Plant Foods for Human Nutrition - The composition of garlic (Allium sativum L.) may vary among cultivars and, moreover, change over time, thereby affecting both biological activity and flavour.... 相似文献
Landscape Ecology - Small forest fragments are often the most abundant type of semi-natural habitat in intensive agricultural landscapes. Wild pollinators can use these forest patches as nesting or... 相似文献
Background : Nepal's traditional rice–wheat rotation systems are subject to continuing changes. Changing consumer demand currently drives a replacement of wheat by high‐value vegetables during the dry season, while emerging water shortages lead to a substitution of rice by maize in the wet season. Hence, associated changes in soil aeration status and shifting conditions of soil nutrient supply to match crop nutrient demand are expected to increase the requirements for the principle limiting micro‐nutrients such as boron (B) and zinc (Zn). Aim: Our aim was to investigate the changes in B and Zn availability as well as crop yields and nutrient uptake after system shifts from rice to maize and from wheat to vegetables. Method : We analyzed the B and Zn availability in rice‐ and maize‐based systems as well as crop yields and the nutrient uptake by wheat, cauliflower, and tomato during the dry season in Nepal. Plants were grown at two field sites (midhills vs. lowland) and under greenhouse conditions using soils from the field sites. Results : A change from irrigated rice to maize reduced soil C and N contents with resulting decreases in dry season crop yields. Low soil Zn after rice cultivation led to shortage in Zn uptake by vegetables in both greenhouse and field experiments. The shift from wheat to vegetables increased the demand for B and to a lesser extent for Zn, and consequently vegetables showed visual symptoms of B deficiency. Boron concentrations in dry biomass were below the critical limits with < 10 mg B kg?1 in wheat, < 21 mg B kg?1 in cauliflower, and < 23 mg B kg?1 in tomato. Conclusions: Soils in larger parts of Nepal are low in available B and that the ongoing system shifts increase in the demand for B and Zn in the currently emerging and more diversified production systems. 相似文献
Bacterial cooperation and competition in biofilms are being recognized as important factors in regulating structure and function of microbial communities. However, knowledge about soil bacterial interactions in biofilms and how these may be influenced by different fertilization practices is still limited. This study aims to investigate interspecific interactions in biofilms and the effects of fertilization practices on these interactions.
Materials and methods
We assessed bacterial interactions according to a classification criterion proposed recently via comparing biomass of single-species biofilms with dual-species biofilms. Biofilm biomass was measured by crystal violet staining using the modified Calgary biofilm device.
Results and discussion
Increased biofilm formation was detected in 67% of co-cultures that were composed of strains isolated from unfertilized soil, indicating a high prevalence of cooperation among the strains in natural soil. In contrast, decreased biofilm formation was detected in 74% of co-cultures that contained strains isolated from soil receiving chemical fertilizer. Interestingly, combinations of bacterial isolates from soils amended with chemical fertilizer in combination with composted chicken manure or mushroom residues showed higher level of synergism and biofilm induction in dual-species biofilms than the strains from chemically fertilized soils, suggesting integrated fertilization with composted chicken manure or mushroom residues may help maintain the native microbial interaction network dominated by synergistic interactions.
Conclusions
Together, these findings indicate that social interactions, required for biofilm formation, among soil bacteria are affected by fertilization practices. Cooperation is dominant in dual-species biofilms in unfertilized soil. Organic manure could mitigate the negative impacts on bacterial social interactions caused by chemical fertilizers.
For a better understanding of the physiological background of microspore embryogenesis (ME), the protein profile was analyzed in four winter triticale DH lines, which show extremely different embryogenic potential. The analysis were conducted with anthers at the phase of development optimal for ME induction and then after low temperature (LT, 3 weeks at 4 °C) ME-inducing tillers treatment. The sub-proteome of anthers was mapped by two-dimensional gel electrophoresis (2-DE). The protein species significantly more abundant (at least 2-fold) in responsive DH lines after LT treatment were chosen for identification by MALDI-TOF/TOF analysis. In total, 31 protein species were successfully identified as involved in the determination of microspore competence, stress response and in the regulation of ME induction. Microspore competence required sufficient energy supply and efficient system of cell protection that determine survival under prolonged LT stress treatment. LT stress was associated with increased accumulation of proteins typical for cell defence against oxidative stress (e.g., l-ascorbate peroxidase), chaperons (e.g., HSP70) and other enzymes/factors ensuring protein biosynthesis, stability and active cell divisions. Also here, effective cell defence required undisturbed energy supply. Among proteins that accumulated differentially in accordance with microspore embryogenic potential again the most important role seems to be played by the enzymes ensuring energy production and determining ability of plant stress adaptation. Two protein species (enolase, 12S storage protein), proposed earlier as candidates for markers of embryogenesis in other in vitro plant culture systems confirmed their utility for triticale anther cultures. 相似文献
Management of heavy metal-contaminated soil under drought and other harsh hydrological conditions is critical for protecting soil ecosystem services. In this study, we examined the effect of pig manure digestate-derived biochar as a soil amendment (15 t ha−1) with N fertilizer (180 kg ha−1) on soil and plant heavy metal levels and nutrient availability under various moisture regimes (optimal moisture ~15%, drought condition ≤5%, and flooded condition ≥35% wt.). It was observed that biochar applications significantly decreased heavy metals in the spring wheat plants, lowering Cr by 90%, Ni by 50%, Cd by 9% and Pb by 34% compared to non-biochar (control) treatments. However, the pig digestate-derived biochar increased heavy metals in soil under all moisture regimes, increasing soil Cr by 21%, Ni by 43%, Cu by 55%, Zn by 70%, and Pb by 12%. The availability of macroelements also increased with the biochar applications under the optimum moisture regimes in both soil and plants, increasing Mg2+ by 11%, P by 4%, K+ by 50%, and Ca2+ by 56% in the soil, and Mg2+ by 13%, P by 69%, K+ by 29, and Ca2+ by 39% in plants. Biochar addition also improved chlorophyll fluorescence (CF) levels in the crop for the entire season (12th to 62nd day) and the aboveground crop biomass and dry matter contents both increased. Consequently, the use of pig manure digestate-derived biochar with N fertilizer under normal moisture conditions was able to reduce heavy metal availability to plants and thus could be used in contaminated soils to maintain better crop growth and development. 相似文献
