| 老芒麦衰老过程中叶片叶绿素和光合作用变化特征及对养分的响应 |
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| 引用本文： | 张永超,梁国玲,秦燕,刘文辉,贾志锋,刘勇,马祥.老芒麦衰老过程中叶片叶绿素和光合作用变化特征及对养分的响应[J].草业学报,2022,31(1):229-237. |
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| 作者姓名： | 张永超 梁国玲 秦燕 刘文辉 贾志锋 刘勇 马祥 |
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| 作者单位： | 青海省畜牧兽医科学院，青海大学，青海 西宁 810000 |
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| 基金项目： | 青海省科技厅基础研究项目(2018-ZJ-968Q);牧草体系海北综合试验站(CARS-34)资助。 |
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| 摘 要： | 试验以青藏高原青海省高寒草地中广泛分布和退化草地补播改良中的常用牧草品种-青牧1号老芒麦为研究对象，分析老芒麦衰老过程中叶片叶绿素和光合作用变化特征及对养分的响应。在青藏高原东北部，青海湖湖东地区设置1~6龄老芒麦自然生长田，6龄老芒麦施肥田和老芒麦连续施肥田（6年）3个处理。从2015年开始，每年5月进行老芒麦种植，播量2.25 g·m-2，行距30 cm，小区面积15 m2 （3 m×5 m）。采用KONICA MINOLTA， INC公司的SPAD分析仪，每个处理随机选取10株健康植株，从旗叶开始从上往下依次测定3片叶子的叶绿素相对含量。采用LI-COR公司的LI-6400XT便携式光合作用测量系统，在老芒麦开花期（7月底-8月初），选择天气晴朗早上10：30-11：30，随机选取5株健康植株对其旗叶进行测量。结果表明：3龄时老芒麦叶片叶绿素相对含量出现降低趋势，6龄时老芒麦叶片出现了逆向衰老现象；随着老芒麦年龄增加，旗叶净光合速率持续降低，而胞间二氧化碳浓度呈上升趋势，气孔导度和蒸腾速率从3龄开始显著降低，且3~6龄间无显著差异；青牧1号老芒麦6龄田，氮肥和磷肥施入普遍提高老芒麦叶片叶绿素相对含量，且不同部位叶片叶绿素相对含量（33.30%~48.23%）均显著高于对照组（27.05%~30.72%），叶片逆向衰老现象在高氮处理下得到缓解，氮肥和磷肥施入普遍提高老芒麦叶片净光合速率，N（60 kg·hm-2）处理下叶片净光合速率最高（10.77 μmol·m-2·s-1）；青牧1号老芒麦在连续施肥6年处理下，低氮（45 kg·hm-2）施肥下叶片叶绿素相对含量较高，磷肥对保持老芒麦叶片叶绿素相对含量效果不显著；中度氮肥（60 kg·hm-2），同时配合磷肥添加长期施入，可有效维持高龄老芒麦叶片的光合效率。
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| 关 键 词： | 老芒麦 衰老 叶绿素 光合作用 土壤养分添加 |
| 收稿时间： | 2020-11-18 |
| 修稿时间： | 2021-02-02 |
Characteristics of chlorophyll and photosynthesis in leaves and their response to nutrients during aging of Elymus sibiricus |
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| ZHANG Yong-chao,LIANG Guo-ling,QIN Yan,LIU Wen-hui,JIA Zhi-feng,LIU Yong,MA Xiang.Characteristics of chlorophyll and photosynthesis in leaves and their response to nutrients during aging of Elymus sibiricus[J].Acta Prataculturae Sinica,2022,31(1):229-237. |
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| Authors: | ZHANG Yong-chao LIANG Guo-ling QIN Yan LIU Wen-hui JIA Zhi-feng LIU Yong MA Xiang |
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| Institution: | Qinghai Academy of Animal Science and Veterinary Medicine，Qinghai University，Xining 810000，China |
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| Abstract: | In this study， we investigated the changes in leaf chlorophyll content and photosynthesis parameters of Elymus sibiricus cv. Qinghai No.1 in response to fertilization and aging. E. sibiricus is distributed and used widely in the grassland of Qinghai province on the Qinghai-Tibetan plateau. Three field experiments were set up： 1） a time series of plots from one to six years old without any treatments， 2） fertilizer addition to six-year-old plots， 3） annual fertilizer addition to field plots for six years since 2015. From 2015，sowings were carried out in May of each year. The seeding rate was 2.25 g?m-2 in row with 30 cm in spacing between rows and 15 m2 （3 m×5 m） per plot. The chlorophyll content of leaves was measured at the flowering stage for 10 randomly chosen plants from the flag leaf down to the third leaf， using a SPAD analyzer from Konica Minolta， Inc. The photosynthesis parameters of the flag leaf were recorded from 10：30 to 11：30 am in a sunny day at the flowering stage （July-August） with a LI-COR LI-6400XT portable photosynthesis meter. It was found that chlorophyll content was decreased from the three years of age， but increased again at six years of age. In the age-series of E. sibiricus cv. Qinghai No.1， the net photosynthesis rate decreased， intercellular CO2 concentration increased， stomatal conductance and transpiration rate decreased significantly at three years of age， and remained unchanged thereafter from three to six years of age. When nitrogen and phosphorous fertilizer was applied to previously unfertilized six-year-old field plots of E. sibiricus cv. Qinghai No.1， the relative chlorophyll content （which varied in different parts of leaves from 33.30% to 48.23%）， and the net photosynthesis rate increased， and signs of ageing were reversed. The highest net photosynthesis rate observed （10.77 μmol·m-2·s-1） occurred at the nitrogen level of 60 kg?ha-1. In the long-term fertilizer addition field， low level nitrogen addition （45 kg·ha-1） enhanced chlorophyll content， while phosphorous addition had no significant effect. An intermediate nitrogen addition level （60 kg·ha-1） with phosphorous resulted in six-year-old plants retaining a high net photosynthesis rate. |
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| Keywords: | Elymus sibiricus leaf ageing chlorophyll photosynthesis fertilization |
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