Host genotype and the formation and function of VA mycorrhizae |
| |
Authors: | J H Graham D M Eissenstat |
| |
Institution: | (1) Citrus Research and Education Centre, University of Florida, IFAS, 700 Experiment Station Road, 33850 Lake Alfred, FL, USA |
| |
Abstract: | VA mycorrhizae, the most ancient type of mycorrhizal symbiosis, are present in the most phytogenetically advanced groups.
Few plants have evolved mechanisms to completely prevent infection by VAM fungi. Yet, plant species that are less dependent
on VA mycorrhizae for nutrient acquisition (e.g., grasses) generally have less root colonization in the field than more dependent
species (e.g., Citrus). Among closely related Citrus genotypes, there is a greater tendency for less dependent species to limit the rate but not
the extent of colonization, even in high-P soils. We hypothesize that colonization represents a significant carbon cost that
may be regulated by the host genotype. Carbon expenditure on the fungus at high P may result in mycorrhizal-induced growth
depression. The potential value of breeding plants for greater susceptibility to colonization will depend on the cost/benefit
of VA mycorrhizae for the specific crop, soil and environmental conditions. Although the genetics and physiology of host control
over VAM colonization are barely known, recently discovered mycorrhizal colonization mutants (myc-) of pea offer great promise for the study of host-fungus compatibility.
Florida Agricultural Experiment Station Journal Series No. R-02765.
Florida Agricultural Experiment Station Journal Series No. R-02765. |
| |
Keywords: | carbon cost carbon expenditure citrus genotypes host-fungus compatibility mycorrhizal dependency root colonization rate |
本文献已被 SpringerLink 等数据库收录! |
|