空气修根对水曲柳无纺布袋容器苗生长及根系发育的影响

摘要

Objective]The objectives of this study were to deepen the understanding of air-cutting mechanism and to provide theoretical basis for popularizing the air-cutting technique. [Method]One-year-old Manchurian ash Fraxinus mandshurica seedlings grown in two types of containers ( non-waven bags and plastic containers) were used to investigate the effects of air cutting on growth ( height,stem collar diameter) ,morphology ( e. g. total leaf area,root diameter) and biomass of different organs above-and under-ground,as well as on root development. [Results]The height,the ratio of height to diameter,the total leaf area and the quality index of seedlings in non-woven bags were all significantly (P<0. 05 ) larger than those in plastic containers. The individual plant biomass,the total nitrogen and total phosphorus contents of seedlings in non-woven container were 6. 98%,12. 09%, and 10. 3% higher than those in plastic container, respectively,the root length,the root superficial area,and the root apical number were 14. 56%,32. 91% ,and 11. 18%greater (P<0. 05) respectively than those in plastic containers. Air cutting significantly increased the number of lateral roots more than 0. 5 mm at diameter (P<0. 05). More dead cells of root apical meristem were found in seedlings under air-cutting treatment,however,the number of sprouted lateral roots in mature zone of these seedlings was 35. 34% higher than those in control ( P <0 . 05 ) .[Conclusion]Our findings indicated that air-cutting inhibited root apical growth and increased the number of lateral roots and root biomass,which may greatly promote the growth in height and leaf area,and result in improved quality of Manchurian ash seedlings.%【目的】明确无纺布育苗袋空气修根对容器苗生长及根系发育的影响，为进一步推广水曲柳网袋容器育苗技术提供理论依据。【方法】以水曲柳1年生无纺布袋容器苗和塑料育苗盘容器苗为对象，采用石蜡切片技术研究根系解剖结构特征，同时观察苗木的苗高、地茎、叶面积、各营养器官生物量及养分含量差异，分析空气修根对苗木生长和根系发育的影响。【结果】无纺布袋容器苗苗高、高径比、叶面积和质量指数均显著优于育苗盘的容器苗(P＜0.05)，单株生物量、全氮和全磷含量分别比育苗盘的容器苗高6.98%，12.09%和10.3%(P ＜0.05)，根系的比根长、表面积和根尖数也分别比育苗盘容器苗高14.56%，32.9%和11.18%( P ＜0.05)，直径大于0.5 mm 侧根数显著高于育苗盘(P＜0.05)；无纺布袋容器边缘根尖分生区的细胞发生大面积死亡，塑料育苗盘容器苗的根尖分生区细胞仍具有旺盛的分裂能力，无纺布袋容器苗一级根成熟区萌生侧根数比育苗盘容器苗多35%( P ＜0.05)。【结论】空气修根显著抑制水曲柳无纺布袋容器苗根尖分区细胞的分裂，促进了成熟区侧根的生成，增加了侧根数量和根系生物量，促进了苗高、叶面积生长，提高植物生物量及养分含量。