关键词: 杏, 杏芽瘿, 梅下毛瘿螨, 组织病理学, 生理指标

Abstract: Apricot bud gall caused by Acalitus phloeocoptes（Nalepa）was investigated and studied in field and indoor. The morphology of injured apricot bud was observed and described by paraffin sections. And the content of soluble sugar，soluble protein and hydrogen peroxidase activity of injured apricot bud was determined by anthrone colorimetry，coomassie brilliant blue G-250 and UV spectrophotometry. The results showed that apricot bud gall has been found from all investigated apricot cultivars，including 10 cultivars such as Italian apricot，Shuangrenxing，Goldsun etc. The highest disease index was 48 in Qinwangchuan District，Lanzhou City. A. phloeocoptesmainly injured apricot bud and caused it proliferated and deformed gradually，and formed acanthoid gall tumor structure. The anatomy of injured buds showed obvious changes by tissue sectioning. The injured bud axis inflated obviously from the basal to the upper parts. Degree of lignifications of immature leaves aggravated gradually from inside to outside. External immature leaves lignified seriously，especially the lower part of leaves nearby bud axis，which lignified completely and thickened remarkably，resulting in leaves’ stretching outward and internal immature leaves’ disclosing completely. The epidermal cells had different sizes，and epidermis of leaves had much thickened and lignified completely. Mesophyll cells arranged loosely and in disorder and disintegrated at last. Compared with healthy apricot buds，the physiology of injured ones had obvious change. The content of soluble sugar decreased，with the largest decrease 49.85%. While the content of soluble protein，free amino acid，and free proline，as well as the activity of hydrogen peroxidase increased，with the highest increase 9.85%，96.87%，69.44% and 106.82%，respectively.

Key words: apricot, apricot bud gall, Acalitus phloeocoptes, histopathology, physiology