Articles
SELECTING EFFECTIVE INDICES FOR EVALUATION OF FIRE BLIGHT RESISTANCE IN QUINCE GERMPLASM UNDER ORCHARD SETTINGS
Article number
1056_41
Pages
247 – 251
Language
English
Abstract
Quinces display a rather divergent growth pattern compared to apples and pears.
Therefore, evaluation of fire blight susceptibility of quince germplasm by the same indices used in other hosts will be result in uncertain and doubtful scoring.
This research was conducted to investigate and compare the efficiency of the indices used to evaluate fire blight susceptibility of quince germplasm in orchard conditions.
Thirty quince genotypes from Iranian National Quince Collection were selected and the disease severity was monitored by three indices including index of Beltsville, developed by USDA (IUSDA), index of varietal susceptibility (IVS) and index of frequency (IF) during fire blight outbreaks in 2011 and 2012. All indices were judged against the total percentage of fire blight damage on the trees, indexed as IT. Correlation analysis showed that IF had the highest affinity with IT, but each single index demonstrated a different competence for evaluation the real disease damage and severity.
Due to these variant results, the genotypes were ranked differently for disease resistance using the different indices.
Cluster analysis was applied on all indices to obtain more effective ranking of fire blight susceptibility in quince.
Therefore, evaluation of fire blight susceptibility of quince germplasm by the same indices used in other hosts will be result in uncertain and doubtful scoring.
This research was conducted to investigate and compare the efficiency of the indices used to evaluate fire blight susceptibility of quince germplasm in orchard conditions.
Thirty quince genotypes from Iranian National Quince Collection were selected and the disease severity was monitored by three indices including index of Beltsville, developed by USDA (IUSDA), index of varietal susceptibility (IVS) and index of frequency (IF) during fire blight outbreaks in 2011 and 2012. All indices were judged against the total percentage of fire blight damage on the trees, indexed as IT. Correlation analysis showed that IF had the highest affinity with IT, but each single index demonstrated a different competence for evaluation the real disease damage and severity.
Due to these variant results, the genotypes were ranked differently for disease resistance using the different indices.
Cluster analysis was applied on all indices to obtain more effective ranking of fire blight susceptibility in quince.
Publication
Authors
Z. Ghahremani, M. Alipour, S. Ahmadi, H. Abdollahi, M. Mohamadi, A.A. Ghasemi, M. Adli
Keywords
Cydonia oblonga Mill., Erwinia amylovora, resistant cultivars, Beltsville index, cluster analysis
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