Cov kab mob cog tsis tu ncua yog qhov nyuaj rau kev ua liaj ua teb niaj hnub no. Txawm hais tias kev nce qib hauv kev cog qoob loo, kev tswj hwm tshuaj lom neeg, thiab kev tiv thaiv tshuaj lom neeg tau muab cov cuab yeej ntau ntxiv rau cov neeg cog qoob loo, qee yam kab mob tseem nyuaj heev los tswj. Oomycetes, tshwj xeeb tshaj yog, tau txais kev saib xyuas tseem ceeb vim tias lawv tuaj yeem kis tau sai nyob rau hauv ib puag ncig zoo thiab ua rau muaj kab mob hnyav hauv ntau cov qoob loo.
Downy mildew, lig blight, thiab kab mob tshwm sim los ntawm Phytophthora thiab Pythium hom yog classic piv txwv ntawm cov teeb meem tshwm sim los ntawm oomycete pathogens. Txawm hais tias cov kab mob no feem ntau koom nrog cov kab mob fungi, lawv yog cov kab mob sib txawv. Qhov kev sib txawv no yog qhov tseem ceeb rau kev tswj hwm kab mob thiab tau tsav cov kws tshawb fawb los tsim cov tebchaw uas tsom rau lawv cov txheej txheem lom neeg tshwj xeeb.
Ib cheeb tsam tseem ceeb ntawm kev tshawb fawb tsom mus rau phenylamide fungicides-ib chav ntawm cov tshuaj tsim tshwj xeeb los tawm tsam cov kab mob oomycete. Raws li Fungicide Resistance Action Committee (FRAC) kev faib tawm, phenylamides suav nrog cov tshuaj xws li metalaxyl, metalaxyl-M, benalaxyl, thiab benalaxyl-M. Muab faib raws li FRAC Group 4, lawv hom kev ua haujlwm cuam tshuam nrog inhibiting RNA polymerase I kev ua haujlwm thiab ribosomal RNA synthesis nyob rau hauv cov hom phiaj kab mob.
Vim li cas oomycetes tsim teeb meem tshwj xeeb rau kev tiv thaiv qoob loo?
Oomycetes suav nrog ntau hom kab mob tseem ceeb uas cuam tshuam rau zaub, txiv hmab txiv ntoo, qoob loo, thiab cov nroj tsuag ornamental. Cov tsiaj nyob hauv genera xws li Phytophthora, Pythium, Plasmopara, Peronospora, thiab Bremia yog cov kab mob cuam tshuam rau cov qoob loo tseem ceeb.
Kev nkag siab txog lawv cov yam ntxwv lom neeg pab piav qhia vim li cas lawv yog qhov tseem ceeb ntawm kev tshawb fawb txog kev ua liaj ua teb. Qee cov oomycetes tsim motile zoospores muaj peev xwm txav los ntawm dej, thaum lwm tus tuaj yeem muaj sia nyob hauv av lossis hauv cov khib nyiab. Nyob rau hauv cov xwm txheej zoo, cov txheej txheem kis tau sai heev, feem ntau tso sijhawm tsawg heev rau kev tswj hwm kev cuam tshuam.
Cov kab mob lig, tshwm sim los ntawm Phytophthora infestans, ua tus piv txwv tseem ceeb; nws tau ntev dhau los ntawm kev tshawb fawb tseem ceeb vim tias ib puag ncig ib puag ncig cuam tshuam rau kev loj hlob ntawm tus kab mob. Cov huab cua txias, av noo nyiam qhov kev sib kis ntawm tus kab mob, qhia txog qhov tseem ceeb ntawm cov tswv yim tswj kom raws sijhawm.
Qhov no tau ua rau cov kws tshawb fawb tsom mus rau cov tshuaj fungicides nrog kev ua haujlwm hauv lub cev -cov khoom muaj peev xwm hloov pauv hauv cov ntaub so ntswg es tsis yog tsuas yog nyob rau saum npoo. Phenylamide fungicides tshwj xeeb tshaj yog nyob rau hauv no hais txog, raws li lawv muaj peev xwm nkag mus rau cov ntaub so ntswg thiab txav acropetally (upward) nyob rau hauv cov nroj tsuag.
Txawm li cas los xij, kev ua tau zoo ntawm cov tshuaj tua kab mob yog nyob ntawm ntau tshaj li qhov sib xyaw ua haujlwm tawm tsam cov kab mob. Cov kws tshawb fawb tseem yuav tsum xav txog kev txhim kho kev tiv thaiv, kev siv cov tswv yim, kev coj tus cwj pwm ib puag ncig, kev cog qoob loo, thiab kev sib raug zoo nrog lwm yam kev tswj hwm kab mob.
Lub hom phiaj RNA synthesis pab tswj cov nroj tsuag kab mob li cas?
Ib qho laj thawj phenylamide fungicides txuas ntxiv nyiam kev txaus siab rau kev tshawb fawb yog lawv qhov tshwj xeeb ntawm kev ua.
Kev tshawb fawb sau los ntawm FRAC (Fungicide Resistance Action Committee) qhia tias phenylamides cuam tshuam nrog ribosomal RNA (rRNA) biosynthesis hauv cov kab mob oomycete, tshwj xeeb cuam tshuam rau kev ua haujlwm ntawm RNA polymerase I. Txij li thaum RNA ntau lawm yog qhov tseem ceeb rau kev loj hlob ntawm tes thiab protein synthesis, thaiv cov txheej txheem kev loj hlob.
Hom kev ua no txawv ntawm cov fungicides tsom cov txheej txheem xws li sterol biosynthesis, ua pa, lossis cell phab ntsa tsim. Kev nkag siab txog qhov sib txawv no yog qhov tseem ceeb thaum tsim cov kev tswj hwm kab mob sib xyaw.
Cov khoom siv tshuaj ntawm cov tebchaw tshwj xeeb kuj tseem ceeb. Piv txwv li, Benalaxyl-M yog R-enantiomer ntawm benalaxyl (tseem hu ua kiralaxyl). PubChem muab faib ua acyl-amino acid thiab anilide fungicide.
Qhov txawv ntawm benalaxyl thiab nws ntau yam stereoisomers yog qhov tseem ceeb tshwj xeeb hauv kev tshawb fawb tshuaj. Benalaxyl muaj ib qho chaw chiral hauv nws cov molecule, ua rau muaj qhov sib txawv enantiomers. Kev tshawb fawb qhia tias R-enantiomer nthuav tawm cov haujlwm fungicidal ntau dua li S-enantiomer; Qhov no yog ib qho laj thawj vim li cas cov khoom stereochemical yog qhov tseem ceeb thaum ntsuas cov tebchaw.
Qhov no qhia txog kev nthuav dav hauv agrochemistry: cov kws tshawb fawb tab tom tsom tsis tsuas yog seb lub molecule puas muaj txiaj ntsig zoo tab sis kuj tseem nyob rau ntawm daim ntawv molecular uas xa cov kev ua haujlwm lom neeg xav tau, nrog rau daim ntawv hloov pauv cov yam ntxwv hauv cov nroj tsuag thiab nws tus cwj pwm hauv ib puag ncig.
Puas yog cov tshuaj tiv thaiv kab mob tuaj yeem hloov kho lub neej yav tom ntej ntawm kev tswj kab mob oomycete?
Ib qho ntawm cov kev sib tw loj tshaj plaws ntsib cov phiaj xwm fungicides yog qhov teeb meem ntawm kev tiv thaiv.
Thaum cov tshuaj tua kab mob ua rau ntawm lub hom phiaj lom neeg tshwj xeeb, daim ntawv thov rov ua dua los xaiv lub siab rau cov kab mob. Yog hais tias cov neeg uas muaj resistant muaj nyob rau hauv cov pej xeem, lawv muaj peev xwm ciaj sia nyob rau hauv kev kho mob thiab yug me nyuam. Nyob rau tib lub sijhawm, qhov no tuaj yeem cuam tshuam qhov kev ua tau zoo ntawm kev tiv thaiv kab mob yav dhau los.
Pawg Fungicide Resistance Action Committee (FRAC) faib cov tshuaj phenylamide fungicides raws li siab - pheej hmoo rau kev txhim kho kev tiv thaiv, thiab kev tiv thaiv- nrog rau tus ntoo khaub lig- tsis kam- rau chav kawm no tau raug sau tseg hauv ntau yam kab mob oomycete. Yog li ntawd, lub koom haum hais txog qhov xav tau ntawm cov tswv yim tswj kev tawm tsam es tsis yog rov ua dua ntawm ib hom kev ua.
Qhov teeb meem no tshwj xeeb tshaj yog rau cov tebchaw xws li benalaxyl-M. Raws li ib tug phenylamide fungicide, benalaxyl-M yog cov ntsiab lus ntawm kev tshawb fawb uas txuas ntxiv tshaj qhov tsuas yog ntsuas nws cov kev cuam tshuam ncaj qha rau cov kab mob; Cov kws tshawb fawb tseem tshawb xyuas cov kev hloov pauv hauv cov kab mob rhiab heev, hla- cov qauv kev tiv thaiv, cov tswv yim tsim, thiab kev ua tau zoo ntawm kev sib txuas nrog cov tebchaw uas muaj ntau hom kev ua.
Kev tshawb fawb txog kev ua liaj ua teb tsis ntev los no tau tsom mus ntxiv rau kev sib xyaw ua ke uas muaj benalaxyl-M. Piv txwv li, cov kev tshawb fawb tsom rau cov nroj tsuag kab mob tau soj ntsuam qhov ua tau zoo ntawm kev sib txuas ntawm benalaxyl-M nrog mancozeb thiab lwm yam fungicides, ua kom pom tias kev sib xyaw ua ke no tuaj yeem pab txhawb txoj kev tswj kab mob dav dav.
Yog li ntawd, thaj chaw tau hloov mus rau kev tswj hwm kab mob sib koom ua ke es tsis yog tso siab rau ib leeg cov khoom xyaw nquag. Cov kev coj ua xws li tig cov tshuaj fungicides nrog ntau hom kev ua, sib txuas cov khoom sib xyaw ua ke, saib xyuas cov kab mob rhiab heev, thiab sib koom ua ke tsis yog - tshuaj tswj kev ntsuas txhua yam pab txo qis kev xaiv.
Qhov no tsim ib qho kev xav tau ntawm cov kws tshawb fawb txog kev ua liaj ua teb rau cov khoom siv sib txuas thiab cov khoom xyaw nquag nrog zoo -cov yam ntxwv zoo, uas yog qhov tseem ceeb rau kev tshawb fawb hauv chav kuaj, kev tsim kho, kev soj ntsuam kev tiv thaiv, thiab kev sib piv kev ua tau zoo. Raws li kev tshawb fawb rau hauv cov nroj tsuag - cov kab mob sib cuam tshuam tob zuj zus, cov tebchaw xws li benalaxyl-M tseem muaj txiaj ntsig zoo li cov cuab yeej tshawb fawb tshuaj rau kev tshawb xyuas cov haujlwm ntawm phenylamide fungicides, tswj oomycetes, stereochemistry, thiab cov tswv yim tswj kev tiv thaiv. Lawv qhov tseem ceeb tshaj li kev tswj hwm ntawm cov qoob loo tshwj xeeb lossis kab mob; es, lawv pab txhawb rau txoj kev tshawb fawb dav dav: tshawb nrhiav seb cov tshuaj siv tshuaj li cas tuaj yeem txhawb kev tiv thaiv qoob loo kom ruaj khov.
Lub neej yav tom ntej ntawm kev tswj kab mob oomycete tsis zoo li vam khom rau ib qho kev daws teeb meem. Hloov chaw, txuas ntxiv hauv - kev tshawb fawb tob rau hauv cov kab mob biology, hom fungicides ntawm kev ua, cov qauv kev tiv thaiv, qhov sib txawv ntawm cov tshuaj tsis zoo, thiab cov tswv yim kev sib koom ua ke tuaj yeem ua rau cov kws tshawb fawb los tsim cov txheej txheem tiv thaiv qoob loo yooj yim dua thaum khaws cov txiaj ntsig ntawm cov tshuaj uas twb muaj lawm.