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The Australian tomato Solanum orbiculatum ssp. orbiculatum is an edible bush tomato endemic to the more arid areas of Western Australia, South Australia, and the Northern Territory. Breeding system data indicate that the plants are potentially self-compatible but are unable to carry out spontaneous autogamy or agamospermy. The flower is protogynous, as the stigma become receptive to pollen germination while still in bud condition and the anthers do not release pollen immediately after anthesis. This arrangement is a simple and common way to avoid too much self-pollination, favours cross pollination, and would allow forced bud pollination for hybrid development. The floral structure and morphology of this species can also encourage cross pollination, as the stigma is mostly exserted above the anther's tips. In an attempt to examine the hypothesis of a positive correlation between pollen grain size and style length, we found a statistically significant difference between the pollen size of the long-styled and short-styled flowers. Pollen in vitro germination and viability tests have been optimised to facilitate effective breeding work on this species. A modified Brewbake and Kwack (BK) medium supplemented with 20% sucrose and 2.5% PEG 4000 has been found to be the most efficient media components for the in vitro germination of viable pollen grains. Alternatively, Alexander's and acetocarmine (1%) stains have shown the highest positive correlation with the in vitro pollen germination test and, therefore, can be used as quick tests for checking pollen viability. Moreover, pollen grains stored for three months under 4 °C and dry conditions can be used efficiently to effect fertilisation in breeding programs, as it can maintain more than 50% of the original viability. This study will contribute to understanding the evolution and systematic relationships of species and for founding effective conservation programs. Furthermore, understanding the reproductive biology of this species is also of interest because of its potential for tomato breeding. [ABSTRACT FROM AUTHOR]

Tedera is a forage legume that can provide out-of-season green feed in Mediterranean climates. To date, growers have had no comprehensive soil nutrition guidelines to optimise tedera production. We undertook field and glasshouse studies to understand tedera's macronutrient requirements. Three field experiments were sown with tedera cv. Lanza® at Cunderdin, Dandaragan and Three Springs in Western Australia. These experiments evaluated seven levels of phosphorus (P) (0–30 kg ha−1) and potassium (K) (0–80 kg ha−1) and two combined treatments with P and K. Glasshouse pot experiments were conducted using tedera cultivars Lanza® and Palma and lucerne cultivar SARDI Grazer. Ten concentrations of added P (0–256 mg kg−1), ten of K (0–256 mg kg−1) and ten of sulphur (S) (0–16 mg kg−1) were tested. There was no significant response to P or K in field soils at Cunderdin or Three Springs. There was no response to K at Dandaragan, but P produced a positive response in the July and October growing season cuts. In the glasshouse, tedera cultivars reached peak productivity at lower soil Colwell P (7.6 to 12 mg kg−1) than lucerne (22 mg kg−1). Lanza® had a moderate biomass response, and Palma did not show a significant response to Colwell K (0.8 to 142 mg kg−1) or soil S (1.3 to 12.5 mg kg−1). Nodulation was greatly reduced at the extremes in P and K treatments. For the first time, these field and glasshouse results have allowed us to establish guidelines for optimal soil nutrition for tedera that growers can use to benchmark the soil or shoot nutrient status of their tedera pastures and assess the economic benefit of correcting deficiencies. [ABSTRACT FROM AUTHOR]

Seed germination and seedling growth are two essential early determinants of subsequent crop yield and quality. A high germination percentage of industrial hemp (Cannabis sativa L.) seed is required to import into Australia. The viability of hemp seed can decline rapidly depending on storage and other factors; hence, the quality of imported seed is not always reliable. Here, we aimed to investigate germination and early seedling growth responses of 14 industrial hemp varieties after being imported from various countries. Germination trials were conducted with 100 seeds of 14 varieties using a soil-less Petri dish assay and a compost growth medium under glasshouse conditions. We also assessed the effect of seed pre-treatments such as gibberellic acid (500 and 1000 mg·L−1), chlorine dioxide (500 and 1000 mg·L−1) and cold temperature (4 °C for 72 h) using 300 seeds of each of the three selected varieties in compost growth medium. Hemp varieties imported from China had higher germination and better seedling growth indices than those imported from Europe. All seed pre-treatments were associated with a decreasing trend in germination, but a positive effect on early growth responses was observed. Our findings indicate that the hemp variety Han FNQ performed better than many other varieties did regarding seed germination and seedling growth. Hemp seeds sanitising with 500 mg·L−1 of chlorine dioxide might improve the germination and early growth of seedlings. [ABSTRACT FROM AUTHOR]