Time filter

Source Type

Zhang W.,State Key Laboratory of Grassland Agro Ecosystems | Hu M.,Chinese Academy of Sciences | Liu G.,Chinese Academy of Sciences | Gao Z.,Chinese Academy of Sciences | And 2 more authors.
European Journal of Plant Pathology | Year: 2014

Red thread caused by Laetisaria fuciformis and pink patch caused by Limonomyces roseipellis often occur on many cool-season turfgrass species in temperate regions throughout the world. Incidences of L. fuciformis causing red thread on seashore paspalum (Paspalum vaginatum) and Li. roseipellis causing pink patch on hybrid bermuda grass (Cynodon dactylon × C. transvaalensis) have been reported as new diseases in Hainan Province, a Chinese island with a tropical climate. Field investigations were carried out at 14 golf courses and three college lawns in six cities of Hainan Province from April 2011 to April 2013. Red thread disease was observed on four warm-season turfgrasses throughout the period in all six cities, while pink patch was found on two warm-season turfgrasses in three cities. A total of 21 red thread isolates and five pink patch isolates were collected from these infected turfgrasses. These isolates were identified based on morphological and culture characteristics as well as nucleotide sequences from partial mitochondrial small subunit ribosomal RNA (mtSSU) and nuclear large subunit ribosomal RNA (nuLSU) genes. The optimal temperature for hyphal growth was either 25 or 28 °C for red thread isolates and 28 °C for pink patch isolates. The growth rate of all isolates was significantly less when cultures were grown under continuous light compared to the 12 h light/12 h dark or 24 h dark regimes. Arthroconidia production was optimized under the 12 h light/12 h dark regime. Selected fungal isolates were tested for pathogenicity by inoculating on ‘Seaspray’ seashore paspalum, ‘Princess 77’ bermuda grass (Cynodon dactylon), and ‘Lanyin No 3’ japanese lawngrass (Zoysia japonica) under controlled environmental conditions. All tested L. fuciformis and Li. roseipellis induced foliar blight in the turfgrass species. © 2014, Koninklijke Nederlandse Planteziektenkundige Vereniging.

Tian L.H.,State Key Laboratory of Grassland Agro Ecosystems | Tian L.H.,Lanzhou University | Bell L.W.,CSIRO | Shen Y.Y.,State Key Laboratory of Grassland Agro Ecosystems | And 2 more authors.
Crop and Pasture Science | Year: 2012

Conventional rainfed mixed croplivestock systems of western China lack high-quality forage and restrict livestock production. This study explored the forage potential from wheat and its effects on subsequent grain yield. Different cutting times were imposed on winter wheat (Triticum aestivum) at Qingyang, Gansu Province, in two growing seasons, and the effect of nitrogen (N) topdressing rates (0, 60, and 120kgN/ha) on grain yield recovery was explored. Results showed the potential to produce 0.81.6tDM/ha of wheat forage with high nutritive value when cut before stem elongation (GS 30). In the wetter year, cutting before stem elongation did not delay crop development significantly (3 days at anthesis and 5 days at maturity), but grain yields were reduced by 1728% compared with the uncut crop (5.8tDM/ha), mainly due to reductions in number of spikes per m2 and, consequently, number of grains per m2. In both seasons, more forage biomass was available if crops were cut later than GS 32, but this came with large reductions (62%) in grain yield and delays in crop development (9 days or 131 degree-days). Crops cut later than GS 30 had greatly reduced harvest index, tillers per m2, and total N uptake but higher grain protein content. There was no significant effect of N topdressing rate on grain yield, although provided the crop was cut before GS 30, higher rates of N increased maturity biomass and crop N uptake by replacing N removed in cut biomass. This study showed that physiological delay of wheat due to cutting was not significant. The forage harvested from winter wheat before stem elongation could be a valuable feed resource to fill the feed gap in western China. Journal compilation © CSIRO 2012.

Yang Q.,State Key Laboratory of Grassland Agro Ecosystems | Yang Q.,Lanzhou University | Wang X.,State Key Laboratory of Grassland Agro Ecosystems | Wang X.,Lanzhou University | And 2 more authors.
Journal of Soil Science and Plant Nutrition | Year: 2013

The effects of long term no-till and crop residue on soil microbial community catabolic function and relevant carbon cycle in the rhizosphere and bulk soils were assessed in the 10th year of a maize-winter wheat-soybean crop rotation. Conventional and zero tillage were coupled with residue removal and residue retention in a factorial design. Soil microbial community catabolic diversity was determined using Biolog-Eco plate. Average well colour development value (AWCD) of the microbial community in the rhizosphere soil was significantly higher than that in the bulk soil. Soil organic carbon (SOC) and microbial biomass carbon (MB-C) content of rhizosphere soil under both zero tillage and residue removal treatments were significantly higher than those in the bulk soil. Microbes in bulk soil presented a preferential utilization of diverse carbon sources when crop residue was retained. Zero tillage significantly increased the utilization of most carbon sources of microbial in the rhizosphere compared to conventional tillage. Principal component analysis (PCA) of the distribution of carbon substrate utilization for all treatments suggests that the microbial community catabolic diversity is different between the tillage management treatments and between soil sampling positions. Effects of zero tillage and crop residue retention were different with respect to the microbial catabolic diversity in the rhizosphere and the bulk soil.

Yang Q.,State Key Laboratory of Grassland Agro Ecosystems | Yang Q.,Lanzhou University of Technology | Wang X.,State Key Laboratory of Grassland Agro Ecosystems | Wang X.,Lanzhou University of Technology | And 3 more authors.
Soil Science and Plant Nutrition | Year: 2013

This study reports the effects of a long-term tillage and crop residue experiment on the soil microbial ecology of a Loess soil located in Gansu Province, western China. Tillage and residue management treatments were imposed on a nine-year continuous rotation of maize (Zea mays L. cv Zhongdan No. 2), winter wheat (Triticum aestivum L. cv Xifeng No. 24) and soybean (Glycine max L. cv Fengshou No. 12). After nine years, there were significant effects on topsoil (0-10 cm) carbon, nitrogen, microbial activity, microbial composition and function. The retention of crop residues compared to residue removal significantly improved all measures of chemical and biological soil fertility. The values of average well color development (AWCD), a measure of the metabolic utilization of organic compounds, for the residue retention treatments were always higher than those with residue removal treatments, and the differences increased with increasing incubation time. Principal component analysis indicated that crop residue retention significantly altered topsoil microbial activity and community functional diversity. Our research clearly demonstrates that retention of crop residues significantly enhances soil microbial metabolic capacity, compared to no tillage, and can therefore contribute to sustainable agriculture on the Loess Plateau. Promotion of conservation agriculture has the potential to rehabilitate soil fertility and improve agricultural sustainability and food security on the region. © 2013 Copyright Japanese Society of Soil Science and Plant Nutrition.

Yu B.H.,Lanzhou University | Yu B.H.,State Key Laboratory of Grassland Agro Ecosystems | Nan Z.B.,Lanzhou University | Nan Z.B.,State Key Laboratory of Grassland Agro Ecosystems | And 4 more authors.
Crop and Pasture Science | Year: 2012

Yellow stunt and root rot caused by Embellisia astragali are major factors contributing to declining yields of standing milkvetch (Astragalus adsurgens). The resistance of ten varieties of standing milkvetch to E. astragali was evaluated under laboratory, greenhouse, and field conditions. Seed germination/emergence, shoot and root length, plant dry weight, disease incidence, mortality, and disease severity index were monitored. The results show that Shanxi and Zhongsha No. 1 varieties had the best agronomic traits and lowest levels of disease in all experiments, while the varieties Neimeng and Ningxia had the highest susceptibility to disease. Germination/emergence differed significantly (P<0.05) between varieties after inoculation, and compared with the control, germination/emergence of inoculated treatments of nine varieties decreased on average by 1.5% in laboratory experiments and by 4.1% in greenhouse experiments at 15 days after inoculation. Inoculation reduced shoot length by an average of 24.4% and 41.5% (P<0.05) in laboratory and greenhouse experiments, respectively, in six of ten varieties. All varieties showed significantly (P<0.05) lower plant dry weight following inoculation, with reductions ranging from 0.3 to 0.6mg in the laboratory and from 82.6 to 149.4mg in the greenhouse. Resistance to the pathogen was evaluated on the basis of disease incidence, a disease severity index (DSI), and mortality; varieties showing different resistance were grouped using cluster analysis. There were significant correlations between the results of laboratory and greenhouse experiments (r=0.79; P<0.01) and between greenhouse and field experiments (r=0.83; P<0.01) across all varieties. Multiple regression analysis between laboratory/greenhouse and field experiments on DSI suggested that screening in the laboratory/greenhouse could be an alternative method of rapidly estimating DSI under field conditions. © 2012 CSIRO.

Discover hidden collaborations