不同树龄苹果园土壤微生物的差异及对苹果砧木生长的影响

以平顶海棠(Malus robusta Rehd.)为试验材料,以4个不同树龄苹果园的土壤为对象,研究了不同树龄苹果园土壤对再植平顶海棠幼苗生长的影响。结果表明,在前茬树龄为3、8、15和24 a苹果园土种植的平顶海棠幼苗比正茬土对照的平均株高分别减少31.22%、46.38%、57.66%和63.10%;再植平顶海棠幼苗地上部干质量分别减少0.96%、57.58%、76.88%和78.10%;地下部干质量分别减少40.38%、48.79%、64.03%和79.43%。在24 a生苹果树土壤中再植海棠幼苗校正发病率达到了72.73%,而在3 a生苹果树的土壤中再植海棠幼苗校正发病率只有18.18%。对不同树龄的苹果园土壤根际细菌和真菌群落结构的差异进行分析,其结果为,随着苹果树龄的提高,根际土壤中真菌种类和数量显著增加,而细菌的种类和数量则随着树龄的增加显著减少。

Rhizosphere microbial community variation of apple orchard soil with different tree age and the effect on replanted apple rootstock

Malus robusta Rehd.seedlings were planted in the soil collected from four apple orchards with different tree ages located in Qingyuan County to explore the influence of the soil with different tree ages on the plant growth and disease severity of replanted M.robusta seedlings.The results indicated that the seedlings planted in 3,8,15 and 24-year old orchard soils decreased by an average of 31.22%,46.38%,57.66% and 63.10% in height;0.96%,57.58%,76.88% and 78.10% in shoot dry weight,40.38%、48.79%,64.03% and 79.43% in root dry weight.The corrected disease incidence of the seedlings in the 24-year old soil reached 72.73% while only 18.18% in the 3 year-old soil.The total DNA was extracted from the soil and amplified by PCR with the 16S rDNA and 18S rDNA specific primer pairs,Subsequently,the rhizosphere bacteria and fungal community structure differences among the apple orchard soil with different tree age were analyzed by denaturing gradient gel electrophoresis(DGGE).The results showed that the composition of soil fungal species increased greatly with the extension of the tree age,however,the opposite trend of bacteria community development was observed.