丛枝菌根真菌对澳洲坚果幼苗耐旱性的影响

Effect of Arbuscular Mycorrhizal Fungi Inoculation on the Drought Tolerance of Macadamia ternifolia Seedling

基于云南热区季节性干旱的自然条件,探讨AM真菌接种对具有排根的引种作物——澳洲坚果幼苗生长及耐旱性的影响,旨在为外来物种的本地驯化栽培提供科学的理论依据。在正常水分与水分胁迫条件下,对盆栽澳洲坚果幼苗分别接种土著AM真菌(N-AM)和摩西球囊霉(G-AM),测定澳洲坚果幼苗生长、菌根定殖、可溶性糖含量、脯氨酸含量等指标。结果表明,两个接种处理下,AM真菌均能与澳洲坚果幼苗建立共生关系,接种土著AM真菌(N-AM)处理的澳洲坚果幼苗根系的侵染率均显著高于接种摩西球囊霉(G-AM)处理,以正常水分条件下N-AM处理的苗木根系中AM侵染率为最高;接种AM真菌能促进澳洲坚果幼苗的生长,在正常水分条件下接种土著AM真菌的澳洲坚果幼苗干物质累积量最大;接种AM真菌后澳洲坚果幼苗中可溶性糖含量比不接种显著增加,叶片和排根中增加幅度较大;澳洲坚果幼苗在水分胁迫条件下接种土著AM真菌后可溶性糖含量增幅最大,如叶片可溶性糖含量比G-AM处理和对照增加71.82%和98.64%;澳洲坚果幼苗叶片和根系中脯氨酸含量仅在水分胁迫时显著升高,脯氨酸累积量呈现CK<G-AM<N-AM,研究结果表明可溶性糖和脯氨酸在澳洲坚果的耐旱性中发挥不同的作用。两个接种处理中AM真菌均能与澳洲坚果幼苗很好地共生,并促进澳洲坚果幼苗生长和耐旱性,接种土著AM真菌的幼苗各指标显著优于接种摩西球囊霉的,可能是由于拥有多样性优势的土著AM真菌在澳洲坚果幼苗根系中定殖能力较强。

For providing a scientific theoretical basis for domestication and cultivation of alien species,the effects of arbuscular mycorrhizal fungi(AMF)inoculation on drought tolerance in Macadamia ternifolia seedlings with cluster roots were studied based on seasonal drought in Yunnan tropical regions.Under Native-AMF,or Glomus mosseae treatments with well-watered or drought condition,relevant indicators such as AMF colonization,soluble sugar content,proline content of Macadamia ternifolia seedlings were detected.The results showed that the two inoculation treatments could establish symbiotic relationship with macadamia seedling.The colonization rate of N-AM treatment on cluster roots or no cluster roots of Macadamia ternifolia seedlings was significantly higher than that of G-AM treatment.Under well-watered,the colonization rate of N-AM treatment was the highest.AMF inoculation significantly enhanced the growth of Macadamia ternifolia seedlings under well-watered or drought condition,and the dry matter of Macadamia ternifolia seedlings was the largest under well-watered.Soluble sugar of Macadamia ternifolia seedlings with AMF inoculation was increased significantly,there were significant differences among different treatments,increased significantly in leaves and cluster roots under drought condition,the soluble sugar content in leaves under N-AM treatment was 71.82%and 98.64%higher than that that of G-AM treatment and control.The proline content in leaves and roots of Macadamia ternifolia seedlings increased significantly only under water stress.The change of proline under different treatments showed CK<G-AM<N-AM.Soluble sugar and proline may play different roles in drought tolerance.Two AMF inoculation treatments had well colonization with the macadamia seedlings,and could promote the growth and drought tolerance of Macadamia ternifolia seedlings.Native-AMF was more efficient than Glomus mosseae,especially under drought stress condition.Native-AMF,which may have a diversity advantage,has a strong inoculation ability in the root of Macadamia ternifolia seedlings.