| 和娟,唐燕,李晓瑞,李海兰,周春菊,吕金印.水分亏缺对小麦芒和旗叶光合特性及蔗糖、淀粉合成的影响[J].干旱地区农业研究,2021,39(6):53~61 |
| 水分亏缺对小麦芒和旗叶光合特性及蔗糖、淀粉合成的影响 |
| Effects of water deficit on photosynthetic characteristic and sucrose\|starch synthesis of wheat awns and flag leaf |
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| DOI：10.7606/j.issn.1000-7601.2021.06.06 |
| 中文关键词: 水分亏缺 小麦 芒 旗叶 光合特性 蔗糖 淀粉 |
| 英文关键词:water deficit wheat awns flag leaf photosynthesis characteristic sucrose starch |
| 基金项目:国家自然科学基金项目（31971835） |
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| 中文摘要: |
| 为明确水分亏缺对小麦芒和旗叶光合特性及蔗糖、淀粉合成的影响，选用盆栽试验，在小麦灌浆期对盆栽采用正常供水（CK）及水分亏缺（WD）处理，测定旗叶和芒光合参数、相对水分含量、叶绿素含量等生理指标，分析蔗糖和淀粉合成关键酶活性及相关基因表达水平。结果表明，水分亏缺下旗叶净光合速率（Pn）、叶绿素（Chl）含量和相对水分含量（RWC）相比芒显著下降，花后24 d旗叶和芒Pn分别下降了87.7%和14.4%，Chl含量分别下降了54.1%和12.3%，RWC分别下降了13.9%和1.5%；同时，水分亏缺减少了光合碳同化物的产生，花后24 d旗叶和芒中蔗糖含量分别下降了50.1%和18.2%，淀粉含量分别下降了46.4%和18%，表明芒中碳同化物合成受水分亏缺影响较旗叶小。灌浆过程中旗叶和芒中丙二醛（MDA）含量均持续上升，水分亏缺下花后24 d旗叶和芒中MDA含量分别增加了50.8%和14.0%，表明在逆境下芒的抗氧化能力优于旗叶。总之，水分亏缺下芒具有较高的光合效率、保水性以及衰老延迟特性，并且在灌浆中后期仍有较高的蔗糖和淀粉合成能力，从而保障对小麦籽粒产量的光合贡献。 |
| 英文摘要: |
| To understand the effects of water deficit on photosynthetic characteristic and sucrose\|starch synthesis of wheat awns and flag leaf, potted wheat plants growing in normal water supply (CK) and water deficit (WD) conditions during the filling period were set up to determine photosynthetic parameters, relative water content (RWC), content of chlorophyll (Chl) and malondialdehyde (MDA), and activities of key enzymes for sucrose and starch synthesis of wheat flag leaf and awns. The expression of SS1, SS2, SPS1, AGPase, and SSS for sucrose and starch synthesis were also measured. The results showed that the net photosynthetic rate (Pn), Chl content and RWC of the flag leaf decreased significantly under water deficit conditions compared with that of awns. Specifically, the Pn was decreased by 87.7% in flag leaf but 14.4% in awns at 24 days after anthesis. The Chl content was decreased by 54.1% in flag leaf but 12.3% in awns. Moreover, RWC was decreased by 13.9% in the flag leaf but 1.5% in awns. Meanwhile, the content of sucrose of the flag leaf and awns was reduced by 50.1% and 18.2% at 24 days after anthesis, respectively, and starch was reduced by 50.8% and 14%, indicating the synthesis of carbon assimilates in awns was less affected by water deficit condition than in flag leaf. During the filling stage, the malondialdehyde (MDA) content of flag leaf and awns increased continuously. The MDA content of flag leaf and awns was increased by 50.8% and 14.0% at 24 days after anthesis under water deficit condition, respectively, indicating a better antioxidant capacity in awns than in flag leaf under adverse conditions. In conclusion, compared with flag leaf, awns maintained relatively normal photosynthetic contribution to wheat grain yield under water deficit conditions because of its high photosynthetic efficiency, water retention, senescence delay characteristics, and prominent ability of sucrose and starch synthesis during the middle and late filling stages of wheat. |
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