山羽藓对青海云杉种子萌发和幼苗生长的化感作用

采用培养皿滤纸法用不同浓度山羽藓水提取物(0,0.04 g/L,0.40 g/L,4.00 g/L)处理青海云杉种子,探究山羽藓对青海云杉种子萌发和幼苗生长的化感作用。结果显示,高浓度(4.00 g/L)山羽藓水提取物对青海云杉种子的发芽势和发芽指数及幼苗的胚根和干重均表现出抑制作用,而中等浓度(4.00 g/L)水提物则促进幼苗胚根和胚轴的生长,但各浓度水提物均对青海云杉种子发芽率无显著影响。与对照组比较,各浓度山羽藓水提物均显著降低CAT和SOD酶活性;对POD酶表现为中、低浓度促进,高浓度抑制的作用;对APX酶活性仅在低浓度(0.04 g/L)存在促进作用。各浓度山羽藓水提物均显著抑制青海云杉幼苗根尖细胞有丝分裂指数,处于分裂期细胞数量随处理浓度的升高而减少。本研究证实了高浓度山羽藓水提物对青海云杉存在化感抑制作用,这将为自然保护区青海云杉林下的地被层管理提供理论依据。

The Allelopathy of Abietinella abietina on Seed Germination and Seedling Growth of Picea crassifolia

The allelopathic effects of Abietinella abietina aqueous extract at different concentration(0,0.04 g/L,0.40 g/L,4.00 g/L)on seed germination and seedling growth of Picea crassifolia were investigated in petri dishes with filter papers.The results showed that the germination potential,germination index,seedling radicle and dry weight of P.crassifolia were inhibited by A.abietina aqueous extract at high concentration(4.00 g/L),but the medium concentration(0.40 g/L)extract promoted the seedling radicle and hypocotyl growth of P.crassifolia.The seed germination rate was not affected markedly at all experimental concentrations.Compared with control group,the activities of catalase and superoxide dismutase were decreased significantly in all extract groups.The activity of peroxidase was promoted at low and medium concentration and inhibited at high concentration,and the activity of ascorbate peroxidase was promoted only at low concentration(0.04 g/L).The mitotic index of root tip cell was inhibited by extracts at 3 concentrations,and the number of cells in mitotic phase decre ased with the rise of the extract concentration.This study confirmed that the allelopathic inhibition of high concentration aqueous extract from A.abietina does exist on P.crassifolia.This results will provide theoretical basis for the management of cover layer under the Qinghai spruce forest in nature reserves.