Comparison of osmotic adjustment, leaf proline concentration, canopy temperature and root depth for yield of juncea canola under terminal drought

Abstract

Two glasshouse and two field experiments were conducted in 2013 and 2014 to compare the relative importance of four physiological traits: osmotic adjustment (OA), leaf proline concentration, canopy temperature depression (CTD) and root depth on drought performance of canola quality B. juncea (juncea canola). Glasshouse experiments were conducted at The University of Melbourne, Parkville, and field experiments were conducted at Horsham, Victoria. The experiments used juncea canola hybrids and their parental lines and were laid out in a randomised complete block design with three replications. The glasshouse experiments consisted of two treatments, well watered and water deficit from first open flower to maturity, whereas the field experiments were sown at a site that received 266 mm annual rainfall in 2014. In the glasshouse, canopy temperature depression was the only trait to show a positive and consistent association with drought performance of juncea canola. Cooler canopy temperature was also associated with improved yield in field experiments. Root depth was positively correlated with CTD in 2014 in glasshouse,whereas no correlation of root depth with OA and leaf proline was observed. The results indicated that CTD was the only reliable trait among those tested to screen juncea canola for drought tolerance. Root depth of juncea canola hybrids was a constitutive trait and probably was a result of hybrid vigour.

Use of Thermography to Evaluate Alternative Crops for Off-Season in the Cerrado Region

“…An increase in canopy temperature strongly influenced the grain yield and plant biomass of the four studied crops. Similar results were obtained for other crops, such as rice and canola [35,61]. The highest water regimes (535 mm and 410 m), in general, showed the lowest canopy temperature for the studied crops, and presented the highest plant biomass and grain yield.…”

Drought‐induced osmotic adjustment and changes in carbohydrate distribution in leaves and flowers of cotton (Gossypium hirsutum L.)

“…Identification of physiological traits conferring tolerance to drought, including carbohydrate distribution and osmotic adjustment, and the use of them as selection criteria into biotechnology programs would serve as new tools for plant improvement to increase yield stability (Tuberosa & Salvi, ). Although the importance of osmotic adjustment and carbohydrate distribution in plants under drought stress has been widely acknowledged (Jones & Turner, ; Pandey, Burton, Salisbury, & Nicolas, ; Timpa et al., ), the deployment of these strategies in the cotton flower and it's associated subtending leaf has not been fully investigated. It was hypothesized that (a) higher accumulation of compatible solutes will occur in drought‐stressed cotton plants as a result of osmoregulation, and subtending leaves will have lower osmotic potential than flowers as a protective mechanism; and (b) carbohydrate balance within flowers and subtending leaves will vary based on water availability, which will directly influence growth of the organ assessed.…”