The functional diversity of native mesorhizobial genotypes nodulating chickpea was assessed using two chickpea cultivars under pot culture conditions. The symbiotic effectiveness ratio of the mesorhizobial genotypes showed the existence of wide functional diversity among the isolates in Haryana soils. Mesorhizobial isolates belonging to the third genotype (MG III) were more efficient than the other genotypes. The majority of the isolates (94%) had intermediate effectiveness and only a very small percentage (2%) were ineffective, while 4–6% of the isolates were highly effective with a symbiotic ratio > 4.0. These included CP2381A, CP741, CP1423 and CP2437. Among all the isolates, strain CP2381A was the most efficient isolate for both cvs HC1 and HC5. The symbiotic ratio of the shoot N contents varied for both the cultivars after inoculation with mesorhizobial isolates from different districts. The most efficient chickpea mesorhizobial isolates were found to be present in soils from the Bhiwani district followed by that from RDS Farm, Hisar, but isolates from Mahendragarh, Fatehabad and Jhajjar were less efficient.
and K. Grigulis. 2007. Functionaldiversity — at the crossroads between ecosystem functioning and environmental filters. In: J.G. Canadell, D. Pataki and L. Pitelka (eds),
Terrestrial Ecosystems in a Changing World
. Springer-Verlag, Berlin
Authors:J. Podani, C. Ricotta, J.G. Pausas, and D. Schmera
A new approach to the measurement of functional diversity based on two-state nominal traits is developed from the florula diversity concept of P. Juhász-Nagy. For evaluating functional diversity of an assemblage, first a traits by species matrix is compiled. Various information theory functions are used to examine structural properties in this matrix, including the frequency distribution of trait combinations. The method is illustrated by actual examples, the first from plant communities prone to fire in Spain, and the second from running water invertebrate assemblages in Hungary. The results suggest that of the various functions used the standardized joint entropy, termed combinatorial functional evenness supplies most meaningful results. In plant communities, high fire recurrence decreased combinatorial functional evenness, while this measure for freshwater assemblages was uncorrelated with stream width and negatively correlated with the degree of human impact. Stream width is negatively correlated with the number of manifested functional combinations. In both case studies, combinatorial functional evenness has an inverse relationship to species richness — i.e., fewer species have a larger chance to produce equiprobable functional combinations.
., Takács, T. (2005): Importance of functionaldiversity of
strains in phytoremediation.
Innovation and Utility in the Visegrad Fours. Proceedings of the International Scientific Conference
. 13–15 October 2005, Nyíregyháza, Hungary
Due to its nonlinearity with respect to species addition, some applications of the Rao quadratic diversity are meaningful only if they are first transformed into their equivalent number of species, which is the theoretical species richness of a maximally distinct and perfectly even community with the same diversity as the original community. In this paper, relaxing the requirement of maximal distinction among species, we generalize the notion of the equivalent number of species for the Rao diversity to partially distinct species. The biological meaning of this proposal is illustrated with one dedicated case study in sand dune communities in Italy. According to our results, the proposed approach proved appropriate for comparing the functional diversity of different plant communities with varying levels of environmental constraints.
Authors:Tünde Takács, I. Biró, A. Anton, and He Chaoxing
(AM) fungi are obligatory biotrophic symbionts living in the roots of most
terrestrial plants. AM fungi (AMF) have a positive effect on plant growth and
plant nutrition, especially under stress conditions. The aim of the present study was to observe
the relationship between the mycorrhizal dependency and nutrient uptake of host
plants and the rate of AMF colonization in a pot experiment. The degree of host
growth responses to AMF colonization is expressed as mycorrhizal dependency
(MD). The pot trial was set up with a
sterilized calcareous chernozem soil from Nagyhörcsök (Hungary) in a growth
chamber under controlled climatic conditions. Tomato
L.) plants were inoculated with
(BEG12) strains and a
AMF culture produced by
authors. The dry biomass production, the micro- and macronutrient
concentrations of the shoots and the parameters of the mycorrhizal infection
were determined. Each AM fungi species or isolate caused different and
distinct changes in host plant growth and nutrient uptake. The biomass
production of tomato increased significantly in the presence of AM symbiosis.
The mean values of MD, calculated from shoot dry matter, varied between 36% and
55%. Mycorrhizal inoculation improved the P, N and K uptake of tomato. The
highest values for root colonization, frequency of infection or arbuscular
richness were found in the root of tomato inoculated with the two
strains. The highest MD and nutrient contents appeared in the shoot
of tomato treated withour
strain, which may
indicate a stronger affinity (compatibility) between the symbiotic partners.
The results confirmed that the selected AMF strains are applicable in