Growth and Physiological Responses of Quinoa to Drought and Temperature Stress

Quinoa (Chenopodium quinoa Willd.), traditionally called the mother of grains, has the potential to grow under high temperatures and drought, tolerating levels regarded as stresses in other crop species. A pot experiment was conducted in a climate chamber to investigate the potential of quinoa tolerance to increasing drought and temperature. Quinoa plants were subjected to three irrigation and two temperature regimes. At low temperature, the day/night climate chamber temperature was maintained at 18/8 °C and 25/20 °C for high temperature throughout the treatment period. The irrigation treatments were full irrigation (FI), deficit irrigation (DI) and alternate root‐zone drying (ARD). FI plants were irrigated daily to the level of the pot's water‐holding capacity. In DI and ARD, 70 % water of FI was applied either to the whole pot or to one side of the pot alternating, respectively. The results indicated that plant height and shoot dry weight significantly decreased by ARD and DI compared to FI treatment both at low and at high temperatures. However, plants in ARD treatment showed significantly higher plant height and shoot dry weight compared to DI especially at higher temperature, which is linked to increased xylem ion content. Higher quinoa plant growth in ARD was associated with increase in water‐use efficiency (WUE_i) due to higher abscisic acid concentration and higher nutrient contents compared to DI. From results, it can be concluded that quinoa plant growth is favoured by high temperature (25/20 °C) and ARD is an effective irrigation strategy to increase WUE in drought prone areas.     

不同粒径生物质炭对石林石漠化农地土壤氮磷流失的影响

研究旨在探究生物质炭粒径变化及施用比例对石林石漠化农地土壤氮磷流失的影响,为筛选制备适宜石林石漠化地区的土壤调理剂和缓释肥料栽体提供理论依据.选取粒径为0～1 mm(粉末炭)的稻壳炭、橡胶木炭、竹炭和粒径1～3 mm(颗粒炭)的竹炭,每种生物质炭设置3个处理梯度(按炭土比1％、3％、5％添加),外加无生物质炭添加对照C...     

Phosphorus Fertilization and Fungal Inoculations Affected the Physiology,Phosphorus Uptake and Growth of Spring Wheat Under Rainfed Conditions on the Canadian Prairies

Some fungal species have been shown to improve plant growth under drought conditions and to increase plant phosphorus (P) uptake from the soil. How moisture limitation, P availability and fungal inoculation interact to affect plant physiology and growth is, however, poorly understood. Here, we studied the combined effects of fungal (arbuscular mycorrhizal fungi (AMF) or Penicillium spp.) inoculations and phosphorus (P) fertilization (0, 45 and 90 kg ha^?1) on the net rate of photosynthesis, water‐use efficiency, P uptake and growth of spring wheat (Triticum aestivum var. Superb) under field conditions at two locations (Castor and Vegreville) in Alberta, Canada. Both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AMF inoculation had a greater positive effect on the rate of photosynthesis than Penicillium inoculation. The AMF inoculation increased the instantaneous water‐use efficiency (WUEi) of plants at Castor, but not at Vegreville. Leaf carbon isotope discrimination (CID, Δ¹³C) increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AMF inoculation showing the largest effects. The interaction between P addition and fungal inoculation was significant for stem P concentration in Vegreville. Both fungal inoculation and P application increased the leaf area index (LAI), biomass production and grain yield at both locations. Under the same P level, AMF inoculation had a greater positive effect on LAI, biomass production and grain yields than Penicillium inoculation. Morphological characters such as spike length and kernels/spike were also improved by fungal inoculation and P application at both locations. We conclude that the studied sites were deficient in P availability, and both fungal inoculation and P application improved P uptake and crop productivity, while the effect of fungal inoculation on water‐use efficiency was site specific.     

Vitamin C,B5, and B6 contents of segregating potato populations detected by GC‐MS: a method facilitating breeding potatoes with improved vitamin content

Vitamin C, B5, and B6 contents of potato tubers were measured by gas chromatography‐mass spectrometry (GC‐MS). Two diploid potato populations derived from two different crosses were analyzed. Plants were grown at two locations under different environmental conditions. Measurements of vitamin content of tubers showed high variation in both populations. A weak correlation was found between the vitamin concentrations of tubers harvested at the two locations. Correlations between the mean values of vitamins in field‐grown tubers and in different tissues derived from in vitro or greenhouse‐grown potato plants were also determined. A very high correlation between the vitamin content of field‐ and greenhouse‐grown tubers, and between field‐grown tubers and sink leaves of greenhouse‐grown plants was detected. This finding can facilitate breeding by preselection of individuals with improved vitamin content under greenhouse conditions at their early developmental stage.