施肥方式及接种菌根真菌对1年生油松苗木根系构型的影响

Responses of the Root System Architecture of One-Year-Old Pinus tabuliformis Seedlings to Fertilization and Ectomycorrhizal Fungus Inoculation

为探究施肥方式和接种外生菌根真菌处理对油松苗木根系构型的影响,在大田条件下,以1年生油松菌根苗(混合接菌,HJ)和非菌根苗(未接菌,WJ)为研究对象,设置4种施肥处理:不施肥(CK)、常规施肥(CF)、指数施肥(EF)、2倍指数施肥(DEF),对比分析苗木根系的形态(总根长、总表面积、总体积、根尖数)、根系功能(比根长、比表面积、根组织密度)及生物量等指标。结果表明:1)接种菌根真菌处理显著影响1年生油松苗木菌根侵染率;各施肥处理下,菌根侵染率均为HJ高于WJ处理。2)施肥处理显著影响苗木直径0~0.5 mm根系的形态指标;2种接菌处理下,EF处理的总根长、总表面积、总体积、根尖数均最高。3)各施肥处理下,油松苗木比根长、比表面积均为HJ低于WJ处理,而根组织密度及根系总生物量为HJ高于WJ处理。接种菌根真菌处理下,苗木根系生物量变化规律均为EF>DEF>CF>CK。综上所述,指数施肥结合接种菌根真菌处理有利于促进油松苗木根系形态构建。

In order to investigate the responses of the root morphology of one-year-old Pinus tabuliformis seedlings to fertilization and inoculation treatments,the indicators of root morphology(including total root length,surface area,volume and tips)and function(including specific root length,specific root surface area and root biomass density)and root biomass were measured under field condition.Different inoculated seedlings of P.tabuliformis were selected,including no inoculation(WJ)and inoculated with 8 ectomycorrhizal fungi(HJ)treatments.Four fertilization treatments were set,including no fertilization(CK),conventional fertilization(CF),exponential fertilization(EF)and double exponential fertilization(DEF).The results indicated that 1)the mycorrhizal colonization rate of the seedlings were significantly affected by inoculation treatments.Among different treatments,the rate of mycorrhizal colonization in HJ treatment was higher than that in WJ treatment.2)The morphology of roots with diameter of 0-0.5 mm was significantly affected by fertilization treatment.The total root length,surface area,volume and number and root tips of EF treatment were the highest among different the inoculation treatments.3)The specific root length and specific root surface area of P.tabuliformis seedlings in WJ treatment were higher than those of HJ treatment,and the change rules of root biomass and root biomass density were opposite under the fertilization treatment.The root biomass of the seedlings under different inoculation treatments was in the order of EF>DEF>CF>CK.It was concluded that the root system architecture of P.tabuliformis seedlings could be promoted effectively by exponential fertilization combined with the inoculation of ectomycorrhizal fungi.