|Authors: ||M.H. Shintaku, H.L. Kimball, A.D. Brown, S.C. Miyasaka, S.B. Sim, S.M. Geib|
|Keywords: ||taro, leaf blight, oomycete, Hawaii, SNP, linkage, kalo|
One of the greatest 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 (UH) 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 '230'×'255' 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 cultivars '230' and '255', were subjected to genotyping by sequencing (GBS). We present a summary of our virulence assays, and a draft linkage map of taro, using the SNPRSQUOs 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, as reflected in our QTL analysis of SNP linkage to TLB resistance.
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