Selection of corymbia clones responsive to the inoculation of ectomicorryzal fungi

A sele??o de clones de Corymbia menos dependentes da aduba??o fosfatada e mais responsivos as ectomicorrizas poder? tornar o cultivo desta planta menos dependente deste insumo. O objetivo deste trabalho foi avaliar o efeito de inoculantes de isolados de Pisolithus sp. na produ??o de mudas de clones de Corymbia pela miniestaquia, em condi??es de viveiro. Os clones de Corymbia AEC0007, AEC0022, AEC0043 e AEC0045 inoculados com os isolados de Pisolithus sp. C9C, C16 com a mistura dos dois isolados (MIX = C9C+C16), foram crescidos em substrato com redu??o da aduba??o fosfatada. Como controle, os mesmos clones, n?o inoculados, foram crescidos em substrato com (Controle) e sem (Comercial) redu??o da aduba??o fosfatada. A sobreviv?ncia das mudas nos clones AEC0007 e AEC0043 n?o foi influenciada pela inocula??o. Para os demais clones, as mudas inoculadas com C16 foram at? 75 % maiores que as mudas do Comercial. A inocula??o com MIX aumentou a altura das mudas do AEC0007, AEC0043 e AEC0045, todos em rela??o ?s mudas do Comercial e do Controle. O C16 aumentou o di?metro das mudas do AEC0007 e AEC0045 em at? 25 % em rela??o ?s do Comercial, e para os demais clones, a inocula??o n?o teve influ?ncia. As maiores porcentagens de coloniza??o foram observadas nas mudas do AEC0007, AEC0022 e AEC0043 inoculadas com C9C e com MIX. A inocula??o, em geral, aumentou a frequ?ncia de torr?es firmes e parcialmente enraizados e firmes e bem enraizados, exceto para o AEC0045. Os teores de P, N, K, Ca e Mg estavam abaixo do considerado ideal e os teores de Zn e Fe estavam acima da faixa adequada. Apenas os teores de Mn permaneceram dentro da faixa considerada adequada. As porcentagens de pontas colonizadas se correlacionaram positivamente com par?metros de crescimento e nutri??o nos clones AEC0007, AEC0022 e AEC0043, mas a quantidade de par?metros e a intensidade da correla??o foram dependentes do clone. A inocula??o com Pisolithus sp. aumenta a coloniza??o ectomicorr?zica e o crescimento de mudas Corymbia em viveiro comercial, mas isto ? dependente do clone e do isolado. Os inoculantes mais promissores foram MIX> C9C>C16, pois promoveram maiores crescimento, sobreviv?ncia, massa seca, coloniza??o e qualidade de torr?es das mudas de Corymbia. O clone AEC0043 foi o mais responsivo ? inocula??o por fungos ectomicorr?zicos, obtendo maiores benef?cios.AperamCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.The selection of Corymbia clones less dependent on phosphate fertilization and more responsive to ectomycorrhizae may make the cultivation of this plant less dependent on this input. The objective of this work was to evaluate the effect of inoculants of Pisolithus sp. in the production of mini-cuttings of Corymbia clones, under nursery conditions. The Corymbia clones AEC0007, AEC0022, AEC0043 and AEC0045 inoculated with the isolates of Pisolithus sp. C9C, C16 with the mixture of the two isolates (MIX = C9C + C16) were grown on substrate with reduction of phosphate fertilization. As a control, the same uninoculated clones were grown on substrate with (Control) and without (Commercial) reduction of phosphate fertilization. The survival of the mini cuttings in clones AEC0007 and AEC0043 was not influenced by inoculation. The survival of the AEC0022 mini-cuttings inoculated with C16 was 75% greater than those from the commercial, but this effect was dependent on the isolate and the clone. The inoculation with the MIX increased the height of the mini-cuttings of AEC0007, AEC0043 and AEC0045, all in relation to the Commercial and Control mini-cuttings. The C16 increased the diameter of the AEC0007 and AEC0045 mini-cuttings by up to 25% compared to the Commercial ones and for the other clones inoculation it had no influence. The highest percentages of colonization were observed in the AEC0007, AEC0022 and AEC0043 mini-cuttings inoculated with C9C and MIX. The inoculation, in general, increased the frequencies of firm and partially rooted and firm and well rooted clods, except for AEC0045. The concentration of P, N, K, Ca and Mg were below the ideal level and the Zn and Fe concentration were above the appropriate range. Only Mn concentration remained within the range considered adequate. The percentages of colonized tips correlated positively with growth and nutrition parameters in clones AEC0007, AEC0022 and AEC0043, but the number of parameters and the intensity of the correlation was dependent on the clone. The inoculation with Pisolithus sp. increases ectomycorrhizal colonization and growth of Corymbia mini-cuttings in commercial nursery, but this is dependent on the clone and isolate. The most promising inoculants were MIX> C9C> C16, as they promoted greater growth, survival, dry mass, colonization and quality of clods of Corymbia mini-cuttings. Clone AEC0043 was the most responsive to inoculation of ectomycorrhizal fungi, obtaining greater benefits