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Abstracts

cidate the efect of landscape structure on the 42. Potential use of vegetative indices to 43. Metalaxyl sensitivity of Phytophthora
abundance of cabbage seedpod weevil lygus detect and estimate disease severities spp. associated with red raspberry in
bugs crop damage and provide knowledge of Monilinia and Botrytis blight on wild British Columbia
to improve sustainable management of these blueberry fields S SAPKOTA AND R R BURL AKOTI AgassiZ Re­
pests K E ANKU D C PERCIVAL AND M VANKOU­ search and Development Centre Agriculture
GHNETT Department of Plant, Food, and and Agri­Food Canada 6947 Hwy#7 AgassiZ
41. Role of tomato ringspot virus in tree Environmental Sciences, Faculty of Agriculture, BC V0M 1A0 Canada
fruit decline in the Niagara region Dalhousie University, 50 Pictou Road, P.O. Box,
J PROSSER A LOFANO AND J GRIFFITHS 550, Truro NS B2N 5E3, Canada.; (M.V) Applied Root rot and wilting complex (RRWC) caused
(J.P., A.L., J.G.) Vineland Research Farm, Agri­ Environmental/Agriculture Research Team, by Phytophthora spp is the most devastating
culture and Agri-Food Canada, 4902 Victoria Nova Scotia Community College, 50 Elliot Road, disease of red raspberr y in British Colum­
Avenue North, Vineland, ON, Canada, L0R 2E0; Lawrencetown, Nova Scotia BOS 1MO. bia (BC) Metalaxyl is the most commonly
(J.P) Brock University, Department of Biological used fungicide to manage the disease in the
Sciences, 1812 Sir Isaac Brock Way, St. Cathari­ Monilinia blight (MB) and Botr ytis blossom province P rubi and P. gonapodyides were
nes, ON, L2S 3A, Canada. blight (BB) diseases are endemic to most wild isolated from red raspberr y samples showing
blueberr y fields and afect both foliage and symptoms of RRWC The metalaxyl sensitivity
Stone fruits are economically important crops flowers The se verity of these diseases de­ of strains of Phytophthora spp (12 strains of P.
in the Niagara region producing $66 million pends on the conditions present on the field rubi and 6 strains of P. gonapodyides) isolated
annually and have recently come under threat Present disease monitoring depends on the from diverse raspberr y farms of BC were eva­
from a devastating disease Tree Fruit Decline use of intensive sampling using line transect luated in vitro using the radial growth method
(TFD) is an emerging disease that results in among population structure Therefore the Metalaxyl was amended to 20% clarified V8
rapid decline and death up to 25% mortality ob ective of this study is to assess the poten­ agar to yield final concentrations of 0 0 001
of stone fruit trees to which there is no known tial of using vegetative indices (VI's) to detect 0 01 0 1 1 10 fg ml Each strain was tested in
­1
cause Numerous symptoms have been and assess the se verities of Monilinia blight triplicate for treatments and experiments were
obser ved including leaf chlorosis and wilting and Botr ytis blight disease on wild blueberr y repeated twice independently Fify percent
increased gummosis cankers and death plants Three patches each of Monilinia Bo­ efective concentration (EC ) values and dose
50
Viral infection of fruit trees can result in similar trytis blight and healthy plant treatments were response cur ves were determined for each
symptoms to TFD In order to identify the identified and disease progression monitored strain Results showed that � 83% of P. rubi
potential cause of TFD we employed RNA seq Disease sampling were grouped into 3 forms and 100% of P gonapodyides strains were
to identify all viruses present in diseased fruit low (1 - 30%) moderate (30 - 70%) and se ve­ highly sensitive to metalaxyl with mean EC 50
trees Total RNA was extracted from diseased re (70 - 100%) disease damage Assessments values of 0 0576 (range from 0 0375 to 0 0738)
tree samples and sequenced using Ilumina of plant damage was conducted using VI's for P rubi and 0 0542 (range from 0 0244 to
NovaSeq Multiple plant viruses were identi­ and data analyZed using analysis of variance 0 0758) for P. gonapodyides A detailed sensi­
fied including Prunus necrotic ringspot virus Results indicated that there were significant tivity study of a large number of Phytophthora
Tobacco streak virus Grapevine associated diferences (p<0 05) between the VI's com­ isolates is in progress
ilar virus Tomato ringspot virus (ToRSV) and puted for the healthy Monilinia and botr ytis
Peach latent mosaic viroid ToRSV was the blight diseased patch At each damage level Session 9. Student poster flash­
most prominent virus in these samples and healthy plants showed the highest signifi­ talks: Genetics, Biotechnology
infection by ToRSV ofen results in similar cance with Botr ytis blight being significantly
symptoms to TFD To investigate further PCR diferent from Monilinia blight A discriminant and Breeding
screening of 507 trees in the Niagara region re­ accuracy of 94 4% showed that normaliZed
vealed that ToRSV was present in 13% of fruit diference vegetative index (NDVI) can be used 44. Novel mutations in the CYP51 gene in
trees ToRSV was most prominent in peach to diferentiate between healthy and diseased a global collection of Pyrenophora triti-
trees with 27% prevalence rate Whereas the plants Green leaf index (GLI) gave an accuracy ci-repentis (tan spot of wheat)
least prominent were plum and cherr y trees of 83 3% with enhanced NDVI (ENDVI) giving B WEI M HAFEZ R GOURLIE S E STRELKOV
with 6% and 5% respectively We obser ved 72 2% accuracy NDVI performed better than AND R ABOUKHADDOUR (B.W., M.H., R.G.,
that multiple diseased trees failed to test po­ the other VI's in the determination of disease R.A.) Lethbridge Research and Development
sitive for ToRSV and multiple healthy trees did severity These results have illustrated the po­ Centre, Agriculture and Agri-Food Canada,
test positive for ToRSV Therefore suggesting tential to use VI's to discriminate healthy and 5403 1 Ave S, Lethbridge, AB T1J 4B1, Canada;
that ToRSV is likely not the sole cause of TFD disease plants and to assess disease pressures (B.W., S.E.S.) Department of Agricultural, Food
but may be a contributing factor in diseased on wild blueberr y fields & Nutritional Science, University of Alberta, 410
trees Agriculture/Forestry Centre, Edmonton, AB T6G
2P5, Canada.

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