西南地区牛鞭草种质资源抗寒性的初步鉴定

本文对96种牛鞭草种质资源在四川省不同海拔、不同区域、不同气候条件下进行了抗寒性评价,为选育抗寒的牛鞭草品种提供参考.     

Effects of Increased Night Temperature on Cellulose Synthesis and the Activity of Sucrose Metabolism Enzymes in Cotton Fiber

Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.     

施氮对南疆荒漠绿洲滴灌棉田产量及棉纤维品质的影响

设计0、150、300、450、600、750 kg/hm² 6种纯氮投入量,600～750 kg/hm²为农民习惯投入量,研究超量施氮对棉花产量、品质及氮肥利用效率的影响。结果表明：农民习惯施氮量是经济施氮量的1.53～1.91倍,产量仅为78.00%～78.60%,氮肥的利用效率显著降低,减少20％～60％的氮肥用量是可行的。增施氮肥对单株结铃数影响显著,对铃质量、衣分等无显著影响,过低、过高的氮肥均不利于高产结构的形成。随施氮量的增加纤维长度、麦克隆值,呈开口向下的抛物线状,超量施氮显著降低纤维的强力。在纤维品质的空间变异性方面,长度、强力受氮肥的影响较大,麦克隆值、短绒指数、伸长率受影响相对较小。可见,300～450 kg/hm²的氮肥投入增产效果最显著,氮肥利用效率最高,纤维品质较优。     

从广西-东盟农业比较优势看农业现代化

农业现代化的内涵随着时代变迁和经济发展而不断调整,并因区域特点和农业比较优势而存在差异.中国广西地区和东盟国家同具农业发展的资源优势,但在全球一体化的经济背景下,农业发展面临新的机遇和挑战.应用数据分析探讨通过发挥区域农业比较优势,有效建立区域间农业合作,促进农业现代化发展并为农业现代化赋予新的内涵.     

超声辅助CaO改性粉煤灰对Mn2+吸附性能研究

以CaO和粉煤灰为原料,超声辅助制备改性粉煤灰,利用SEM、FTIR对其微观形貌进行观察及结构表征,考察其制备及吸附条件对锰离子的吸附性能的影响。结果表明:制备时,当CaO与粉煤灰的质量比为1:10,超声时间为15min;吸附时,废水pH为6,吸附时间为120min,吸附剂用量为20g/L时,Mn2+去除率达91.2%。     

霉菌毒素吸附剂蒙脱石对泌乳奶牛生产性能和血清生化指标的影响

本试验旨在确定中国荷斯坦奶牛饲粮中霉菌毒素吸附剂蒙脱石的适宜添加量。选择45头体况、胎次、泌乳天数、产奶量相近的健康中国荷斯坦泌乳奶牛,采用完全随机区组设计分为5组,每组9头,分别在基础饲粮中添加0(对照组)、0.5%、1.0%、1.5%和2.0%的蒙脱石,测定奶牛生产性能和血清生化指标的变化。预试期10 d,正试期60 d。结果表明:奶牛的日均采食量、产奶量和4%标准乳产量在蒙脱石添加量为0.5%时最高,之后随着蒙脱石添加量的升高而逐渐下降,且添加量为0.5%～2.0%的试验组日均采食量、产奶量与对照组无显著差异(P>0.05);乳尿素氮和血清尿素氮浓度随着蒙脱石添加量的升高而逐渐下降,且蒙脱石添加量为0.5%时乳体细胞数最低,乳脂率最高;蒙脱石对饲料转化效率及其他乳成分和血清生化指标无显著影响(P>0.05)。由此可见,本试验条件下(霉菌毒素含量在安全范围内),奶牛饲粮中霉菌毒素吸附剂蒙脱石的安全添加量为2.0%以内;为达到预防霉菌毒素目的,同时从经济成本角度考虑,推荐添加量为0.5%。     

Role of hepatitis B virus in intrahepatic TGF-β1/Smads signaling pathway

AIM:To explore the effects of hepatitis B virus (HBV) on intrahepatic expression of transforming growth factor β1（TGF-β1） and Smads. METHODS:The expression of intrahepatic TGF-β1, HBsAg and HBcAg in control group and chronic hepatitis B (CHB) group was detected by immunohistochemical method.The serum HBV DNA content was determined by real-time PCR. The role of HBV in the expression of TGF-β1, Smad3 and Smad7 in human hepatic stellate cell line LX-2 in vitro was observed by cell culture and Western blotting. RESULTS:The average score of intrahepatic TGF-β1 expression in CHB group was higher than that in control group. With the increase in serum HBV DNA content, intrahepatic TGF-β1 expression was also enhanced. In the HBcAg positive hepatic tissue, there was higher TGF-β1 expression than that in the liver tissue of HBcAg negative. Compared with control group and HBV+anti-TGF-β1 group, HBV caused increased expression of TGF-β1 and Smad3 in HBV group in vitro. No difference of Smad7 protein among control group, HBV group and HBV+anti-TGF-β1 group was observed. CONCLUSION: The expression of intrahepatic TGF-β1 is related to serum HBV DNA and hepatocellular HBcAg in the patients with CHB. HBV-induced liver fibrosis mainly relies on positive regulatory mechanisms of Smad3,and the negative regulation by Smad7 almost does not function.     

2021年黄羽肉鸡营养与饲料技术研究进展

2021年黄羽肉鸡营养与饲料相关研究依然是热点,有大量文献报道.本文从国外地方品种肉鸡营养与饲料研究和技术发展动态、国内黄羽肉鸡营养参数研究、国内黄羽肉鸡饲料资源开发与利用研究、国内黄羽肉鸡营养代谢、营养与免疫、肉品质营养调控等多方面展开综述,最后提出研究中存在的问题与相关发展建议,以期为黄羽肉鸡生产提供技术支撑和指导...     

Individual Cotton Boll Weight as Influenced by Different Production Eco-Regions and Meteorological Factors

In order to explore systematically the physiological mechanism of high-yield cotton (Gossypium hirsutum L.) in Xinjiang, and further improve yield, the yield components were compared between three ecological regions. Boll number per plant was lower in South and North Xinjiang, but the harvested plant population were nearly 1.5 times higher than that in Nangong, so total boll numbers per unit area were greater in South and North Xinjiang. Weight per boll in south and north of Xinjiang was 5.89-6.50 g and 5.43-6.12 g respectively, 24 to 51% heavier than that in Nangong. The diurnal temperature difference between day and night was relatively greater in Xinjiang than in Nangong, benefitting the accumulation of photosynthetic product in bolls. The temperature difference and total hours of sunshine in boll period are the main reasons for cottons higher boll weight and yield in Xinjiang than in Nangong.     

Relationship of subclasses of serum HDL and Apo A-Ⅰ gene polymorphism in hyperlipidemia

AIM: To investigate apolipoprotein A-Ⅰ gene (Apo A-Ⅰ) polymorphism and its relationship with serum HDL subclasses in patients with hyperlipidemia (HL). METHODS: Apo A-Ⅰ genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 118 patients with hyperlipidemia and 109 healthy subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. RESULTS: Both in HL group and the control group, G/G and C/C genotypes were the most frequent at －78 bp and ＋83 bp of Apo A-Ⅰ gene, respectively. The frequency of rare A allele at －78 bp in HL group was significantly higher than that in control group. In HL group, subjects with G/A mutation had higher serum levels of TG, Apo C-Ⅲ, pre β1-HDL and HDL3a, and lower levels of HDL2a and HDL2b compared to the subjects with G/G genotype. CONCLUSION: The G/A transition in the －78 bp position of the Apo A-Ⅰ gene promoter in patients with hyperlipidemia is associated with HDL subclasses. There is a general shift toward smaller sized HDL, which, in turn, indicates that HDL maturation might be abnormal.