毛竹各器官和根际土浸提液对杉木种子萌发的化感作用

Allelopathy of Phyllostachys pubescens extract on the seed germination of Chinese fir

随着毛竹杉木混交林面积的不断扩大,它们之间既会产生促进作用,又会产生抑制作用。本研究对比分析了不同浓度毛竹各器官(鲜叶、干叶、枝条、竹杆、竹鞭和鞭根)的浸提液及枯落物、根际土浸提液对杉木种子发芽率的影响,探讨了毛竹各器官浸提液及枯落物、根际土浸提液对杉木种子萌发的化感作用。结果表明:(1)处理前期,毛竹各器官浸提液对杉木种子萌发具有抑制作用,且当浸提液浓度为1∶25和1∶50的高浓度时,相对于低浓度浸提液对杉木种子萌发的抑制作用更为持久;(2)处理后期,低浓度的毛竹各器官浸提液对杉木种子萌发促进作用较快,而高浓度的浸提液仍呈现抑制作用,促进作用出现较为缓慢;(3)枯落叶浸提液总体上对杉木种子萌发具有抑制作用,在整个实验过程中低于对照组的发芽率,仅在1∶50浓度时略高对照组实验;而根际土浸提液对杉木种子萌发自始至终都具有促进作用,其中低浓度的促进作用十分显著。故在实际的毛竹杉木混交林生产营林过程中可选用毛竹根际土制备浸提液,促进杉木种子萌发,为毛竹杉木混交林的生产经营提供参考。

Mixed forestry with bamboo( Phyllostachys heterocycla cv. pubescens) and Chinese fir( Cunninghamia lanceolata) has expanded; however,the relationship between the species is both positive and negative. In the present study,the influence of the extract of several organs( including fresh leaves,dry leaves,branches,stems,rhizomes,and roots),litter,and rhizosphere soil of P. heterocycla cv. pubescens on C. lanceolata seed germination,as well as the allelopathy between the two species were analyzed. The results showed that( 1) the extract from the organs of P. heterocycla cv. pubescens inhibited C. lanceolata seed germination during the early stage of the process. Further,when the extract solution concentrations were high at 1∶ 25 and 1∶ 50,C. lanceolata seed germination inhibition was higher than that at thelower concentrations.( 2) Low concentrations of the extract promoted C. lanceolata seed germination,whereas high concentrations inhibited it during the late stage of the process and the effect appeared more slowly.( 3) The litter extract inhibited C. lanceolata seed germination,except when the concentration was 1∶50,the germination rate was slightly higher than that of the control. However,the extract liquid of rhizosphere soil generally promoted C. lanceolata seed germination;especially low concentrations,significantly enhanced germination. Therefore,the extract liquid of P. heterocycla cv.pubescens rhizosphere soil could be used to promote C. lanceolata seed germination in mixed forest management,and this study provided a reference for the mixed forest management and production of these two species.