Exploiting genotype × management interactions to increase rainfed crop production: a case study from south-eastern Australia.

Crop yield must increase to keep pace with growing global demand. Past increases in crop production have rarely been attributable to an individual innovation but have occurred when technologies and practices combine to form improved farming systems. Inevitably this has involved synergy between genotypic and management improvements. We argue that research focused on developing synergistic systems that overcome clear production constraints will accelerate increases in yield. This offers the opportunity to better focus and multiply the impact of discipline-focused research. Here we use the rainfed grain production systems of south-eastern Australia as a case study of how transformational change in water productivity can be achieved with research focused on genotype × management synergies. In this region, rainfall is low and variable and has declined since 1990. Despite this, growers have maintained yields by implementing synergistic systems combining innovations in (i) soil water conservation, (ii) crop diversity, (iii) earlier sowing, and (iv) matching nitrogen fertilizer to water-limited demand. Further increases are emerging from synergies between genetic improvements to deliver flowering time stability, adjusted sowing times, and potential dual-purpose use. Collaboration between agronomists, physiologists, and crop breeders has led to development of commercial genotypes with stable flowering time that are in early phases of testing and adoption.

Expression of ABA synthesis and metabolism genes under different irrigation strategies and atmospheric VPDs is associated with stomatal conductance in grapevine (Vitis vinifera L. cv Cabernet Sauvignon).

The influence of different levels of irrigation and of variation in atmospheric vapour pressure deficit (VPD) on the synthesis, metabolism, and transport of abscisic acid (ABA) and the effects on stomatal conductance were examined in field-grown Cabernet Sauvignon grapevines. Xylem sap, leaf tissue, and root tissue were collected at regular intervals during two seasons in conjunction with measurements of leaf water potential (Ψleaf) and stomatal conductance (gs). The different irrigation levels significantly altered the Ψleaf and gs of the vines across both seasons. ABA abundance in the xylem sap was correlated with gs. The expression of genes associated with ABA synthesis, NCED1 and NCED2, was higher in the roots than in the leaves throughout and highest in the roots in mid January, a time when soil moisture declined and VPD was at its highest. Their expression in roots was also inversely related to the levels of irrigation and correlated with ABA abundance in the roots, xylem sap, and leaves. Three genes encoding ABA 8'-hydroxylases were isolated and their identities confirmed by expression in yeast cells. The expression of one of these, Hyd1, was elevated in leaves when VPD was below 2.0-2.5 kPa and minimal at higher VPD levels. The results provide evidence that ABA plays an important role in linking stomatal response to soil moisture status and that changes in ABA catabolism at or near its site of action allows optimization of gas exchange to current environmental conditions.

Residency research requirements and the CanMEDS-FM scholar role: perspectives of residents and recent graduates.

OBJECTIVE: To explore the perspectives of family medicine residents and recent family medicine graduates on the research requirements and other CanMEDS scholar competencies in family practice residency training. DESIGN: Semistructured focus groups and individual interviews. SETTING: Family practice residency program at the University of British Columbia in Vancouver. PARTICIPANTS: Convenience sample of 6 second-year family medicine residents and 6 family physicians who had graduated from the University of British Columbia family practice residency program within the previous 5 years. METHODS: Two focus groups with residents and individual interviews with each of the 6 recently graduated physicians. All interviews were audiotaped, transcribed, and analyzed for thematic content. MAIN FINDINGS: Three themes emerged that captured key issues around research requirements in family practice training: 1) relating the scholar role to family practice, 2) realizing that scholarship is more than simply the creation or discovery of new knowledge, and 3) addressing barriers to integrating research into a clinical career. CONCLUSION: Creation of new medical knowledge is just one aspect of the CanMEDS scholar role, and more attention should be paid to the other competencies, including teaching, enhancing professional activities through ongoing learning, critical appraisal of information, and learning how to better contribute to the dissemination, application, and translation of knowledge. Research is valued as important, but opinions still vary as to whether a formal research study should be required in residency. Completion of residency research projects is viewed as somewhat rewarding, but with an equivocal effect on future research intentions.

Awareness of do-not-resuscitate orders: what do patients know and want?

OBJECTIVE: To assess outpatient understanding of and previous experiences with do-not-resuscitate (DNR) orders and to gauge patient preferences with respect to DNR discussions. DESIGN: Cross-sectional, self-administered survey. SETTING: Four urban primary care physician offices in Vancouver, BC. PARTICIPANTS: A total of 429 consecutive patients 40 years of age and older presenting for routine primary care between March and May 2009. MAIN OUTCOME MEASURES: Awareness of, knowledge about, and experiences with DNR decisions; when, where, and with whom patients wished to discuss DNR decisions; and differences in responses by sex, age, and ethnicity, assessed using χ² tests of independence. RESULTS: The response rate was 90%, with 386 of 429 patients completing the surveys. Most (84%) respondents had heard of the terms do not resuscitate or DNR. Eighty-six percent chose family physicians as among the people they most preferred to discuss DNR decisions with; 56% believed that initial DNR discussions should occur while they were healthy; and 46% thought the discussion should take place in the office setting. Of those who were previously aware of DNR orders, 70% had contemplated DNR for their own care, with those older than 60 years more likely to have done so (P = .02); however, only 8% of respondents who were aware of DNR orders had ever discussed the subject with a health care provider. Few patients (16%) found this topic stressful. CONCLUSION: Most respondents were well informed about the meaning of DNR, thought DNR discussions should take place when patients were still healthy, preferred to discuss DNR decisions with family physicians, and did not consider the topic stressful. Yet few respondents reported having had a conversation about DNR decisions with any health care provider. Disparity between patient preferences and experiences suggests that family physicians can and should initiate DNR discussions with younger and healthier patients.

Irrigated Shiraz vines (Vitis vinifera) upregulate gas exchange and maintain berry growth in response to short spells of high maximum temperature in the field.

We tested the hypotheses that (i) a short period of high maximum temperature disrupts gas exchange and arrests berry growth and sugar accumulation in irrigated Shiraz vines (Vitis vinifera L.), and (ii) the magnitude of these effects depend on the phenological window when stress occur. Using a system combining passive heating (greenhouse effect) and active cooling (fans) to control daytime temperature, we compared vines heated to a nominal maximum of 40°C for three consecutive days and untreated controls. Maximum air temperature in heated treatments was 7.3°C (2006-07) and 6.5°C (2007-08) above ambient. Heat episodes were aligned with the beginning of a weekly irrigation cycle and applied in one of four phenological windows, namely post-fruit set, pre-veraison, veraison and pre-harvest. Heating systems did not affect relative humidity, hence vapour pressure deficit (VPD) was increased in the heated treatments and tracked the daily cycle of temperature. Heat did not affect the dynamics of berry growth and sugar accumulation, except for a 16% reduction in berry size and sugar content in vines heated shortly after fruit set in 2006-07. Vines upregulated stomatal conductance and gas exchange in response to heat. Stomatal conductance, photosynthesis and transpiration at a common VPD were consistently higher in heated vines than in controls. We suggest that stomatal behaviour previously described as part of Shiraz anisohydric syndrome may be adaptive in terms of heat tolerance at the expense of short-term transpiration efficiency.