Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.

2013 ◽  
Vol 41 (2) ◽  
pp. 265-298
Author(s):  
Peter Congdon

Constitutional systems of Westminster heritage are increasingly moving towards fixed-term parliaments to, amongst other things, prevent the Premier or Prime Minister opportunistically calling a ‘snap election’. Amongst the Australian states, qualified fixed-term parliaments currently exist in New South Wales, South Australia and Victoria. Queensland, Tasmania and Western Australia have also deliberated over whether to establish similar fixed-term parliaments. However, manner and form provisions in those states' constitutions entrench the Parliament's duration, Governor's Office and dissolution power. In Western Australia and Queensland, unlike Tasmania, such provisions are doubly entrenched. This article considers whether these entrenching provisions present legal obstacles to constitutional amendments establishing fixed-term parliaments in those two states. This involves examining whether laws fixing parliamentary terms fall within section 6 of the Australia Acts 1986 (Cth) & (UK). The article concludes by examining recent amendments to the Electoral Act 1907 (WA) designed to enable fixed election dates in Western Australia without requiring a successful referendum.


Author(s):  
D. W. Minter

Abstract A description is provided for Podospora excentrica. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (South America (Venezuela), Atlantic Ocean (Portugal (Madeira)), Australasia (Australia (New South Wales, South Australia, Victoria, Western Australia)), New Zealand, Europe (Belgium, Denmark, Germany, Ireland, Italy, Netherlands, Spain, Sweden, UK)).


Zootaxa ◽  
2020 ◽  
Vol 4832 (1) ◽  
pp. 1-75
Author(s):  
SVATOPLUK BÍLÝ ◽  
MARK HANLON

Taxonomic revision of the genus Bubastes Laporte & Gory, 1836. Thirteen new species are described: Bubastes barkeri sp. nov. (New South Wales, Queensland, Victoria), B. deserta sp. nov. (South Australia), B. dichroa sp. nov. (Western Australia), B. flavocaerulea sp. nov. (New South Wales, Queensland), B. hasenpuschi sp. nov. (Queensland), B. iridiventris sp. nov. (Western Australia), B. iris sp. nov. (Western Australia), B. macmillani sp. nov. (Western Australia), B. magnifica sp. nov. (Queensland, New South Wales), B. michaelpowelli sp. nov. (Western Australia), B. pilbarensis sp. nov. (Western Australia), B. remota sp. nov. (Northern Territory) and B. viridiaurea sp. nov. (Western Australia). The following seventeen new synonyms are proposed: Bubastes thomsoni Obenberger, 1928, syn. nov. = B. australasiae Obenberger, 1922, B. olivina Obenberger, 1920, syn. nov. = Neraldus bostrychoides Théry 1910, B. boisduvali Obenberger, 1941, syn. nov. = B. erbeni Obenberger, 1941, B. borealis Obenberger, 1941, syn. nov. = B. globicollis Thomson, 1879, B. laticollis Blackburn, 1888, syn. nov. = B. globicollis Thomson, 1879, B. simillima Obenberger, 1922, syn. nov. = B. globicollis Thomson, 1879, B. obscura Obenberger, 1922, syn. nov. = B. inconsistans Thomson, 1879, B. septentrionalis Obenberger, 1941, syn. nov. = B. inconsistans Thomson, 1879, B. viridicupraea Obenberger, 1922, syn. nov. = B. inconsistans Thomson, 1879, B. blackburni Obenberger, 1941, syn. nov. = B. kirbyi Obenberger, 1928, B. chapmani Obenberger, 1941, syn. nov. = B. kirbyi Obenberger, 1928, B. aenea Obenberger, 1922, syn. nov. = B. niveiventris Obenberger, 1922, B. saundersi Obenberger, 1928, syn. nov. = B. odewahni Obenberger, 1928, B. occidentalis Blackburn, 1891, syn. nov. = B. sphaenoida Laporte & Gory, 1836, B. persplendens Obenberger, 1920, syn. nov. = B. sphaenoida Laporte & Gory, 1836, B. splendens Blackburn, 1891, syn. nov. = B. sphaenoida Laporte & Gory, 1836 and B. strandi Obenberger, 1920, syn. nov. = B. suturalis Carter, 1915. Neotype is designated and redescribed for Bubastes cylindrica W. J. Macleay, 1888 and lectotypes are designated for Bubastes thomsoni Obenberger, 1928 and B. leai Carter, 1924. Morphological characters of the genus are presented and all species are illustrated (incl. historical types) and a key is provided for all species of the genus. 


1975 ◽  
Vol 26 (4) ◽  
pp. 647 ◽  
Author(s):  
K Helms

Seedlings of six cultivars of Trifolium subterraneum were tested during germination for resistance to Kabatiella caulivora, and gave results comparable with those obtained with seedlings inoculated by spraying at 1–4 weeks after sowing. Advantages of the method were that a large number of seedlings could be screened under uniform conditions with the minimum of time and space. Within the more susceptible group of cultivars, Woogenellup and Bacchus Marsh were usually more susceptible than Yarloop and Mt. Barker; these in turn were more susceptible than Clare, and Clare more susceptible than Daliak. For all cultivars except the highly resistant cultivar, Daliak, there was a correlation between the rate of trifoliolate leaf production and susceptibility to the disease, the most susceptible being those with most leaves expanded at the time of inoculation and with most leaves present at the time of harvest. Physiologic specialization in isolates of the pathogen from different parts of Australia was demonstrated. In general, one isolate from South Australia was more pathogenic than a group of isolates from South Australia, Victoria and Western Australia; these in turn were more pathogenic than one isolate from New South Wales, which was somewhat atypical in culture, and one from Victoria which was markedly atypical in culture.


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