Solving high-temperature plastic mulching film-induced leaf burning in the first week during tobacco cultivation would take much time and effort. In the present study, the growth as well as the leaf sugar and nicotine...Solving high-temperature plastic mulching film-induced leaf burning in the first week during tobacco cultivation would take much time and effort. In the present study, the growth as well as the leaf sugar and nicotine contents of seedlings with or without leaf burning induced by high-temperature plastic mulching film were tested at two independent sites in 2015 and 2016 to identify the influence of leaf burning on seedling growth. The results showed that the growth of seedlings with leaf burning was improved with increased leaf area, leaf number and plant height compared to those without leaf burning, combined with an increased seedling survival rate at two sites in two years. In seedlings with leaf burning, the contents of fructose and glucose increased and peaked at 11:00 and 13:00 in the leaf and root, respectively, with an increased root nicotine content beginning at 13:00, highlighting the signalling role of sugars. Activities of antioxidant enzymes including peroxidase(POD), superoxide dismutase(SOD) and catalase(CAT) were all increased in seedlings with leaf burning. More plant biomass was allocated to roots in seedlings with leaf burning with increased root volume compared to control seedlings, which might facilitate the absorption of water and nutrients from the soil. Our findings demonstrate that high-temperature plastic mulching film-induced leaf burning not inhibited but benefited seedling survival and growth, suggesting that the time and labour-consuming manual plucking of burnt leaves can be avoided during tobacco cultivation.展开更多
Naked oat(Avena nuda L.)was originated from China,where soil nitrogen(N)is low availability.The responses of chlorophyll(Chl.)fluorescence parameters and leaf gas exchange to N application were analysed in this study....Naked oat(Avena nuda L.)was originated from China,where soil nitrogen(N)is low availability.The responses of chlorophyll(Chl.)fluorescence parameters and leaf gas exchange to N application were analysed in this study.After the N application rate ranged from 60 to 120 kg ha-1,variable fluorescence(F v),the maximal fluorescence(F m),the maximal photochemical efficiency(F v/F m),quantum yield(ΦPS II)of the photosynthetic system II(PS II),electron transport rate(ETR),and photochemical quenching coefficient(qP)increased with N application level,however,non-photochemical quenching coefficient(qN)decreased.Moreover,there was no difference in initial fluorescence(F o)with further more N enhancement.The maximum net photosynthetic rate(P max),apparent dark respiration rate(R d)and light saturation point(LSP)were improved with 40-56 kg N ha-1as basal fertilizer and 24-40 kg N ha-1as top dressing fertilizer applied at jointing stage.Initial quantum yield(α)was decreased with 24 kg N ha-1as basal fertilizer and 56 kg N ha-1as top dressing fertilizer.Flag-leaf net photosynthetic rate(P n)was significantly enhanced at the jointing and heading stages with 40-56 kg N ha-1as basal fertilizer;in addition,increased at grain filling stage of naked oat with 40-56 kg N ha-1as top dressing fertilizer.90 kg N ha-1(50-70%as basal fertilizer and 30-50%as top dressing fertilizer)application is recommended to alleviate photodamage of photosystem and improve the photosynthetic rate in naked oat.展开更多
基金supported by the Science and Technology Foundation of Guizhou Province,China (20146015-2,20152099 and 20161097)the Special Fund for Excellent Young Talents of Guizhou Province,China (201534)the Foundation of Guizhou Academy of Tobacco Science,China (GZYKS2018-02)
文摘Solving high-temperature plastic mulching film-induced leaf burning in the first week during tobacco cultivation would take much time and effort. In the present study, the growth as well as the leaf sugar and nicotine contents of seedlings with or without leaf burning induced by high-temperature plastic mulching film were tested at two independent sites in 2015 and 2016 to identify the influence of leaf burning on seedling growth. The results showed that the growth of seedlings with leaf burning was improved with increased leaf area, leaf number and plant height compared to those without leaf burning, combined with an increased seedling survival rate at two sites in two years. In seedlings with leaf burning, the contents of fructose and glucose increased and peaked at 11:00 and 13:00 in the leaf and root, respectively, with an increased root nicotine content beginning at 13:00, highlighting the signalling role of sugars. Activities of antioxidant enzymes including peroxidase(POD), superoxide dismutase(SOD) and catalase(CAT) were all increased in seedlings with leaf burning. More plant biomass was allocated to roots in seedlings with leaf burning with increased root volume compared to control seedlings, which might facilitate the absorption of water and nutrients from the soil. Our findings demonstrate that high-temperature plastic mulching film-induced leaf burning not inhibited but benefited seedling survival and growth, suggesting that the time and labour-consuming manual plucking of burnt leaves can be avoided during tobacco cultivation.
基金the study grants from the Special Fund for Agro-Scientific Research in the Public Interest,China(nyhyzx07-009-2)the Earmarked Fund for China Agriculture Research System(CARS-08-B-1)
文摘Naked oat(Avena nuda L.)was originated from China,where soil nitrogen(N)is low availability.The responses of chlorophyll(Chl.)fluorescence parameters and leaf gas exchange to N application were analysed in this study.After the N application rate ranged from 60 to 120 kg ha-1,variable fluorescence(F v),the maximal fluorescence(F m),the maximal photochemical efficiency(F v/F m),quantum yield(ΦPS II)of the photosynthetic system II(PS II),electron transport rate(ETR),and photochemical quenching coefficient(qP)increased with N application level,however,non-photochemical quenching coefficient(qN)decreased.Moreover,there was no difference in initial fluorescence(F o)with further more N enhancement.The maximum net photosynthetic rate(P max),apparent dark respiration rate(R d)and light saturation point(LSP)were improved with 40-56 kg N ha-1as basal fertilizer and 24-40 kg N ha-1as top dressing fertilizer applied at jointing stage.Initial quantum yield(α)was decreased with 24 kg N ha-1as basal fertilizer and 56 kg N ha-1as top dressing fertilizer.Flag-leaf net photosynthetic rate(P n)was significantly enhanced at the jointing and heading stages with 40-56 kg N ha-1as basal fertilizer;in addition,increased at grain filling stage of naked oat with 40-56 kg N ha-1as top dressing fertilizer.90 kg N ha-1(50-70%as basal fertilizer and 30-50%as top dressing fertilizer)application is recommended to alleviate photodamage of photosystem and improve the photosynthetic rate in naked oat.
