Ama-Oomycetes: izimpawu nokwelashwa

Kuvamile ukudida ama-oomycetes nesikhunta sangempela, ngoba izimpawu nomonakalo abawenzayo cishe uyafana. Kepha ngaphezu kwalokho, ukwelashwa okusetshenziselwa abanye kungasetshenziselwa nabanye.

Noma kunjalo, ngicabanga kubaluleke kakhulu ukwazi ama-oomycetes, izinto ezithinta izinhlobo eziningi zezitshalo emhlabeni wonke.

Yini ama-oomycetes?

Ama-oomycetes zingumbumbulu-mbumbulu (isikhunta samanga) eseqenjini labaphikisi i-Oomycota (noma i-Oomycetes). Izinhlobo zihlukaniswa kuye ngokuthi zondla kanjani. Ngakho-ke, ngakolunye uhlangothi sinama-saprophyte, okuyilawo adla ngezinto ezibolayo ezibolayo, nezinambuzane.

Lezi zamuva zinentshisekelo ekhethekile kwezolimo nasezingadini, ngoba yizo ezingaphelisa impilo yezitshalo uma kungathathwa izinyathelo ngesikhathi.

Ziziphi izici zayo?

Uchungechunge lwezinto eziphilayo ezinodonga lweseli olwakhiwe nge-cellulose. Yini enye, kuzo zonke izigaba zabo zokuphila, lapho amaseli ethula khona ama-chromosomes amabili e-homologous kuma-cell nuclei awo, anezigaba ze-haploid lapho amaseli aneqoqo elilodwa lama-chromosomes.

Isigaba se-haploid, kulezi zidalwa, yisigaba sokukhiqiza kabusha. Lokhu ngokocansi lapho kukhiqiza i-gametangia; okungukuthi, i-antheridia ne-oogonia. Kuzo, ukwahlukana kwe-meiotic kuyenzeka, okuzoveza i-diploid oospore ezoba nezindonga zeseli ezijiyile. Lokhu kuzokhishwa, futhi kuzogcina kukhiqiza ama-hyphae lapho i-sporangium izothuthukiswa khona.

Ngakolunye uhlangothi, isigaba se-asexual yiso esenzeka lapho izinhlamvu ze-motile asexual, ezibizwa ngokuthi ama-zoospores, zine-flagellum ebheke phambili, kanti enye ibheke ngemuva. Lezi itholakala ezindaweni lapho umswakama uhlala uphakeme khona, njenge-substrate yesitshalo.

Kungani ama-oomycetes engesona isikhunta?

Isikhathi eside bekukholelwa ukuthi kunjalo. Eqinisweni, babekwa ngaphansi kombuso weFungi. Kepha namuhla ama-oomycetes nesikhunta aziwa ngokuhluka okumbalwa kodwa okubalulekile:

• Udonga lweseli lwama-oomycetes yi-cellulose. Isikhunta sinaso kusuka ku-chitin.
• Ngokuvamile azihlukanisi izinto eziphilayo. Amaseli wesikhunta, ngakolunye uhlangothi, ahlukana ngezindonga zawo zangaphakathi.
• Njengoba bekhula, abalingiswa bethu abaphambili bane-diploid nuclei, Hhayi haploid njengamakhowe.

Kukho konke lokhu, manje bangaphakathi kwekilasi iHeterokonta noma i-estramenopilos, ababelana ngakho nge-diatoms ngokwesibonelo.

Izinhlobo zama-oomycetes

Kulinganiselwa ukuthi kunezinhlobo ezingama-700 zama-oomycetes, phakathi kwazo esikuhlukanisa okulandelayo:

Isikhunta

El isikhutha yisifo esivame kakhulu ezitshalweni, okuyi kubangela ukuthi amaqabunga ambozwe ngothuli olumhlophe. Ngokuya ngezinhlobonhlobo, sithola ezinye ezibonakala zinokhetho lohlobo oluthile lwezinhlobo zezitshalo.

Isibonelo, i I-Plasmopara viticola Uthinta kakhulu umvini, yingakho waziwa ngokuthi umvini isikhutha.

I-Phythium

IPhythium yiqembu lama-oomycetes athinta inani elikhulu kakhulu lezitshalo. TO Izitshalo ezisencane, njengezithombo, zingadala umonakalo ongalungiseki ngisho nokufa. Kepha uma sebekhulile, futhi uma bephilile, kunzima kubo ukudala izinkinga ezinkulu, ngaphezu kwezimpawu ezithile ezinomusa njengamabala ambalwa ansundu emaqabungeni.

Ngokufanayo, kuyathakazelisa ukusho ukuthi uhlobo lwe-P. oligandrum lukhubaza amanye ama-oomycetes, yingakho lisetshenziswa njenge-ejenti yokulawula izinto eziphilayo.

I-Phytophthora

Luhlobo lwe-oomycetes oluhlasela izinhlobo eziningi zezitshalo. Zicacise kakhulu izinhlobo ezihlasela zona; Ngisho, lezo zinhlobo ze I-Phytopthora banokuthandwa kohlobo oluthile lwesitshalo.

Isibonelo, i-P. ramorum ithinta ikakhulukazi izihlahla ze-oki, ibangele ukufa; no P. infestans kuvamile ezitshalweni ezinjengotamatisi.

Ziyini izimpawu nomonakalo ezikudalayo?

Kuzoncika kakhulu ezinhlotsheni ze-oomycete ezihlasela izitshalo. Kepha ngokujwayelekile, izimpawu nomonakalo esizozibona yilezi ezilandelayo:

• Emashidini: amabala aphuzi noma ansundu, impuphu emhlophe, ukuwa ngaphambi kwesikhathi.
• Esiqwini: chancres, imifantu. Ukufa kwasekuqaleni kwamagatsha.
• Ezithelweni: izindawo ezinsundu noma ezimnyama, ukubola kwezithelo. Imvamisa isiqu esibaxhuma emagatsheni siba mnyama, njengakwitamatisi.

Baphathwa kanjani?

Yize bengesona isikhunta, bangelashwa ngemikhiqizo efanayo; okungukuthi, ngama-fungicides. Kepha ukuze umphumela ube yilokho okulindelekile, kubalulekile ukukhomba isifo kuqala bese ufuna ukwelashwa okwenzelwe ukwelapha leso sifo.

Enye yezinto ezinconywe kakhulu yi- ithusi. Ama-fungicides e-Cupric asebenza ngokuxhumana, futhi kuye ngokuthi ukwakheka kungaba ngokwemvelo ngakho-ke kufanelekile ukulima okuphilayo. Iwusizo ikakhulukazi njengokuvikela izithombo nezitshalo ezincane, kepha futhi iyasebenza njengokwelapha.

El I-Fosetyl-Al iyi-fungicic ehlelekile. Amaqabunga ayamunca, futhi ukusuka lapho asatshalaliswa kuso sonke isitshalo. Isetshenziswa kabanzi ukulwa nesikhunta nePhytopthora. Umkhiqizo owaziwa kakhulu onalokhu kuqanjwa ngu-Aliette, waseBayer, onconyelwe ikakhulukazi i- ukugqanyiswa kwama-conifers. Ungayithenga lapha.

Ngabe ama-oomycetes angavinjelwa?

Njengenjwayelo lapho kukhulunywa ngezinto eziphilayo ze-pathogenic, akunakuvinjelwa i-100%. Okwenziwe ukuthatha uchungechunge lwezinyathelo ezizosiza ukunciphisa ubungozi. Zimi kanje:

• Thenga izitshalo ezinempilo. Uma zinamabala ansundu, iziqu ezimnyama, noma ekugcineni zibukeka zimbi, akufanele zisiwe ekhaya.
• Nisela kuphela lapho kunesidingo. Umswakama omningi ezimpandeni wenza buthakathaka iningi lezitshalo, ngaphandle kwalezo ezisemanzini.
• Qiniseka ukuthi umsele wamanzi wenhlabathi muhle, bese ufaka amasistimu okuyithuthukisa uma kwenzeka kwakha izintuba ezithatha amahora noma izinsuku ukumunca. Ulwazi oluningi.
• Hlukanisa, ngangokunokwenzeka, izitshalo ezigulayo kwezinempilo. Okufanelekile ukuthi kube nesikhala esivunyelwe ukuthi singaba nazo kuphi, lapho zizohlukaniswa khona zize zithuthuke.
• Okwezimbiza: sebenzisa iziqeshana ezifanele zezitshalo, nezintsha. Ngaphezu kwalokho, amabhodwe kumele ahlanzeke futhi abulawe amagciwane.

Sithemba ukuthi kube nentshisekelo kuwe.