【作者】 郝敬喆；

【导师】 马德英； 日孜旺古丽；

【作者基本信息】 新疆农业大学 ， 植物病理学， 2006， 硕士

【摘要】 通过对小麦黑胚病病原分离、病原的鉴定及致病性研究结果表明,引致新疆小麦黑胚病的病原由多种病原组成,确立了Alternaria consortiale (Thüm.) Hughes,Alternaria alternate (Fr.)Keissler与Bipolaris sorokiniana (SaccetSorokin)Shoems是引发新疆小麦黑胚病的主要致病原,A. consortiale可侵染小麦种粒且成为新疆小麦黑胚病的优势病源,这在我国文献的报道中尚属于首次。通过对小麦黑胚病病原侵染机制研究,3种主要病原菌均可侵染小麦植株但对麦粒的致病性表现持差异,A.consortiale和A. alternate对小麦苗期及成株期幼嫩组织侵染致病力弱,相反B.sorokiniana是这时期的主要致病原。进入小麦接穗期后却表现相反,B. sorokiniana对麦粒的致病力表现较弱,而苗期致病力强; A. consortiale与A. alternate适宜的侵染致病期均出现在小麦的乳熟期至黄熟期。在小麦黑胚病病原的侵染机制研究中,总表现在穗轴部位首先发病,然后由病变处的菌丝体穿透过小穗的基部再过渡到胚尖,才使得小麦的胚也感染变黑。实验结果已表明,大田环境高温多湿,是引致小麦黑胚病高发的首要成因。2004～2005年在新疆农业大学试验田,对25份小麦品种进行籽粒黑胚病抗感性差异田间鉴定,研究结果表明,不同品种对Alternaria alternate(Fr.) Keissler与Bipolaris sorokiniana (Sacc et Sorokin) Shoems引致的小麦黒胚病抗性不同。在单独接种链格孢的25份供试材料中未发现免疫品种,表现感病的品种有新春6号、新春8号、新春7号等9个品种,占鉴定总数的36%;表现中感的品种有新春2号、新春5号、8131等11个品种占48%;发病率低于6%的抗小麦籽粒黑胚病品种有新春15号、945-304、64--1、1-147等4个品种,仅占鉴定总数的16%。而单独接种根腐离蠕孢菌各材料的黑胚率调查结果表明:表现感病的品种有宁春4号、新春13号、新春9号等3个品种;新春2号等7个品种表现中感品种特征;新春15号、64—1等15个品种表现抗病,占鉴定总数的60%。试验调查了成熟小麦的株高、芒长、穗长与小麦黑胚病的相关性,分析表明种子发病率与小麦株高矮呈负相关,芒长、穗长与小麦籽粒发病率呈负相关性。解剖新春6号种粒的组织切片观察菌丝在小麦籽粒内部的生活状态显示,病原菌菌丝潜伏麦粒果皮下危害组织细更多还原

【Abstract】 According to results on pathogen isolation, identification and pathogenicity, there are threepathogens, Alternaria consortiale (Thüm.) Hughes,Alternaria alternate (Fr.) Keissler and Bipolarissorokiniana (Sacc et Sorokin) Shoems., which causing black point diseases of wheat were determined inXinjiang. It was the first report in China that A. Consortiale infected kernel and became to thepredominantpathogen.Resultsalsoshowedthatthepathogenicitiesofthreepathogensweredifferent. Thepathogenicity of B. sorokiniana on seedling was stronger than that of the other two pathogens, but thesituation changed to the opposite after the heading stage. The pathogenicities of A. consortiale and A.alternateonkernelwerestrongerthanthatof B.sorokiniana,theirinfectionperiodsarefrommilkstagetothe yellow ripe stage and fromheading stage to milk stage, respectively. On the pathogens of wheat blackpointdisease infection mechanismStudyisobserved. Pathogens always infectthe rachilla first, there aftermyceliuminfected embryo throughthe bottomof ear then causing the whole embryo getting black. it wasproved that high temperature and air humidity in field are the principal reasons of high frequency ofdisease. A 2-yr field studies have been conducted, at the experimental station in Xinjiang agricultureuniversity. There are 25 wheat cultivars including the main cultivars and regional trial wheat varietieswere evaluated on susceptibility and resistance to black point disease. The varieties showed differentabilityto disease caused bydifferentpathogen. Regarding the disease caused byA.alternate., there are noimmunevarietiesbeendetected,whereas9varietiesaccountfor36%outoftotaltestedvarieties,includingXinchun6, 7, 8 and etc. showed high susceptibilityto the disease, 11 varietiesaccountfor48%outoftotaltested varieties, including Xinchun2, 5, 8131 and etc. showed middle susceptibility to the disease.However, there are only 4 varieties account for 16% out of total tested varieties, including Xinchun15、945-304、64-1and1-147,showedresistancetothedisease. Tothediseasecausedby B.sorokiniana,thereare no immune varieties been detected too, only 3 varieties, including Ningchun 4, Xinchun 13 and 9,showed high susceptibility to the disease, 7 varieties including Xinchun 2 and etc. showed middlesusceptibilitytothedisease;15varietiesaccountfor60%outoftotaltestedvarieties,includingXinchun15,64-1andetc.,showedresistancetothedisease. Resultsalsosuggestedthatthegrowthfactorsincluding theheightofwheatplant, the lengthsoftheearand thearista,displayed minusrelativity with the incidence ofwheat black point disease.The observation on dissected embryo of grains showed that, the hyphainvadedthe inner area just below the coat layer without extending to the center area. The infested area wascontainminatedtohoneyyellowwithfewspores.更多还原