Citrus root responses to localized drying soil: A new approach to studying mycorrhizal effects on the roots of mature trees |
| |
Authors: | Javier F Espeleta David M Eissenstat James H Graham |
| |
Institution: | (1) Citrus Research and Education Center, University of Florida, Institute of Food and Agricultural Sciences, Lake Alfred, FL 33850–2299, USA;(2) Department of Horticulture, The Pennsylvania State University, University Park, PA 16803, USA;(3) Present address: Department of Botany, University of Georgia, Athens, GA 30602, USA |
| |
Abstract: | Because fine roots tend to be concentrated at the soil surface, exposure to dry surface soil can have a large influence on
patterns of root growth, death and respiration. We studied the effects of arbuscular mycorrhizas (AM) formation on specific
root length (SRL), respiration and mortality of fine roots of bearing red grapefruit (Citrus paradisi Macf.) trees on Volkamer
lemon (C. volkameriana Tan. & Pasq.) rootstock exposed to drying soil. For each tree, the fine roots were removed from two
woody lateral roots, the roots were surface sterilized and then each woody root was placed in a separate pair of vertically
divided and independently irrigated soil compartments. The two split-pot systems were filled with sterilized soil and one
was inoculated with arbuscular mycorrhizal fungi (Glomus etunicatum/G. intraradices). New fine lateral roots that emerged
from the woody laterals were permitted to grow inside the pots over a 10-month period. Irrigation was then removed from the
top compartment for a 15-week period. At the end of the study, roots inoculated with AM fungi exhibited about 20% incidence
of AM formation, whereas the uninoculated roots were completely void of AM fungi. Arbuscular mycorrhizal roots exhibited lower
SRL, lower root/soil respiration and about 10% lower fine root mortality than nonmycorrhizal roots after 15 weeks of exposure
to dry surface soil. This study demonstrates the feasibility of examining mycorrhizal effects on the fine roots of adult trees
in the field using simple inexpensive methods. |
| |
Keywords: | arbuscular mycorrhizal fungi citrus Citrus volkameriana dry soil fine roots Glomus etunicatum Glomus intraradices root death root respiration Rutaceae specific root length vesicular-arbuscular mycorrhizal fungi Volkamer lemon |
本文献已被 SpringerLink 等数据库收录! |
|