Occurrence of Phytophthora macrochlamydospora in New South Wales and its pathogenicity to some legume species
Herbarium material of a Phytophthora species recorded on soybeans in New South Wales during 1985 was re-examined and identified as P. macrochlamydospora Irwin. A range of soybean cultivars and some legumes that occur naturally on the north coast region of New South Wales were tested for their reaction to artificial inoculation with P. macrochlamydospora. On soybeans, variable reactions were recorded indicating resistance in some cultivars. A number of the legumes were susceptible to infection. P. macrochlamydospora appears to be endemic on the north coast of New South Wales but has not been recorded from other areas of New South Wales.
Arkoola nigra gen. et sp.nov. (Venturiaceae) causing black leaf blight of soybean in Australia.
Arkoola nigra gen. et sp.nov. (Venturiaceae) is described, causing black leaf blight of soybean in New South Wales. It forms a superficial black mycelial web on infected plants and penetrates the host from large appressoria, causing severe spotting and blighting of leaves, stems and pods. Ascocarps develop on dead fallen leaves and on detached leaves inoculated in culture. They are black, setose and contain large cylindrical bitunicate asci with pale greenish two-celled ascospores and abundant pseudoparaphyses. The connexion between ascosporic and mycelial states has been proved by pure culture studies, and plant inoculations reproduce the disease symptoms. It is transmitted to a limited extent with seed. A range of native legumes were infected in artificial inoculation tests. The relationship of A. nigra to other genera of Venturiaceae, its possible origin, host range and associated matters are discussed.
Characterization of Aqueous Dispersions and Gels Made of Sodium Caseinate and Basil Seed Gum: Phase Behavior, Rheology, and Microstructure
The interactions between sodium caseinate (NaCas) and basil seed gum (BSG) in the presence of calcium chloride (CaCl 2 ) were investigated. The phase behavior of the mixed aqueous dispersions and their gels revealed a homogeneous mixture, obtained at the higher concentrations of both CaCl 2 and BSG. The Herschel-Bulkley model sufficiently fitted the flow behavior of the mixture solution data. Apparent viscosity increased significantly ( p  < 0.05) by increasing the concentration of BSG, where the addition of CaCl 2 had no significant effect on the viscosity of the samples ( p  > 0.05). Furthermore, there was an increase in thixotropy due to the higher concentrations of BSG and CaCl 2 . Based on the frequency sweep test, at the low frequencies, a more gel-like behavior was observed in the case of the higher concentrations of either BSG or CaCl 2 . The rheological and SEM data suggested that the stronger structure of NaCas-BSG gel in the presence of the higher concentrations of CaCl 2 was related to the induction of complex formation between the two biopolymers.