Ubuchwepheshe bobunjiniyela bezolimo bokulima ingadi eluhlaza okwesibhakabhakaKushicilelwe eBeijing ngo-17:30 ngoJanuwari 13, 2023.

Ukumuncwa kwezakhi eziningi zezakhamzimba kuyinqubo ehlobene eduze nemisebenzi ye-metabolic yezimpande zezitshalo. Lezi zinqubo zidinga amandla akhiqizwa ukuphefumula kweseli lezimpande, futhi ukumuncwa kwamanzi kulawulwa futhi izinga lokushisa nokuphefumula, kanti ukuphefumula kudinga ukubamba iqhaza komoya-mpilo, ngakho-ke umoya-mpilo endaweni yezimpande unomthelela obalulekile ekukhuleni okuvamile kwezitshalo. Okuqukethwe komoya-mpilo oncibilikisiwe emanzini kuthintwa izinga lokushisa nosawoti, futhi isakhiwo se-substrate sinquma okuqukethwe komoya endaweni yezimpande. Ukunisela kunomehluko omkhulu ekuvuseleleni nasekungezeni okuqukethwe komoya-mpilo ezindaweni ezinezimo ezahlukene zokuqukethwe kwamanzi. Kunezici eziningi zokwenza ngcono okuqukethwe komoya-mpilo endaweni yezimpande, kodwa izinga lethonya lento ngayinye lihlukile kakhulu. Ukugcina amandla okugcina amanzi endaweni yezimpande afanele (okuqukethwe komoya) kuyisiqalo sokugcina okuqukethwe komoya-mpilo okuphezulu endaweni yezimpande.

Imiphumela yokushisa kanye nosawoti kokuqukethwe komoya-mpilo ogcwele esixazululweni

Okuqukethwe kwe-oxygen okuncibilikisiwe emanzini

I-oxygen encibilikisiwe incibilikiswa ku-oxygen engaboshiwe noma ekhululekile emanzini, futhi okuqukethwe kwe-oxygen encibilikisiwe emanzini kuzofinyelela izinga eliphezulu ekushiseni okuthile, okungukuthi okuqukethwe kwe-oxygen egcwalisiwe. Okuqukethwe kwe-oxygen egcwalisiwe emanzini kuyashintsha ngokushisa, futhi lapho izinga lokushisa likhuphuka, okuqukethwe kwe-oxygen kuyehla. Okuqukethwe kwe-oxygen egcwalisiwe emanzini acwebile kuphakeme kunokwamanzi olwandle aqukethe usawoti (Isithombe 1), ngakho-ke okuqukethwe kwe-oxygen egcwalisiwe kwezixazululo zezakhamzimba ezinamazinga ahlukene kuzohluka.

Ukuthuthwa komoya-mpilo ku-matrix

I-oxygen engatholwa yizimpande zezitshalo eziluhlaza okwesibhakabhaka ngesisombululo sezakhamzimba kumele ibe sesimweni esikhululekile, futhi i-oxygen ithuthwa ku-substrate ngomoya namanzi namanzi azungeze izimpande. Uma ilingana nokuqukethwe kwe-oxygen emoyeni ekushiseni okunikeziwe, i-oxygen encibilikisiwe emanzini ifinyelela esiphezulu, futhi ushintsho lokuqukethwe kwe-oxygen emoyeni luzoholela ekushintsheni okulingana kokuqukethwe kwe-oxygen emanzini.

Imiphumela yokucindezeleka kwe-hypoxia endaweni yezimpande ezitshalweni

Izimbangela ze-root hypoxia

Kunezizathu eziningana zokuthi kungani ingozi ye-hypoxia kuma-hydroponics kanye nezinhlelo zokulima ze-substrate iphezulu ehlobo. Okokuqala, okuqukethwe kwe-oxygen egcwele emanzini kuzoncipha njengoba izinga lokushisa likhuphuka. Okwesibili, i-oxygen edingekayo ukuze kugcinwe ukukhula kwezimpande iyanda ngokwanda kwezinga lokushisa. Ngaphezu kwalokho, inani lokumuncwa kwezakhamzimba liphezulu ehlobo, ngakho-ke isidingo se-oxygen sokumuncwa kwezakhamzimba siphezulu. Kuholela ekwehleni kokuqukethwe kwe-oxygen endaweni yezimpande kanye nokuntuleka kwesengezo esisebenzayo, okuholela ku-hypoxia endaweni yezimpande.

Ukumuncwa nokukhula

Ukumuncwa kwezakhamzimba eziningi ezibalulekile kuncike ezinqubweni ezihlobene kakhulu nokuguqulwa kwezimpande, ezidinga amandla akhiqizwa ukuphefumula kwamaseli ezimpande, okungukuthi, ukubola kwemikhiqizo ye-photosynthetic lapho kukhona umoya-mpilo. Izifundo zibonise ukuthi u-10% ~ 20% wezinto ezihlanganisiwe zezitshalo zikatamatisi zisetshenziswa ezimpandeni, u-50% wazo usetshenziselwa ukumuncwa kwe-ion yezakhamzimba, u-40% wokukhula kanye no-10% kuphela wokugcinwa. Izimpande kumele zithole umoya-mpilo endaweni eqondile lapho zikhipha khona i-CO2.₂Ngaphansi kwezimo ze-anaerobic ezibangelwa ukungabi nomoya kahle ezindaweni ezingaphansi komhlaba kanye ne-hydroponics, i-hypoxia izothinta ukumuncwa kwamanzi nezakhamzimba. I-Hypoxia inempendulo esheshayo ekumuncweni okusebenzayo kwezakhamzimba, okungukuthi i-nitrate (NO).₃^-), i-potassium (K) kanye ne-phosphate (PO2)₄^3-), okuzophazamisa ukumuncwa kwe-calcium (Ca) kanye ne-magnesium (Mg) ngaphandle kokwenza lutho.

Ukukhula kwezimpande zezitshalo kudinga amandla, umsebenzi ojwayelekile wezimpande udinga ukugcwala kwe-oxygen okuphansi kakhulu, kanti ukugcwala kwe-oxygen okungaphansi kwe-COP value kuba yisici esivimbela ukusebenza kahle kweseli lezimpande (i-hypoxia). Uma izinga lokuqukethwe kwe-oxygen liphansi, ukukhula kuyehla noma kuyeke. Uma i-healthy yezimpande engaphelele ithinta amagatsha namaqabunga kuphela, uhlelo lwezimpande lungakhokhela ingxenye yesistimu yezimpande engasasebenzi ngesizathu esithile ngokwandisa ukumuncwa kwendawo.

Indlela yokusebenza kwezitshalo incike kumoya-mpilo njengokwamukela ama-electron. Ngaphandle komoya-mpilo, ukukhiqizwa kwe-ATP kuzoma. Ngaphandle kwe-ATP, ukuphuma kwama-proton ezimpandeni kuzoma, ijusi lamaseli ezimpande lizoba yi-acidic, futhi lawa maseli azofa zingakapheli amahora ambalwa. I-hypoxia yesikhashana neyesikhashana ngeke ibangele ukucindezeleka okungapheli kokudla ezitshalweni. Ngenxa yendlela "yokuphefumula kwe-nitrate", kungaba ukuzivumelanisa kwesikhathi esifushane ukubhekana ne-hypoxia njengendlela ehlukile ngesikhathi se-root hypoxia. Kodwa-ke, i-hypoxia yesikhathi eside izoholela ekukhuleni okuhamba kancane, ukwehla kwendawo yamaqabunga kanye nokwehla kwesisindo esisha nesomile, okuzoholela ekwehleni okukhulu kwesivuno sezitshalo.

I-Ethylene

Izitshalo zizokwakha i-ethylene endaweni yazo ngaphansi kokucindezeleka okukhulu. Ngokuvamile, i-ethylene isuswa ezimpandeni ngokusabalala emoyeni wenhlabathi. Lapho amanzi egcwala, ukwakheka kwe-ethylene ngeke kugcine ngokwanda, kodwa futhi ukusabalala kuzoncishiswa kakhulu ngoba izimpande zizungezwe amanzi. Ukwanda kokuhlushwa kwe-ethylene kuzoholela ekwakhekeni kwezicubu zomoya ezimpandeni (Isithombe 2). I-ethylene ingabangela nokuguga kwamaqabunga, futhi ukusebenzisana phakathi kwe-ethylene ne-auxin kuzokhulisa ukwakheka kwezimpande ezizithelayo.

Ukucindezeleka komoya-mpilo kuholela ekunciphiseni ukukhula kwamaqabunga

I-ABA ikhiqizwa ezimpandeni nasemaqabungeni ukuze ibhekane nokucindezeleka okuhlukahlukene kwemvelo. Endaweni yezimpande, impendulo evamile ekucindezelekeni ukuvalwa kwe-stomatal, okuhlanganisa ukwakheka kwe-ABA. Ngaphambi kokuba i-stomata ivalwe, ingxenye ephezulu yesitshalo ilahlekelwa ukucindezeleka kokuvuvukala, amaqabunga aphezulu ayabuna, kanye nokusebenza kahle kwe-photosynthesis nakho kungancipha. Izifundo eziningi zikhombisile ukuthi i-stomata isabela ekwandeni kokuhlushwa kwe-ABA ku-apoplast ngokuvala, okungukuthi, okuqukethwe okuphelele kwe-ABA kumaqabungeni angewona amaqabunga ngokukhulula i-ABA yangaphakathi kweseli, izitshalo zingakhulisa ukuhlushwa kwe-apoplast ABA ngokushesha okukhulu. Lapho izitshalo zingaphansi kokucindezeleka kwemvelo, ziqala ukukhulula i-ABA kumaseli, futhi isignali yokukhululwa kwezimpande ingadluliselwa ngemizuzu esikhundleni samahora. Ukwanda kwe-ABA ezicutshini zamaqabungeni kunganciphisa ukunwebeka kodonga lwamaseli futhi kuholele ekwehleni kokunwebeka kwamaqabungeni. Omunye umphumela we-hypoxia ukuthi isikhathi sokuphila samaqabunga siyafinyezwa, okuzothinta wonke amaqabunga. I-Hypoxia ivame ukuholela ekwehleni kokuthuthwa kwe-cytokinin ne-nitrate. Ukuntuleka kwe-nitrogen noma i-cytokinin kuzonciphisa isikhathi sokugcinwa kwendawo yamaqabunga futhi kumise ukukhula kwamagatsha namaqabunga zingakapheli izinsuku ezimbalwa.

Ukuthuthukisa indawo ye-oxygen yesistimu yezimpande zezitshalo

Izici ze-substrate zinquma ukusatshalaliswa kwamanzi nomoya-mpilo. Ukuhlushwa komoya-mpilo endaweni yezimpande zemifino ebamba ukushisa kuhlobene kakhulu namandla okugcina amanzi e-substrate, ukunisela (usayizi kanye nemvamisa), isakhiwo se-substrate kanye nokushisa komcu we-substrate. Kuphela uma okuqukethwe komoya-mpilo endaweni yezimpande okungenani kungaphezu kuka-10% (4~5mg/L) lapho umsebenzi wezimpande ungagcinwa usesimweni esihle kakhulu.

Uhlelo lwezimpande zezitshalo lubaluleke kakhulu ekukhuleni kwezitshalo kanye nokumelana nezifo zezitshalo. Amanzi kanye nezakhamzimba kuzomuncwa ngokwezidingo zezitshalo. Kodwa-ke, izinga lomoya-mpilo endaweni yezimpande linquma kakhulu ukusebenza kahle kokumuncwa kwezakhamzimba namanzi kanye nekhwalithi yohlelo lwezimpande. Izinga lomoya-mpilo elanele endaweni yezimpande lingaqinisekisa impilo yohlelo lwezimpande, ukuze izitshalo zibe nokumelana okungcono nezinambuzane ezibangela izifo (Isithombe 3). Izinga lomoya-mpilo elanele endaweni engaphansi komhlaba linciphisa nengozi yezimo ezibangelwa yi-anaerobic, ngaleyo ndlela kuncishiswe ingozi yezinambuzane ezibangela izifo.

Ukusetshenziswa kwe-oksijini endaweni ezungezile

Ukusetshenziswa komoya-mpilo okuphezulu kwezitshalo kungaba phezulu ku-40mg/m2/h (ukusetshenziswa kuncike ezitshalweni). Kuye ngokushisa, amanzi okunisela angaba nomoya-mpilo ofinyelela ku-7~8mg/L (Isithombe 4). Ukuze kufinyelelwe ku-40 mg, amalitha ama-5 amanzi kumele anikezwe njalo ngehora ukuze kuhlangatshezwane nesidingo somoya-mpilo, kodwa empeleni, inani lokunisela ngosuku olulodwa lingase lingafinyelelwa. Lokhu kusho ukuthi umoya-mpilo ohlinzekwa ngokunisela udlala indima encane kuphela. Iningi lokunikezwa komoya-mpilo lifinyelela endaweni yezimpande ngama-pores ku-matrix, futhi umnikelo wokunikezwa komoya-mpilo ngama-pores ufinyelela ku-90%, kuye ngesikhathi sosuku. Lapho ukuhwamuka kwezitshalo kufinyelela esiphezulu, inani lokunisela lifinyelela esiphezulu, okulingana no-1~1.5L/m2/h. Uma amanzi okunisela aqukethe umoya-mpilo ongu-7mg/L, azohlinzeka ngomoya-mpilo ongu-7~11mg/m2/h endaweni yezimpande. Lokhu kufana no-17%~25% wesidingo. Yiqiniso, lokhu kusebenza kuphela esimweni sokuthi amanzi okunisela angenayo i-oxygen e-substrate athathelwa indawo ngamanzi okunisela amasha.

Ngaphezu kokusetshenziswa kwezimpande, ama-microorganisms endaweni yezimpande nawo asebenzisa umoya-mpilo. Kunzima ukukala lokhu ngoba akukho silinganiso esenziwe kulokhu. Njengoba ama-substrates amasha eshintshwa minyaka yonke, kungacatshangwa ukuthi ama-microorganisms adlala indima encane kakhulu ekusetshenzisweni komoya-mpilo.

Lungiselela izinga lokushisa lemvelo lezimpande

Izinga lokushisa lemvelo lesistimu yezimpande libaluleke kakhulu ekukhuleni nasekusebenzeni okuvamile kwesistimu yezimpande, futhi liyisici esibalulekile esithinta ukumuncwa kwamanzi nezakhamzimba yisistimu yezimpande.

Izinga lokushisa eliphansi kakhulu le-substrate (izinga lokushisa lezimpande) lingaholela enkingeni yokumuncwa kwamanzi. Ku-5℃, ukumuncwa kungaphansi ngo-70% ~ 80% kunaku-20℃. Uma izinga lokushisa eliphansi le-substrate lihambisana nokushisa okuphezulu, kuzoholela ekubuneni kwezitshalo. Ukumuncwa kwe-ion ngokusobala kuncike ekushiseni, okuvimbela ukumuncwa kwe-ion ekushiseni okuphansi, futhi ukuzwela kwezakhi ezahlukene zezakhamzimba ekushiseni kuhlukile.

Izinga lokushisa eliphezulu kakhulu le-substrate nalo alisizi ngalutho, futhi lingaholela ohlelweni lwezimpande olukhulu kakhulu. Ngamanye amazwi, kukhona ukusatshalaliswa okungalingani kwezinto ezomile ezitshalweni. Ngenxa yokuthi uhlelo lwezimpande lukhulu kakhulu, ukulahlekelwa okungadingekile kuzokwenzeka ngokuphefumula, futhi le ngxenye yamandla alahlekile ngabe isetshenziselwe ingxenye yokuvuna yesitshalo. Ezingeni lokushisa eliphezulu le-substrate, okuqukethwe kwe-oxygen encibilikisiwe kuphansi, okunomthelela omkhulu kakhulu kokuqukethwe kwe-oxygen endaweni yezimpande kunomoya-mpilo odliwa yizinto ezincane. Uhlelo lwezimpande ludla umoya-mpilo omningi, futhi luze luholele ku-hypoxia uma kwenzeka i-substrate noma isakhiwo somhlabathi esibi, ngaleyo ndlela kuncishiswe ukumuncwa kwamanzi nama-ion.

Gcina umthamo ofanele wokuphatha amanzi we-matrix.

Kukhona ubudlelwano obungebuhle phakathi kokuqukethwe kwamanzi kanye nephesenti lokuqukethwe komoya-mpilo ku-matrix. Lapho okuqukethwe kwamanzi kwanda, okuqukethwe komoya-mpilo kwehla, futhi okuphambene nalokho. Kukhona ububanzi obubalulekile phakathi kokuqukethwe kwamanzi nomoya-mpilo ku-matrix, okungukuthi, okuqukethwe kwamanzi okungu-80% ~ 85% (Isithombe 5). Ukugcinwa kwesikhathi eside kokuqukethwe kwamanzi okungaphezu kuka-85% ku-substrate kuzothinta ukunikezwa komoya-mpilo. Iningi lokunikezwa komoya-mpilo (75% ~ 90%) lidlula ezimbotsheni ku-matrix.

Ukwengezwa kokunisela kokuqukethwe komoya-mpilo ku-substrate

Ukukhanya kwelanga okwengeziwe kuzoholela ekusetshenzisweni okuphezulu komoya-mpilo kanye nokugcwala komoya-mpilo okuphansi ezimpandeni (Isithombe 6), kanti ushukela omningi uzokwenza ukusetshenziswa komoya-mpilo kube kukhulu ebusuku. Ukuphefumulela kunamandla, ukumuncwa kwamanzi kukhulu, futhi kunomoya omningi kanye nomoya-mpilo omningi ku-substrate. Kungabonakala ngakwesobunxele ku-Isithombe 7 ukuthi okuqukethwe komoya-mpilo ku-substrate kuzokhula kancane ngemva kokunisela ngaphansi kwesimo sokuthi umthamo wamanzi wokubamba i-substrate uphakeme kanye nokuqukethwe komoya kuphansi kakhulu. Njengoba kuboniswe ngakwesokudla ku-Fig. 7, ngaphansi kwesimo sokukhanya okungcono kakhulu, okuqukethwe komoya ku-substrate kuyanda ngenxa yokumuncwa kwamanzi amaningi (izikhathi ezifanayo zokunisela). Ithonya elihlobene lokunisela kokuqukethwe komoya-mpilo ku-substrate lincane kakhulu kunomthamo wokubamba amanzi (okuqukethwe komoya) ku-substrate.

Xoxa

Ekukhiqizweni kwangempela, okuqukethwe umoya-mpilo (umoya) endaweni yezimpande zezitshalo kulula ukunganakwa, kodwa kuyisici esibalulekile ukuqinisekisa ukukhula okuvamile kwezitshalo kanye nokukhula okunempilo kwezimpande.

Ukuze uthole isivuno esiphezulu ngesikhathi sokukhiqizwa kwezitshalo, kubaluleke kakhulu ukuvikela indawo yesistimu yezimpande esimweni esihle kakhulu ngangokunokwenzeka. Izifundo zikhombisile ukuthi i-O₂okuqukethwe endaweni yezimpande ngaphansi kuka-4mg/L kuzoba nomthelela omubi ekukhuleni kwezitshalo.₂Okuqukethwe endaweni yezimpande kuthonywa kakhulu ukuchelela (inani lokunisela kanye nokuvama), isakhiwo se-substrate, okuqukethwe kwamanzi e-substrate, izinga lokushisa le-greenhouse kanye ne-substrate, kanye namaphethini okutshala ahlukene azohluka. Ama-algae nama-microorganisms nawo anobuhlobo obuthile nokuqukethwe komoya-mpilo endaweni yezimpande zezitshalo ze-hydroponic. I-Hypoxia ayibangeli nje kuphela ukukhula okuhamba kancane kwezitshalo, kodwa futhi ikhulisa ingcindezi yamagciwane ezimpande (i-pythium, i-phytophthora, i-fusarium) ekukhuleni kwezimpande.

Isu lokunisela linethonya elikhulu ku-O₂okuqukethwe ku-substrate, futhi kuyindlela elawulwa kakhulu enqubweni yokutshala. Ezinye izifundo zokutshala ama-rose zithole ukuthi ukwandisa kancane kancane okuqukethwe kwamanzi ku-substrate (ekuseni) kungenza isimo se-oxygen sibe ngcono. Ku-substrate enekhono eliphansi lokubamba amanzi, i-substrate ingagcina okuqukethwe okuphezulu kwe-oxygen, futhi ngesikhathi esifanayo, kubalulekile ukugwema umehluko wokuqukethwe kwamanzi phakathi kwe-substrate ngokusebenzisa imvamisa ephezulu yokunisela kanye nesikhashana esifushane. Uma umthamo wokubamba amanzi we-substrate uphansi, umehluko omkhulu phakathi kwe-substrate. I-substrate emanzi, imvamisa yokunisela ephansi kanye nesikhashana eside kuqinisekisa ukufakwa komoya okwengeziwe kanye nezimo ezinhle ze-oxygen.

Ukugeleza kwamanzi kwe-substrate kungenye into enomthelela omkhulu esilinganisweni sokuvuselelwa kanye nokugeleza kokugxila kwe-oxygen ku-substrate, kuye ngohlobo kanye namandla okugcina amanzi e-substrate. Uketshezi lokunisela akufanele luhlale phansi kwe-substrate isikhathi eside kakhulu, kodwa kufanele lukhishwe ngokushesha ukuze amanzi okunisela amasha acebile nge-oxygen akwazi ukufinyelela phansi kwe-substrate futhi. Ijubane lokugeleza kwamanzi lingathonywa ezinye izindlela ezilula, njengokugeleza kwamanzi kwe-substrate eziqondisweni ezinde nezibanzi. Uma i-gradient inkulu, ijubane lokugeleza kwamanzi lishesha. Ama-substrate ahlukene anezimbobo ezahlukene futhi inani lezindawo zokuphuma nalo lihlukile.

ISIPHETHO

[ulwazi lokucaphuna]

Xie Yuanpei. Imiphumela yokuqukethwe komoya-mpilo endaweni ezungezile ezimpandeni zezitshalo eziluhlaza okwesibhakabhaka ekukhuleni kwezitshalo [J]. Ubuchwepheshe Bobunjiniyela Bezolimo, 2022,42(31):21-24.