Time filter

Source Type

Wicklow, Canada

Hamzehzarghani H.,Shiraz University | Vikram A.,Potato Development Center | Abu-Nada Y.,University of Sainte-Anne | Kushalappa A.C.,University of Sainte-Anne
European Journal of Plant Pathology | Year: 2015

Selection of disease resistant potato varieties for conventional breeders is a time consuming and labor intensive process and most of the times lead to the results that are spatiotemporally inconsistent. Metabolic phenotyping was employed to develop metabolic criteria that can be used to distinguish potato genotypes with disease resistance. Tubers of potato varieties (Caesar and AC Novachip) moderately resistant and susceptible to Phytophthora infestans were inoculated with pathogen or water, and metabolites were analyzed using Gas Chromatography-mass Spectrometry (GS/MS). Disease severity was measured as the volume of diseased tissue calculated based on lesions volume at 2-day intervals after inoculation. Disease severity was 4.17 and 0.61 cm3 for varieties Caesar and AC Novachip respectively. Seventy seven metabolites were tentatively identified using Automated Mass spectral Deconvolution and Identification System (AMDIS) and univariate ANOVA showed that 37 metabolites had significant treatment effects with nine identified as resistance related and five as constitutive metabolites. Four metabolites, constitutive or induced showed significant increase in their abundance in pathogen inoculated tubers. A total of 21 metabolites were considered as pathogenesis related which showed changes in abundance after pathogen challenge. A canonical discriminant analysis of the 37 metabolites identified metabolic phenotypes correlating to disease severity phenotypes. The metabolites were mainly from sugars, fatty acids, and phenolic compounds which of some may have potential antimicrobial activity. Among resistance related metabolites, the abundances of 1H-Indole-3-acetonitrile, trihydroxybutyrate, D-Mannitol, dihydocoumarin, and propanoate were significantly higher in Caesar. The potential application of metabolic profiling technology for high throughput screening of potato breeding lines against potato late blight is discussed. © 2015 Koninklijke Nederlandse Planteziektenkundige Vereniging

Tavadjoh Z.,Islamic Azad University at Tehran | Hamzehzarghani H.,Shiraz University | Khalghani J.,Evin Plant Disease and Pest Research Institute | Vikram A.,Potato Development Center
Journal of Insect Science | Year: 2010

Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae) is considered as one of the most important natural biological control agents of the ash whitefly, Siphoninus phillyreae (Haliday) (Hemiptera: Aleyrodidae) in Iran. In the current survey, the development, survival, longevity, fecundity, feeding behaviour, and population dynamics of the predator under laboratory and field conditions were studied. The longevity of female insects was significantly longer than that of males. Total feeding of 4th larval instars and females was significantly higher than males and other larval instars. The overall mortality rate from egg to adult under laboratory conditions was 22.7% while under field conditions it was 38.2%. Copulation lasted approximately 67 minutes while the average pre-mating and pre-oviposition times recorded were 3.8 and 1.8 days, respectively. The mean number of eggs laid by each female was 181. The adults could survive starvation for 4 days with a normal longevity of 6273 days. The maximum population density of the predator was recorded in late August that coincided with the decline of the S. phillyreae population. C. arcuatus had four generations per year, and the adults were observed until mid December. Possible application of C. arcuatus for biological control of S. phillyreae in integrated pest management programs is discussed.

Al-Mughrabi K.I.,Potato Development Center | Vikram A.,Potato Development Center | Poirier R.,Potato Development Center | Jayasuriya K.,Potato Development Center | Moreau G.,McCain Foods Canada
Biocontrol Science and Technology | Year: 2016

Common scab, caused by Streptomyces scabiei is an economically important potato disease worldwide. The potato industry in New Brunswick, Canada experience $1.2 million loss every year due to this disease. Superficial, raised, or deep-pitted brownish lesions on infected tubers reduce the quality and marketability of both fresh-market and processing potatoes, and hence, common scab is considered a priority disease for which adequate control measures are lacking. The objective of this research was to compare various potential treatments in suppressing the disease. Two field experiments were conducted at McCain's Research Farm, Florenceville-Bristol, New Brunswick, Canada, in 2008 and 2009 to assess the efficacy of Bacillus subtilis, Enterobacter cloacae, Chloropicrin, Pic-Plus, manganese sulphate and mustard meal in comparison with the chemical controls fludioxonil and mancozeb against common scab of potato. The disease incidence was significantly reduced by 36% due to the addition of mustard meal to the soil; 35.4% due to fludioxonil seed treatment; 30.0% due to soil fumigation with Pic-Plus; or by 27.2% due to soil fumigation with Chloropicrin. Potato tubers with scab severity ≥5% which are considered unmarketable in Canada were significantly reduced by 56.1% due to seed treatments with B. subtilis; by 57.8% due to fludioxonil; or by 63.1% due to the soil addition of mustard meal. The same treatments significantly increased marketable yield by 32.5%, 24.6%, and 24.6%, respectively. Soil fumigation with Chloropicrin or Pic-Plus increased marketable yield by 9.5% or 7.1%, respectively. These findings indicate that, in addition to the fludioxonil seed treatment, the seed treatment with the biopesticide containing B. subtilis and the soil addition of mustard meal treatments are potential alternatives for managing common scab of potatoes. © 2015 Her Majesty the Queen in Right of Canada, as represented by the New Brunswick Department of Agriculture and McCain Foods (Canada).

Al-Mughrabi K.I.,Potato Development Center | Coleman W.K.,Agriculture and Agri Food Canada | Vikram A.,Potato Development Center | Poirier R.,Potato Development Center | Jayasuriya K.E.,Potato Development Center
Journal of Essential Oil-Bearing Plants | Year: 2013

S-carvone, L-menthone, peppermint and spearmint oils were tested in vitro against Fusarium coeruleum, F. sambucinum, F. avenaceum, F. oxysporum, Alternaria solani, Rhizoctonia solani, Helminthosporium solani, Phytophthora infestans (A1 and A2 mating types), Phytophthora erythroseptica, Phoma exigua and Pythium ultimum which are causal agents of major potato storage diseases. The majority of these pathogens were completely inhibited due to pure oils, although F. sambucinum, F. avenaceum, A. solani and P. exigua were not completely inhibited by one or more pure oils. Peppermint oil was the least effective among tested oils. However, R. solani, H. solani, P. erythroseptica, and P. infestans (A1 and A2 mating types) were completely inhibited for a period of 1-18 weeks by single treatments of all four pure oils. Effects of mixtures of aluminum starch octenylsuccinate (ASOS) and L-menthol or peppermint oil on F. sambucinum and R. solani were also tested in vitro for a period of over 5 weeks. Percent inhibition of F. sambucinum by single application of mixtures of ASOS and L-menthol or peppermint oil decreased over 11-13 days after treatment, while the mixtures at the same rates consistently inhibited the growth of R. solani for over 15 days. Mixtures of 10 g of ASOS and 4 g or 8 g doses of essential oils were the most effective in inhibiting pathogens growth for periods over 13 or 20 days, respectively. The antifungal effects of essential oils and their components against all tested pathogens suggest their potential use as alternative tools for controlling potato storage diseases. © 2013, Copyright Har Krishan Bhalla & Sons.

Discover hidden collaborations