中国农业科学 ›› 2017, Vol. 50 ›› Issue (20): 3871-3884.doi: 10.3864/j.issn.0578-1752.2017.20.004

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

外源6-BA对两种氮素水平下小麦幼苗叶片光合性能及内源激素含量的影响

杨东清1,董文华1,骆永丽1,2,宋文挺1,蔡铁3,李勇1,尹燕枰1,王振林1

 
  

  1. 1山东农业大学农学院/作物生物学国家重点实验室,山东泰安 271018;2山东农业大学生命科学学院,山东泰安 271018;3西北农林科技大学农学院,陕西杨凌 712100
  • 收稿日期:2017-02-27 出版日期:2017-10-16 发布日期:2017-10-16
  • 通讯作者: 王振林,E-mail:zlwang@sdau.edu.cn
  • 作者简介:杨东清,E-mail:chengyang2364@126.com。董文华,E-mail:whdong105@126.com。杨东清和董文华为同等贡献作者。
  • 基金资助:
    国家重点基础研究发展计划(“973”计划)(2015CB150404)、国家重点研发计划(2016YFD0300400)、山东省泰山产业领军人才项目、山东省农业重大应用技术创新课题、山东省高等学校科技计划(J14LF12)、作物生物学国家重点实验室开放课题基金(2016KF04)

Effects of Exogenous 6-BA on Photosynthetic Characteristics and Endogenous Hormone Content in Wheat Leaves Under Two Nitrogen Application Levels at Seedling Stage

YANG DongQing1, DONG WenHua1,LUO YongLi1, 2, SONG WenTing1, CAI Te3, LI Yong1, YIN YanPing1, WANG ZhenLin1   

  1. 1College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an 271018, Shandong;  2College of Life Sciences, Shandong Agricultural University, Tai’an 271018, Shandong; 3 College of Agronomy, Northwest      A&F University, Yangling 712100, Shaanxi
  • Received:2017-02-27 Online:2017-10-16 Published:2017-10-16

摘要: 【目的】在盆栽和大田种植条件下,研究两种氮素水平与喷施外源细胞分裂素(6-BA)对小麦幼苗叶片叶绿素含量、光合参数、叶绿素荧光参数、硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性和内源激素含量、产量和其构成因素的影响,为外源激素调控苗期小麦生长提供理论依据。【方法】选用济麦22(JM22)为试验材料,盆栽种植条件下,设置低浓度氮(0.63 mmol·L-1)、高浓度氮(3.75 mmol·L-1)和叶面喷施清水、30 mg·L-1的6-苄基腺嘌呤(6-BA)及300 mg·L-1的洛伐他汀(Lovastatin)6个喷施组合处理,即高氮下喷清水的对照(HN)、高氮下喷施外源细胞分裂素(HN+6-BA)、高氮下喷施细胞分裂素合成抑制剂(HN+Lov)、低氮下喷清水的对照(LN)、低氮下喷施外源细胞分裂素(LN+6-BA)、低氮下喷施细胞分裂素合成抑制剂(LN+Lov)。处理后每隔3 d,测定叶绿素含量、光合参数、叶绿素荧光参数、GS和NR活性、内源激素含量。大田条件下,设置低施氮量(120 kg·hm-2,N1)、常规施氮量(240 kg·hm-2,N2)、叶面喷施清水、30 mg·L-1的6-BA和300 mg·L-1的Lovastatin 6个喷施组合处理,即N1、N1+6-BA、N1+Lov、N2、N2+6-BA、N2+Lov。于成熟期测定籽粒产量、单位面积穗数、千粒重和穗粒数。【结果】盆栽条件下,与对照相比,喷施外源6-BA显著提高了小麦幼苗地上部植株干重;喷施抑制剂Lovastatin则显著降低小麦幼苗地上部植株干重。与对照HN和LN相比,处理后12d,HN+6-BA和LN+6-BA两处理的植株干重分别提高21.39%、43.92%。与对照HN相比,HN+6-BA处理显著提高了叶片气孔导度(Gs)、蒸腾速率(Tr)、胞间二氧化碳浓度(Ci)、净光合速率(Pn);处理后12 d,HN+6-BA处理的GsTrPNCi分别提高68.32%、58.66%、30.72%、51.61%。高氮水平的叶绿素a(Chl a)、叶绿素b(Chl b)分别比低氮水平高103.39%、94.44%。与对照HN相比,HN+6-BA处理显著提高了9—12 d Chl a含量和3—12 d 的叶片Chl b含量。高低氮水平下,喷施Lovastatin均显著降低了Chl a和Chl b含量。高低氮水平下,喷施6-BA显著体高了叶片硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性,而外喷Lovastatin则显著降低了叶片NR及GS活性。快速叶绿素a荧光诱导动力学分析表明外源6-BA处理改变了OJIP曲线。与对照HN相比,HN+6-BA显著提高了Ψo和PIabs,降低了Wk和Vj值。与对照LN处理相比,LN+6-BA处理的Wk和Vj分别降低22.09%和36.05%。外源6-BA对小麦幼苗叶片内源激素含量影响显著。与对照HN相比,HN+6-BA显著提高了3—12 d 叶片Zt含量和6—12 d叶片IAA含量。喷施6-BA显著降低了叶片ABA含量,而Lovastatin处理则显著提高了叶片ABA含量。大田试验结果表明,与对照N1和N2相比,喷施外源6-BA显著提高了小麦籽粒产量,N1+6-BA和N2+6-BA处理的籽粒产量分别提高10.48%和16.61%。【结论】外源6-BA与氮素配合施用,通过提高内源Zt含量,降低内源ABA含量,一方面提高了Chl a及CHl b含量和NR及GS活性,进而改善了叶片氮素同化能力和光能捕获、传递转化能力;另一方面提高了PSII反应中心电子传递链供体侧和受体侧的电子传递能力,进而改善了改善光系统性能,提高叶片光合性能,叶片积累较多的光合产物,从而提高苗期地上部植株干重,最终提高了籽粒产量。

关键词: 小麦苗期, 氮素, 激素, 光合作用, 叶绿素a荧光

Abstract: 【Objective】The purpose of this study was to test the effects of nitrogen concentrations and spraying exogenous cytokinin (6-BA) on photosynthetic characteristics, chlorophyll a fluorescence, nitrate reductase (NR) and glutamine synthetase (GS) activities, changes of endogenous hormones in leaves of wheat at seedling stage and grain yield, and then provide a theoretical basis for improving the development of winter wheat seedlings. 【Method】Wheat (Jimai 22) was sown in the field and pot culture experiments with two nitrogen levels ( N1, 120 kg·hm-2; N2, 240 kg·hm-2) and modified Hoagland nutrient solutions containing two nitrogen levels (HN, 3.75 mmol·L-1; LN, 0.63 mmol·L-1), respectively. 6-BA (30 mg·L-1) and lovastatin (300 mg·L-1) were sprayed to the whole plants at a rate of 100 mL·m-2 at the three-leaf stage. Ten wheat plants were sampled at 3 d intervals to test chlorophyll contents, NR and GS activities, photosynthetic parameters (Gs, Tr, Ci and Pn), chlorophyll fluorescence parameters (Wk, Vj, Ψo and PIabs), and endogenous hormones. In addition, grain yield, kernels per spike, 1000-grain weight, and ear numbers were determined at maturity stage.【Result】The above ground biomass (AGBM) was significantly increased by exogenous 6-BA treatment in the pot experiment. Conversely, application of lovastatin significantly decreased AGBM. Compared with HN treatment, AGBM under HN+6-BA treatment increased by 21.39% at 12 days after treatment (DAT), and that of LN+6-BA treatment increased by 43.92%, compared with LN treatment. Application of 6-BA significantly increased values of Gs, Tr, Ci and Pn under high nitrogen condition. Especially, Gs, Tr, Pn and Ci increased by 68.32%、58.66%、30.72%、51.61% at 12 DAT, respectively. Chl a increased by application of 6-BA at 9 to 12 DAT, while content of Chl b has significantly increased by exogenous 6-BA from 3 to 12 DAT. Conversely, both Chl a and Chl b have significantly decreased by application of lovastatin. Compared with HN treatment, HN+6-BA treatment significantly increased the activity of nitrate reductase (NR) and glutamine synthetase (GS). While application of lovastatin significantly decreased NR and GS activity. Exogenous 6-BA treatments changed the fast chlorophyll fluorescence induction kinetics curves. Application of 6-BA significantly increased Ψo and PIabs, and decreased Wk and Vj. Wk and Vj decreased by 22.09% and 36.05%, respectively, under LN+6-BA treatment, compared with LN treatment. Application of 6-BA significantly increased Zt content from 3 to 12 DAT, increased IAA content from 6 to 12 DAT, and decreased ABA content. However, spraying exogenous lovastatin obviously increased ABA content. Application of 6-BA significantly increased grain yield in the field experiment. Compared with N1 and N2, grain yield of N1+6-BA and N2+6-BA increased by 10.48% and 16.61%, respectively. 【Conclusion】Exogenous 6-BA increased aboveground biomass due to increasing the leaf photosynthesis and nitrogen assimilation through regulating endogenous hormones contents to enhance chlorophyll content and NR and GS activity, and to improve the electron transfer capability of both the donor and the acceptor sides at PSII reaction center resulting in improved PSII performance. Grain yield has significantly increased under 6-BA combined with nitrogen application treatments.

Key words: wheat seedling, nitrogen, hormone, photosynthetic characteristics, chlorophyll a fluorescence