多效唑对多年生黑麦草扩展性和根系特性的影响

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 on the Extension and Root Characteristics of Lolium perenne. L

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 from 100 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.