Page 196 - PC2019 Program & Proceedings

PLANT CANADA 2019

S177. The implications of drought stress on the nutritional quality of potato
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Da Ros, L. ; R. Elferjani ; R. Soolanayakanahally ; S. Kagale ; J. Wahab ; B. Bizimungu 2
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1 University of British Columbia
2 Agriculture and Agri-Food Canada
3 National Research Council Canada

Potato is among one of the most important food crops, yet maintaining plant productivity in this drought
sensitive crop has become a challenge. Competition for scarce water resources and the continued effects
of global warming exacerbate current constraints on crop production. While plant response to drought in
above ground tissues and the corresponding effects on yield have been well documented, the regulatory
cascades and the metabolic consequences in developing tubers have been largely unexplored. Using the
commercial Canadian cultivar ‘Vigor’, plants were subjected to a drought treatment under high-tunnels in
the field with demonstrated effects on plant physiology, as seen by a 4℃ increase in canopy temperature
and a 44% decrease in leaf Fv/Fm ratios when compared to the well-watered control. Tubers at the tuber
bulking phase were sampled for RNAseq and metabolite analysis. 2600 genes and 5232 transcripts were
differentially expressed by at least four-fold in drought-stressed potato tubers, with approximately 71‒75
% of those being downregulated. A further 229 smRNA were implicated in gene regulation during
drought. The comparison of protein homologues between Solanum tuberosum and Arabidopsis thaliana
indicates that downregulated genes are associated with an array of metabolic pathways including
phenylpropanoid, flavonoid, carotenoid, and amino acid biosynthesis. This suggests that there are both
yield and dietary implications to drought stress occurring during the potato tuber bulking phase in
sensitive cultivars.

Raju Soolanayakanahally (raju.soolanayakanahally@canada.ca)

S178. Whole genome comparisons of commercial Phaseolus vulgaris varieties and interspecific
hybrids
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Perry, G. ; S. Munholland ; Y. Reinprecht ; E. Morneau ; W. Xie ; P.K. Pauls ; B. Crosby
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1 University of Guelph
2 University of Windsor
Among Phaseolus species, Phaseolus vulgaris is the most widely cultivated member for direct human
consumption. The dry bean breeding program at the University of Guelph has produced a wide range of
varieties, including those derived from interspecific hybridization with Phaseolus acutifolius (PI440795
and PI319443), which brought over strong genetic resistance to CBB caused by Xanthomonas spp. OAC-
Rex was the first commercial variety released to contain this resistant trait in 2001, and its genome was
sequenced in 2015, with a formal V1.0 release occurring in 2019. As OAC-Rex has been extensively used
in the bean breeding program to date, this has created an opportunity to leverage new bioinformatics
techniques and directly compare the genetic diversity present in the population. A total of 10 dry bean
varieties were each crossed with a single parental line, Ex Rico, and the genomes of each of these parental
lines are being fully sequenced using a combination of PacBio, and Illumina sequencing platforms. Here
we describe whole genome comparisons between the preliminary assemblies of Ex Rico, Rexeter, and
Mist, along with the previously released P. vulgaris genomes, G19833, OAC-Rex, and Bat93. Overall
gene order and orientation is highly conserved across all sequenced lines, and a sliding window analysis
has shown that the individual pedigrees of these varieties can be distinguished, including conserved
regions that are derived from interspecific hybridization.

Gregory Perry (perryg@uoguelph.ca)

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