| 摘要: |
| 为探究燕麦光合作用对干旱胁迫下喷施腐植酸的响应机制，采用盆栽方式在正常供水(75%田间持水量)、中度干旱胁迫(60%田间持水量)和重度干旱胁迫(45%田间持水量)3个水分条件下喷施腐植酸(HA)和等量清水(CK)处理，用(CIRAS-3)光合测定系统测定并拟合燕麦叶片的光响应过程。结果表明:1)在直角双曲线模型、非直角双曲线模型、指数模型和直角双曲线修正模型中，只有直角双曲线修正模型拟合得到的各项特征参数比较精确。2)喷施HA可以有效缓解重度干旱胁迫造成的光抑制现象。3)重度干旱胁迫下喷施HA相比于CK，燕麦叶片的最大净光合速率(Pnmax)、暗呼吸速率(Rd)和表观量子效率(Φ)显著提升，光饱和点(LSP)与光补偿点(LCP)降低。随着光合有效辐射(PAR)的增加，叶片蒸腾速率(Tr)和气孔导度(Gs)的提升速率加快，胞间CO2浓度(Ci)的下降速率减缓。4)喷施HA显著增加重度干旱胁迫下的燕麦产量，籽粒产量和生物产量均与光饱和点(LSP)和光补偿点(LCP)呈极显著负相关，与最大净光合速率(Pnmax)和暗呼吸速率(Rd)呈极显著正相关。综上所述，重度干旱胁迫下，燕麦叶片光合机构受到损伤，喷施HA缓解燕麦叶片光合机构受害程度。 |
| 关键词: 燕麦 干旱胁迫 腐植酸 光响应模型 净光合速率 |
| DOI：10.11841/j.issn.1007-4333.2020.11.04 |
| 投稿时间：2019-12-26 |
| 基金项目:燕麦种质资源引进与新品种选育项目(YZGC2017020)；燕麦加工技术研究与旱作高产栽培示范推广项目；国家自然科学基金(31560373)；国家燕麦荞麦产业技术体系项目(CARS-08-B-5) |
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| Effect of humic acid fertilizer on the light response curve of oat under drought stress |
|
LI Yinghao,LIU Jinghui,ZHAO Baoping,TIAN Lu,MI Junzhen,WANG Qi,DAI Yunxian
|
| (Collaborative Innovation Center of Grain Industry, Inner Mongolia Agricultural University, Hohhot 010019, China) |
| Abstract: |
| In order to investigate the response law and adaptation mechanism of oat photosynthesis to spraying humic acid under drought stress, pot experiments were conducted. Humic acid(HA)and equal amount of clear water(CK)were sprayed under three water conditions including normal water supply(75% field capacity), moderate drought stress(60% field capacity)and severe drought stress(45% field capacity). The(CIRAS-3)photosynthesis measurement system was adopted to measure and fit the light response process of oat leaves. The results showed that: 1)Among the right angle hyperbolic model, non-right angle hyperbolic model, exponential model and right angle hyperbolic correction model, only the characteristic parameters obtained by fitting the right-angle hyperbola correction model were relatively accurate. 2)HA effectively alleviated photo inhibition caused by severe drought stress. 3)After spraying HA under severe drought stress, the maximum net photosynthetic rate(Pnmax), dark respiration rate(Rd), and apparent quantum efficiency(Φ)of oat leaves significantly were increased. The light saturation point(LSP)and light compensation point(LCP)were decreased. With the increasing of photosynthetic active radiation(PAR), the increasing rate of transpiration rate(Tr)and stomatal conductance(Gs)were increased, and the decreasing rate of intercellular CO2 concentration(Ci)was slowed down. 4)HA significantly increased oat yield under severe drought stress. Both grain yield and biological yield of oats were extremely significantly negatively correlated with light saturation point and light compensation point, and were significantly positively correlated with maximum net photosynthetic rate(Pnmax)and dark respiration rate(Rd). In summary, under severe drought stress, the photosynthetic mechanism of oat leaves were damaged, and HA reduced the damage of photosynthetic mechanisms by increasing the photosynthetic performance of oat leaves. |
| Key words: oat drought stress humic acid light response model net photosynthetic rate |
