Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/31094
標題: 黃后日衛矛苗枯病之防治試驗
Experiments in Control of Seedling Clight of Euonymus japonicus
作者: 李昱輝
Lee, Yu-Iuei
關鍵字: Euonymus japonicus
黃后日衛矛
Rhizoctonia seedling blight
R. solani AG-4
Chemical control
integrated control
organic amendment
NH4+_N
OO2-_N
NH3
blood meal
扦插
苗枯病菌
插穗苗
藥漿
插穗切口
栽培介質
有機添加物
牛血粉
抑菌效果
銨態氮
亞硝酸態氮
硝酸態氮
出版社: 植物病理學系
摘要: ? 黃后日衛矛(Euonymus japonicus)為花材用木本植物,扦插時易罹患 由Rhizoctonia solani AG-4 引起的苗枯病。本病原菌主要經由插穗苗的 莖基部或嫩葉侵入植體,導致插穗苗枯死,是扦插苗床主要病原菌之一。 黃后日衛矛苗枯病最適發病溫度為24℃;相對濕度92%以上才會發病黃后 日衛矛插穗的長度及在濕室的放置長短,均可顯著影響插穗苗枯病的發生 率,六至十公分長插穗苗的罹病率是 50∼62.5%,至於一般採取的五公分 穗之發病率則為82.5%∼87.5%;插穗剪取後保濕置放 0, 2,4,6,8 與10天後,分別扦插於含有0.6(v/v)的病菌介質中時,放置十天者發病率 是37.5∼42.5%,放置二至八天者發病率為50∼75%,至於剪穗後隨即扦插 者發病率為82.5∼92.5%。利用易感染本病菌之第二位葉,篩選防治R. solani AG-4的殺菌劑,發現5%菲克利水懸劑3000倍、25%賓克隆可濕性粉 劑2000倍、50%脫克松可濕性粉劑2000倍、75%滅普寧可濕性粉劑1000倍 及50%福多寧可濕性粉劑3000倍等均具有優良防病效果。溫室中,用前三 種藥劑之1000倍分別噴佈在黃后日衛矛扦插後經菌絲塊接種的葉片或用少 量水拌成藥漿沾黏於插穗切口後扦插於含病菌苗床,均可有效控制苗枯病 的發生。在溫室,以不等長度及在濕室中置放不同天數之插穗再配合藥藥 處理,發現五或六公分插穗在濕室中置放五或十天後,配合處理25%賓克 隆可濕性粉劑的組合,可使黃后日衛矛幼苗免於R. solani AG-4為害。此 外,六公分長插穗在剪取後隨即處理藥劑的組合,亦具有顯著防病的效果 。 十種不同介質各混入0.6%(v/v)立枯絲核菌後,隨即扦插黃后日衛 矛穗苗,發現種在BVB No.2與HECO兩介質的穗苗受害百分率最高。在接種 病原菌之BVB No.2與HECO介質中,分別添加十一種不同的有機物1%(v/v) ,七天後,發現牛血粉在兩介質中具有明顯抑制立枯絲核菌的效果。於培 養皿內之HECO介質中添加1%(v/v)牛血粉即有顯著抑制立枯絲核菌纏據葉 柄段片的效果,而在BVB No.2介質中添加1%(v/v)牛血粉卻效果不佳。在 HECO介質中添加1%(v/v)牛血粉,隨後每七天種植黃后日衛矛插穗苗,發 現在第三十五天種植者,即完全不罹病。惟在BVB No.2介質添加1%(v/v) 牛血粉者,並無法有效防治本病。HECO介質添加1%(v/v)牛血粉後,銨態 氮的含量逐漸升高,到第10天達最高峰為1190ppm,隨後遞減;亞硝酸態 氮和硝酸態氮則在第五天才開始逐漸增加,隨後僅少量增加;至於立枯絲 核菌之纏據百分率是在銨態氮量急速升高時呈急速下降的趨勢。BVB No.2 介質添加1%(v/v)牛血粉後,銨態氮的含量於第五天達最高峰為896ppm, 隨後遞減;亞硝酸態氮和硝酸態氮在添加後開始逐漸增加;至於立枯絲核 菌之纏據百分率是在亞硝酸態氮和硝酸態氮上昇至200∼300ppm時才微有 下降的趨勢。將消毒及未消毒過的HECO加入未消毒的牛血粉均可表現抑制 立枯絲核菌的纏據效果;惟消毒過之HECO加入消毒過的血粉,卻不具有抑 制立枸絲核菌的功效。若在消毒過之HECO及牛血粉中加入HECO-03或BM-02 等微生物 ,七天後,HECO介質又可完全或部分恢復抑制立枯絲核菌的功效 。因此,微生物對於添加牛血粉之HECO介質的抑菌功效,扮演著非常重要 的角色。 Seedling blight caused by Rhizoctonia solani AG-4 is amajor disease of Euonymus japonicus when its cuttings areplanted in nursery seedbeds under high relative humidity andtemperature conditions. The leaf and cutting stem on youngtissues infected by the pathogen may turn water-soaked, necroticbrown and become eventual death of cuttings. Several factorssuch as temperature, relative humidity (RH), cutting lengthand aging period of cuttings were able to significantly affectdisease severity on leaves and cuttings of E. japonicus infectedby the pathogen. Temperature and RH for the most optimal invasionand colonization of detached leaves by R. solani AG-4 were at 24℃and >92%, respectively. With ≧ 2days aging period, the cuttingsof 6∼10 cm length were more effective to markedly resist thepathogen infection compared to the cuttings of 5-cm length withoutaging treatment adopted treditionally by Taiwnese fermers. Tenfungicides were evaluated for their effect on suppression of R.solani AG-4 infection in leaves and cutting stems of E. japonicus.Among those, Hexaconazole {5% (RS)-2-(2,4- dichlorophenyl)-1-(1H-1,2,4-triazol-1-yl) hexan-2-ol) 3000X, Pencycuron {25% N-[(4-chlorophenyl)-methyl]-N-cyclopentyl-N'- phenylurea] 2000X, andTolclofos methyl (50% 0,2,6-dichloro-o- tolyl-0,0-dimethylphosphhorothioate) 2000X were the most effective to reduce thedisease severity by 35-50% as compared with none treatment as acontrol. Being depoisted for 5 or 10 days in moist chamber,6-cm-length cuttings of E. japonicus treated around wound partswith R. solani AG-4. After three weeks, the combination methodshowed the best result in the control of Rhizoctonia seedling blightof E. japonicus. Ten tested media inoculated respectively with 0.6% (v/v) ofthe inoculum of R. solani AG-4 and perlite mixture showed differencein their ability to suppress Rhizoctonia seedling blight of Euonymusjaponicus. Of those, BVB No.2 and HECO media were the mostconductive to R. solani AG-4. Eleven organic amendments were added(1%, v/v) individually to HECO or BVB No.2 media artificially infestedwith R. solani AG-4 for seven days. Blood meal was significantlyeffective in inhibiting colonzation of petiole-segments of E.japonicus by R. solani AG-4 in both media. Amendment with 1% (v/v)blood meal 35 days prior to planting was effective in controlling Rhizoctonia seedling blight of E. japonicus in amended HECO medium,but was not effective in amended BVB No.2 medium. Upon addition of1% blood meal, the pH of HECO and BVB No.2 media and concentration ofNH4+ _N increased rapidly, reached a peak in BVB No.2 medium at 5th dayor in HECO medium at tenth day, and then decrased; the concentrationof NO2-_N nehan to apper after 5 days and there after increased gradually.Rapid reduction of petiole-segment colonization by R. solani AG-4 in HECOmedium occurred at the time when the concentration of NH4+_N began torapidly increase, but that in BVB No.2 medium occurred at the time whenthe concentration of NO2-_N started a rapid increase. Futhermore, Uponamendment of both media with 1% blood meal, the volatilization of NH3 inamended HECO medium increased rapidly, reached a peak at fifteenth day,and then decreased slowly, but released less than 1 mg of NH3 in 20 g ofBVB No.2 medium 20 days after amendment. Nonautoclaved and autoclavedHECO media amended with 1% (v/v) blood meal did not immediated inhibitpetiole- segment colonization by R. solani AG-4, but 7 days after amendmentthey significantly inhibited the fungus. Petiole- segment colonization byR. solani AG-4 increased 100% after amended HECO medium was sterilized,but inhibitory effect returned 7 days after infestation with bacteriumisolate HECO-03.
URI: http://hdl.handle.net/11455/31094
Appears in Collections:植物病理學系

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.