytochemical Best Poster Award