褐环乳牛肝菌与绿木霉复合接种对辽西北地区樟子松根系的影响

Effects of Combined Inoculation with Suillus luteus and Trichoderma virens on the Roots of Pinus sylvestris var. mongolica in Northwest Liaoning Province

【目的】研究盆栽培养条件下单接种和复合接种褐环乳牛肝菌、绿木霉对樟子松幼苗生长特性、根系结构的影响,进一步揭示根际微生物对植物根系构型的调控作用。【方法】以辽西北种植的樟子松为研究对象,设计4个试验处理:1.接种无菌PD培养基(CK);2.接种绿木霉(T43);3.接种褐环乳牛肝菌(N94);4.接种褐环乳牛肝菌和绿木霉(N94+T43)。1年后分别测定樟子松幼苗在不同处理条件下菌根依赖度、生长指标、根系拓扑指数、分形维数。【结果】1)复合接种(N94+T43)菌根依赖度为84.91%,显著高于单接种和CK(P<0.05)。2)不同处理对樟子松幼苗苗高、地径、鲜质量、干质量提高效果依次为N94+T43>N94>T43>CK。3)根冠比大小依次为T43>CK>N94>N94+T43。4)复合接种N94+T43显著增加了樟子松根系总长度、表面积、体积、平均直径、根尖数、分叉数等根系参数,与其他处理差异显著(P<0.05)。5)不同处理拓扑指数均接近于1,表明樟子松幼苗根系为典型的鱼尾形分枝;2年生樟子松幼苗根系分形维数依次为N94+T43>N94>T43>CK。【结论】复合接种N94+T43菌根依赖度最大,降低了根冠比,提高了幼苗的苗高、地径、干质量、鲜质量,显著增加了樟子松根系总长度、表面积等根系参数,与其他处理差异显著(P<0.05)。各处理均未改变樟子松根系的鱼尾形分枝模式,但复合接种N94+T43根系分形维数最大。表明复合接种褐环乳牛肝菌和绿木霉(N94+T43)对樟子松根系构型的调控作用大于其他处理方式。

【Objective】Our study investigated the effects of single and combined inoculation with Suillus luteus and Trichoderma virens on the growth characteristics and root system architecture of Pinus sylvestris var. mongolica seedlings in the northwestern Liaoning Province,to reveal the regulation of rhizosphere microorganisms on seedling root system architecture.【Method 】In this study, P. sylvestris var. mongolica seedlings grown in northwestern Liaoning were inoculated with the following four agents： 1. Sterile PD（ potato,dextrose） culture medium（ CK）; 2. T. virens（ T43）;3. S. luteus（ N94）; 4. S. luteus and T. virens（ N94 ＋ T43）. In one year after treatments,the mycorrhizal dependence,growth index,root topology architecture and fractal dimension of the seedlings under different treatment conditions were determined.【Result】The results showed that： 1） The mycorrhizal dependence under treatment of combined inoculation（ N94 ＋ T43） was 84. 91%,which was significantly higher than that of single inoculation and CK（ P 〈 0. 05）. 2） The improving effects of different treatments on height,collar diameter,fresh weight and dry weight of the seedlings were： N94＋ T43 〉 N94 〉 T43 〉 CK. 3） The root crown ratio under different treatments were： T43 〉 CK 〉 N94 〉 N94 ＋ T43. 4） The combined inoculation（ N94 ＋ T43） dramatically improved the root system parameters like root length,surface area,volume,average diameter,and tip and branch numbers of seedlings,which were significantly different from those of theother treatments（ P 〈 0. 05）. 5） The topology indexes under different treatments were approximate to 1,suggesting that the seedling root system architecture is a typical fishtail branch. The fractal dimensions of 2-year-old P. sylvestris var.mongolica seedlings roots were： N94 ＋ T43 〉 N94 〉 T43 〉 CK. 【Conclusion 】Under treatment of combined inoculation（ N94 ＋ T43）,the mycorrhizal dependence was the highest,while the root crown ratio was decreased. The combined inoculation promoted the seedling height,collar diameter,fresh weight and dry weight,and increased the root parameters such as root length and surface area were significantly compare to those of other treatments（ P 〈 0. 05）. All treatments did not change the fishtail branch pattern of the roots,but the fractal dimension under combinede inoculation treatment was the largest. The results demonstrate that combined inoculation is more effective in changing the root system architecture than other treatments.