Impact of soil water content on maize responses to the plant growth-promoting rhizobacterium Azospirillum lipoferum CRT1

Members of the bacterial genus Azospirillum are root-associated bacteria that increase yield in cereals by promoting growth and alleviating drought stress. How plants integrate the many bacterium-derived growth-promoting stimuli with other environmental factors to generate a coordinated response remains unresolved. Using a commercial Azospirillum strain, A. lipoferum CRT1 and two host maize cultivars, it was observed that bacterization reduced the drought-induced increase in lateral root growth and enhanced the flood-induced increase in lateral root growth in the more drought- and flood-sensitive cultivar. In the other one, A. lipoferum CRT1 only elicited a moderate root growth response under low soil water potential. The photosynthetic potential and activity were increased in the earlier cultivar and decreased in the later one, irrespective of the soil water content. No impact of the bacterium was seen on the growth of the leaves of both cultivars under both stresses until the third leaf stage, therefore suggesting that it is a consequence of multiple primary adaptations to biotic and abiotic stresses. It is suggested that host–bacteria recognition leads to a stress-specific modulation of the root response and a differential stress-independent effect on photosynthesis. This is the first report of the impact of Azospirillum under flood conditions.     

Sentinel-2 images reveal functional biophysical heterogeneities in crop mosaics

Landscape Ecology - Identifying landscape structure and understanding its functions are crucial for biological control. However, the relationship between the crop mosaic phenological heterogeneity...     

A xenia effect on number and volume of cotyledon cells and on seed weight in faba bean (Vicia faba L.)

The female line 1709, carrying the recessivecharacter green cotyledon, marker of the embryogenotype, was cross-pollinated by bees in the presenceof either male line HG115 or male line Dial63. In thecomparison of seeds which resulted either fromintercrossing or from selfing, a xenia effect wasobserved on volume and number of cotyledon cells andon individual seed weight which was dependent on themale line. The increase of hybrid seed weight inducedby the small-seeded male line Dial63 was larger thanthe one induced by the large-seeded male line HG115.The xenia effect on seed weight was correlated withthe level of heterosis in the F1 plant's growth.     

Long-term continuous cropping in the Pacific Northwest: Tillage and fertilizer effects on winter wheat, spring wheat, and spring barley production

Conventional tillage winter wheat (Triticum aestivum) (WW)–summer fallow reduces soil productivity and increases soil erosion. Conservation tillage management, together with intensive cropping may have the potential to reverse these sustainability concerns. The objective of this study was to determine the effects of conventional tillage (CT) and no-tillage (NT) systems on grain yield of long-term annual cropping of monoculture WW, spring wheat (SW), and spring barley (Hordeum vulgare) (SB) grown with or without fertilizer, in the Pacific Northwest region of the USA. In unfertilized crops, grain yield of WW, SW, and SB was 15%, 25%, and 50% higher, respectively, in CT than in NT plots, an indication of the involvement of yield limiting factors under the NT cropping system. When fertilized, there were no significant differences in grain yield of WW. Yields of SW and SB, however, remained 21% and 15% higher, respectively, in CT than in NT, an indication that factors other than fertility were involved. These results suggest that in order for NT management to be widely adopted by area growers, the yield-limiting factors need to be addressed.     

Sulfated beta-glucan derived from oat bran with potent anti-HIV activity

China is a major producer of oats; the annual harvested area of 350,000 ha yields approximately 465,000 tons, giving an average yield of 1.33 tons/ha. The bran is not used for animal feed as it is of poor digestibility and low nutritive content and is considered a waste byproduct. Therefore, it is advantageous to produce a value-added product from the bran. We extracted the native polysaccharide, a linear (1-3)-, (1-4)-linked beta-glucan (OBG) from the oat bran and synthesized a sulfated derivative OBGS containing 36.5% sulfate. OBGS had potent activity against a primary isolate of human immunodeficiency virus (HIV-1) in peripheral blood mononuclear cells at a concentration (EC(50)=5.98 x 10(-4) microM) approximately 15,000 times below its cytotoxic concentration. OBGS was also active postinfection (EC(50)=5.3 x 10(-4) microM) and protected pretreated peripheral mononuclear cells (EC(50)=5.2 x 10(-2) microM) washed free of the compounds prior to infection. Thus, OBGS has potential as a vaginal microbicide and is the first such report for oat bran derived sulfated beta-glucan.     

An assay to estimate tannins added to postmortem Turkey meat

A method for quantification of tannins in wine was adapted to determine tannins added to turkey meat. Standard curves containing varying amounts of GSE [0, 0.5, 1.0, 1.5, 2.0, 2.5, and 5.0%, (w/w)] as a source of tannins were developed. The R(2) value of the mean standard curve was 0.9992. The overall percent recovery of GSE in meat was determined to be 54.78%. Results showed that estimation of GSE in four out of five of the spiked samples was less than or equal to 10%. It is unclear as to why spiked samples at 0.048 mg of GSE were always underestimated (25.0%). Overall, the method seems applicable for estimation of tannins in poultry meat and is probably applicable to estimation of tannins in other meat products.