Page 207 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

also isolated. However, other known CS pathogens such as S. scabiei were not detected, and this may
be due to the small sample size that was used in the study. The goal of the current study is to provide
new insights into the diversity of Streptomyces species responsible for CS in Newfoundland. Potato
tubers and beets exhibiting superficial, raised and/or deep-pitted scab lesions were collected from
different locations on the Avalon Peninsula and from central Newfoundland, and Streptomyces bacteria
were isolated in pure culture from the lesions. The isolates were screened for pathogenicity using a radish
seedling and potato tuber slice bioassay, and the strains were tested for production of thaxtomin A and
other known Streptomyces phytotoxins. Additional strain isolations are currently in progress, and future
work will include multi-locus sequence analysis for identification of the pathogenic isolates.

[P6] UNDERSTANDING THE INTERACTION BETWEEN BLACKLEG RESISTANCE AND
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VERTICILLIUM STRIPE DISEASE IN CANOLA. Carol. N. Bvindi , Aria Dolatabadian , and W. G.
1 1
Dilantha Fernando . Department of Plant Science, University of Manitoba, 66 Dafoe Road, Winnipeg,
MB, R3T2N2 Canada; and The University of Western Australia, 35 Stirling Highway, 6009, Perth
2
Australia.
Correspondence to: carol.bvindi@umanitoba.ca

Blackleg caused by Leptosphaeria maculans is a common disease of canola, found everywhere across
canola growing areas except in China The most effective control of Blackleg is R gene-mediated
resistance; to date, 19 R genes have been identified in Canola. Recently, verticillium stripe caused
by Verticillium longisporum has emerged as a threat to canola production in Canada. Host-specific
resistance against V. longisporum in canola has not been reported, and none of the commercial varieties
show resistance to verticillium stripe disease. V. longisporum and L. maculans can exist simultaneously in
canola; In the quest for V. longisporum resistance in canola, it is imperative to understand if there is an
interaction between the resistance already recorded in canola-blackleg interaction with V. longisporum
and if this resistance can be used in managing Verticillium stripe disease. We studied the interaction
between the blackleg gene for gene resistance and the three lineages of V. longisporum on blackleg and
verticillium stripe symptoms. We hypothesized that resistance to blackleg in the canola genotype may
reduce the induction of disease by both pathogens, while a breakdown of resistance due to virulence
alleles of the blackleg pathogen would lead to the plant being weakened and allow the vascular disease
caused by verticillium stripe pathogen to cause disease. Topas introgressed with a single R-gene in the
Topas background, were inoculated with the three lineages (A1D1, A1D2, and A1D3) of V. Longisporum
and then with the corresponding Avr/avr genotype of L maculans. At maturity, we evaluated blackleg and
verticillium stripe severity. Our results show that in most Topas lines tested, the interaction between the R
genes and Avr with the A1D1 lineage of V. longisporum. This interaction significantly affects blackleg
symptoms but not Verticillium stripe symptoms. However, the interaction between R genes and avr with
the A1D1 lineage of V. Longisporum does not significantly alter blackleg or verticillium stripe symptoms.
Thus, the known R-gene resistance in blackleg-canola interaction may not effectively manage verticillium
stripe.

*[P7] THE PHASED GENOME AND COLD RESPONSIVE TRANSCRIPTOME FOR
ALLOTETRAPLOID POTATO WILD RELATIVE SOLANUM ACAULE BITTER. Camargo-Tavares,
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2
3,4
1
1
J.C. , Achakkagari, S. , Praslickova, D. , Martini, C. , Bizimungu, B. , Anglin, N.L. , Manrique-
3
3*
2
Carpintero, N. , Lindqvist-Kreuze, H. , Tai, H.H. , and Strömvik M.V. . Department of Plant Science,
1 1
2
McGill University, Sainte-Anne-de-Bellevue, QC, Canada; Agriculture and Agri-Food Canada Fredericton
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Research and Development Centre, Fredericton, NB, Canada; International Potato Center (CIP), Lima,
Peru; and USDA ARS Small Grains and Potato Germplasm Research, Aberdeen, ID, USA
4
Correspondence to: martina.stromvik@mcgill.ca

Potato wild relatives within the Solanum section Petota are an important source of genetic diversity,
contributing to the improvement of modern potato cultivars (S. tuberosum) to withstand various climate-
related challenges. The allotetraploid species Solanum acaule Bitter has been particularly valuable in
introducing cold tolerance traits into potato breeding programs. This study represents the first sequenced
and phased subgenomes of an allopolyploid Solanum species. Our phylogenetic analysis shows that a
Clade 4 species is the progenitor of subgenome 2 of S. acaule, while the progenitor of subgenome 1
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