摘要
选用来自我国西南酸性土壤上的松乳菇、褐环乳牛肝菌和来自西北石灰性土壤的厚环乳牛肝菌、土生空团菌作为供试菌株,采用液体培养的方法,研究不同浓度铝对4种外生菌根真菌的生长、草酸分泌及氮磷钾吸收的影响。结果表明:铝胁迫下,4种外生菌根真菌生物量均出现不同程度的下降,且松乳菇与褐环乳牛肝菌生物量下降幅度较厚环乳牛肝菌、土生空团菌少;同时,松乳菇与褐环乳牛肝菌无论在是否含铝的培养基中均有较高的草酸分泌量。这可能是由于草酸能够与培养基中的铝螯合,从而降低铝离子的活性、减轻对菌株的伤害。在大多数铝处理的菌丝中,松乳菇与褐环乳牛肝菌的氮磷钾吸收量高于厚环乳牛肝菌与土生空团菌。根据菌株在铝胁迫下的生物量与养分吸收状况可知,选自酸性土壤上的菌种具有较强的抗铝性,这可能是酸性土壤上自然选择的结果。另外,培养基中适当的铝浓度能够增加4种菌株的磷含量,这可能是有益于沉淀细胞内的铝以减轻铝毒。
Growth,oxalate efflux,and nitrogen,phosphorus and potassium uptake,by isolates of four ectomycorrhizal species：Lactarius deliciosus（Agaricales）,Suillus luteus（Agaricales）,Suillus grevillei（Agaricales） and Cenococcum geophilum（Eurotiales） were compared in pure culture in liquid media with variable concentrations of Al3＋（0,0.20,0.40 and 1.00 mmol·L-1）.The growth of the four ectomycorrhizal species were negatively but variably affected by Al3＋.The two isolates originating from acidic soils in southwest China（L.deliciosus and Suillus luteus） showed less reduction in biomass compared to S.grevillei and C.geophilum originating from calcareous soils in northwest China.L.deliciosus and S.luteus also produced high oxalate accumulation in the culture solution with and without addition of Al3＋.This could be beneficial to the fungi in reducing the concentrations of active Al3＋ in culture solutions through the formation of chelate.In most cases of Al stress,higher accumulations of nitrogen,phosphorus,and potassium were observed in the mycelium of S.luteus and L.deliciosus than in S.grevillei and C.geophilum.Taking into account of higher biomass and larger nutrient absorption under Al exposure,S.luteus and L.deliciosus,indicating higher Al resistance of the fungal isolates from acidic soils than those from the calcareous,could be due to evolution and natural selection in acidic conditions.Furthermore,appropriate Al3＋ in culture medium also increased in phosphorus concentrations in all of four fungal isolates,which could be one of beneficial patterns to precipitate intracellular Al3＋ and diminish Al toxicity.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2012年第2期82-88,共7页
Scientia Silvae Sinicae
基金
Funded by the Natural Science Foundation of China(40771112)
the Basic Research Funds of Central Universities in China (XDJK2009C121)
关键词
外生菌根真菌
铝
草酸
养分
ectomycorrhizal fungi
aluminum
oxalate
nutrient
