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A concern commonly raised in literature and in media relates to the declining proportions of students who enter and remain in the ‘science pipeline’, and whether many countries, including Australia and New Zealand, have enough budding scientists to fill research and industry positions in the coming years. In addition, there is concern that insufficient numbers of students continue in science to ensure an informed, scientifically literate citizenry. The aim of the research presented in this paper was to survey current Australian and New Zealand scientists to explore their reasons for choosing to study science. An online survey was conducted via a link to SurveyGizmo. The data presented are from 726 respondents who answered 22 forced-choice items and an open-ended question about the reasons they chose to study science. The quantitative data were analysed using t tests and analyses of variance followed by Duncan’s multiple range tests, and the qualitative data were analysed thematically. The quantitative data showed that the main reasons scientists reported choosing to study science were because they were interested in science and because they were good at science. Secondary school science classes and one particular science teacher also were found to be important factors. Of much less importance were the prestige of science and financial considerations. The qualitative data expanded on these findings and showed that passion for science and/or curiosity about the world were important factors and also highlighted the importance of recreational pursuits, such as camping when a child. In the words of one respondent, ‘People don’t go into science for the money and glory. It’s passion for knowledge and science that always attracted me to the field’.

Lathyrus cicera is a grain legume that is well adapted to grow in low rainfall regions. However, it contains a neurotoxin, 3-(-N-oxalyl)-l-2,3-diaminopropionic acid (ODAP), which can cause paralysis of the lower limbs, known as "lathyrism". An experiment was conducted to measure the nutrient content and ileal digestible amino acid content of a recently-released low ODAP Lathyrus variety chalus. Chemical analyses and total tract digestibility showed that the new Lathyrus variety chalus contained 0.9 g ODAP/kg, 265 g crude protein/kg and 13.5 MJ digestible energy/kg on an as-fed basis. The ileal digestible nutrient content of chalus was measured with six grower pigs (Large White×Landrace, 43 ± 0.3 kg) fitted with a simple T-piece cannula. The chalus contained 12.9, 1.4 and 5.4 g of apparent ileal digestible lysine, methionine and threonine, respectively/kg. Standardised ileal digestible amino acid content was calculated using published endogenous amino acid losses determined in 34-kg-growing pigs under a protein-free method. The chalus contained 14.3, 1.5 and 6.0 g of standardised ileal digestible lysine, methionine and threonine, respectively/kg.

• Background and Aims Root axes elongate slowly and swell radially under mechanical impedance. However, temporal and spatial changes to impeded root apices have only been described qualitatively. This paper aims (a) to quantify morphological changes to root apices and (b) assess whether these changes pre-dispose young root tissues to hypoxia. • Methods Lupin (Lupinus angustifolius) seedlings were grown into coarse sand that was pressurized through a diaphragm to generate mechanical impedance on growing root axes. In situ observations yielded growth rates and root response to hypoxia. Roots were then removed to assess morphology, cell lengths and local growth velocities. Oxygen uptake into excised segments was measured. • Key Results An applied pressure of 15 kPa slowed root extension by 75 % after 10–20 h while the same axes thickened by about 50 %. The most terminal 2–3 mm of axes did not respond morphologically to impedance, in spite of the slower flux of cells out of this region. The basal boundary of root extension encroached to within 4 mm of the apex (cf. 10 mm in unimpeded roots), while radial swelling extended 10 mm behind the apex in impeded roots. Oxygen demand by segments of these short, thick, impeded roots was significantly different from segments of unimpeded roots when the zones of elongation in each treatment were compared. Specifically, impeded roots consumed O2 faster and O2 consumption was more likely to be O2-limited over a substantial proportion of the elongation zone, making these roots more susceptible to O2 deficit. Impeded roots used more O2 per unit growth (measured as either unit of elongation or unit of volumetric expansion) than unimpeded roots. Extension of impeded roots in situ was O2-limited at sub-atmospheric O2 levels (21 % O2), while unimpeded roots were only limited below 11 % O2. • Conclusions The shift in the zone of extension towards the apex in impeded roots coincided with greater vulnerability to hypoxia even after soil was removed. Roots still encased in impeded soil are likely to suffer from marked O2 deficits.

Certain Lathyrus species have recently been found suitable as multipurpose legume crops in the southern Australian dryland regions, with a potential growing area of 100,000–300,000 ha. However, their use is limited by the presence, mainly in seeds, of 3-(- N -oxalyl)- l -2,3-diamino propionic acid (ODAP), an agent which causes lathyrism. Researchers at the Centre for Legumes in Mediterranean Agriculture (CLIMA) have selected a high yielding variety of Lathyrus cicera (cv. Chalus) which contains consistently low levels of ODAP. The aim of the present study was to assess the nutritional value and animal health aspects of L. cicera cv. Chalus grain as a feed for sheep. Comparisons were made against lupin grain ( Lupinus angustifolius ). Eighty individually penned Merino wethers (35±0.3 kg) were allocated to four treatment groups of 20 sheep. Following a 4-week adjustment period, sheep were fed ad libitum the following treatment diets for up to 13 weeks: 35% lathyrus, 35% lupin, 70% lathyrus and 70% lupin. The remainder of the diet was oaten hay and minerals. After 10 weeks on treatments, 14 sheep per group were killed for carcass assessment. The remaining six sheep were fed to maintenance ME requirements for 1 week followed by a 10-day faecal and urinary collection period. Analysis of the grains showed that lathyrus contained less protein (28% versus 36%), fat (0.7 versus 4.1%) and fibre (25% versus 36% NDF), but more starch (42% versus 1%) and anti-nutritional compounds (ODAP, tannins, trypsin inhibitor) than lupin. Essential amino acid composition was similar for the two grains, as were in sacco degradabilities of dry matter (DM) (84% versus 81%) and protein (92% versus 94%). The feeding experiment showed that lathyrus had a higher nutritional value than lupin in terms of voluntary feed intake, liveweight gain ( P P P =0.05). Wool growth reflected ME intake, and there was no independent effect of grain type ( P >0.05). Results from the balance study showed that ME concentration was the same for both grains (14 MJ/kg DM). Microbial crude protein (CP) synthesis, estimated from urinary purine derivatives, was significantly lower for lathyrus than lupin, and was lower at 70% grain inclusion than at 35% ( P There were no visible or biochemical signs of ill health (in-appetence, lethargy, shaking or instability) in any sheep fed lathyrus. Several sheep fed the 70% lupin diet had mild diarrhoea, and two were eventually removed from the experiment due to anorexia. Meat from sheep fed lupin tended to be yellower than that from those fed lathyrus ( P =0.05). Apart from this, there were no differences in meat quality due to grain type (e.g. redness, pH, taste or tenderness). In conclusion, compared with lupin grain, low ODAP L. cicera grain appears to be of high nutritional value for sheep, with no evidence of adverse effects on sheep health.

The use of two closely related species, Lathyrus cicera and L. sativus, as grain legumes for human and animal consumption, dates to the Neolithic period. Due to its tolerance to harsh environmental conditions L. sativus is still used widely for human food in Ethiopia and the Indian sub-continent, although cultivation has diminished in many other regions. The grain of both L. cicera and L. sativus contains a neurotoxin, 3-(-N-oxalyl)-L-2,3-diamino propionic acid (ODAP), which can cause a paralysis of the lower limbs (lathyrism). Due to the occurrence of lathyrism in humans recent plant breeding has produced cultivars with low ODAP concentrations. The susceptibility of animal species to lathyrism is poorly understood, although horses and young animals are more susceptible. Older published animal feeding studies are of limited use, since the presence and role of ODAP was unknown until the 1960s. More recent feeding studies indicate that low ODAP lines of L. cicera or L. sativus can be safely incorporated at inclusion rates up to 40, 30 and 70% of the diet of poultry, pigs and sheep, respectively, without growth reductions. The compositions of both L. cicera and L. sativus are similar to other commonly used feed grain legumes, respective protein contents are 25 and 27%. Antinutritional factors (ANFs), other than ODAP, are present in both L. cicera and L. sativus at concentrations similar to those found in other grain legumes; including trypsin inhibitors, chymotrypsin inhibitors, amylase inhibitors, lectins, tannins, phytate and oligosaccharides. The effect of ANFs in L. cicera and L. sativus on animal performance is not well understood and sometimes confounded with ODAP effects. Heating of grain will reduce levels of the proteinaceous ANFs and in some cases ODAP as well. Variation recorded in the germplasm of L. cicera and L. sativus has not been greatly utilised in plant breeding to lower levels of ANFs, with the exception of ODAP, leaving considerable potential for rapid improvement of cultivars. L. cicera and L. sativus are low production cost legumes

Summary In 1994, 407 L. sativus and 96 L. cicera lines were evaluated for phenology, seed yield and seed ODAP (a neurotoxin) concentration in the Mediterranean-type climate of south-western Australia. A selected number of lines from this study were grown at three sites in south-western Australia in 1995 and 1996, to examine genotype-environment interactions on seed yield and ODAP concentration in the seed of the two Lathyrus spp. Principal components analysis showed that L. sativus lines grown in 1995 and 1996 could be divided into two geographical origins: Indian sub-continent and Mediterranean/European. Those lines of Mediterranean/European origin were consistently higher yielding (both in 1994 and 1995/96), with much larger seeds and later phenology. In L. cicera seed yield was closely associated with greater mean seed weight and to a lesser extent with early phenology. The genotype-environment study indicated that higher yielding lines of both species generally responded to favourable environments; in the case of L. sativus the Mediterranean/European lines and for L. cicera the larger seeded, earlier phenology lines. For both species, genotype was the most important determinant of ODAP concentration and environment had less influence. Genotype-environment interactions had no effect on seed ODAP concentrations. In terms of seed yield, both species showed substantial potential in the environments tested. Further improvements in adaptation, seed yield and reduction in ODAP are possible in both species. Abbreviations: ODAP: 3-(-N-oxalyl)-L-2,3-diamino propionic acid

This study evaluated the types of gene action governing the inheritance of resistance to Phytophthora nicotianae necrosis in populations derived from two crosses involving two susceptible (Beldi and Nabeul II) and one resistant (CM334) cultivars of pepper (Capsicum annuum L.). Populations, composed of Pr, Ps, F(1) , F (2) , BC (1) Pr, and BC (1) Ps generations, were inoculated with six P. nicotianae isolates. Generation means analysis indicated that an additive-dominance model was appropriate for P. nicotianae isolates Pn (Ko1) , Pn (Ko2) and Pn (Kr1) , which showed low aggressiveness in the two crosses. For the more aggressive isolates Pn (Bz1) , Pn (Bz2) and Pn (Kr2) , epistasis was an integral component of resistance in the two crosses. The presence of epistasis in the resistance of pepper to P. nicotianae was dependent on the level of aggressiveness of the isolates. Selection in pepper with less aggressive isolates was efficient, but not with more aggressive isolates; on the other hand, selection with more aggressive isolates was more stable. The minimum number of genes controlling resistance was estimated at up to 2.71. In the majority of cases, the additive variance was significant and greater than the environmental and dominance variance.