氮素水平对狗牙根光合生理及饲用品质的影响  

Effects of nitrogen levels on the photosynthetic physiology and forage quality of bermudagrass

作　　者：王宏力 张寅坤 赵春程 张婷[1] 傅金民 徐筱 WANG Hongli;ZHANG Yinkun;ZHAO Chuncheng;ZHANG Ting;FU Jinmin;XU Xiao(Coastal Grass Tolerant Engineering and Technology Research Center,Ludong University,Yantai 264025,Shandong,China)

机构地区：[1]鲁东大学滨海耐盐草业工程技术中心,山东烟台264025

出　　处：《草业科学》2021年第3期514-522,共9页Pratacultural Science

基　　金：国家重点研发计划(2019YFD0900702);山东省农业良种工程项目(2019LZGC010)。

摘　　要：氮是植物体内蛋白质、核酸、叶绿素等的重要组成部分,是植物生长必需的营养元素,不同植物对氮素的需求不同。本研究以饲用狗牙根(Cynodon dactylon)‘Wrangler’为试验材料,采用营养液水培方式研究了施用不同氮素水平[2 mmol·L^(-1)(N1)、5 mmol·L^(-1)(N2)、10 mmol·L^(-1)(N3)]对狗牙根光合生理及牧草品质的影响,旨在确定其生长、光合及牧草品质最优的施氮量。结果表明:与施加N1相比,施加N2和N3时狗牙根‘Wrangler’的长势明显更好,株高显著提高(P<0.05);叶绿素含量、叶绿素荧光动力学曲线以及PSⅡ的最大光化学速率(Fv/Fm)等光合生理指标显著升高(P<0.05);饲用品质指标粗纤维含量显著提高,粗灰分含量显著降低(P<0.05)。但是,与施加N1和N2相比,施加N3时狗牙根的光合性能(PICS)最强,含氮量和粗蛋白含量显著增加(P<0.05)。因此,本研究认为10 mmol·L^(-1)是饲用狗牙根‘Wrangler’的最优氮素供应水平,研究结果为饲用狗牙根‘Wrangler’的日常施氮提供了理论指导。Nitrogen is an important component of proteins,nucleic acids,chlorophyll in plants.It is thus an essential nutrient element for plant growth,and different plants are known to have different nitrogen requirements.In this study,Cynodon dactylon‘Wrangler’was used as the experimental material to examine the effects of different nitrogen levels(N1,N2,and N3)on photosynthetic physiology and forage quality based on nutrient solution hydroponics.The purpose of the study was to determine the optimal levels of nitrogen with respect to growth,photosynthesis,and forage quality.The results revealed that compared with the N1 conditions,plant growth was better and plant height increased significantly(P<0.05)under the N2 and N3 conditions.Moreover,there were significant increases in chlorophyll content,the chlorophyll fluorescence kinetic curve,Fv/Fm value,and other photosynthetic indices(P<0.05).In addition,forage quality indices,including the crude fiber content,were significantly higher,whereas there was a significant reduction in the content of ash(P<0.05).Overall,the best photosynthetic characteristics(PICS)of bermudagrass were detected in plants subjected to the N3 treatment,and these plants had significantly higher contents of nitrogen and crude protein than those receiving the N2 and N1 levels of nitrogen(P<0.05).The findings of this study therefore indicate that the 10 mmol·L^(-1)level would be the optimal level of nitrogen application for‘Wrangler’bermudagrass.This information will accordingly provide theoretical guidance for the practical application of nitrogen for this crop.

关 键 词：‘Wrangler’狗牙根 氮浓度 叶绿素含量 光合特性 粗蛋白含量 牧草品质 

分 类 号：S543.9[农业科学—作物学]