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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Crop and Commodity Protection Research » Research » Publications at this Location » Publication #310575
Title: Using genotyping by sequencing (GBS) to identify Loci in Colocasiae esculenta linked to Phytophthora colocasiae resistance

Author
item SHINTAKU, MICHAEL - University Of Hawaii
item KIMBALL, HEATHER - University Of Hawaii
item BROWN, A - University Of Hawaii
item MIYASAKA, S - University Of Hawaii
item SIM, SHEINA - University Of Hawaii
item Geib, Scott

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2015
Publication Date: 5/31/2016
Citation: Shintaku, M.H., Kimball, H., Brown, A., Miyasaka, S., Sim, S., Geib, S.M. 2016. Using genotyping by sequencing (GBS) to identify Loci in Colocasiae esculenta linked to Phytophthora colocasiae resistance. Acta Horticulturae. 1118:131-138.

Interpretive Summary: One of the most significant threats to taro production is a disease called taro leaf blight (TLB), particularly to Hawaiian taro varieties. While there are many varieties of taro throughout the Pacific Basin, several cultivars from Palau, Micronesia and other locations exhibit good field resistance to TLB. Despite this disease resistance, these taro varieties do not carry other quality traits that are preferred in Hawaiian taro varieties. To better understand resistance in the taro, a UH breeding program has been established which evaluated several thousand plants resulting from 27 crosses for TLB resistance. One of these crosses resulted in progeny with a striking degree of resistance in this assay. These progeny were much more resistant than either parent, and are seemingly immune to the pathogen. To identify the genetic association of the resistance a genotype-by-seqeuncing (GBS) approach was used to build a linkage map using over 100 newly characterized single nucleotide polymorphisms (SNPs). We present a summary of our virulence assays, and a draft linkage map of taro using the SNP’s obtained from GBS. The resistance phenotype described here is not inherited in a dominant manner and is likely a complex trait, determined by more than one locus, reflected in our analysis of SNP linkage to TLB resistance.

Technical Abstract: One of the most significant threats to taro production is taro leaf blight (TLB) caused by the oomycete pathogen Phytophthora colocasiae. Therefore, one of the primary selection criteria for the University of Hawaii taro breeding program is TLB resistance. Some cultivars from Palau, Micronesia and other locations exhibit good field resistance to TLB, and they have been incorporated into the UH breeding program. We recently evaluated several thousand plants resulting from 27 crosses for TLB resistance, using an excised leaf disc assay. A cross between two hybrid cultivars (255 × 230) resulted in a number of progeny with a striking degree of resistance in this assay. These progeny were much more resistant than either parent, and are seemingly immune to the pathogen. Extracted DNAs from a selection of 48 resistant and 48 susceptible progeny from that cross, along with the parental cvs. 255 and 230, were subjected to genotyping by sequencing (GBS). We present a summary of our virulence assays, and a draft linkage map of taro using the SNP’s obtained from GBS. The resistance phenotype described here is not inherited in a dominant manner and is likely a complex trait, determined by more than one locus, reflected in our analysis of SNP linkage to TLB resistance.