TL;DR: I-homogeneity ekhanyayo iyisici esibalulekile ekukhuleni kwezitshalo. Ukukhanya okungalingani kusho ukuthi ezinye izindawo zithola ukukhanya okukhulu kanti ezinye zithola okuncane kakhulu, okuholela ekukhuleni kwezitshalo ngokungalingani. Ngaphezu kwalokho, ukukhanya okugqagqene kungaholela ekuqineni okuphezulu, kubangele ukulimala kwamaqabunga futhi kube nomthelela omkhulu empilweni yezitshalo. Ukuqinisekisa ukusatshalaliswa kokukhanya okungaguquki, ukukhanyisa kufanele kulungiswe kahle, futhi ukukhanya kwe-QS Pro kuklanyelwe ukunikeza ukumboza okubanzi ngisho nokukhanyisa, okwenza le nqubo ibe lula kakhulu.
I-homogeneity ekhanyayo ibalulekile ekukhuleni kwezitshalo, kanye nezinye izici ezibalulekile njenge-PPF ne-PPFD. Ukukhanya okungalingani kungaba yingozi ezitshalweni. Ngisho nokungalingani okuncane kungaholela ekukhuleni kwezitshalo okungajwayelekile. Ngenxa yokungalingani kokukhanya kokusabalalisa, amanye amaqabunga angase athole ukukhanya okukhulu, kanti amanye angase angakutholi okwanele ukufeza i-photosynthesis. Lokhu kungalingani kubangela ukukhula okungalingani, okuholela izitshalo ukuthi zitshekele ngasemthonjeni wokukhanya, okuholela ekubeni neziqu ezinwetshiwe kanye namacembe amancane, okugcina kukhinyabeze ukuqina kwesakhiwo sesitshalo. Ukukhanya okugxilile kunganikeza amandla okwanele, kodwa uma kungalawulwa kahle, kungadalula izingxenye ezithile zesitshalo ekukhanyeni okukhulu.
I-homogeneity ekhanyayo ibalulekile ekukhuleni kwezitshalo, kanye nezinye izici ezibalulekile njenge-PPF ne-PPFD. Ukukhanya okungalingani kungaba yingozi ezitshalweni. Ngisho nokungalingani okuncane kungaholela ekukhuleni kwezitshalo okungajwayelekile. Ngenxa yokungalingani kokukhanya kokusabalalisa, amanye amaqabunga angase athole ukukhanya okukhulu, kanti amanye angase angakutholi okwanele ukufeza i-photosynthesis. Izitshalo ezinamaqabunga angalingani zingase zibe nalezi zinkinga: uhlangothi olulodwa lwamaqabunga luba luncane, lulandelwe ukutsheka kwesitshalo njengoba sikhula, futhi ekugcineni, isiqu siyagoba. Njengamanje, izibani eziningi zikhula emakethe zigxila ekukhanyeni, futhi uma zisetshenziswa endaweni enkulu, izinkinga ezingenhla zingenzeka kalula-ngoba izindawo ezigqagqene zemithombo yokukhanya okugxilile zingaholela ekukhanyeni okukhulu kakhulu. Imithombo yokukhanya egxilile inganikeza amandla okukhanya okwanele ezitshalweni, kodwa ngokuvamile idinga abalimi abangochwepheshe ukuze balungise umthombo wokukhanya. Uma ungakwazi ukubeka izibani ngendlela efanele, maningi amathuba okuthi ezinye izitshalo zithole ukukhanya okungafanele.
Kungani izitshalo zigwema ukukhanya okugqame kakhulu? Ukuze siphendule lesi sihloko, kufanele siqale sichaze ijika lempendulo ye-photosynthetic.
Ososayensi baqale bahlongoza ijika lempendulo ye-photosynthetic ngasekupheleni kwekhulu leshumi nesishiyagalolunye. Njengoba ucwaningo lwesayensi luthuthuka, inani elandayo lokuhlola lasebenzisa ikhono lezitshalo lokumunca i-carbon dioxide phakathi ne-photosynthesis ukuze kuhlolwe ukusebenza kahle kwe-photosynthesis. Abacwaningi baqinisekisile ukuthi i-photosynthesis yezitshalo iyahlukahluka kuye ngenani lokukhanya ezikutholayo. Lokhu kuguquguquka kubonakala ngejika lempendulo ye-photosynthetic.
Kunezigaba ezintathu zejika lempendulo ye-photosynthetic:
Isigaba sokuqala:
Njengoba ukukhanya kukhula, izinga le-photosynthetic lesitshalo liyakhula. Lesi isimo esiyinhloko sokukhula kwezitshalo ezilungiselelweni zemvelo.
Ukugcwaliswa kwesikhala:
Uma amandla okukhanya afinyelela izinga elithile, izinga le-photosynthetic liyazinza, okuphakamisa ukuthi lifinyelele iphoyinti lokugcwala kokukhanya, okusho ukuthi ukukhanya okwengeziwe ngeke kuthuthukise ukusebenza kahle.
Ukweqile:
Ngale kwephoyinti lokugcwala kokukhanya, ukukhuphuka kokukhanya kunciphisa izinga le-photosynthetic. Lokhu kungenxa yokuthi ukukhanya okunamandla kubangela izindlela zokuzivikela zesitshalo, okuholela ekulimaleni kwamaqabunga okungenakulungiseka ! !
Uma amandla okukhanya edlula indawo yokugcwala ukukhanya kwesitshalo, isilinganiso se-photosynthesis sensalela (Pn) siyehla. Isitshalo sikakotini i-Pn sikhuphuka ku-0-200 μmol·m⁻²·s⁻¹ ububanzi njengoba imisebe ye-photosynthetically esebenzayo inyuka, kodwa bese iwela kancane ngemva kokufinyelela iphuzu lokugcwala. Lokhu kusikisela ukuthi ukusebenza kahle kwe-photosynthesis kungancishiswa, kube nomthelela ekuthuthukisweni kwezitshalo kanye nokuqoqwa kwe-biomass. (Li, Y., & Wang, J. (Unyaka). Imithelela yemodi yokumisa ekuphenduleni kokukhanya. Isihloko sejenali/Inkomfa.)
Imodeli yokulungiswa kwe-hyperbolic engunxande ilingana nejika lempendulo yokukhanya. (T: izinga lokushisa leqabunga; Ca: i-reference chamber CO2 concentration; R2: coefficient of determination; Pmax: the maximum net photosynthetic rate; LSP: light saturation point; LCP: light compensation point; Rd: dark respiration rate; AQE: ukusebenza kahle kwe-quantum).
Olunye ucwaningo ku-canna*** luthole ukuthi ukukhanya okuphezulu ngaphezu kwephuzu lokugcwala kubangele ukwehla kwezinga le-photosynthetic, isimo esaziwa ngokuthi yi-photosihibition. Kutholwe ukuthi ukwanda kokukhanya okungaphezu kwaleli nani akukhulisi ngempela ukuhlangana kwamakhemikhali abalulekile njenge-THC, okusho ukuthi ukukhanya okuningi kungalimaza ukwakheka kwamakhemikhali. (Rodriguez-Morrison, N., et al. (2021). Imithelela yokuqina kokukhanya nokuchayeka kwe-UV ekuvunweni nasekubunjweni kwesibili kwe-metabolite ye-cann****. Ijenali ye-Horticultural Science & Biotechnology, 96(1), 1-10.)
Ukukhanya okudlulele kungalimaza amaqabunga ezitshalo. UMaganini et al. (2018) ithole ukuthi amaqabunga e-cann**** ahlukumezeke kakhulu ngenxa yokukhanya kwe-UV okunamandla kakhulu, okuhlanganisa ukuwohloka kwe-chlorophyll kanye nokuwohloka kwesakhiwo samaselula. Lokhu akuthinti nje kuphela ukusebenza kahle kwe-photosynthetic kodwa futhi kunomthelela omubi empilweni jikelele yesitshalo. Ucwaningo lwathola ukuthi izitshalo zenza kusebenze izinhlelo zokuvimbela, njenge-antioxidant synthesis, ukumelana nokulimala okuqhubekayo kwe-oxidative, kodwa lezi zinqubo azanele ukukhokhela ngokugcwele umonakalo okhiqizwa ukukhanya okuphezulu. (Magagnini, G., et al. (2018) Indima yemisebe ye-UV ekukhiqizeni ama-metabolites esibili ezitshalweni ze-canna ***. Izitshalo, i-7 (4), i-59.)
Lezi ziphutha zingaba nomthelela omkhulu ekukhiqizeni kwezitshalo, ngakho-ke ukulungiswa kokufana kokukhanya okwenziwa ngesandla kuyadingeka. izindawo ezine-PPFD ephansi kufanele zizuze ekukhanyeni okugqagqene, kuyilapho izindawo ezine-PPFD ephezulu kufanele zigweme ukuqina okwengeziwe. Ngokwale thiyori, ukulawula ukuhlakazeka kokukhanya kufinyelele ezingeni elilinganayo kubalulekile ekukhuleni kwezitshalo. Uchungechunge lwe-QS Pro luhloselwe ukunciphisa izinselele zokulungisa ngokunikeza ukumbozwa okubanzi nokuhlakazeka kokukhanya okulinganayo, okwandisa kakhulu ulwazi lomlimi.