干旱胁迫下不同形态氮素对多年生黑麦草生长、叶片生理和草坪质量的影响

Effects of different nitrogen forms on growth, leaf physiology and lawn quality of Lolium perenne under drought stress

摘要:

以多年生黑麦草(Lolium perenne)品种绿宝石为供试材料，通过水培试验探究干旱胁迫下氮素形态及其浓度对多年生黑麦草生长、叶片生理和草坪质量的影响。试验设 4 个干旱水平，3 种氮素形态(尿素、硝酸钙、硫酸铵)，3 种氮素形态分别设 5 个浓度 0、0. 4、0. 8、1. 2、1. 6g/L。结果表明：在干旱胁迫下 3 种不同形态的氮素均能增加多年生黑麦草的叶片表面积、叶长、叶片相对含水量和叶绿素含量， 减小其根冠比和叶片相对电导率。在重度干旱胁迫下，3 种氮素形态中，硝酸钙在增大多年生黑麦草地上部分表现最好 ，1. 6 g/L 硝酸钙处理的叶表面积和叶片长度较无氮素处理增加了 31. 04% 和 53. 87%；硫酸铵在降低多年生黑麦草叶片相对电导率和增加叶绿素含量中表现最好，与无氮处理相比分别降低了 54. 65% 和增加了 26. 51%；而在提高多年生黑麦草叶片相对含水量方面，尿素表现最好， 1. 6 g/L 尿素处理的叶片相对含水量较无氮素处理增加了 31. 04%。

Abstract:

The effects of nitrogen form and concentration on the growth，leaf physiology and lawn quality of pe‐ rennial ryegrass(Lolium perenne )under drought stress were investigated by hydroponic experiment. In the experi‐ ment，four drought levels were set，three nitrogen forms(urea，calcium nitrate，ammonium sulfate)were set，and the concentrations of three forms of nitrogen were 0，0. 4，0. 8，1. 2 and 1. 6 g/L，respectively. The results showed that three different forms of nitrogen could increase the leaf surface area，leaf length，relative water content and chlo‐ rophyll content of perennial ryegrass，while decrease its root‐shoot ratio and the relative conductivity of perennial rye‐ grass under drought stress，among which 1. 6 g/L nitrogen concentration was the best. The results also demon‐ strated that under severe drought stress，among the three forms of nitrogen，calcium nitrate showed the best perfor‐ mance in increasing the above‐ground part of perennial ryegrass. The leaf surface area and leaf length under 1. 6 g/L calcium nitrate treatment increased by 31. 04% and 53. 87% compared with those without nitrogen treatment. Am‐ monium sulfate had the best effect in decreasing relative electrical conductivity and increasing chlorophyll content of perennial ryegrass leaves，which decreased by 54. 65% and increased by 26. 51%，respectively，compared with nitro‐ gen free treatment. However，Urea was the best in increasing relative water content of perennial ryegrass leaves. The relative water content of perennial ryegrass leaves was increased by 31. 04% in 1. 6 g/L urea treatment com‐ pared with no nitrogen treatment.