Response of endangered plant species to inoculation with arbuscular mycorrhizal fungi and soil bacteria.
ABSTRACT Three endangered plant species, Plantago atrata and Pulsatilla slavica, which are on the IUCN red list of plants, and Senecio umbrosus, which is extinct in the wild in Poland, were inoculated with soil microorganisms to evaluate their responsiveness to inoculation and to select the most effective microbial consortium for application in conservation projects. Individuals of these taxa were cultivated with (1) native arbuscular mycorrhizal fungi (AMF) isolated from natural habitats of the investigated species, (2) a mixture of AMF strains available in the laboratory, and (3) a combination of AMF lab strains with rhizobacteria. The plants were found to be dependent on AMF for their growth; the mycorrhizal dependency for P. atrata was 91%, S. umbrosus-95%, and P. slavica-65%. The applied inocula did not significantly differ in the stimulation of the growth of P. atrata and S. umbrosus, while in P. slavica, native AMF proved to be the less efficient. We therefore conclude that AMF application can improve the ex situ propagation of these three threatened taxa and may contribute to the success of S. umbrosus reintroduction. A multilevel analysis of chlorophyll a fluorescence transients by the JIP test permitted an in vivo evaluation of plant vitality in terms of biophysical parameters quantifying photosynthetic energy conservation, which was found to be in good agreement with the results concerning physiological parameters. Therefore, the JIP test can be used to evaluate the influence of AMF on endangered plants, with the additional advantage of being applicable in monitoring in a noninvasive way the acclimatization of reintroduced species in nature.
SourceAvailable from: Mary Grace B Saldajeno03/2012, Degree: PhD, Supervisor: Dr. Mitsuro Hyakumachi
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ABSTRACT: A pot experiment was conducted to evaluate the effects of two arbuscular mycorrhizal fungi (AMF), Dentiscutata heterogama and Rhizophagus manihotis on the growth and nutrition of Juglans venezuelensis Manning. This species is currently considered a threatened tree species and the successful restoration of its populations depends on an increased understanding of the ecological and physiological aspects of its response to inoculation with AMF. In general, shoot and total dry weight, and leaf area were significantly higher in seedlings inoculated with AMF than in non-inoculated ones. Differences in height and leaf number between the inoculated and non-inoculated treatments become apparent after 30 days of plant growth. Inoculated plants had a greater leaf area as the result of the higher allocation of resources to leaf biomass (leaf mass ratio, LMR). The fraction allocated to the roots (RMR) was not significantly different between treatments. Differences between vital stain (SDH) and non-vital trypan blue stain (TB) showed that the D. heterogama colonization was almost entirely active compared to the R. manihotis colonization. The relative responsiveness (RR) of J. venezuelensis to inoculation with D. heterogama and R. manihotis was 21.8 and 25.4 % respectively, but colonization values were never greater than 45 %, despite low P content in the soils used. The growth and physiological responses of J. venezuelensis to inoculation with two AMF species indicate that these microorganisms should be employed when propagating this threatened species for its subsequence reintroduction into its natural habitat.Symbiosis 10/2014; 64(2):63-71. DOI:10.1007/s13199-014-0304-0 · 0.94 Impact Factor