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Resistance in water yam ( Dioscorea alata ) cultivars in the French West Indies to anthracnose disease based on tissue culture‐derived whole‐plant assay
Author(s) -
Onyeka T. J.,
Pétro D.,
Ano G.,
Etienne S.,
Rubens S.
Publication year - 2006
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/j.1365-3059.2006.01436.x
Subject(s) - cultivar , biology , pathosystem , inoculation , horticulture , plant disease resistance , pathogen , botany , veterinary medicine , microbiology and biotechnology , medicine , biochemistry , gene
Reactions of 60 water yam ( Dioscorea alata ) cultivars to three isolates of the yam anthracnose fungal pathogen ( Colletotrichum gloeosporioides ) were evaluated using tissue culture‐derived whole‐plant assay. Three disease parameters: single score on a scale of 0–6 at the seventh day after inoculation (SD7); area under the disease progress curve (AUDPC); and disease progress rate ( R d ) were compared, and cultivars were classified into disease‐response groups using a rank‐sum method based on AUDPC scores for the two most virulent isolates. A wide range of variation in resistance of the D. alata cultivars, and significant effects of pathogen isolate and isolate–cultivar interactions, were observed for all disease parameters. The three disease parameters were positively correlated; however, four cultivars showed great dispersions from the regression lines for comparisons of SD7 with the multiple assessments based AUDPC and R d . The 60 cultivars were separated into resistant ( n = 12), moderately resistant ( n = 19), moderately susceptible ( n = 18) and susceptible ( n = 11) groups. The potential of the tissue culture‐derived whole‐plant assay to resistance breeding programmes and further understanding of the yam anthracnose pathosystem is discussed.