关键词: 梨, 植物病害, 黑星病

Abstract: Four varieties of pear inoculated with conidia (Venturia nashicola) wer used. The contents of total Phenols. OD phenol were analysed. The results have shown that the phenolics compounds, especially OD phenols, were connected with the resistance of pear to scab. There were different forms of expression in two species of pear. In the species of Pyrus bretchneider Rohd the scab-resistant variety contained more total phenols and OD phenols and OD phenol than those in scab-susceptible variety. It was contrary to the species of Pyrus bretchneider Nakai. The infection of V. nashicola increased the content of total phenols particularly ODphenol in both varieties of the specious of Pyrus bretchneider. The change in resistant variety was more obvious and faster. In the second species of Pyrus bretchneider, the infection of V. nashfcola increased the total phenols at the sec. day and the OD phenol from sec. to the 10th day bud decreased later in the resistant variety. In the susceptible variety, the infection redued the total phenols and OD phenol at first but incresed after the 5th day.

Key words: PEAR, PLANTDISEAS, APPLE SCAB