【作者】 李焕宇；

【导师】 孙广宇；

【作者基本信息】 西北农林科技大学 ， 植物病理学， 2009， 硕士

【摘要】 煤污病和蝇粪病是仁果类果实生长晚期的两种重要病害,在果实表面形成污斑或污点,严重降低果实商品品质。煤污病和蝇粪病菌体类型多样,病原菌种类复杂,寄主也极为广泛。本试验主要对苹果煤污病和蝇粪病进行了研究,并对山楂和梨煤污病和蝇粪病病原菌多样性进行了初步探讨。于2006和2007年在中国陕西、山西、河南和甘肃4省25个地区共采集苹果煤污病和蝇粪病样品529份,分离得到纯菌种342株。对42株代表性菌株测定其核糖体基因rDNA的大亚基LSU区域部分序列,进行系统发育分析,结果显示:39个菌株归于月盾霉属Peltaster、Xenostigmina、Stomiopeltis、假小尾孢属Pseudocercosporella、接瓶霉属Zygophiala、锥梗孢属Dissoconium、链丝孢属Catenolaria、枝氯孢属Ramichloridium、球腔菌属Mycosphaerella、钉孢属Passalora、Strelitziana等11个属,其余3个菌株不能归属。总结了11个属在PDA培养基上的菌落培养性状,据此对所有菌株进行初步归属。供试菌株中317个菌株均可归于上述11个属,其余25个菌株不属于这些属。这一结果表明苹果煤污病和蝇粪病病原菌具有多样性,同时为根据菌落特征将病原菌分离物归类到属提供了一种简易方法。根据菌体类型分类标准将供试标苹果煤污病样品菌体划分为分支状、刻点状、蜂巢状和煤烟状四种类型。进一步比较发现菌体类型与病原菌归属表现出明显的相关性:分支状类型主要由Stomiopeltis spp.引起,刻点状类型主要由Peltaster spp.引起,蜂巢状类型主要由Pseudocercosporella spp.引起,煤烟状类型主要由Mycosphaerella spp.引起;蝇粪病病原菌主要包括Dissoconium spp.、Stomiopeltis spp.、Zygophiala spp.和Catenolaria spp.。菌体类型与病原菌归属之间虽不是一一对应,但可作为田间初步判断与归类的一个很有用的工具。结合ITS序列分析、菌落培养性状和形态学特征着重对3个属进行了鉴定描述。包括接瓶霉属Zygophiala 2种,隐性接瓶霉Z. cryptogama和柱孢接瓶霉Z. cylindrica;月盾霉属Peltaster 2种,同形孢月盾霉Pe. uniformis和礼泉月盾霉Pe. Liquanensis;假小尾孢属Pseudocercosporella2种,倒棍形假小尾孢Ps. obclavata和梭假小尾孢Ps. fusiformis;其中Z. cryptogama为我国新纪录种,其余5个种为新种。根据LSU序列分析将已报道的Ramularia-like真菌初步确定为一个新属,命名为链丝孢属Catenolaria,鉴定描述了该属中的三个新种:灵宝链丝孢C. lingbaosum、黄链丝孢C. flavus和粉链丝孢C. pulveris。采集得到40和12份山楂和梨煤污病和蝇粪病样品,分别得到纯菌株37和7株。对其中42株病原菌的ITS序列进行系统发育分析,将其初步归于锥梗孢属Dissoconium、月盾霉属Peltaster和球腔菌属Mycosphaerella等3个属的8个种。其中,山楂煤污病病原菌包括Dissoconium sp. FG5.2、Peltaster sp. 1、Pe. liquanensis、Pe. uniformis、Mycosphaerella sp. 1和Mycosphaerella sp. 2等3个属的6个种,梨煤污病和蝇粪病病原菌包括Mycosphaerella sp. 1、Mycosphaerella sp. 3和D. mali等2个属的3个种。表明山楂和梨煤污病和蝇粪病病原菌具有多样性,其中一些种类与苹果上病原相同,另外一些种类在苹果上尚未发现,可能为这些寄主所特有。更多还原

【Abstract】 Sooty blotch and flyspeck, a late season disease complex of pomaceous fruit in moist areas worldwide, blemishes fruit surface with dark smudges and tiny black spots, inciting cosmetic damage that cause significant economic losses. Sooty blotch and flyspeck is characterized by variety of mycelial types on fruit surface, diversity of pathogen complex, and wide host range. This paper mainly analyzed apple sooty blotch and flyspeck, and pathogen diversity of sooty blotch and flyspeck associated with hawthorn and pear were also discussed.Apples with sooty blotch and flyspeck signs were collected from 25 loci of Shaanxi, Shanxi, Henan and Gansu Provinces in 2006 and 2007, and 529 samples were preserved. Within the 342 pure strains obtained, partial sequences of large subunit (LSU) region of rDNA from 42 representative strains were sequenced and phynogenetically analyzed. And except 3 strains, other 39 strains grouped into 11 genera: Peltaster, Xenostigmina, Zygophiala, Dissoconium, Pseudocercosporella, Strelitziana, Stomiopeltis, Passalora, catenolaria, Ramichloridium, and Mycosphaerella. Distinct colony morphology on PDA medium of these 11 genera was summarized, and all 342 strains were ascribed into the 11 genera except 25 strains. These results revealed pathogen diversity of apple sooty blotch and flyspeck complex fully. Besides, colony morphology on PDA medium can be used as an available indicator to identify apple sooty blotch and flyspeck pathogen complex into genus.Sooty blotch and flyspeck signs on apple peels were distinguished. The former were classified into four mycelial types: ramose, punctate, ridged-honeycomb and fuliginous, and they were comprised mostly of Stomiopeltis spp., Peltaster spp., Pseudocercosporella spp. and Mycosphaerella spp. respectively. While apple flyspeck complex included Dissoconium spp., Stomiopeltis spp., Zygophiala spp. and catenolaria spp. Thus though mycelial type is not a reliable character to identify species, it still be a useful tool to observer apple sooty blotch and flyspeck in field and to estimate the main pathogen complex.Six species in 3 genera of apple sooty blotch and flyspeck complex, Z. cryptogama, Z. cylindrica, Pe. uniformis, Pe. liquanensis, Ps. obclavata, and Ps. fusiformis,were identified and described based on morphological characteristics in combination with phylogenetic analysis of ITS sequences. Of these species, Z. cryptogama was a new record in China and other 5 species were new. What was called Ramularia spp. in previous study was renamed to a new genus, Catenolaria spp., based on phylogenetic analysis of LSU sequences, and three new species, C. lingbaosum、C. flavus and C. pulveris, were described.Fruit of hawthorn and pear blemished with sooty blotch and flyspeck were also collected in 2007. Samples preserved were 40, 12 respectively, and 37, 7 pure strains were obtained. Forty-two strains grouped into 8 putative species in Dissoconium, Peltaster and Mycosphaerella, based on phylogenetic analysis of ITS sequences. Sooty blotch complex of hawthorn were comprised of Dissoconium sp. FG5.2, Peltaster sp. 1, Pe. uniformis, Pe. liquanensis , Mycosphaerella sp. 1 and Mycosphaerella sp. 2. Pear sooty blotch and flyspeck complex included Mycosphaerella sp. 1, Mycosphaerella sp. 3 and D. mali. This result indicated diversity of sooty blotch and flyspeck associated with hawthorn and pear. And of these fungi, some were identical with those of apple, while others were different and they may only occur on hawthorn and pear.更多还原