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71.
Lignin and cellulose contents and wood basic density were related to diameter at breast height (DBH) in six fast-growing and five slow-growing families from a combined progeny test and seedling seed orchard of Eucalyptus urophylla grown for 10 years in northern Vietnam. The mean cellulose content of the fast-growing families was significantly higher than that of the slow growing-families (40.0 and 37.1%, respectively), and for individual trees cellulose content was significantly correlated phenotypically with DBH. Wood basic density was significantly lower in the fast-growing group than in the slow-growing group (0.506 and 0.535 g cm−3, respectively), and was significantly negatively correlated phenotypically with DBH. The lignin contents were not significantly different between groups. Cellulose content and wood basic density were not correlated. The main conclusion is that there is no obstacle to combining high growth rate with high cellulose content, for plantation of forests intended mainly for pulpwood.  相似文献   
72.
为揭示新疆家畜地理分布气候规律,利用畜牧业统计资料及其气候资料,应用相关分析方法研究了新疆各种草食家畜的地理分布与气候条件之间关系,并在此基础上采用回归方法建立了新疆家畜地理分布气候模式。结果表明:(1)牛、马要求温凉湿润的气候条件,驴、骡、骆驼、山羊和绵羊对炎热干燥的气候条件有很强的适应能力。骆驼、山羊和骡对强光照条件的适应能力强,而绵羊的适应能力较差。(2)草食家畜的地理分布与气候条件关系密切,气候模式能够反映气候条件对草食家畜地理分布的影响。  相似文献   
73.
74.
Journal of Crop Science and Biotechnology - There is great interest in the enhancement of isoflavones as one of the functional ingredients in soybean. This study aimed to investigate the effects of...  相似文献   
75.
Abalones ( Haliotis species) are a popular delicacy and commonly preserved in dried form either whole or in slices or small pieces for consumption in Asian countries. Driven by the huge profit from trading abalones, dishonest traders may substitute other molluscan species for processed abalone, of which the morphological characteristics are frequently lost in the processed form. For protection of consumer rights and law enforcement against fraud, there is a need for an effective methodology to differentiate between fake and genuine abalone. This paper describes a method (validated according to the international forensic guidelines provided by SWGDAM) for the identification of fake abalone species using forensically informative nucleotide sequence (FINS) analysis. A study of the local market revealed that many claimed "abalone slice" samples on sale are not genuine. The fake abalone samples were found to be either volutids of the genus Cymbium (93%) or the muricid Concholepas concholepas (7%). This is the first report of Cymbium species being used for the preparation and sale as "abalone" in dried sliced form in Hong Kong.  相似文献   
76.
The Vietnamese Ban pig is a precious genetic resource that needs to be preserved. In vitro embryo production from in vitro matured (IVM) oocytes is an important tool for the utilization of cryopreserved porcine sperm. The aim of this study was to compare two media for the IVM of Ban pig oocytes. Immature oocytes were subjected to IVM either in a non‐defined (TCM‐199 + pig follicular fluid) or in a defined base medium (POM + epidermal growth factor). At the end of IVM, the oocytes were in vitro fertilized (IVF) with frozen Ban sperm. Ten hours after IVF, the oocytes were either subjected to orcein staining to check fertilization and maturation status or cultured in vitro for 7 days. There was no difference between the two IVM media in terms of percentages of oocyte maturation and blastocyst production. However, the percentage of male pronuclear formation after IVF and the total cell numbers in blastocysts were higher with the defined system. Zygotes obtained by the two IVM systems survived vitrification at similar rates. In conclusion, the two IVM systems were both effective for the production of Ban pig embryos; however, better embryo quality was achieved with the defined one.  相似文献   
77.
[目的]为了研究同期发情处理方法、繁殖状况、品种、体重等对肉牛同期发情效果的影响,[方法]选择140头不同繁殖状况、品种、体重的肉牛,随机分为3组,分别采用CIDR+第10天肌注PMSG+第11天肌注PGF(埋栓Ⅰ组)、CIDR+第9天肌注PMSG+第11天肌注PGF(埋栓Ⅱ组)、肌注PGF+PMSG(PGF组)的方法进行同期发情处理。[结果]3种不同处理方法相比,PGF组发情率为87.10%,埋栓Ⅰ组、Ⅱ组母牛发情率分别为97.83%、98.41%,显著高于PGF组(P<0.05);PGF组处理牛受胎率为83.87%,埋栓Ⅰ组、Ⅱ组处理牛受胎率分别为89.13%、84.13%,高于PGF组,但差异不显著(P>0.05);育成牛与经产牛发情时间相比,埋栓组12~24 h内出现发情症状的经产牛占比为27.27%,育成牛占比为60%,显著高于经产牛(P<0.05),2...  相似文献   
78.
Ginseng is an important medicinal plant, but almost no genomic information is known for it. For the primary step to understand the Panax genome, we inspected the chloroplast genome sequence diversity and used that to infer the evolution of Panax species using them. We inspected a total of 101 intergenic spacers (IGS) covering 44,563 bp (96.8 % of the total IGS) from four Panax species. Diversity was inspected by three steps: gel electrophoresis, high resolution melting (HRM) analysis, and further confirmation by sequencing. Even though low levels of InDel polymorphism were detected by gel electrophoresis, high levels of reproducible polymorphisms were identified by HRM analysis. Sequencing of the HRM-polymorphic spaces and pair-wise multiple sequence alignments revealed up to 247 sequence variations between species. We have identified 62 IGS showing polymorphism between species. Among them, the trnE-trnT, trnT-psbD, ndhF-rpl32, and rpl14-rpl16 spaces are more informative for studying the diversity of Panax relatives. Phylogenetic analysis and molecular evolution studies revealed that P. notoginseng is most diverged from the other Panax species, with a nucleotide substitution rate of 0.0039. P. quinquefolius shows a close relationship with P. ginseng and P. japonicus, with a nucleotide substitution rate of 0.0009. Meanwhile, no sequence variation was detected between P. ginseng and P. japonicus. Calculation of molecular clocks revealed that P. notoginseng diverged more than 1.30 million years ago from the other Panax species and then, P. quinquefolius diverged from P. ginseng by migration in the American continent more than 0.29 million years ago.  相似文献   
79.
Abstract

Soil dispersion induces soil erosion and colloidal leaching. Nutrients are lost at the same time and this causes water contamination. Phosphate is an essential element for living organisms. Because phosphate influences soil dispersion and it is an important limited resource, this influence must be evaluated well in order to diminish negative effects on soil structure. In this paper, we firstly evaluated the influence of phosphate sorption on soil dispersion by calculating repulsive potential energy between soil particles. Ferralsol, which is a typical soil in rainy tropical regions, was used as the material. The dispersion-flocculation phenomena were investigated with absorbance of soil suspension under different pH, phosphate adsorption and electrolyte concentration in an Na-NO3-PO4 system. The repulsive potential energy was calculated based on the diffuse double layer theory and the measured zeta potential. We indicated that the measured absorbance increased with the increase of the repulsive potential energy. The repulsive potential energy increased with increasing phosphate sorption up to about 5 to 20 mmol kg?1 at all pH, and it induced the soil dispersion, because phosphate sorption increased the negative charge of the soil. After its peak, it decreased with increasing phosphate sorption because the electrolyte concentration increased and the electrolyte screened the electric field near the soil surface. The repulsive potential energy also increased with increasing pH because of the increase of the negative charge of the soil. Even at low pH, after a certain amount of phosphate sorption, the soil dispersed due to the increase of repulsive potential energy, although the soil flocculated before phosphate application. Because the soil dispersion causes soil and phosphorus loss, the influence of soil pH and phosphate sorption on the soil dispersion should be considered for good soil management.  相似文献   
80.

Fineroots (≤ 2 mm diameter) are dynamic components of the forest ecosystems and play important role in water and nutrient acquisition in forests. These roots are sensitive to forest fertilization and therefore, the response of fineroots to nutrient application would provide better understanding of the forest carbon and nutrient dynamics that will be helpful in sustainable forest management plans. Two fertilization treatments, including (1) F400: 400 g P2O5 (16.5%)/tree and (2) F600: 600 g P2O5 /tree, and F0: control (without fertilization), were applied in an Acacia mangium plantation with a planting density of 1100 trees/ha (3 m?×?3 m). The evaluation of fineroot growth across seasons showed that fertilization significantly increased production and subsequent mortality and decomposition. The total decomposition associated with F600 application was 7.95 tons ha?1 year?1, equaling 121% of F400 and 160% of the control. Mortality in F600 was 8.75 tons ha?1 year?1, equaling 111% of F400 and 198% of F0, while production in F600 was 10.40 tons ha?1 year?1, equaling 127% of F400 and 143% of F0. Fineroot production, mortality, and decomposition are seasonally dependent, with higher values measured in the rainy season than in the dry season. Stand basal area increment was significantly correlated with fineroot production (R2?=?0.75), mortality (R2?=?0.44), and decomposition (R2?=?0.48). This study showed that fertilization could facilitate fineroot production, which can then lead to a higher turnover of carbon and nutrients through the decomposition of the greater mass of the fineroots.

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