Cross-amplification and characterization of polymorphic microsatellite markers from Acacia (Senegalia) mellifera and Acacia brevispica to Acacia senegal (L.) Willd.

Seven polymorphic microsatellite markers isolated from Acacia brevispica and Acacia mellifera were successfully cross-amplified in Acacia senegal. The loci were surveyed for polymorphism using 30 samples. Allelic diversity ranged from 4 (Ame02, Ab06 and Ab18) to 13 (Ab26) per locus. The expected heterozygosity (HE) ranged from 0.543 (Ame02) to 0.868 (Ab26) while observed heterozygosity (HO) ranged from 0.516 (Ame05) to 0.800 (Ame03). Cross amplification of these loci represents a potential source of co-dominant marker and will be useful in the study of genetic diversity, structure, gene flow and breeding systems of this important Acacia species

Mobilisation of potassium and phosphorus from iron ore by ectomycorrhizal fungi

Mutualistic roles of ectomycorrhizal (ECM) fungi have been linked to their ability to produce organic acids that aid in the dissolution of insoluble minerals in the rhizosphere. This ability of ECM fungi was utilised to investigate their potential participation in the mobilisation of nutrients such as phosphorus (P) and potassium (K) from a typical insoluble ore-iron ore. In vitro pure cultures of four different ECM fungi; Pisolithus tinctorius, Paxillus involutus, Phialocephala fortini, and Suillus tomentosus were screened for their ability to mobilise P and K from two types of non-exportable Sishen iron ore. When present in iron ore, these elements are deleterious and reduce the commercial values of the ore. Experiment was set up with different treatments that included two ore types (KGT and SK) and five particle sizes of each ore type. Results indicated the potential of the four fungi to mobilise P and K from the two iron ore types though at different levels. Ore type, particle size, organic acid production and attachment of the fungi to the iron ore were all found to play important roles in the mobilisation of nutrients from these ores. © 2010 Springer Science+Business Media B.V.Articl

Profitability of sheep grazing in young conifer plantations of British Columbia, Canada

PosterIn British Columbia (BC), sheep grazing, as a silvopastoral system, is occasionally used as a biological weed control method in young conifer plantations. As it is a relatively new method in BC, there is presently a lack of information about the profitability of the practice. For instance, there is no scientific data about the gain in profitability as a function of the number of grazing treatments applied. What is known is that at least two grazing treatments in a given year or one treatment per year for two or more consecutive years are required to effectively deplete fireweed (Epilobium angustifolium) root reserves, the predominant herbaceous competing vegetation. Our main objective was to analyze the profitability of sheep grazing for herbaceous vegetation control in young conifer plantations. The profitability was tested under two grazing treatments: a single sheep grazing treatment and two sheep grazing treatments applied over two years. Since comparing the profitability of treatments requires financial data on all the rotational period and is often not available, we used a simple approach that can determine profitability with little detailed information. Using this approach, grazing treatments could be compared in terms of time gain. Assuming that a grazing treatment shortens the rotational period by “X” years allowing a certain time gain, the additional relative cost can be compared with the break-even additional relative cost. Preliminary results indicated that two grazing treatments have the potential to decrease the time to declare a stand free-growing compared to one grazing treatment. Thus, this time gain, at a young age (e.g., 10 yr) could potentially result in a time gain at the end of the rotational period (e.g., 80 yr). This presentation will examinate the profitability of sheep grazing with more detail and show how this method has the potential to shortened the rotational period