梅下毛瘿螨为害对杏树幼芽结构和生理的影响

Effect of Acalitus phloeocoptes Injury on Morphology and Physiology of Apricot Bud

针对梅下毛瘿螨[Acalitus phloeocoptes(Nalepa)]为害造成的杏芽瘿进行了田间调查和室内研究。用石蜡切片法对受害芽组织形态进行了观察描述,采用蒽酮比色法、考马斯亮蓝G-250法及紫外分光光度法对受害芽可溶性糖、可溶性蛋白质、过氧化氢酶活性等进行了测定。结果表明:在所调查杏树栽培品种中杏芽瘿普遍发生,包括意大利杏、双仁杏、金太阳等10个品种,在甘肃省兰州市秦王川地区发生最严重时病情指数为48。梅下毛瘿螨主要侵染杏树幼芽,受害芽增生畸变,形成大小不等的刺状瘿瘤。瘿瘤切片观察结果表明:受害芽解剖结构发生了明显变化,芽轴自下而上膨大,木质化程度由内向外逐渐加剧,外侧幼叶木质化程度高,尤其是靠近芽轴的基部已完全木质化并且明显增厚,叶片外张,内层幼叶外露;幼叶表皮细胞大小不一,表皮显著增厚并且完全木质化,叶肉细胞排列乱而松弛,后期解体。受害芽与正常芽相比可溶性糖含量下降,最大降幅为49.85%,受害芽的可溶性蛋白质、游离氨基酸和游离脯氨酸含量均升高,最高分别上升9.85%、96.87%和69.44%,过氧化氢酶活性亦增加,最高增加106.82%。

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. phloeocoptes mainly 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.