外源GA3对毛竹实生苗新分蘖竹株秆形与竹材纤维质量的影响

为探索竹类植物秆形生长机制,研究利用激素调控竹材纤维生长质量,采用不同质量浓度(0、20、40、60 mg/L)赤霉素(GA₃)处理毛竹实生苗,观察并测定处理后新分蘖竹株数量、秆形及竹材纤维质量变化情况。结果表明:毛竹实生苗叶面喷施不同浓度GA₃后,新分蘖竹株秆高、节间长和叶片数量均有极显著增加(P<0.01),20、40和60 mg/L GA₃处理实生苗新分蘖竹株秆高分别比对照(0 mg/L)增长0.56、1.19和1.21倍,平均节长度增加0.49、1.05和1.10倍,叶片数量增加35.61%、48.35%和38.68%; 新分蘖竹株数量、单株节数和地径在处理与对照之间无显著差异。伴随秆形变化,新分蘖竹株竹材纤维质量也有所改变。20、40和60 mg/L GA₃处理,明显增加了新分蘖竹株竹材纤维细胞长度,分别比对照增加13.17%、20.68%和21.46%; 但各处理对竹材纤维细胞的宽度作用不显著,从而使得处理后竹株竹材纤维的长宽比增加,有利于竹材纤维质量提升。另外发现,不同浓度GA₃处理对竹材纤维细胞的壁厚、腔径和纤维组织比量的影响不显著。分析认为,赤霉素处理能显著改善毛竹实生苗新分蘖竹株的竹材纤维质量,但对提高竹材纤维产量无显著作用。

Effects of exogenous GA3 on culm form and culm fiber quality of Phyllostachys edulis seedlings neonatal tiller

In order to study the growth mechanism of bamboo culm, and explore the methods of regulating bamboo fiber quality, different mass concentration(0, 20, 40, 60 mg/L)of gibberellin(GA₃)were sprayed on moso bamboo seedlings, and the neonatal tiller number, culm form and fiber quality were measured after treatments. Results showed that the culm height, internode length and leaf number of neonatal tillers increased significantly, the culm height of neonatal tiller under 20, 40 and 60 mg/L GA₃ treatments were 0.56, 1.19 and 1.21 times higher respectively than that under the control(0 mg/L). The mean internode length increased 0.49, 1.05 and 1.10 times, and the number of leaves increased 35.61%, 48.35% and 38.68%, respectively. Nevertheless, no significant difference was presented among treatments on the neonatal tiller number, node number and the ground diameter. With the changes of culm form, the fiber quality of neonatal tiller also varied. The length of fiber cell under the 20, 40 and 60 mg/L GA₃ treatments all had been increased significantly, 13.17%,20.68% and 31.46% longer than that under the control, respectively. However, the effects of each treatment on fiber cell width were not obvious, resulting in increasing of the fiber aspect ratio which is conducive to the fiber quality improvement. Besides, the effects of GA₃ treatment on fiber cell wall thickness, lumen diameter and fiber tissue proportion were not obvious. Research showed that the use of GA₃ could significantly improve the fiber quality of moso bamboo seedlings neonatal tiller, but couldn't significantly improve fiber production.