接种丛枝菌根真菌后干旱胁迫对木棉根区土壤和体内养分的影响

Drought stress effects of nutrients of the Bombax ceiba at the root zone soil and plant's body after inoculation of AMF

生长在干热河谷的木棉普遍具有丛枝菌根真菌(AMF)共生系统,这是否是它对干旱环境适应的策略之一?为揭示AMF是否促进木棉吸收养分能力从而提高其抗旱能力,采用盆栽试验对接种和不接种丛枝菌根真菌木棉幼苗进行干旱胁迫处理,测定不同处理下木棉根区土壤养分及植株营养成分含量。结果表明:中度干旱胁迫下,接菌提高了植株根区土壤AK、NO3--N含量而降低了TN、TP含量,在干旱胁迫第30、60、90d时,AK、NO3--N含量分别比未接菌株多37.35%、20.48%、17.77%和173.61%、285.94%、84.62%,TN、TP分别比未接菌株少19.18、2.53、6.32 mg/kg和20.13、29.00、31.40 mg/kg。接菌提高了根茎中TP含量,分别比未接菌株多183.09、292.42 mg/kg,提高了根茎叶中TK含量,分别超出未接菌株189.43、164.79、77.99 mg/kg。重度干旱胁迫下,接菌提高了根区土壤TK、AK、NH_4^+-N含量,干旱胁迫30、60、90 d时,分别比未接菌株多0.40、0.90、0.58 mg/kg,49.53%、68.58%、58.43%和55.72%、393.49%、16.13%。干旱胁迫后期(60、90 d)接菌降低了根区土壤AP含量,分别比未接菌株少15.7%、38.49%。接菌株根茎TP含量大于未接菌株,分别超出9.75、52.78 mg/kg,接菌提高了根茎中TK含量,分别比未接菌株多26.86、45.76、173.30 mg/kg。此外接菌明显降低了植株根区NH_4^+-N含量,中度和重度干旱胁迫下,接菌株和未接菌株降幅分别为3.48、0.10和2.44、0.70 mg/kg。由此可见,接菌改善了木棉植株根区土壤和植株体内营养元素含量,这将为进一步研究木棉的抗旱机理提供理论依据。

The symbiont composed by Bombax ceiba L and arbuscular mycorrhizal fungi （AMF） is very popular in the Dry-hot Valley. Our objective is to clarify whether the formation of symbiosis plays a role in the adaption mechanism ofB. ceiba which survive in such harsh condition at Dry-hot Valley. Using pot experiment and inoculated arbuscular mycorrhizal fungi Bombax ceiba L seedling drought stress treaanent, determination of Bombax ceiba L under different processing root zone soil nutrient and plant nutrient content. Under moderate drought stress, the inoculation increased the plant root zone soil AK, NO^- N content and reduce the content of TN and TP in drought stress 30, 60, 90 d, AK, NOa-- N content than not meet strains respectively 37.35%, 20.48%, 17.77% and 173.61%, 285.94%, 84.62%, TIN and TP were less than 19.18, 2.53, 6.32, did not answer the strains, 29.00, 31.40 mg/kg and 20.13 mg/kg. The inoculation increased the TP content in roots, than not meet strains respectively 183.09, 292.42 mg/kg, improves the rhizome TK content in leaf, don＇t answer beyond strains respectively 189.43, 164.79, 77.99 mg/kg. Under severe drought stress, the inoculation increased the root zone soil TK, AK, NI-L＋-N content, 30, 60, 90 d, drought stress than not meet strains respectively 0.40, 0.90, 0.58 mg/kg, 49.53%, 68.58%, 58.43% and 55.72%, 68.58% and 16.13%. Drought stress （60, 90 d） late inoculation reduces the root zone soil AP content, less than not meet strains were respectively 15.7% and 38.49%. Joint strain rhizome TP content than not to strain, beyond 9.75, 52.78 mg/kg, respectively, the inoculation TK content in roots was increased, the than not meet strains respectively 26.86, 45.76, 173.3 mg/kg. In addition the inoculation significantly reduces the plant root zone NI-I4^-N content, moderate and severe drought stress, strain and did not answer the strain drop were 3.48, 0.10 and 2.44 and 0.70 mg/kg.Inoculation, therefore, is to improve the kapok plant root zone soil and plant nutrient element content, which will provide theoretical basis for fttrther study kapok drought resistance mechanism.