Figure 12 - uploaded by Catherine Patricia Denise Borger
Content may be subject to copyright.
Salsola australis infected by the rust fungus, Uromyces salsolae, where the fungus is indicated by arrows (image from M. Jourdan, CSIRO Australia).
Similar publications
Digitaria insularis (L.) Fedde stands out for its resistance to glyphosate and this characteristic may have a relationship with structural alterations. In such context, this research aimed at the characterization of the foliar anatomical structure of two populations of D. insularis (glyphosate-resistant and glyphosate-susceptible biotypes) collecte...
Citations
Weed seeds are introduced to agronomic systems naturally or through human‐mediated seed dispersal, and introduced seeds have a high chance of being resistant to selective, in‐crop herbicides. However, colonisation (invasion) rates for a weed species are usually much lower than rates of seed dispersal. The current research investigated colonisation of a winter annual wheat cropping system in Western Australia by a range of winter or summer annual weed species. The weed seeds were sown (at 100 seeds/m2) directly before seeding the crop in 2016 and allowed to grow in the following 3 years of wheat. Selective herbicides were not applied, to simulate growth of weed populations if the initial seed had been resistant to herbicide. Bromus diandrus, Hordeum leporinum, Rumex hypogaeus, Sonchus oleraceus, Polygonum aviculare, Lolium rigidum, Citrullus amarus and Tribulus terrestris colonised the crop, while Dactyloctenium radulans, Chloris truncata and Salsola australis failed to establish over 3 years. The most successful weed was B. diandrus, with a plant density of 1,170/m2 by the third year and seed production of 67,740/m2. The high density of B. diandrus reduced wheat density by 76% in the third year and reduced average yield by 36%. Lolium rigidum reduced average yield by 11%, and the other weed species did not affect crop yield. Further research is required on the invasiveness of these species in other regions, but it is clear that the spread of B. diandrus to new areas or the introduction of resistant B. diandrus seeds via contaminated grain should be avoided.
Taxonomic opinions on Australian taxa of Salsola sensu stricto (Chenopodiaceae) are analyzed in a historical context. It is concluded, based on available evidence, that the genus is probably represented in Australia and adjacent regions of southeasternmost Asia by several (4–5 or more) native species, including the currently recognized S. australis R. Br. (also naturalized in southwestern North America and southern Africa) and supposedly related taxa (S. macrophylla R. Br., S. brachypteris Moq., S. australis var. strobilifera (Benth.) Domin, etc.); the presence of introduced Eurasian species cannot be excluded as well. The new name Salsola sabrinae Mosyakin is proposed for the native Australian taxon originally described as S. tragus L. subsp. grandiflora S. Rilke (non S. grandiflora Link ex Steud.) and reported mainly from northern tropical and subtropical regions of Australia (northern Western Australia, Northern Territory, and Queensland). It is emphasized that further dedicated morphological, molecular phylogenetic, and phylogeographic studies are needed, in comparison with Eurasian species, for achieving a reliable taxonomic scheme for Australian/Australasian species of Salsola and for clarifying issues of their immigration to and diversification in Australia.
