Mapping soil salinity and pH across an estuarine and alluvial plain using electromagnetic and digital elevation model data

Increasing pressures from agriculture and urbanization have resulted in drainage of many floodplains along the eastern Australian coastline, which are underlain by sulphidic sediments, to lower water tables and reduce soil salinity. This leads to oxidation of the sediments with a rapid decline in pH and an increase in salinity. Accurately mapping soil salinity and pH in coastal acid sulphate soil (CASS) landscapes is therefore important. One required map is the extent of highly acidic (i.e. pH < 4.5) areas, so that the application of alkaline amendments (e.g. lime) to neutralize the acid produced can be specifically targeted to the variation in pH. One approach is to use digital soil mapping (DSM) using ancillary information, such as an EM38, digital elevation models (DEM – elevation) and trend surface parameters (east and north). We used an EM38 in the horizontal (EM38h) and vertical (EM38v) modes together with elevation data to develop multiple linear regressions (MLR) for predicting EC_1:5 and pH. For pH, best results were achieved when the EM38 EC_a data were log‐transformed. By comparing MLR models using REML analysis, we found that using all ancillary data was optimal for mapping EC_1:5, whereas the best predictors for pH were north, log‐EM38v and elevation. Using residual maximum likelihood (REML), the final EC_1:5 and pH maps produced were consistent with previously defined soil landscape units, particularly CASS. The DSM approach used is amenable for mapping saline soils and identifying areas requiring the application of lime to manage acidic soil conditions in CASS landscape.     

水杨酸对盐胁迫下豇豆幼苗生长发育的影响

在300 mmol/L Na Cl胁迫条件下,研究了水杨酸对豇豆[Vigna unguiculata(L.)Walp]幼苗生长发育的影响。结果表明,经水杨酸处理的豇豆幼苗株高、茎粗明显提高,促进了幼苗的形态构建。并且幼苗的超氧化物歧化酶和过氧化物酶活性均显著高于对照,丙二醛含量和电解质渗透率显著或明显降低;水杨酸在适宜的施用浓度范围内能够缓解豇豆幼苗的盐害症状,提高抗盐能力,对豇豆幼苗的生长有一定的促进作用,当水杨酸的处理浓度为100~150 mg/L时,作用效果最明显。     

钼蓝比色法测定笃斯越橘成熟果实中还原型抗坏血酸含量及体系优化

以笃斯越橘(Vaccinium uliginosum)成熟果实为试材,以钼蓝比色法测定笃斯越橘果实还原型抗坏血酸(Reduced ascorbic acid,As A)含量进行条件优化。结果表明,3%偏磷酸-乙酸用量为100μL、5%硫酸和5%钼酸铵用量均为200μL、以去离子水补充至1 500μL,30℃干热恒温浴显色40 min,取出室温下放置1 h后,在700 nm下测定,所得数据稳定,准确性适合用于笃斯越橘果实As A含量的测定;测得含量为(40.20±6.23)mg/100 g FW。     

Nanostructured liquid crystalline particle assisted delivery of 2,4-dichlorophenoxyacetic acid to weeds,crops and model plants

Routine agricultural practices are heavily dependent on the use of surfactants, many of which are toxic to humans and detrimental to the environment. In proof of concept work we have previously shown the potential of nanostructured liquid crystalline particles (NLCP) to safely interact with plant leaf cuticular surfaces with minimal impact on epicuticular waxes. Here we demonstrate the use of NLCP to effectively deliver the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) to plant leaves in laboratory and field studies. In the laboratory, the physiological stress responses of lupin, Lupinus angustifolius (L.) (Fabaceae) towards NLCP spray applications were shown to be much reduced in comparison with application of two common surfactants. Phytotoxicity assays of 2,4-D loaded NLCP were used to validate the herbicidal effects on Arabidopsis thaliana (L.) Heynth. (Brassicaceae) and established a similarity with that of surfactant assisted 2,4-D delivery when tested at a concentration of 0.1%. Field trials were conducted to test the efficacy of NLCP-assisted delivery of 2,4-D in comparison with commercial surfactants for the control of the invasive weed wild radish, Raphanus raphanistrum (L.) (Brassicaceae), in wheat, Triticum aestivum (L.) (Poaceae) crop fields. Compared against Estercide 800, a commercially available 2,4-D formulation, NLCP assisted delivery of 2,4-D was effective at low concentrations of 0.03% and 0.06%. The crop yield remained similar for all the tested concentrations and formulations of 2,4-D loaded NLCP and Estercide 800. This is the first report to directly show that, as an alternative to conventional methods, NLCP can be used under both laboratory and field conditions to successfully delivery an agrochemical.     

Contribution of incident solar radiation on leaves and pods to soybean seed weight and composition

The weight and composition of soybean seeds (Glycine Max L. Merrill) depend on changes in carbon and nitrogen assimilate supply during grain filling. Soybean pods and seeds are green, evidencing their capacity to capture light. However, the current physiological knowledge does not consider any effect of incident solar radiation reaching the pods on seed weight and composition. The objective of this work was to investigate the response of seed weight and composition to changes in assimilate supply from leaves, to the incident solar radiation reaching the pods and to the combination of both, changes in assimilate supply from the leaves and incident solar radiation on pods of soybean plants. Field experiments were performed during two growing seasons at Balcarce, Argentina. Treatments modified the amount of assimilates supplied by the leaves (plant shading, defoliation), the solar radiation reaching the pods (pod shading) or both (defoliation and pod shading) during seed filling. Plant shading and defoliation reduced seed weight, oil concentration and oil and protein content and increased the concentration of saturated and poli-unsaturated fatty acids while reduced oleic acid percentage. Pod shading increased the concentration of stearic acid and reduced the concentration of linolenic acid. When pods were shaded on defoliated plants, seed weight and oil and protein content decreased while fatty acid composition was similar to values obtained under defoliation treatment. Based on these results, a conceptual model that considers photoheterotrophic nature of reproductive structures of soybean is proposed. Seed weight, oil and protein content and oil fatty acid composition depended on assimilate availability for the seeds. The response of oil and protein content to assimilate supply depended on whether leaves were present or not. The effect of solar radiation incident on pods depended on the amount of assimilates available for the seeds: (i) when carbon allocated was low (defoliation treatments), pods contributed to seed carbon economy but solar radiation incident on them did not affect fatty acid composition; (ii) when carbon allocated to the seeds was high (intact plants), contribution of pods to seed carbon economy was not significant, but the amount of solar radiation incident on pods produced significant changes in fatty acid composition.     

向日葵副产物的营养特性及在反刍动物中的应用

饲料资源缺乏一直以来都是制约中国畜牧业发展的主要因素。从长远看，常规饲料已不能维持中国畜牧业的可持续发展，开发新的饲料资源是解决饲料不足的重要途径之一。向日葵副产物营养价值较高、来源广、价格低，是一种非常具有开发价值的新型饲料。向日葵副产物包括向日葵饼粕、向日葵盘、向日葵秸秆及葵花籽壳：向日葵饼粕蛋白质含量高、纤维含量低，是一种优质的植物蛋白来源，可以提高奶牛乳汁的营养价值、促进肉牛生长、提高羊的瘤胃发酵效果；向日葵盘粗脂肪含量高，含有大量的膳食纤维，可以提高奶牛的产奶量和乳脂率，促进肉牛增重，提高羊瘤胃挥发性脂肪酸浓度以及粗蛋白质、粗纤维、中性洗涤纤维的消化率；向日葵秸秆富含氮、磷、钾、钙、镁等矿物质元素以及少量的蛋白质，可以为肉牛提供一些常量元素和微量元素，提高羊的日增重，降低料重比；葵花籽壳的主要成分是纤维素和木质素，含有丰富的生物活性物质，可以提高奶牛日增重、肉牛饲料转化率。作者具体介绍了向日葵副产物饼粕、葵盘、秸秆、葵花籽壳的营养价值，以及目前它们在反刍动物饲料中的应用情况，以期为今后向日葵副产物的开发利用提供理论依据。     

HPLC法测定玉米酒糟中绿原酸的含量

采用浸提法提取玉米酒糟中绿原酸并用HPLC法测定其中的含量,采用安捷伦色C18（4.6mm×150mm,5μm）色谱柱,乙腈-0.5％磷酸溶液为流动相,流速为1.0mL·min-1,检测波长为327nm.结果表明绿原酸在0.232～2.784μg呈现良好的线性关系,玉米酒糟中绿原酸含量0.028％,平均回收率为95.80％,RSD=2.72％.试验证明了玉米酒糟中含有绿原酸,且其含量较高,为玉米酒糟的进一步开发提供科学依据.     

Changes in peroxidase activity and lignin content of cultured tea cells in response to excess manganese

Abstract

The present study was undertaken to identify the effects of manganese (Mn) on the activity of peroxidase (PO) and the amount of ascorbic acid (AsA) and lignin, as well as the cell viability of suspension-cultured tea cells (Camellia sinensis L. cv. Yabukita). Cells were grown in B5 medium (containing 0.06 mmol L^?1 Mn) and cultured for 24 h in medium with a Mn concentration of 0.9 mmol L^?1 as an excess treatment. No significant difference was observed between cellular growth and the viability of the cultured tea cells after treatment with excess Mn compared with cells grown under control conditions, although the content of Mn in cells in the excess Mn treatment was 12-fold higher than that of the control cells. The amount of total AsA was also not affected by the Mn treatment. The activity of ionically wall-bound peroxidase (IPO) increased in the presence of excess Mn, unlike the content of lignin. Conversely, the activities of soluble PO and covalently wall-bound PO decreased with excess Mn. These findings suggested that IPO might contribute to Mn tolerance in tea cells. However, its role in the mechanism(s) of Mn tolerance has not been elucidated.     

The effects of maternal nutrition during the first 50 d of gestation on the location and abundance of hexose and cationic amino acid transporters in beef heifer uteroplacental tissues

We hypothesized that maternal nutrition during the first 50 d of gestation would influence the abundance of hexose transporters, SLC2A1, SLC2A3, and SLC2A5, and cationic amino acid transporters, SLC7A1 and SLC7A2, in heifer uteroplacental tissues. Angus-cross heifers (n = 43) were estrus synchronized, bred via artificial insemination, and assigned at breeding to 1 of 2 dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d of BW gain or RES = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d) in a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross-sections were collected from the horn ipsilateral to the corpus luteum, fixed in 10% neutral buffered formalin, sectioned at 5 µm, and stained via immunofluorescence for transporters. For each image, areas of fetal membrane (FM; chorioallantois), luminal epithelium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted for days 34 and 50. No transporters in target areas were influenced by a day × treatment interaction (P ≥ 0.06). In ENDO, all transporters were differentially abundant from days 16 to 50 of gestation (P ≤ 0.04), and SLC7A2 was greater (P = 0.05) for RES vs. CON. In SG, SLC7A1 and SLC7A2 were greater (P ≤ 0.04) at day 34 vs. day 16. In DG, SLC2A3 and SLC7A1 were greater (P ≤ 0.05) for CON vs. RES heifers; furthermore, SLC7A1 was greater (P < 0.01) at day 50 vs. days 16 and 34 of gestation. In MYO, SLC7A1 was greater (P < 0.01) for CON vs. RES and was greater (P = 0.02) at days 34 and 50 vs. day 16. There were no differences in FM (P ≥ 0.06). Analysis of all uterine tissues at day 16 determined that SLC2A1, SLC2A3, and SLC7A2 were all differentially abundant across uterine tissue type (P < 0.01), and SLC7A1 was greater (P = 0.02) for CON vs. RES. Analysis of all uteroplacental tissues at days 34 and 50 demonstrated that all transporters differed (P < 0.01) across uteroplacental tissues, and SLC7A1 was greater (P < 0.01) for CON vs. RES. These data are interpreted to imply that transporters are differentially affected by day of gestation, and that hexose and cationic amino acid transporters are differentially abundant across utero-placental tissue types, and that SLC7A1 is responsive to maternal nutritional treatment.