Submitted to: Phytopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/10/2004
Publication Date: 1/10/2004
Citation: Mlikota-Gabler, F., Smilanick, J.L., Mansour, M., Ramming, D.W., Mackey, B.E. 2004. Correlations of morphological, anatomical, and chemical features of grape berries with resistance to botrytis cinerea. phytopathology. Phytopathology 93:1263-1273. Interpretive Summary: Gray mold, caused by Botrytis cinerea, is one of the most destructive diseases of grapes, both before and after harvest, worldwide. In this paper, we show which features of grape berries were associated with resistance to infection by this pathogen. This work facilitates the identification and incorporation of resistance to this important disease, and perhaps other diseases as well, into grape cultivar development programs. The release of disease resistant cultivars an important step to eliminate the need for fungicide applications now done to control this disease.
Technical Abstract: Resistance of mature berries of grapevine cultivars and selections to postharvest infection by Boirvtis cinerea was assessed. Little or no resistance existed in most popular table grape Vitis vinifera cultivars. except in moderately resistant 'Emperor' and 'Autumn Black'. Highly resistant grapes were V rotundifolia, V labrusca. or other complex hybrids. Morphological, anatomical, and chemical characteristics of 42 genetically diverse cultivars and selections with various levels of resistance to B. cinerea were examined to determine which features were associated with resistance. We quantified the (i) density of berries within a cluster; (ii) number of pores and lenticels on the berry surface; (iii) thickness and number of cell layers in the epidermis and external hypodermis; iv) amount of cuticle and wax; (v) berry skin protein content; (vi) total phenolic content of the skin before and after B. cinerea inoculation; and (vii) catechin and nuns- and cis-resveratrol contents of the skin before and after inoculation. The number of pores was negatively correlated with resistance. Highly resistant cultivars had few or no pores in the berry surface. The number and thickness of epidermal and hypodermal cell layers and cuticle and wax contents were positively correlated with resistance. Other characteristics evaluated were not associated with resistance. trans-Resveratrol and cis-resveratrol were induced by B. cinerea inoculation only in sensitive and moderately resistant cultivars and selections.