TY - JOUR
T1 - Inoculation with arbuscular mycorrhizal fungi enhances growth of Litchi chinensis sonn. trees after propagation by air-layering
AU - Janos, David P.
AU - Schroeder, Michelle S.
AU - Schaffer, Bruce
AU - Crane, Jonathan H.
PY - 2001
Y1 - 2001
N2 - Lychee (Litchi chinensis Sonn.) is typically propagated by air-layering mature tree branches which are potted in fertilized, soil-free media after cutting. The size of these branches, low phosphorus retention by pot substrates, and fertilization all might combine to preclude benefits of arbuscular mycorrhizas to lychee. In order to examine the potential of lychee to benefit from arbuscular mycorrhizas in an agriculturally realistic context, lychee air-layers were grown for 469 days in ca. 95-1 pots of soil-free substrate inoculated with field-collected arbuscular mycorrhizal roots or not at two different levels of phosphorus fertilization. High phosphorus fertilization (a one-time addition of ca. 1.32 g 1-1 slow-release triple-superphosphate) had no detectable effects on mycorrhiza formation, lychee survival, net CO2 assimilation, or growth. Inoculation with indigenous South Florida arbuscular mycorrhizal fungi improved leaflet expansion as early as 120 days after inoculation, and subsequently enhanced height growth and leaf production but did not affect stem diameter growth, net CO2 assimilation, or survival. At harvest, although mycorrhizal colonization was low (average 7.4% colonized root length), mycorrhizal plants had 39% higher above-ground dry weight than control plants. Below-ground dry weights did not differ, but inoculated plants had lower fine root to leaf dry weight ratios than control plants. Leaflets of inoculated plants had higher concentrations of P, K, Cu, and Zn, and lower concentrations of Ca, Mg, and Mn than those of control plants, but total Kjeldahl nitrogen and iron concentrations did not differ significantly 10 months after inoculation. Mycorrhiza enhancement of lychee growth occurred even though phosphorus clearly was not limiting for growth. Out observations suggest that in this soil-free medium, arbuscular mycorrhizal fungus enhancement of copper and iron nutrition improved lychee growth.
AB - Lychee (Litchi chinensis Sonn.) is typically propagated by air-layering mature tree branches which are potted in fertilized, soil-free media after cutting. The size of these branches, low phosphorus retention by pot substrates, and fertilization all might combine to preclude benefits of arbuscular mycorrhizas to lychee. In order to examine the potential of lychee to benefit from arbuscular mycorrhizas in an agriculturally realistic context, lychee air-layers were grown for 469 days in ca. 95-1 pots of soil-free substrate inoculated with field-collected arbuscular mycorrhizal roots or not at two different levels of phosphorus fertilization. High phosphorus fertilization (a one-time addition of ca. 1.32 g 1-1 slow-release triple-superphosphate) had no detectable effects on mycorrhiza formation, lychee survival, net CO2 assimilation, or growth. Inoculation with indigenous South Florida arbuscular mycorrhizal fungi improved leaflet expansion as early as 120 days after inoculation, and subsequently enhanced height growth and leaf production but did not affect stem diameter growth, net CO2 assimilation, or survival. At harvest, although mycorrhizal colonization was low (average 7.4% colonized root length), mycorrhizal plants had 39% higher above-ground dry weight than control plants. Below-ground dry weights did not differ, but inoculated plants had lower fine root to leaf dry weight ratios than control plants. Leaflets of inoculated plants had higher concentrations of P, K, Cu, and Zn, and lower concentrations of Ca, Mg, and Mn than those of control plants, but total Kjeldahl nitrogen and iron concentrations did not differ significantly 10 months after inoculation. Mycorrhiza enhancement of lychee growth occurred even though phosphorus clearly was not limiting for growth. Out observations suggest that in this soil-free medium, arbuscular mycorrhizal fungus enhancement of copper and iron nutrition improved lychee growth.
KW - Glomales
KW - Mineral nutrition
KW - Phosphorus fertilization
KW - Sapindaceae
KW - Soil-free medium
KW - Stem cuttings
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U2 - 10.1023/A:1010329618152
DO - 10.1023/A:1010329618152
M3 - Article
AN - SCOPUS:0034960576
VL - 233
SP - 85
EP - 94
JO - Plant and Soil
JF - Plant and Soil
SN - 0032-079X
IS - 1
ER -