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1.
We studied the performance of different seed mixtures and the influence of liming on the establishment of a montane pasture under acidic site conditions during a wood-pasture separation process from 1998 to 2001 in Styria, Austria. Two treatments (with and without liming) were established, each with four seeding treatments (without seeding, commercial, site-adapted and site-specific mixtures), and all plots were regularly fertilized from 1998 to 2002. Vegetation surveys and forage analyses regarding development of vegetation cover, seeded species persistence, quality and yield parameters were conducted again in 2014 and 2016; soil samples were taken in 2015. After cessation of regular fertilization, the analysed soil parameters declined to levels that were sufficient or low for grasslands. pH decreased again over time, but still was significantly higher (p = .0034) in the liming treatment. The single liming during experimental set-up also caused better long-term performance for nearly all vegetation, quality and yield parameters. The site-specific seed mixture performed best regarding most analysed parameters, under both liming treatments. Concerning seeded species, the habitat-typical species Agrostis capillaris, Festuca rubra agg. and Trifolium repens persisted best with and without liming. All analysed vegetation and yield parameters stayed far behind their results of 2001 and their potential. The use of site-specific seed mixtures supports the establishment of productive grassland on specific locations. The long-term results also illustrated that even low-input management like liming in multi-annual intervals can help to improve acidic site and growing conditions significantly and thereby increases the sustainability of cost-intensive wood-pasture separation processes under similar conditions.  相似文献   

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Chitosan—one of the natural multifunctional polymers—due to its unique and versatile biological properties is regarded as a useful compound in medical and pharmaceutical technology. Recently, considerable research effort has been made in order to develop safe and efficient chitosan products. However, the problem of poor stability of chitosan-based systems restricts its practical applicability; thus, it has become a great challenge to establish sufficient shelf-life for chitosan formulations. Improved stability can be assessed by controlling the environmental factors, manipulating processing conditions (e.g., temperature), introducing a proper stabilizing compound, developing chitosan blends with another polymer, or modifying the chitosan structure using chemical or ionic agents. This review covers the influence of internal, environmental, and processing factors on the long-term stability of chitosan products. The aim of this paper is also to highlight the latest developments which enable the physicochemical properties of chitosan-based applications to be preserved upon storage.  相似文献   

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A multipurpose chemical modification of cellulose to yield soluble cellulose derivatives was investigated on the basis of (i) O-acylation of the parent cellulose using N-Boc-protected Gly, αAla, and βAla, and subsequent Boc-removal, (ii) N-acylation of amino acid-modified cellulose in homogenous solution reaction system using Boc-oligopeptides with multiple types of the side-chain functionalities, and (iii) N-acylation of βAla-Cellulose using 10 kinds of simple Boc-oligopeptides. As for the (i), Thermochemical computation to estimate ΔG transition was well coincided with the observed yields in Oacylations. In the case of (ii), beside the similar ΔG-schemes, a strain energy profile, which is coupled with the preferred conformer transition of the amino acid-modified cellulose, was involved to rule out the N-acylation. The symmetric anhydrate in the N-acylating agents in the (iii) are tend to be in torsions due to the β-strand-like steric stabilizations in the peptides, resulting in the highest N-acylation yields as much as 98 %.  相似文献   

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Use of big bale silage and haylage can be difficult on farms where daily forage consumption is comparatively low as speed of deterioration of forage after bale opening may be faster than feed-out rate. Production of smaller bales at harvest is possible, but expensive and work-intensive. Therefore, a pilot study of rebaling forage stored in big bales to smaller bales was conducted. Three separate experiments were included, where microbial and chemical composition of silage and haylage was studied before and after rebaling. In Experiment III, residual big bale forage stored and opened together with rebaled forage was included. Results showed that rebaled haylage and silage had higher yeast counts compared to initial forage; however, residual bales in Experiment III had yeast counts similar to rebaled forage, indicating an effect of storage time rather than of rebaling. In Experiment II, mould counts were higher in rebaled compared to initial silage, but not in haylage. Chemical composition was similar in initial and rebaled forage except for ammonia-N. In Experiment III, ammonia-N was higher in rebaled compared to initial and residual forage and was the only chemical variable affected by rebaling. Bale temperature during aerobic storage followed ambient temperature until day 6–8 in Experiment I and until day 14 in Experiment III where ambient temperature was lower. In conclusion, rebaling can be done without large changes in chemical composition of the forage, but yeast and mould counts may be higher in rebaled forage, and this risk should be considered when using this procedure.  相似文献   

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Great achievements have been madein breeding of semidwarf varieties(indica) since 1960e. Resultsshowed that the dwarf traits widelyused at present were controlled by thesame recessive major gene, sd-1,thus we faced the potential danger oflosing genetic diversity. The low yieldof semidwarf varieties newly-bred indomestic or abroad may be related tothe narrow use of dwarf resource. Soit was important to explore, appraise,  相似文献   

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Solanum tuberosum Group Tuberosum haploids (2n = 2x = 24) were inter-mated using bulk pollen. Nearly half of the resulting progeny were tetraploid, arising from bilateral sexual polyploidization. Subsequent yield trials indicated that the diploid progeny did not yield significantly more than the original haploids, but the tetraploid progeny did yield significantly more than their diploid sibs and the original haploids. Tetraploid cultivars and conventional tetraploid breeding families significantly out-yielded the haploid-derived tetraploids. These results and the theoretical considerations which are presented indicate that inter-mating haploidsper se does not increase heterozygosity. More importantly, these results indicate that without the introduction of new germplasm, haploidization followed by repolyploidization can only be expected to result in tetraploids with heterozygosity equal to or below that of their parents.  相似文献   

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Some locally available fruits and vegetables of the arid zone of Rajasthanwere analyzed for their -carotene content; the selected fruits and vegetables were: Dansra (Rhus myserensis), Kachri (Cucumis collosus), fruit Kachri (Cucumis collosus), Kair (Capparisdecidua) and Sanghri (Prosopis cineriria). The -carotene contents of the samples were estimated in fresh and various processed states (blanched, dried and roasted). The results showed the heat lability of -carotene. Among the samples, kair was found to be the richest source of -carotene. Variety, too, had an impact on the content of this fat soluble vitamin.  相似文献   

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Typical japonica type rice is sensitive to high temperature. Pon-Lai rice is a special japonica type with adaptation to the subtropical climate in Taiwan. Facing climate change, rising temperatures would damage the yield and quality of rice production. This research was conducted using Pon-Lai rice in the field of a subtropical climate. We conducted 2 experiments, including a year-round experiment and collection of samples from different districts for building different temperature conditions. We analyzed the correlation between rising temperature and rice yield or quality. In our results, the critical period of temperature effect is 0–15 days after heading (H15). The threshold of high temperature damage in yield and appearance quality was 25–27 °C. Grain weight decreased about 2–6%, while the temperature of H15 was raised 1 °C above the thresholds. Perfect grain ratio and chalky grain ratio decreased and increased, respectively, while the temperature of H15 was raised above the thresholds. However, the high temperature in H15 affected the physicochemical characteristics. In addition, we found positive correlation between grain length to width ratio and perfect grain ratio. Grain length to width ratio could be an index of temperature effects for grain quality. In our study, when the temperature was below 30 °C, a rising temperature of H15 could damage rice yield and appearance quality, and change grain shape. Our results could provide reference for dealing with the warming future in other temperate rice-cultivated countries.  相似文献   

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The importance of the potato tuber disease powdery scab, caused by the zoosporic pathogen Spongospora subterranea f. sp. subterranea, has increased worldwide, and the disease is one of the most important problems facing potato production in some regions. This soilborne pathogen produces many resting spores which can remain dormant for long periods, are highly resistant to environmental stresses and can spread the disease on seed potatoes and in contaminated soil. The enigmatic nature of this organism exacerbates the development of effective powdery scab control methods. Substantial knowledge has been gained in the last decade on the biology of the pathogen and the epidemiology of the disease, but no single effective control measure is, or is likely to be, available. An integrated approach to powdery scab management is the aim, with host resistance as a substantial and sustainable component. Further research on the epidemiology of powdery scab and population genetics of the pathogen is urgently required. All stakeholders involved in the potato industry must become aware that solution of the powdery scab problem is likely to be a long-term goal. When resistant cultivars with all the other characteristics demanded for marketing high-quality potatoes are available, and when disease risk from the pathogen on seed and/or in soil can be accurately determined, then the mission to develop effective powdery scab control will become achievable.  相似文献   

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Green smut bails were collected from diseased rice panicles and surtace sterilized in sodium chloride for 5 minutes. The orange colored internal tissues were placed on PDA medium kept at 25℃ for 5 d to get pure cultures. PDA plates with the pathogen mycelial pieces in diameter of 5mm were incubated under 9 temperature grades ranged from 13 to 35℃.  相似文献   

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Intersubspecies hybrid rice have strong heterosis but low seed-setting rate, Researches have showed that most of unfilled and partiallyfilled grains occurred in late-flowering spikelets on the base of a panicle, which usually maintain quiescent state for a period after flowering.  相似文献   

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The exploration of nature as a source of sustainable, novel bioactive substances continues to grow as natural products play a significant role in the search for new therapeutic and agricultural agents. In this context, plants of the genus Pereskia (Cactaceae) have been studied for their biological activities, and are evolving as an interesting subject in the search for new, bioactive compounds. These species are commonly used as human foodstuffs and in traditional medicine to treat a variety of diseases. This review focuses on the bioactivity and chemical composition of the genus Pereskia, and aims to stimulate further studies on the chemistry and biological potential of the genus.  相似文献   

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