Oyang'anira kukula kwa zomera agwiritsidwa ntchito ngati njira yochepetsera kutentha kwa mbewu zosiyanasiyana

Kupanga mpunga kukuchepa chifukwa cha kusintha kwa nyengo komanso kusinthasintha kwa nyengo ku Colombia.Oyang'anira kukula kwa zomeraZagwiritsidwa ntchito ngati njira yochepetsera kupsinjika kwa kutentha m'mbewu zosiyanasiyana. Chifukwa chake, cholinga cha kafukufukuyu chinali kuwunika momwe thupi limakhudzira (kuyendetsa m'mimba, kuyendetsa m'mimba, kuchuluka kwa chlorophyll, chiŵerengero cha Fv/Fm cha mitundu iwiri ya mpunga wamalonda yomwe yakhudzidwa ndi kutentha kophatikizana (kutentha kwambiri masana ndi usiku), kutentha kwa denga ndi kuchuluka kwa madzi) ndi zinthu zina za biochemical (malondialdehyde (MDA) ndi kuchuluka kwa prolinic acid). Kuyesa koyamba ndi kwachiwiri kunachitika pogwiritsa ntchito zomera za mitundu iwiri ya mpunga Federrose 67 ("F67") ndi Federrose 2000 ("F2000"), motsatana. Kuyesa konseku kunasanthulidwa pamodzi ngati mndandanda wa zoyesera. Mankhwala odziwika anali motere: absolute control (AC) (zomera za mpunga zomwe zimakula pa kutentha koyenera (kutentha kwa masana/usiku 30/25°C)), heat stress control (SC) [zomera za mpunga zomwe zakhudzidwa ndi kutentha kophatikizana kokha (40/ 25°C). 30°C)], ndipo zomera za mpunga zinakakamizidwa ndi kupopera ndi mankhwala owongolera kukula kwa zomera (stress+AUX, stress+BR, stress+CK kapena stress+GA) kawiri (masiku 5 isanafike komanso masiku 5 pambuyo pa kutentha). Kupopera ndi SA kunawonjezera kuchuluka kwa chlorophyll kwa mitundu yonse iwiri (kulemera kwatsopano kwa zomera za mpunga "F67″ ndi "F2000" kunali 3.25 ndi 3.65 mg/g, motsatana) poyerekeza ndi zomera za SC (kulemera kwatsopano kwa zomera "F67″ kunali 2.36 ndi 2.56 mg). g-1)" ndi mpunga "F2000", kugwiritsa ntchito CK pamasamba nthawi zambiri kunathandiza kuti m'mimba mwa zomera za mpunga "F2000" (499.25 vs. 150.60 mmol m-2 s) poyerekeza ndi kutentha. kutentha, kutentha kwa korona wa chomera kumachepa ndi 2–3 °C, ndipo kuchuluka kwa MDA m'zomera kumachepa. Chizindikiro cha kulekerera kwa mbewu chikuwonetsa kuti kugwiritsa ntchito CK (97.69%) ndi BR (60.73%) pa masamba kungathandize kuchepetsa vuto la kutentha kophatikizana. makamaka m'minda ya mpunga ya F2000. Pomaliza, kupopera BR kapena CK pa masamba kungaganizidwe ngati njira yothandiza polima kuti kuchepetse zotsatira zoyipa za kutentha kophatikizana pa khalidwe la zomera za mpunga.
Mpunga (Oryza sativa) ndi wa banja la Poaceae ndipo ndi umodzi mwa mbewu zomwe zimalimidwa kwambiri padziko lonse lapansi pamodzi ndi chimanga ndi tirigu (Bajaj ndi Mohanty, 2005). Malo omwe mpunga umalimidwa ndi mahekitala 617,934, ndipo kupanga kwa dziko lonse mu 2020 kunali matani 2,937,840 ndi zokolola zapakati pa matani 5.02 pa hekita (Federarroz (Federación Nacional de Arroceros), 2021).
Kutentha kwa dziko lapansi kukukhudza mbewu za mpunga, zomwe zikuchititsa mitundu yosiyanasiyana ya kupsinjika kwachilengedwe monga kutentha kwambiri ndi nthawi ya chilala. Kusintha kwa nyengo kukuchititsa kutentha kwa dziko lapansi kukwera; Kutentha kukuyembekezeka kukwera ndi 1.0–3.7°C m'zaka za m'ma 2000, zomwe zitha kuwonjezera kuchuluka ndi mphamvu ya kutentha. Kutentha kwakukulu kwa chilengedwe kwakhudza mpunga, zomwe zikuchititsa kuti zokolola za mbewu zichepe ndi 6–7%. Kumbali ina, kusintha kwa nyengo kumabweretsanso mikhalidwe yoipa ya chilengedwe kwa mbewu, monga nthawi ya chilala chachikulu kapena kutentha kwambiri m'madera otentha ndi otentha. Kuphatikiza apo, zochitika zosiyanasiyana monga El Niño zingayambitse kutentha kwambiri ndikuwonjezera kuwonongeka kwa mbewu m'madera otentha. Ku Colombia, kutentha m'madera omwe amapanga mpunga kukuyembekezeka kukwera ndi 2–2.5°C pofika chaka cha 2050, kuchepetsa kupanga mpunga ndikukhudza kuyenda kwa zinthu kupita kumisika ndi maunyolo ogulitsa.
Mpunga wambiri umalimidwa m'madera omwe kutentha kwake kuli pafupi ndi mulingo woyenera kwambiri kuti mbewu zikule (Shah et al., 2011). Zanenedwa kuti kutentha kwapakati pa usana ndi usiku kwakukula ndi chitukuko cha mpungaKawirikawiri ndi 28°C ndi 22°C, motsatana (Kilasi et al., 2018; Calderón-Páez et al., 2021). Kutentha kopitirira malire awa kungayambitse nthawi ya kutentha pang'ono mpaka kwakukulu panthawi yovuta ya kukula kwa mpunga (kulima, kusakaniza, maluwa, ndi kudzaza tirigu), motero kumakhudza kwambiri zokolola za tirigu. Kuchepa kwa zokolola kumeneku kumachitika makamaka chifukwa cha nthawi yayitali ya kutentha, zomwe zimakhudza kapangidwe ka zomera. Chifukwa cha kuyanjana kwa zinthu zosiyanasiyana, monga nthawi yopsinjika ndi kutentha kwakukulu komwe kwafika, kutentha kumatha kuyambitsa kuwonongeka kosasinthika kwa kagayidwe kachakudya ndi chitukuko cha zomera.
Kupsinjika kwa kutentha kumakhudza njira zosiyanasiyana za thupi ndi zamoyo m'zomera. Kusinthasintha kwa masamba ndi njira imodzi yomwe imakhudzidwa kwambiri ndi kutentha m'zomera za mpunga, chifukwa kuchuluka kwa photosynthesis kumachepa ndi 50% pamene kutentha kwa tsiku ndi tsiku kumapitirira 35°C. Mayankho a zomera za mpunga amasiyana malinga ndi mtundu wa kutentha. Mwachitsanzo, kuchuluka kwa photosynthesis ndi kayendedwe ka m'mimba zimalepheretsedwa pamene zomera zimakumana ndi kutentha kwakukulu masana (33–40°C) kapena kutentha kwakukulu masana ndi usiku (35–40°C masana, 28–30°C). C amatanthauza usiku) (Lü et al., 2013; Fahad et al., 2016; Chaturvedi et al., 2017). Kutentha kwambiri usiku (30°C) kumayambitsa kuletsa pang'ono kwa photosynthesis koma kumawonjezera kupuma usiku (Fahad et al., 2016; Alvarado-Sanabria et al., 2017). Mosasamala kanthu za nthawi ya kupsinjika, kupsinjika kwa kutentha kumakhudzanso kuchuluka kwa chlorophyll m'masamba, chiŵerengero cha chlorophyll variable fluorescence ku maximum chlorophyll fluorescence (Fv/Fm), ndi Rubisco activation mu zomera za mpunga (Cao et al. 2009; Yin et al. 2010). ) Sanchez Reynoso et al., 2014).
Kusintha kwa biochemical ndi mbali ina ya zomera zomwe zimasinthasintha kutentha (Wahid et al., 2007). Kuchuluka kwa proline kwagwiritsidwa ntchito ngati chizindikiro cha biochemical cha kupsinjika kwa zomera (Ahmed ndi Hassan 2011). Proline imagwira ntchito yofunika kwambiri pa kagayidwe kachakudya ka zomera chifukwa imagwira ntchito ngati gwero la kaboni kapena nayitrogeni komanso ngati chokhazikika cha nembanemba pansi pa kutentha kwakukulu (Sánchez-Reinoso et al., 2014). Kutentha kwambiri kumakhudzanso kukhazikika kwa nembanemba kudzera mu lipid peroxidation, zomwe zimapangitsa kuti malondialdehyde (MDA) ipangidwe (Wahid et al., 2007). Chifukwa chake, kuchuluka kwa MDA kwagwiritsidwanso ntchito kumvetsetsa kulimba kwa kapangidwe ka nembanemba za maselo pansi pa kutentha (Cao et al., 2009; Chavez-Arias et al., 2018). Pomaliza, kupsinjika kwa kutentha pamodzi [37/30°C (usana/usiku)] kunawonjezera kuchuluka kwa kutuluka kwa electrolyte ndi malondialdehyde mu mpunga (Liu et al., 2013).
Kugwiritsa ntchito zida zowongolera kukula kwa zomera (GRs) kwayesedwa kuti kuchepetse zotsatira zoyipa za kutentha, chifukwa zinthuzi zimagwira ntchito mwachangu poyankha zomera kapena njira zodzitetezera ku kutentha kotere (Peleg ndi Blumald, 2011; Yin et al. et al., 2011; Ahmed et al., 2015). Kugwiritsa ntchito zinthu za majini kunja kwa dziko kwakhala ndi zotsatira zabwino pa kupirira kutentha m'minda yosiyanasiyana. Kafukufuku wasonyeza kuti ma phytohormones monga gibberellins (GA), cytokinins (CK), auxins (AUX) kapena brassinosteroids (BR) amachititsa kuti pakhale kuwonjezeka kwa zinthu zosiyanasiyana za thupi ndi zamoyo (Peleg ndi Blumald, 2011; Yin et al. Ren, 2011; Mitler et al., 2012; Zhou et al., 2014). Ku Colombia, kugwiritsa ntchito zinthu za majini kunja kwa dziko komanso momwe zimakhudzira mbewu za mpunga sikunamvetsetsedwe bwino komanso kuphunziridwa. Komabe, kafukufuku wakale adawonetsa kuti kupopera masamba a BR kungathandize kupirira mpunga mwa kusintha mawonekedwe a mpweya, chlorophyll kapena kuchuluka kwa proline m'masamba a mbande za mpunga (Quintero-Calderón et al., 2021).
Ma cytokinins amathandizira kuyankhidwa kwa zomera ku zovuta za abiotic, kuphatikizapo kupsinjika kwa kutentha (Ha et al., 2012). Kuphatikiza apo, zanenedwa kuti kugwiritsa ntchito CK kunja kungachepetse kuwonongeka kwa kutentha. Mwachitsanzo, kugwiritsa ntchito zeatin kunja kwawonjezera kuchuluka kwa photosynthesis, kuchuluka kwa chlorophyll a ndi b, komanso kuyendetsa bwino ma electron mu creeping bentgrass (Agrotis estolonifera) panthawi ya kupsinjika kwa kutentha (Xu ndi Huang, 2009; Jespersen ndi Huang, 2015). Kugwiritsa ntchito zeatin kunja kwa zomera kungathandizenso ntchito ya antioxidant, kuwonjezera kupanga mapuloteni osiyanasiyana, kuchepetsa kuwonongeka kwa reactive oxygen species (ROS) ndi malondialdehyde (MDA) m'maselo a zomera (Chernyadyev, 2009; Yang et al., 2009). , 2016; Kumar et al., 2020).
Kugwiritsa ntchito gibberellic acid kwawonetsanso kuti kuyankha bwino ku kutentha. Kafukufuku wasonyeza kuti GA biosynthesis imayambitsa njira zosiyanasiyana za kagayidwe kachakudya ndipo imawonjezera kulekerera pansi pa kutentha kwambiri (Alonso-Ramirez et al. 2009; Khan et al. 2020). Abdel-Nabi et al. (2020) adapeza kuti kupopera masamba a GA yakunja (25 kapena 50 mg*L) kumatha kuwonjezera kuchuluka kwa photosynthesis ndi ntchito ya antioxidant m'zomera za lalanje zomwe zimakhudzidwa ndi kutentha poyerekeza ndi zomera zowongolera. Zawonedwanso kuti kugwiritsa ntchito HA kunja kumawonjezera kuchuluka kwa chinyezi, chlorophyll ndi carotenoid ndikuchepetsa lipid peroxidation mu date palm (Phoenix dactylifera) pansi pa kutentha kwambiri (Khan et al., 2020). Auxin imagwiranso ntchito yofunika kwambiri pakulamulira mayankho osinthika a kukula ku kutentha kwambiri (Sun et al., 2012; Wang et al., 2016). Woyang'anira kukula kumeneku amagwira ntchito ngati chizindikiro cha biochemical mu njira zosiyanasiyana monga kupanga proline kapena kuwonongeka pansi pa abiotic stress (Ali et al. 2007). Kuphatikiza apo, AUX imawonjezeranso ntchito ya antioxidant, zomwe zimapangitsa kuti MDA ichepe m'zomera chifukwa cha kuchepa kwa lipid peroxidation (Bielach et al., 2017). Sergeev et al. (2018) adawona kuti mu zomera za nandolo (Pisum sativum) pansi pa kutentha, kuchuluka kwa proline - dimethylaminoethoxycarbonylmethyl)naphthylchloromethyl ether (TA-14) kumawonjezeka. Mu kuyesera komweko, adawonanso kuchuluka kochepa kwa MDA m'zomera zochiritsidwa poyerekeza ndi zomera zomwe sizinachiritsidwe ndi AUX.
Brassinosteroids ndi gulu lina la owongolera kukula komwe amagwiritsidwa ntchito kuchepetsa zotsatira za kutentha. Ogweno et al. (2008) adanenanso kuti kupopera kwa BR kwakunja kunawonjezera kuchuluka kwa photosynthesis, stomatal conductance ndi kuchuluka kwa Rubisco carboxylation ya zomera za phwetekere (Solanum lycopersicum) zomwe zili ndi kutentha kwa masiku 8. Kupopera kwa epibrassinosteroids kuchokera ku masamba kumatha kuwonjezera kuchuluka kwa photosynthesis ya zomera za nkhaka (Cucumis sativus) zomwe zili ndi kutentha kwamphamvu (Yu et al., 2004). Kuphatikiza apo, kugwiritsa ntchito BR kuchokera kunja kumachedwetsa kuwonongeka kwa chlorophyll ndikuwonjezera kugwiritsa ntchito bwino madzi komanso kuchuluka kwa quantum ya PSII photochemistry m'zomera zomwe zili ndi kutentha kwamphamvu (Holá et al., 2010; Toussagunpanit et al., 2015).
Chifukwa cha kusintha kwa nyengo komanso kusintha kwanyengo, mbewu za mpunga zimakumana ndi kutentha kwambiri tsiku lililonse (Lesk et al., 2016; Garcés, 2020; Federarroz (Federación Nacional de Arroceros), 2021). Mu phenotyping ya zomera, kugwiritsa ntchito phytonutrients kapena biostimulants kwaphunziridwa ngati njira yochepetsera kutentha kwa madera omwe amalima mpunga (Alvarado-Sanabria et al., 2017; Calderón-Páez et al., 2021; Quintero-Calderón et al., 2021). Kuphatikiza apo, kugwiritsa ntchito zinthu zachilengedwe ndi zosinthika za thupi (kutentha kwa masamba, kuyendetsa bwino kwa stomatal, magawo a chlorophyll fluorescence, chlorophyll ndi kuchuluka kwa madzi, malondialdehyde ndi proline synthesis) ndi chida chodalirika chowunikira zomera za mpunga zomwe zili ndi kutentha kwambiri m'deralo komanso padziko lonse lapansi (Sánchez -Reynoso et al., 2014; Alvarado-Sanabria et al., 2017; Komabe, kafukufuku wokhudza kugwiritsa ntchito mankhwala opopera a phytohormonal mu mpunga pamlingo wapafupi akadali ochepa. Chifukwa chake, kuphunzira za momwe thupi limagwirira ntchito ndi biochemical pogwiritsa ntchito owongolera kukula kwa zomera ndikofunikira kwambiri pakupereka njira zothandiza zaulimi pa izi, kuthana ndi zotsatira zoyipa za nthawi yovuta kwambiri ya kutentha mu mpunga. Chifukwa chake, cholinga cha kafukufukuyu chinali kuwunika momwe thupi limagwirira ntchito (kuyendetsa bwino kwa stomatal, magawo a chlorophyll fluorescence ndi kuchuluka kwa madzi) komanso zotsatira za biochemical za kugwiritsa ntchito masamba a owongolera kukula kwa zomera anayi (AUX, CK, GA ndi BR). (Ma pigment a Photosynthetic, malondialdehyde ndi kuchuluka kwa proline) Mitundu iwiri ya mpunga wamalonda yomwe imakhudzidwa ndi kutentha kwambiri (kutentha kwambiri masana/usiku).
Mu kafukufukuyu, mayeso awiri odziyimira pawokha adachitika. Mitundu ya majini Federrose 67 (F67: mtundu wa majini womwe udakula kutentha kwambiri m'zaka khumi zapitazi) ndi Federrose 2000 (F2000: mtundu wa majini womwe udakula m'zaka khumi zapitazi za m'ma 1900 womwe umasonyeza kukana kachilombo ka masamba oyera) idagwiritsidwa ntchito koyamba. mbewu. ndipo kuyesa kwachiwiri, motsatana. Mitundu yonse ya majini imalimidwa kwambiri ndi alimi aku Colombia. Mbewu zidabzalidwa m'mathireyi a 10-L (kutalika 39.6 cm, m'lifupi 28.8 cm, kutalika 16.8 cm) okhala ndi dothi la mchenga lokhala ndi 2% ya zinthu zachilengedwe. Mbewu zisanu zomwe zidamera kale zidabzalidwa muthireyi iliyonse. Mapaleti adayikidwa mu greenhouse ya Faculty of Agricultural Sciences of the National University of Colombia, Bogotá campus (43°50′56″ N, 74°04′051″ W), pamtunda wa 2556 m pamwamba pa nyanja (asl). m.) ndipo zinachitika kuyambira Okutobala mpaka Disembala 2019. Kuyesera kamodzi (Federroz 67) ndi kuyesa kwachiwiri (Federroz 2000) mu nyengo yomweyo ya 2020.
Mkhalidwe wa chilengedwe mu greenhouse nthawi iliyonse yobzala ndi motere: kutentha kwa usana ndi usiku 30/25°C, chinyezi chaching'ono 60~80%, nthawi yachilengedwe yowunikira maola 12 (kuwunikira kwa photosynthetically active 1500 µmol (photons) m-2 s-). 1 masana). Zomera zidapatsidwa feteleza malinga ndi zomwe zili mu chinthu chilichonse patatha masiku 20 mbewu zitamera (DAE), malinga ndi Sánchez-Reinoso et al. (2019): 670 mg ya nayitrogeni pa chomera chilichonse, 110 mg ya phosphorous pa chomera chilichonse, 350 mg ya potaziyamu pa chomera chilichonse, 68 mg ya calcium pa chomera chilichonse, 20 mg ya magnesium pa chomera chilichonse, 20 mg ya sulfure pa chomera chilichonse, 17 mg ya silicon pa chomera chilichonse. Zomerazo zili ndi 10 mg ya boron pa chomera chilichonse, 17 mg ya mkuwa pa chomera chilichonse, ndi 44 mg ya zinc pa chomera chilichonse. Zomera za mpunga zidasungidwa mpaka 47 DAE mu kuyesa kulikonse pamene zidafika pagawo la phenological V5 panthawiyi. Kafukufuku wakale wasonyeza kuti gawo ili la phenological ndi nthawi yoyenera yochitira maphunziro okhudza kutentha mu mpunga (Sánchez-Reinoso et al., 2014; Alvarado-Sanabria et al., 2017).
Mu kuyesera kulikonse, ntchito ziwiri zosiyana za chowongolera kukula kwa masamba zinachitidwa. Seti yoyamba ya mankhwala opopera a phytohormone a foliar anagwiritsidwa ntchito masiku 5 chithandizo cha kutentha chisanachitike (42 DAE) kuti akonzekeretse zomera kupsinjika kwa chilengedwe. Kenako mankhwala ena opopera a foliar anaperekedwa masiku 5 zomera zitakumana ndi zovuta (52 DAE). Ma phytohormone anayi anagwiritsidwa ntchito ndipo makhalidwe a chinthu chilichonse chogwira ntchito chopopera mu kafukufukuyu alembedwa mu Supplementary Table 1. Kuchuluka kwa mankhwala owongolera kukula kwa masamba omwe anagwiritsidwa ntchito anali motere: (i) Auxin (1-naphthylacetic acid: NAA) pa kuchuluka kwa 5 × 10−5 M (ii) 5 × 10–5 M gibberellin (gibberellic acid: NAA); GA3); (iii) Cytokinin (trans-zeatin) 1 × 10-5 M (iv) Brassinosteroids [Spirostan-6-one, 3,5-dihydroxy-, (3b,5a,25R)] 5 × 10-5; M. Kuchuluka kumeneku kunasankhidwa chifukwa kumayambitsa mayankho abwino ndikuwonjezera kukana kwa zomera ku kutentha (Zahir et al., 2001; Wen et al., 2010; El-Bassiony et al., 2012; Salehifar et al., 2017). Mbewu za mpunga zopanda mankhwala oletsa kukula kwa zomera zinachiritsidwa ndi madzi osungunuka okha. Mbewu zonse za mpunga zinapopera ndi chopopera chamanja. Ikani 20 ml H2O pa chomera kuti munyowetse pamwamba ndi pansi pa masamba. Ma spray onse a masamba anagwiritsa ntchito agrotin adjuvant (Agrotin, Bayer CropScience, Colombia) pa 0.1% (v/v). Mtunda pakati pa mphika ndi chopopera ndi 30 cm.
Mankhwala ochepetsa kutentha adaperekedwa patatha masiku 5 kuchokera pamene anathira masamba oyamba (47 DAE) mu kuyesa kulikonse. Zomera za mpunga zinasamutsidwa kuchokera ku greenhouse kupita ku chipinda chokulirapo cha 294 L (MLR-351H, Sanyo, IL, USA) kuti zitsimikizire kutentha kapena kusunga mikhalidwe yofanana ya chilengedwe (47 DAE). Mankhwala ochepetsa kutentha adachitika poika chipindacho kutentha kwa masana/usiku: kutentha kwakukulu kwa masana [40°C kwa maola 5 (kuyambira 11:00 mpaka 16:00)] ndi nthawi yausiku [30°C kwa maola 5]. Masiku 8 motsatizana (kuyambira 19:00 mpaka 24:00). Kutentha kwa kupsinjika ndi nthawi yowonekera zidasankhidwa kutengera maphunziro am'mbuyomu (Sánchez-Reynoso et al. 2014; Alvarado-Sanabía et al. 2017). Kumbali inayi, gulu la zomera zomwe zinasamutsidwira ku chipinda chokulirapo zinasungidwa mu greenhouse kutentha komweko (30°C masana/25°C usiku) kwa masiku 8 otsatizana.
Kumapeto kwa kuyesera, magulu otsatirawa a chithandizo adapezeka: (i) mkhalidwe wa kutentha kwa kukula + kugwiritsa ntchito madzi osungunuka [Absolute control (AC)], (ii) mkhalidwe wa kutentha + kugwiritsa ntchito madzi osungunuka [Heat stress control (SC)], (iii) mkhalidwe wa kutentha + auxin application (AUX), (iv) mkhalidwe wa kutentha + gibberellin application (GA), (v) mkhalidwe wa kutentha + cytokinin application (CK), ndi (vi) mkhalidwe wa kutentha + brassinosteroid (BR) Appendix. Magulu a chithandizo awa adagwiritsidwa ntchito pa majini awiri (F67 ndi F2000). Mankhwala onse adachitika mwadongosolo losasinthika ndi ma replica asanu, iliyonse yokhala ndi chomera chimodzi. Chomera chilichonse chidagwiritsidwa ntchito kuwerenga zosintha zomwe zidapezeka kumapeto kwa kuyesera. Kuyeseraku kudatenga 55 DAE.
Kuchuluka kwa mpweya m'mimba (gs) kunayesedwa pogwiritsa ntchito porosometer yonyamulika (SC-1, METER Group Inc., USA) kuyambira 0 mpaka 1000 mmol m-2 s-1, ndi chivundikiro cha chipinda chachitsanzo cha 6.35 mm. Muyeso umatengedwa poyika choyezera cha stomameter ku tsamba lokhwima ndi mphukira yayikulu ya chomera chokulirapo. Pa chithandizo chilichonse, mawerengedwe a gs adatengedwa pa masamba atatu a chomera chilichonse pakati pa 11:00 ndi 16:00 ndipo amawerengedwa pa avareji.
RWC inapezeka motsatira njira yomwe Ghoulam et al. (2002) adafotokoza. Pepala lokulitsa mokwanira lomwe linagwiritsidwa ntchito pozindikira g linagwiritsidwanso ntchito poyesa RWC. Kulemera kwatsopano (FW) kunapezeka nthawi yomweyo mutakolola pogwiritsa ntchito sikelo ya digito. Kenako masambawo anaikidwa mu chidebe cha pulasitiki chodzazidwa ndi madzi ndikusiyidwa mumdima kutentha kwa chipinda (22°C) kwa maola 48. Kenako yesani pa sikelo ya digito ndikulemba kulemera kowonjezereka (TW). Masamba otupawo anaumitsidwa mu uvuni pa 75°C kwa maola 48 ndipo kulemera kwawo kouma (DW) kunalembedwa.
Kuchuluka kwa chlorophyll kunapezeka pogwiritsa ntchito choyezera cha chlorophyll (atLeafmeter, FT Green LLC, USA) ndipo kunafotokozedwa mu mayunitsi a atLeaf (Dey et al., 2016). Kuwerenga kwa PSII maximum quantum efficiency (Fv/Fm ratio) kunalembedwa pogwiritsa ntchito continuous excitation chlorophyll fluorimeter (Handy PEA, Hansatech Instruments, UK). Masamba anasinthidwa kukhala akuda pogwiritsa ntchito ma leaf clamps kwa mphindi 20 Fv/Fm isanayambe kuyeza (Restrepo-Diaz ndi Garces-Varon, 2013). Masamba atazolowera mdima, baseline (F0) ndi maximum fluorescence (Fm) zinayesedwa. Kuchokera ku deta iyi, kusinthasintha kwa kuwala (Fv = Fm – F0), chiŵerengero cha kusinthasintha kwa kuwala kwa kuwala kwa kuwala (Fv/Fm), kuchuluka kwa kuchuluka kwa quantum kwa PSII photochemistry (Fv/F0) ndi chiŵerengero cha Fm/F0 zinawerengedwa (Baker, 2008; Lee et al. ., 2017). Kuwerengera kwa chlorophyll ndi chlorophyll fluorescence kunatengedwa pa masamba omwewo omwe amagwiritsidwa ntchito poyeza gs.
Pafupifupi 800 mg ya kulemera kwa masamba atsopano inasonkhanitsidwa ngati zinthu zosinthika za biochemical. Zitsanzo za masamba kenako zinasinthidwa kukhala zofanana mu nayitrogeni yamadzimadzi ndikusungidwa kuti ziwunikidwenso. Njira ya spectrometric yomwe imagwiritsidwa ntchito poyesa kuchuluka kwa chlorophyll a, b ndi carotenoid yachokera pa njira ndi ma equation omwe adafotokozedwa ndi Wellburn (1994). Zitsanzo za minofu ya masamba (30 mg) zinasonkhanitsidwa ndikusinthidwa kukhala zofanana mu 3 ml ya 80% acetone. Kenako zitsanzozo zinasinthidwa kukhala centrifuge (model 420101, Becton Dickinson Primary Care Diagnostics, USA) pa 5000 rpm kwa mphindi 10 kuti achotse tinthu tating'onoting'ono. Supernatant inachepetsedwa kufika pa voliyumu yomaliza ya 6 ml powonjezera 80% acetone (Sims ndi Gamon, 2002). Kuchuluka kwa chlorophyll kunapezeka pa 663 (chlorophyll a) ndi 646 (chlorophyll b) nm, ndipo ma carotenoids pa 470 nm pogwiritsa ntchito spectrophotometer (Spectronic BioMate 3 UV-vis, Thermo, USA).
Njira ya thiobarbituric acid (TBA) yomwe Hodges et al. (1999) adafotokoza idagwiritsidwa ntchito poyesa membrane lipid peroxidation (MDA). Pafupifupi 0.3 g ya minofu ya masamba idasinthidwanso kukhala homogenized mu liquid nitrogen. Zitsanzozo zidayikidwa centrifuged pa 5000 rpm ndipo absorbance idayesedwa pa spectrophotometer pa 440, 532 ndi 600 nm. Pomaliza, kuchuluka kwa MDA kudawerengedwa pogwiritsa ntchito extinction coefficient (157 M mL−1).
Kuchuluka kwa proline mu mankhwala onse kunapezeka pogwiritsa ntchito njira yomwe Bates et al. (1973) adafotokoza. Onjezani 10 ml ya yankho lamadzi la 3% la sulfosalicylic acid ku chitsanzo chosungidwa ndikusefa kudzera mu pepala losefera la Whatman (Nambala 2). Kenako 2 ml ya filtrate iyi idayankhidwa ndi 2 ml ya ninhydric acid ndi 2 ml ya glacial acetic acid. Chosakanizacho chidayikidwa mu bafa lamadzi pa 90°C kwa ola limodzi. Siyani kuchitapo kanthu poyika pa ayezi. Gwedezani chubu mwamphamvu pogwiritsa ntchito vortex shaker ndikusungunula yankho lomwe lapezeka mu 4 ml ya toluene. Kuwerengera kwa kuyamwa kunapezeka pa 520 nm pogwiritsa ntchito spectrophotometer yomweyi yomwe imagwiritsidwa ntchito poyesa utoto wa photosynthetic (Spectronic BioMate 3 UV-Vis, Thermo, Madison, WI, USA).
Njira yomwe Gerhards et al. (2016) adafotokoza powerengera kutentha kwa denga ndi CSI. Zithunzi za kutentha zidatengedwa ndi kamera ya FLIR 2 (FLIR Systems Inc., Boston, MA, USA) yolondola ya ±2°C kumapeto kwa nthawi yopsinjika. Ikani malo oyera kumbuyo kwa chomera kuti mujambule zithunzi. Apanso, mafakitale awiri adawonedwa ngati zitsanzo zofotokozera. Zomerazo zidayikidwa pamalo oyera; imodzi idakutidwa ndi chothandizira chaulimi (Agrotin, Bayer CropScience, Bogotá, Colombia) kuti iyerekeze kutseguka kwa stomata yonse [wet mode (Twet)], ndipo inayo inali tsamba lopanda kugwiritsa ntchito [Dry mode (Tdry)] (Castro -Duque et al., 2020). Mtunda pakati pa kamera ndi mphika panthawi yojambulira unali 1 m.
Chizindikiro cha kulekerera kwachibale chinawerengedwa mwanjira ina pogwiritsa ntchito njira yoyendetsera stomatal (gs) ya zomera zomwe zachiritsidwa poyerekeza ndi zomera zowongolera (zomera zopanda mankhwala opsinjika maganizo komanso zowongolera kukula zomwe zagwiritsidwa ntchito) kuti zidziwe kulekerera kwa majini omwe achiritsidwa omwe ayesedwa mu kafukufukuyu. RTI idapezeka pogwiritsa ntchito equation yosinthidwa kuchokera ku Chávez-Arias et al. (2020).
Mu kuyesera kulikonse, zinthu zonse za thupi zomwe zatchulidwa pamwambapa zinapezeka ndikulembedwa pa 55 DAE pogwiritsa ntchito masamba okulirapo omwe anasonkhanitsidwa kuchokera pamwamba pa denga. Kuphatikiza apo, miyeso idachitika mchipinda chokulirapo kuti isasinthe momwe zomera zimakulira.
Deta yochokera ku zoyeserera zoyamba ndi zachiwiri idasanthulidwa pamodzi ngati mndandanda wa zoyeserera. Gulu lililonse loyesera linali ndi zomera 5, ndipo chomera chilichonse chinali gawo loyesera. Kusanthula kwa kusiyana (ANOVA) kunachitika (P ≤ 0.05). Pamene kusiyana kwakukulu kunapezeka, mayeso oyerekeza a Tukey pambuyo pa hoc adagwiritsidwa ntchito pa P ≤ 0.05. Gwiritsani ntchito ntchito ya arcsine kuti musinthe kuchuluka kwa maperesenti. Deta idasanthulidwa pogwiritsa ntchito pulogalamu ya Statistix v 9.0 (Analytical Software, Tallahassee, FL, USA) ndikujambula pogwiritsa ntchito SigmaPlot (version 10.0; Systat Software, San Jose, CA, USA). Kusanthula kwakukulu kwa gawo kunachitika pogwiritsa ntchito pulogalamu ya InfoStat 2016 (Analysis Software, National University of Cordoba, Argentina) kuti adziwe owongolera kukula kwa zomera omwe akuphunziridwa.
Gome 1 likufotokoza mwachidule za ANOVA zomwe zachitika, njira zosiyanasiyana zochiritsira, ndi momwe zimagwirizanirana ndi utoto wa masamba (chlorophyll a, b, total, ndi carotenoids), malondialdehyde (MDA) ndi proline content, ndi stomatal conductance. Zotsatira za gs, relative water content. (RWC), chlorophyll content, chlorophyll alpha fluorescence parameters, crown temperature (PCT) (°C), crop stress index (CSI) ndi relative tolerance index ya mpunga pa 55 DAE.
Gome 1. Chidule cha deta ya ANOVA pa kusintha kwa thupi ndi zamoyo pakati pa zoyeserera (ma genotypes) ndi mankhwala ochepetsa kupsinjika kwa kutentha.
Kusiyana (P≤0.01) mu kuyanjana kwa utoto wa masamba, kuchuluka kwa chlorophyll (kuwerengedwa kwa Atleaf), ndi magawo a alpha-chlorophyll fluorescence pakati pa zoyeserera ndi mankhwala akuwonetsedwa mu Gome 2. Kutentha kwambiri masana ndi usiku kunawonjezera kuchuluka kwa chlorophyll ndi carotenoid. Mbeu za mpunga zopanda kupopera masamba a phytohormones (2.36 mg g-1 ya "F67″ ndi 2.56 mg g-1 ya "F2000″)) poyerekeza ndi zomera zomwe zimakula pansi pa kutentha kwabwino (2.67 mg g -1)) zinawonetsa kuchuluka kochepa kwa chlorophyll. Mu zoyeserera zonse ziwiri, "F67" inali 2.80 mg g-1 ndipo "F2000" inali 2.80 mg g-1. Kuphatikiza apo, mbande za mpunga zomwe zinapatsidwa mankhwala osakaniza AUX ndi GA sprays pansi pa kutentha kwambiri zinasonyezanso kuchepa kwa chlorophyll mu genotypes zonse ziwiri (AUX = 1.96 mg g-1 ndi GA = 1.45 mg g-1 ya “F67”; AUX = 1.96 mg g-1 ndi GA = 1.45 mg g-1 ya “F67″; AUX = 2.24 mg) g-1 ndi GA = 1.43 mg g-1 (ya “F2000″) pansi pa kutentha kwambiri. Pansi pa kutentha kwambiri, chithandizo cha masamba ndi BR chinapangitsa kuti kusinthaku kukhale kwakukulu mu genotypes zonse ziwiri. Pomaliza, CK foliar spray inawonetsa kuchuluka kwa pigment ya photosynthetic pakati pa mankhwala onse (AUX, GA, BR, SC ndi AC treatments) mu genotypes F67 (3.24 mg g-1) ndi F2000 (3.65 mg g-1). Kuchuluka kwa chlorophyll (Atleaf unit) kunachepetsedwanso ndi kutentha kophatikizana. Mitengo yapamwamba kwambiri inalembedwanso m'zomera zomwe zinapopedwa ndi CC m'mitundu yonse iwiri (41.66 ya "F67" ndi 49.30 ya "F2000"). Ma ratios a Fv ndi Fv/Fm adawonetsa kusiyana kwakukulu pakati pa mankhwala ndi mitundu ya mbewu (Table 2). Ponseponse, pakati pa mitundu iyi, mtundu wa F67 sunali wovuta kwambiri kupsinjika ndi kutentha kuposa mtundu wa F2000. Ma ratios a Fv ndi Fv/Fm adavutika kwambiri mu kuyesa kwachiwiri. Mbeu zolimbikitsidwa za 'F2000' zomwe sizinapopedwe ndi ma phytohormones zinali ndi ma ratios otsika kwambiri a Fv (2120.15) ndi ma ratios a Fv/Fm (0.59), koma kupopera masamba ndi CK kunathandiza kubwezeretsa ma ratios awa (Fv: 2591, 89, Fv/Fm ratios: 0.73). , kulandira ziwerengero zofanana ndi zomwe zinalembedwa pa zomera za "F2000" zomwe zimakula pansi pa kutentha kwabwino (Fv: 2955.35, Fv/Fm ratio: 0.73:0.72). Panalibe kusiyana kwakukulu pa fluorescence yoyamba (F0), maximum fluorescence (Fm), maximum photochemical quantum yield ya PSII (Fv/F0) ndi Fm/F0 ratio. Pomaliza, BR inawonetsa zomwezo monga momwe zawonedwera ndi CK (Fv 2545.06, Fv/Fm ratio 0.73).
Gome 2. Zotsatira za kutentha kophatikizana (40°/30°C masana/usiku) pa utoto wa masamba opangidwa ndi photosynthesis [chlorophyll yonse (Chl Total), chlorophyll a (Chl a), chlorophyll b (Chl b) ndi carotenoids Cx+c] effect ], kuchuluka kwa chlorophyll (Atliff unit), magawo a chlorophyll fluorescence (fluorescence yoyamba (F0), maximum fluorescence (Fm), variable fluorescence (Fv), maximum PSII efficiency (Fv/Fm), photochemical maximum quantum yield ya PSII (Fv/F0 ) ndi Fm/F0 m'zomera za mitundu iwiri ya mpunga [Federrose 67 (F67) ndi Federrose 2000 (F2000)] masiku 55 pambuyo pa kumera (DAE)).
Madzi ochulukirapo (RWC) a zomera za mpunga zomwe zimachiritsidwa mosiyana adawonetsa kusiyana (P ≤ 0.05) pakugwirizana pakati pa mankhwala oyesera ndi mankhwala ochiritsa masamba (Chithunzi 1A). Atalandira chithandizo ndi SA, mitengo yotsika kwambiri idalembedwa pa mitundu yonse iwiri ya majini (74.01% ya F67 ndi 76.6% ya F2000). Pansi pa kutentha, RWC ya zomera za mpunga za mitundu yonse iwiri yomwe imachiritsidwa ndi ma phytohormones osiyanasiyana idakwera kwambiri. Ponseponse, kugwiritsa ntchito CK, GA, AUX, kapena BR pamasamba kudakulitsa RWC kufika pamitengo yofanana ndi ya zomera zomwe zimakula pansi pa mikhalidwe yabwino panthawi yoyesera. Kulamulira kwathunthu ndi zomera zomwe zimapopera masamba zidalemba mitengo yozungulira 83% ya mitundu yonse iwiri ya majini. Kumbali ina, gs adawonetsanso kusiyana kwakukulu (P ≤ 0.01) pakugwirizana ndi mankhwala oyesera (Chithunzi 1B). Chomera chowongolera (AC) chinalembanso mitengo yapamwamba kwambiri pa mtundu uliwonse wa genotype (440.65 mmol m-2s-1 ya F67 ndi 511.02 mmol m-2s-1 ya F2000). Zomera za mpunga zomwe zinakhudzidwa ndi kutentha kophatikizana zokha zinawonetsa mitengo yotsika kwambiri ya ma genotype onse awiri (150.60 mmol m-2s-1 ya F67 ndi 171.32 mmol m-2s-1 ya F2000). Kuchiza ndi masamba ndi owongolera kukula kwa zomera zonse kunawonjezekanso g. Pa zomera za mpunga za F2000 zomwe zinapopedwa ndi CC, zotsatira za kupopera masamba ndi ma phytohormones zinali zoonekeratu. Gulu la zomerali silinawonetse kusiyana kulikonse poyerekeza ndi zomera zowongolera (AC 511.02 ndi CC 499.25 mmol m-2s-1).
Chithunzi 1. Zotsatira za kupsinjika kwa kutentha kophatikizana (40°/30°C masana/usiku) pa kuchuluka kwa madzi (RWC) (A), stomatal conductance (gs) (B), malondialdehyde (MDA) kupanga (C), ndi kuchuluka kwa proline. (D) m'zomera za mitundu iwiri ya mpunga (F67 ndi F2000) patatha masiku 55 kuchokera pamene yamera (DAE). Mankhwala omwe adayesedwa pa mtundu uliwonse wa genotype adaphatikizapo: absolute control (AC), heat stress control (SC), heat stress + auxin (AUX), heat stress + gibberellin (GA), heat stress + cell mitogen (CK), ndi heat stress + brassinosteroid. (BR). Mzere uliwonse ukuyimira mean ± standard error ya mfundo zisanu za data (n = 5). Mizere yotsatiridwa ndi zilembo zosiyanasiyana imasonyeza kusiyana kwakukulu kwa ziwerengero malinga ndi mayeso a Tukey (P ≤ 0.05). Zilembo zokhala ndi chizindikiro chofanana zimasonyeza kuti mean si yofunikira kwambiri pa ziwerengero (≤ 0.05).
Zomwe zili mu MDA (P ≤ 0.01) ndi proline (P ≤ 0.01) zinawonetsanso kusiyana kwakukulu pakati pa kuyanjana pakati pa kuyesa ndi mankhwala a phytohormone (Chithunzi 1C, D). Kuwonjezeka kwa lipid peroxidation kunawonedwa ndi chithandizo cha SC mu majini onse awiri (Chithunzi 1C), komabe zomera zomwe zinapatsidwa mankhwala oletsa kukula kwa masamba zinawonetsa kuchepa kwa lipid peroxidation mu majini onse awiri; Kawirikawiri, kugwiritsa ntchito ma phytohormones (CA, AUC, BR kapena GA) kumabweretsa kuchepa kwa lipid peroxidation (MDA). Palibe kusiyana komwe kunapezeka pakati pa zomera za AC za mitundu iwiri ya majini ndi zomera zomwe zinali pansi pa kutentha ndipo zinathiridwa ndi ma phytohormones (anaona kuti kuchuluka kwa FW mu zomera za "F67" kunali kuyambira 4.38–6.77 µmol g-1, ndipo mu zomera za "F2000" "anaona kuti kuchuluka kwa proline kunali kuyambira 2.84 mpaka 9.18 µmol g-1 (zomera). Kumbali inayi, kupanga proline mu zomera za "F67" kunali kotsika kuposa zomera za "F2000" zomwe zinali pansi pa kupsinjika kophatikizana, zomwe zinapangitsa kuti proline ikule. mu zomera za mpunga zomwe zinali pansi pa kutentha, m'mayesero onse awiri, zinaonedwa kuti kupereka mahomoni awa kunawonjezera kwambiri kuchuluka kwa amino acid mu zomera za F2000 (AUX ndi BR zinali 30.44 ndi 18.34 µmol g-1) motsatana (Chithunzi 1G).
Zotsatira za kupopera kwa zomera za masamba ndi kutentha kophatikizana pa kutentha kwa denga la zomera ndi index ya kulekerera (RTI) zikuwonetsedwa mu Zithunzi 2A ndi B. Pa mitundu yonse iwiri ya majini, kutentha kwa denga la zomera za AC kunali pafupi ndi 27°C, ndipo kwa zomera za SC kunali pafupifupi 28°C. WITH. Zinaonedwanso kuti mankhwala a masamba ndi CK ndi BR adapangitsa kuti kutentha kwa denga kuchepe ndi 2–3°C poyerekeza ndi zomera za SC (Chithunzi 2A). RTI idawonetsa khalidwe lofanana ndi zinthu zina zakuthupi, kusonyeza kusiyana kwakukulu (P ≤ 0.01) pakugwirizana pakati pa kuyesa ndi chithandizo (Chithunzi 2B). Zomera za SC zidawonetsa kulekerera kochepa kwa zomera m'mitundu yonse iwiri ya majini (34.18% ndi 33.52% ya zomera za mpunga za "F67" ndi "F2000", motsatana). Kudyetsa zomera za phytohormones kuchokera ku masamba kumawongolera RTI m'zomera zomwe zimakhudzidwa ndi kutentha kwambiri. Zotsatirazi zinali zoonekera kwambiri m'zomera za "F2000" zomwe zinapopedwa ndi CC, pomwe RTI inali 97.69. Kumbali ina, kusiyana kwakukulu kunawonedwa kokha mu yield stress index (CSI) ya zomera za mpunga pansi pa foliar factor stress conditions (P ≤ 0.01) (Chithunzi 2B). Zomera za mpunga zokha zomwe zinapopedwa ndi kutentha kwambiri ndizo zinawonetsa stress index value yapamwamba kwambiri (0.816). Zomera za mpunga zikapopedwa ndi ma phytohormones osiyanasiyana, stress index inali yotsika (mitengo kuyambira 0.6 mpaka 0.67). Pomaliza, chomera cha mpunga chomwe chinalimidwa m'mikhalidwe yabwino chinali ndi mtengo wa 0.138.
Chithunzi 2. Zotsatira za kupsinjika kwa kutentha kophatikizana (40°/30°C masana/usiku) pa kutentha kwa denga (A), index yolekerera (RTI) (B), ndi index yopsinjika kwa mbewu (CSI) (C) ya mitundu iwiri ya zomera. Mitundu ya mpunga wamalonda (F67 ndi F2000) idachitidwa chithandizo chosiyanasiyana cha kutentha. Mankhwala omwe adayesedwa pa mtundu uliwonse wa genotype adaphatikizapo: absolute control (AC), heat stress control (SC), heat stress + auxin (AUX), heat stress + gibberellin (GA), heat stress + cell mitogen (CK), ndi heat stress + brassinosteroid. (BR). Kupsinjika kwa kutentha kophatikizana kumaphatikizapo kuyika zomera za mpunga kutentha kwambiri masana/usiku (40°/30°C masana/usiku). Mzere uliwonse ukuyimira mean ± standard error ya mfundo zisanu za data (n = 5). Mizere yotsatiridwa ndi zilembo zosiyanasiyana imasonyeza kusiyana kwakukulu kwa ziwerengero malinga ndi mayeso a Tukey (P ≤ 0.05). Zilembo zokhala ndi chizindikiro chofanana zimasonyeza kuti mean si yofunikira kwambiri pa ziwerengero (≤ 0.05).
Kusanthula kwakukulu kwa zigawo (PCA) kunavumbula kuti zosintha zomwe zinayesedwa pa 55 DAE zinafotokoza 66.1% ya mayankho a thupi ndi a biochemical a zomera za mpunga zomwe zimakhudzidwa ndi kutentha zomwe zimathandizidwa ndi spray yowongolera kukula (Chithunzi 3). Ma Vectors akuyimira zosintha ndipo madontho akuyimira owongolera kukula kwa zomera (GRs). Ma vectors a gs, kuchuluka kwa chlorophyll, mphamvu yayikulu ya quantum ya PSII (Fv/Fm) ndi magawo a biochemical (TChl, MDA ndi proline) ali pafupi ndi komwe adayambira, zomwe zikusonyeza mgwirizano waukulu pakati pa khalidwe la thupi la zomera ndi zosintha zawo. Gulu limodzi (V) linaphatikizapo mbande za mpunga zomwe zimakula pa kutentha koyenera (AT) ndi zomera za F2000 zomwe zimathandizidwa ndi CK ndi BA. Nthawi yomweyo, zomera zambiri zomwe zimathandizidwa ndi GR zinapanga gulu losiyana (IV), ndipo chithandizo ndi GA mu F2000 chinapanga gulu losiyana (II). Mosiyana ndi zimenezi, mbande za mpunga zomwe zimakhudzidwa ndi kutentha (magulu I ndi III) popanda kupopera ma phytohormones (mitundu yonse ya majini inali SC) zinapezeka m'dera linalake lomwe lili moyang'anizana ndi gulu V, zomwe zikusonyeza momwe kutentha kumakhudzira thupi la zomera.
Chithunzi 3. Kusanthula kwa mbiri ya zotsatira za kutentha kophatikizana (40°/30°C masana/usiku) pa zomera za mitundu iwiri ya mpunga (F67 ndi F2000) patatha masiku 55 kuchokera pamene mbewu zinamera (DAE). Zidule: AC F67, kulamulira kwathunthu F67; SC F67, kulamulira kutentha F67; AUX F67, kupsinjika kutentha + auxin F67; GA F67, kupsinjika kutentha + gibberellin F67; CK F67, kupsinjika kutentha + kugawa maselo BR F67, kupsinjika kutentha + brassinosteroid. F67; AC F2000, kulamulira kwathunthu F2000; SC F2000, Kulamulira Kutentha Kwambiri F2000; AUX F2000, kupsinjika kutentha + auxin F2000; GA F2000, kupsinjika kutentha + gibberellin F2000; CK F2000, kupsinjika kwa kutentha + cytokinin, BR F2000, kupsinjika kwa kutentha + steroid yamkuwa; F2000.
Zinthu monga kuchuluka kwa chlorophyll, stomatal conductance, Fv/Fm ratio, CSI, MDA, RTI ndi kuchuluka kwa proline zingathandize kumvetsetsa kusintha kwa majini a mpunga ndikuwunika momwe njira zaulimi zimakhudzira kutentha (Sarsu et al., 2018; Quintero-Calderon et al., 2021). Cholinga cha kuyeseraku chinali kuwunika momwe zinthu zinayi zoyendetsera kukula zimakhudzira thupi ndi za biochemical za mbande za mpunga pansi pa zovuta zovuta za kutentha. Kuyesa mbande ndi njira yosavuta komanso yachangu yowunikira nthawi imodzi zomera za mpunga kutengera kukula kapena momwe zinthu zilili (Sarsu et al. 2018). Zotsatira za kafukufukuyu zawonetsa kuti kuphatikiza kutentha kumayambitsa mayankho osiyanasiyana a thupi ndi a biochemical m'mitundu iwiri ya mpunga, zomwe zikusonyeza njira yosinthira. Zotsatirazi zikusonyezanso kuti ma spray oletsa kukula kwa masamba (makamaka ma cytokinins ndi ma brassinosteroids) amathandiza mpunga kuti uzitha kusintha kutentha chifukwa kukoma kwake kumakhudza kwambiri gs, RWC, Fv/Fm ratio, photosynthetic pigments ndi kuchuluka kwa proline.
Kugwiritsa ntchito njira zowongolera kukula kumathandiza kukonza momwe madzi a zomera za mpunga zimakhalira pansi pa kutentha, zomwe zingagwirizane ndi kupsinjika kwakukulu komanso kutentha kochepa kwa denga la zomera. Kafukufukuyu adawonetsa kuti pakati pa zomera za "F2000" (zomwe zimakhudzidwa ndi majini), zomera za mpunga zomwe zimachiritsidwa makamaka ndi CK kapena BR zinali ndi ma gs apamwamba komanso ma PCT otsika kuposa zomera zomwe zimachiritsidwa ndi SC. Kafukufuku wakale adawonetsanso kuti gs ndi PCT ndi zizindikiro zolondola za thupi zomwe zimatha kudziwa momwe zomera za mpunga zimayankhira komanso zotsatira za njira zaulimi pa kutentha (Restrepo-Diaz ndi Garces-Varon, 2013; Sarsu et al., 2018; Quintero). -Carr DeLong et al., 2021). Leaf CK kapena BR imakulitsa g pansi pa kupsinjika chifukwa mahomoni a zomera awa amatha kulimbikitsa kutsegula kwa stomatal kudzera mu kuyanjana kopangidwa ndi mamolekyu ena olumikizirana monga ABA (promoter of stomatal closure under abiotic stress) (Macková et al., 2013; Zhou et al., 2013). 2013). , 2014). Kutsegula m'mimba kumathandiza kuziziritsa masamba ndipo kumathandiza kuchepetsa kutentha kwa denga (Sonjaroon et al., 2018; Quintero-Calderón et al., 2021). Pazifukwa izi, kutentha kwa denga la zomera za mpunga zomwe zimapopedwa ndi CK kapena BR kungakhale kotsika pakagwiritsidwa ntchito kutentha kophatikizana.
Kupsinjika kwa kutentha kwambiri kungachepetse kuchuluka kwa utoto wa masamba (Chen et al., 2017; Ahammed et al., 2018). Mu kafukufukuyu, pamene zomera za mpunga zinali ndi kutentha kwambiri ndipo sizinapoperedwe ndi owongolera kukula kwa zomera, utoto wa utoto unkachepa m'mitundu yonse iwiri ya majini (Table 2). Feng et al. (2013) adanenanso kuti kuchepa kwakukulu kwa chlorophyll m'masamba a mitundu iwiri ya tirigu yomwe imakhudzidwa ndi kutentha. Kukhudzidwa ndi kutentha kwambiri nthawi zambiri kumabweretsa kuchepa kwa chlorophyll, komwe kungakhale chifukwa cha kuchepa kwa chlorophyll biosynthesis, kuwonongeka kwa utoto, kapena zotsatira zake pamodzi pansi pa kutentha (Fahad et al., 2017). Komabe, zomera za mpunga zomwe zimachiritsidwa makamaka ndi CK ndi BA zinawonjezera kuchuluka kwa utoto wa masamba womwe umakhudzidwa ndi kutentha. Zotsatira zofananazo zinanenedwanso ndi Jespersen ndi Huang (2015) ndi Suchsagunpanit et al. (2015), omwe adawona kuwonjezeka kwa kuchuluka kwa chlorophyll ya masamba pambuyo pogwiritsa ntchito mahomoni a zeatin ndi epibrassinosteroid mu bentgrass ndi mpunga wopsinjika ndi kutentha, motsatana. Kufotokozera koyenera chifukwa chake CK ndi BR zimathandizira kuchuluka kwa chlorophyll ya masamba pansi pa kutentha kophatikizana ndikuti CK ikhoza kukulitsa kuyambitsa kwa zolimbikitsa zowonetsa nthawi zonse (monga promoter yoyambitsa kukalamba (SAG12) kapena promoter ya HSP18) ndikuchepetsa kutayika kwa chlorophyll m'masamba. , kuchedwetsa kukalamba kwa masamba ndikuwonjezera kukana kwa zomera ku kutentha (Liu et al., 2020). BR ikhoza kuteteza chlorophyll ya masamba ndikuwonjezera kuchuluka kwa chlorophyll ya masamba poyambitsa kapena kuyambitsa kupanga ma enzyme omwe amagwira ntchito mu biosynthesis ya chlorophyll pansi pa zovuta (Sharma et al., 2017; Siddiqui et al., 2018). Pomaliza, ma phytohormone awiri (CK ndi BR) amalimbikitsanso kuwonetsa mapuloteni otenthetsa kutentha ndikuwongolera njira zosiyanasiyana zosinthira kagayidwe kachakudya, monga kuwonjezeka kwa chlorophyll biosynthesis (Sharma et al., 2017; Liu et al., 2020).
Chlorophyll, fluorescence parameters, imapereka njira yachangu komanso yosawononga yomwe ingayese kupirira kwa zomera kapena kusinthana ndi mikhalidwe ya abiotic stress (Chaerle et al. 2007; Kalaji et al. 2017). Ma parameter monga Fv/Fm ratio agwiritsidwa ntchito ngati zizindikiro za kusintha kwa zomera ku mikhalidwe ya stress (Alvarado-Sanabria et al. 2017; Chavez-Arias et al. 2020). Mu kafukufukuyu, zomera za SC zidawonetsa mitengo yotsika kwambiri ya variable iyi, makamaka zomera za mpunga za "F2000". Yin et al. (2010) adapezanso kuti chiŵerengero cha Fv/Fm cha masamba apamwamba kwambiri a mpunga olima chinachepa kwambiri kutentha kuposa 35°C. Malinga ndi Feng et al. (2013), chiŵerengero chotsika cha Fv/Fm pansi pa kutentha chikuwonetsa kuti kuchuluka kwa mphamvu yokopa ndi kusintha kwa PSII reaction center kumachepa, zomwe zikusonyeza kuti PSII reaction center imasweka pansi pa kutentha. Kuwona kumeneku kumatithandiza kunena kuti kusokonezeka kwa chipangizo chopangira photosynthesis kumaonekera kwambiri m'mitundu yovuta kumva (Fedearroz 2000) kuposa m'mitundu yosagonja (Fedearroz 67).
Kugwiritsa ntchito CK kapena BR nthawi zambiri kunawonjezera magwiridwe antchito a PSII pansi pa zovuta za kutentha. Zotsatira zofananazi zidapezeka ndi Suchsagunpanit et al. (2015), omwe adawona kuti kugwiritsa ntchito BR kunawonjezera magwiridwe antchito a PSII pansi pa kutentha mu mpunga. Kumar et al. (2020) adapezanso kuti zomera za nandolo zomwe zidapatsidwa CK (6-benzyladine) ndikuvutika ndi kutentha zidawonjezera chiŵerengero cha Fv/Fm, zomwe zidatsimikiza kuti kugwiritsa ntchito CK pamasamba poyambitsa kuzungulira kwa zeaxanthin pigment kunathandizira ntchito ya PSII. Kuphatikiza apo, kupopera masamba a BR kudakonda photosynthesis ya PSII pansi pa zovuta zophatikizana, zomwe zikusonyeza kuti kugwiritsa ntchito phytohormone iyi kunapangitsa kuti mphamvu yotulutsa ya PSII antennae ichepe ndipo kunalimbikitsa kusonkhanitsa mapuloteni ang'onoang'ono otenthetsa kutentha mu ma chloroplasts (Ogweno et al. 2008; Kothari ndi Lachowitz)., 2021).
Zomwe zili mu MDA ndi proline nthawi zambiri zimawonjezeka pamene zomera zili pansi pa vuto la abiotic poyerekeza ndi zomera zomwe zimakula pansi pa mikhalidwe yabwino (Alvarado-Sanabria et al. 2017). Kafukufuku wakale wasonyezanso kuti kuchuluka kwa MDA ndi proline ndi zizindikiro za biochemical zomwe zingagwiritsidwe ntchito kumvetsetsa njira yosinthira kapena momwe machitidwe a agronomic amakhudzira mpunga pansi pa kutentha kwakukulu masana kapena usiku (Alvarado-Sanabria et al., 2017; Quintero-Calderón et al. . , 2021). Kafukufukuyu adawonetsanso kuti zomwe zili mu MDA ndi proline zimakhala zambiri m'minda ya mpunga yomwe imakhudzidwa ndi kutentha kwakukulu usiku kapena masana, motsatana. Komabe, kupopera masamba a CK ndi BR kunathandizira kuchepa kwa MDA ndi kuwonjezeka kwa kuchuluka kwa proline, makamaka mu genotype yolekerera (Federroz 67). Kupopera kwa CK kungapangitse kuti cytokinin oxidase/dehydrogenase ichuluke, motero kumawonjezera kuchuluka kwa mankhwala oteteza monga betaine ndi proline (Liu et al., 2020). BR imalimbikitsa kuyambitsa ma osmoprotectors monga betaine, shuga, ndi amino acid (kuphatikiza free proline), kusunga bwino ma cell osmotic balance pansi pa zovuta zambiri zachilengedwe (Kothari ndi Lachowiec, 2021).
Chizindikiro cha kupsinjika kwa mbewu (CSI) ndi chiwerengero cha kupirira kwachibale (RTI) zimagwiritsidwa ntchito kudziwa ngati mankhwala omwe akuwunikidwawo amathandiza kuchepetsa kupsinjika kosiyanasiyana (kusasinthika ndi kosasinthika) komanso kukhala ndi zotsatira zabwino pa thupi la zomera (Castro-Duque et al., 2020; Chavez-Arias et al., 2020). Chiwerengero cha CSI chingachokere pa 0 mpaka 1, kuyimira mikhalidwe yopanda kupsinjika ndi kupsinjika, motsatana (Lee et al., 2010). Chiwerengero cha CSI cha zomera zopsinjika ndi kutentha (SC) chinali kuyambira pa 0.8 mpaka 0.9 (Chithunzi 2B), zomwe zikusonyeza kuti mbewu za mpunga zinakhudzidwa kwambiri ndi kupsinjika kophatikizana. Komabe, kupopera masamba a BC (0.6) kapena CK (0.6) makamaka kunapangitsa kuti chizindikirochi chichepe pansi pa mikhalidwe ya kupsinjika kwachilengedwe poyerekeza ndi mbewu za mpunga za SC. Mu zomera za F2000, RTI inasonyeza kuwonjezeka kwakukulu pogwiritsa ntchito CA (97.69%) ndi BC (60.73%) poyerekeza ndi SA (33.52%), zomwe zikusonyeza kuti owongolera kukula kwa zomera awa amathandiziranso kukonza momwe mpunga umayankhira kupirira kwa kapangidwe kake. Kutentha kwambiri. Zizindikirozi zaperekedwa kuti zithetse mavuto m'mitundu yosiyanasiyana. Kafukufuku wochitidwa ndi Lee et al. (2010) adawonetsa kuti CSI ya mitundu iwiri ya thonje yomwe ili ndi vuto la madzi pang'ono inali pafupifupi 0.85, pomwe CSI ya mitundu yothiriridwa bwino inali kuyambira 0.4 mpaka 0.6, zomwe zikutanthauza kuti index iyi ndi chizindikiro cha kusintha kwa madzi kwa mitundu. mikhalidwe yopsinjika. Kuphatikiza apo, Chavez-Arias et al. (2020) adawunika momwe ma exicitors opangidwa amagwirira ntchito ngati njira yonse yowongolera kupsinjika mu zomera za C. elegans ndipo adapeza kuti zomera zomwe zimapopera ndi mankhwalawa zidawonetsa RTI yapamwamba (65%). Kutengera zomwe zili pamwambapa, CK ndi BR zitha kuonedwa ngati njira zowongolera ulimi zomwe cholinga chake ndi kukulitsa kupirira kwa mpunga ku kutentha kwambiri, chifukwa owongolera kukula kwa zomera awa amayambitsa mayankho abwino a biochemical ndi physiological.
M'zaka zingapo zapitazi, kafukufuku wa mpunga ku Colombia wakhala akuyang'ana kwambiri pakuwunika mitundu ya majini yomwe imapirira kutentha kwambiri masana kapena usiku pogwiritsa ntchito makhalidwe a thupi kapena a biochemical (Sánchez-Reinoso et al., 2014; Alvarado-Sanabria et al., 2021). Komabe, m'zaka zingapo zapitazi, kusanthula kwa ukadaulo wothandiza, wokwera mtengo komanso wopindulitsa kwakhala kofunikira kwambiri kuti kupereke malingaliro okhudza kasamalidwe ka mbewu kophatikizana kuti kuwonjezere zotsatira za nthawi zovuta za kutentha mdziko muno (Calderón-Páez et al., 2021; Quintero-Calderon et al., 2021). Chifukwa chake, mayankho a thupi ndi a biochemical a zomera za mpunga ku kutentha kovuta (40°C masana/30°C usiku) omwe awonedwa mu kafukufukuyu akusonyeza kuti kupopera masamba ndi CK kapena BR kungakhale njira yoyenera yoyendetsera mbewu kuti muchepetse zotsatira zoyipa. Zotsatira za nthawi zochepa za kutentha. Mankhwalawa adathandizira kulekerera mitundu yonse ya mpunga (CSI yotsika ndi RTI yayikulu), kuwonetsa chizolowezi chachikulu cha mayankho a thupi ndi a biochemical a zomera pansi pa kutentha kophatikizana. Yankho lalikulu la zomera za mpunga linali kuchepa kwa kuchuluka kwa GC, chlorophyll yonse, chlorophylls α ndi β ndi carotenoids. Kuphatikiza apo, zomera zimavutika ndi kuwonongeka kwa PSII (ma parameter a chlorophyll fluorescence otsika monga Fv/Fm ratio) komanso kuwonjezeka kwa lipid peroxidation. Kumbali ina, mpunga utachiritsidwa ndi CK ndi BR, zotsatirapo zoyipa izi zidachepetsedwa ndipo kuchuluka kwa proline kudakwera (Chithunzi 4).
Chithunzi 4. Chitsanzo cha lingaliro la zotsatira za kupsinjika kwa kutentha pamodzi ndi kupopera kwa zomera za masamba pa zomera za mpunga. Mivi yofiira ndi yabuluu imasonyeza zotsatira zoyipa kapena zabwino za kuyanjana pakati pa kupsinjika kwa kutentha ndi kugwiritsa ntchito BR (brassinosteroid) ndi CK (cytokinin) pa mayankho a thupi ndi a biochemical, motsatana. gs: stomatal conductance; Chiwerengero cha Chl: kuchuluka kwa chlorophyll; Chl α: kuchuluka kwa chlorophyll β; Cx+c: kuchuluka kwa carotenoid;
Mwachidule, mayankho a thupi ndi a biochemical mu kafukufukuyu akusonyeza kuti zomera za mpunga za Fedearroz 2000 zimakhala zosavuta kuvutika ndi kutentha kwambiri kuposa zomera za mpunga za Fedearroz 67. Oyang'anira kukula onse omwe adawunikidwa mu kafukufukuyu (auxins, gibberellins, cytokinins, kapena brassinosteroids) adawonetsa kuchepa kwa kutentha kophatikizana. Komabe, cytokinin ndi brassinosteroids zidapangitsa kuti zomera zizisinthasintha bwino chifukwa owongolera kukula kwa zomera adawonjezera kuchuluka kwa chlorophyll, alpha-chlorophyll fluorescence parameters, gs ndi RWC poyerekeza ndi zomera za mpunga popanda kugwiritsa ntchito, komanso kuchepa kwa kuchuluka kwa MDA ndi kutentha kwa denga. Mwachidule, tikuganiza kuti kugwiritsa ntchito owongolera kukula kwa zomera (cytokinins ndi brassinosteroids) ndi chida chothandiza pothana ndi mavuto m'minda ya mpunga omwe amayamba chifukwa cha kutentha kwambiri panthawi ya kutentha kwambiri.
Zinthu zoyambirira zomwe zaperekedwa mu phunziroli zaphatikizidwa ndi nkhaniyi, ndipo mafunso ena angaperekedwe kwa wolemba woyenerera.