多效唑对多年生黑麦草扩展性和根系特性的影响

Effect of Paclobutrazol on the Extension and Root Characteristics of Lolium perenne. L

在盆栽条件下研究了多效唑对多年生黑麦草(Loliumperenne. L)单株扩展性和根系特性的影响,以期为多效唑在多年生黑麦草草坪的养护管理中提供依据。结果表明,在100～1900mg·L-1质量浓度范围内,多效唑能有效抑制多年生黑麦草植株的生长、地上枝叶的水平扩展、地上植物量的积累和根系的垂直生长,促进分蘖。质量浓度大于400mg·L-1时对地上植物量积累的抑制趋缓,大于700mg·L-1时对最大扩展距离和根系生长的抑制作用减缓,大于1000mg·L-1时对株高的抑制趋缓,大于1300mg·L-1时覆盖面积的减小趋缓。分蘖数、根系表面积和体积、地下植物量随多效唑质量浓度的增加呈先增加后减小的趋势,1300mg·L-1质量浓度处理均达最大值。从扩展性评价结果看,地上枝叶扩展性随多效唑质量浓度的增加而减弱,但质量浓度大于700mg·L-1时减弱趋缓;地下根系扩展性随多效唑质量浓度的增加呈先增强后减弱的趋势,1300mg·L-1质量浓度对地下扩展最为有利;综合扩展性总体呈随多效唑质量浓度的增加而减弱的趋势。

Effect of paclobutrazol（PP333）on the extension and root characteristics of Lolium perenne.L was investigated with a pot experiment.The results showed that,plant growth,shoot extension,shoot biomass growth and vertical growth of root of Lolium perenne.L were all inhibited,while the tillering was enhanced at the PP333 concentration changing from100 to 1 900 mg·L-1.Less obvious inhibition of paclobutrazol on shoot biomass growth,maximum extension distance and root growth,plant height,plant coverage was observed at the PP333 concentration larger than 400,700,1 000 mg·L-1 and 1 300 mg·L-1,respectively.Tillering number,root surface area,volume and biomass of Lolium perenne.L first increased then decreased as the concentration of paclobutrazol increased,all reached their maximum values at the concentration of 1 300 mg·L-1.Shoot extension decreased as the concentration of paclobutrazol increased,slow decrease occurred as the concentration was larger than 700 mg·L-1,the extension of root was first improved then inhibited by paclobutrazol as its concentration increased,1 300 mg·L-1 is the optimal concentration for root extension of the plant,the overall expansibility of the Lolium perenne.L decreased with increasing of paclobutrazol concentration.