Growth Response of Loblolly Pine (Pinus taeda L.) 3–5 Years After Plantation Establishment Using Different Management Intensities     

Phillip D. Jones  Andrew W. Ezell  Stephen Demarais 《Journal of Sustainable Forestry》2013,32(5):486-502

The upward trend of intensive management in Southern pine forests is expected to continue, both in area and intensity level. Much of the Mississippi Lower Coastal Plain (LCP) is managed intensively using some combination of mechanical site preparation, chemical site preparation, and herbaceous weed control (HWC). We studied pine growth response and competition control on loblolly pine (Pinus taeda L.) plantations 3–5 years following establishment using five combinations of chemical site preparation, mechanical site preparation, and HWC. Treatments were designated a priori as 1 (least intensive) through 5 (most intensive) largely on the basis of anticipated impact on the vegetation community. We measured pine height and diameter at breast height (dbh); woody stem density; hardwood basal area (BA); coverage of herbaceous plants, understory woody plants, and pine trees; and estimated differences in pine response using age-shift calculations at age 5. Pine height and dbh were correlated with treatment intensity; treatment 5 maintained an average advantage of 1.4-m height and 2.5-cm dbh over treatment 2, the least responsive treatment. Woody stem density varied widely and was not affected by treatment; understory woody coverage was also unaffected by treatment. Coverage of herbaceous plants was reduced in treatments receiving broadcast HWC, and in treatment 2, where slower establishment of pines may have acted as a release for competing woody plants. Age-shift gains relative to treatment 2 ranged from 0.4–1.0 years. Based on year 5 measurements of hardwood BA, it is likely that treatments 1 and 2 will fall further behind treatments 3–5 as the stands mature. Greatest control of competing vegetation and maximum growth of pines was achieved with the most intensive treatment.  相似文献   

茶树雌蕊总蛋白质双向电泳分离体系的建立     

任燕  陈暄  房婉萍  李垚  黎星辉 《茶叶科学》2013,(5)

为建立一套适合茶树雌蕊总蛋白质分离的双向电泳体系,对茶树雌蕊总蛋白的提取方法、SDS-PAGE凝胶浓度、聚焦条件和IPG胶条pH范围等进行了比较优化。结果表明,TCA/丙酮-clean up kit法提取总蛋白,用17 cm pH 5~8 IPG胶条,13%SDS-聚丙烯酰胺凝胶进行分离,用考马斯亮蓝R250染色,可以获得清晰、分辨率高、重复性好的双向电泳图谱,共检测到约1200个蛋白点,主要分布在pH 5~8,相对分子量14~117 kD范围内,碱性蛋白得到有效分离,可以满足茶树雌蕊的蛋白组学分析和研究。  相似文献   

Design and evaluation of a one-operation shallow up-cut tillage sowing method for soybean production     

Naoki Matsuo  Shinori Tsuchiya  Keiko Nakano  Koichiro Fukami 《Plant Production Science》2013,16(4):465-478

ABSTRACT

Sowing using a rotary tiller rotating in reverse (up-cut) is a labor-saving technology for soybean production because it can perform tillage and sowing, make ridges, and bury winter crop residues in one operation. However, the power requirement of up-cut rotation is higher than of normal rotation (down-cut), resulting in lower working speeds. Shallow tillage sowing methods may be a solution to this problem. Here, we develop a shallow tillage sowing method using an up-cut rotary and a side-disk which could perform the aforementioned works in one operation and conducted field experiments in 2015 and 2016 to study the effect of our sowing method (up-cut shallow tillage; UST) on ridge shape, soil volumetric water content (VWC) and soybean growth and yield, compared to conventional sowing methods (up-cut conventional tillage; UCT, and down-cut conventional tillage; DCT). Ridge shape did not differ among sowing methods. The VWC at 10 and 20 cm depths in DCT was always higher than in UST and UCT, indicating poorer drainage. The VWC at 10 cm depth decreased quickly after rain in UST and UCT, indicating good surface-layer drainage, but at 20 cm depth in UCT, VWC was lower than in UST, especially during dry spells, indicating higher water-holding capacity in UST than in UCT. Shoot and root growth and seed yield did not differ among sowing methods, indicating that UST did not negatively affect soybean growth and yield. These results suggest that UST can be used for soybean production.  相似文献   

沙葱粉和酵母制剂对藏羊生长性能、屠宰性能、肉品质及瘤胃发酵参数的影响     

范娟  苏满春  李讨讨  徐尚荣  马友记 《动物营养学报》2023,(4):2383-2393

本试验旨在评估沙葱粉和酵母制剂对藏羊生长性能、屠宰性能、肉品质及瘤胃发酵参数的影响。选取初始体重为（18.56±1.49） kg的6月龄健康藏羊30只，随机分为3组，分别为对照组、试验Ⅰ组和试验Ⅱ组，每组10只。在每天自由放牧8 h的基础上，对照组每只每天补饲200 g精料，试验Ⅰ组每只每天补饲200 g精料+10 g沙葱粉，试验Ⅱ组每只每天补饲200 g精料+20 g酵母制剂。预试期7 d，正试期75 d。结果表明：1）试验Ⅰ组第1～75天和第1～30天的平均日增重显著高于对照组（P<0.05）；试验Ⅱ组第31～60天的平均日增重显著高于对照组（P<0.05）；各试验组第61～75天的平均日增重均出现负增长，以试验Ⅰ组的降幅最小。2）试验Ⅰ组和试验Ⅱ组的宰前活重、胴体重及眼肌面积均显著高于对照组（P<0.05）。3）与对照组相比，试验Ⅰ组和试验Ⅱ组脾脏的重量和相对重量显著降低（P<0.05）。4）试验Ⅰ组肉色的红度（a*）值与对照组和试验Ⅱ组相比分别提高了33.33%、33.73%，但差异未达显著水平（P>0.05）。5）与对照组相比，试验Ⅰ组和试验Ⅱ组...  相似文献   

中药复方制剂禽康素对鸡免疫功能的影响试验     

王雅华  钱景富  杨光列 《辽宁农业职业技术学院学报》2012,14(1):1-3

将2周龄健康雏鸡,滴鼻免疫新城疫活疫苗,同时肌肉注射新城疫灭活疫苗,随机分为2组,试验组饲料中添加中药复方制剂禽康素,对照组饲料中不添加任何药物,连续给药14d。免疫后7、14、21d,采用β-微量血凝抑制试验检测雏鸡抗体水平,测定鸡的ERFC形成率和EAC花环形成率,计算脾脏、胸腺、法氏囊三种免疫器官指数。试验结果显示,试验组鸡和对照组相比,雏鸡抗体水平、ERFC形成率和EAC花环形成率、三种免疫器官指数均有显著提高。  相似文献   

胎盘提取物的制备与免疫调节功能及应用研究进展     

赵素洵  玉斯日古楞  云皓琪  么宏强 《畜牧与饲料科学》2020,41(5):75-79

主要介绍了胎盘提取物的制备方法、免疫调节功能以及在生产生活中的应用。总结出, 胎盘提取物有着免疫调节、抗氧化、抗肿瘤和营养作用;其制备方法主要有超滤法、酶解法和微生物发酵法, 各自具有优势和不足, 选择胎盘提取物制备方法时可以根据自有的条件和要求及前人的经验综合判断;在皮肤护理方面, 胎盘提取物可以作为抗氧化成分添加到护肤品中以起到延缓皮肤衰老的作用;在疫病治疗方面, 能改善肝炎患者的临床症状和肝功能, 对胰腺癌细胞的增殖有负调控作用, 对于超敏反应也有一定的治疗效果, 在神经再生方向效果显著。胎盘提取物在保健品和护肤品研发、疾病治疗方面应用前景广阔。  相似文献   

YFM复方麻醉剂对野猪血流动力学及内皮源性血管活性因子的影响     

刘焕奇  邹明  张启迪  曲志娜  毕可东 《中国兽医学报》2012,32(4):570-572

以0.1mL/kg.b.w.YFM复方麻醉剂对野猪进行颈部肌肉注射,观察麻醉效果,并利用PHILIPS MP30监护仪和DATEX循环监护仪动态监测麻醉前后血流动力学变化,同步采取血样,应用放免法和比色法测定同时相血液相关细胞因子、神经递质的变化。结果显示,野猪麻醉期间血浆ET水平下降,6-keto-PGF1α水平升高,血浆ET、6-keto-PGF1α的变化与血流动力学各项指标的变化呈现出显著或极显著相关性;血清NO和血浆TXB2水平基本无变化。结果表明,ET、PGI2两大内皮源性血管活性因子参与了野猪YFM合剂麻醉所致的血流动力学变化的调节。  相似文献   

Effects of Compound Bacteria Preparation on Fermentation Quality and Rumen Fermentation Characteristics of Phragmites australis Silage北大核心CSCD     

黄棋  汪水平  黄桥深  刘勇  杨鑫  张永康  李茂春 《动物营养学报》2023,(4):2443-2454

The purpose of this study was to investigate the effects of compound bacteria preparation (including homogeneous Lactobacillus/heterogeneous Lactobacillus, Bacillus subtilis and Aspergillus niger as well as their compatibility) on nutrient composition, fermentation quality and rumen fermentation characteristics of Phragmites australis silage. Taking growing Phragmites australis from Dongting lake as silage material, five groups were set up, which were blank group (CK group), lactic acid bacteria group (LA group, supplemented with Lactobacillus plantarum, Pediococcus pentosaceus and Lactobacillus buchneri), lactic acid bacteria+Bacillus subtilis group (LA+BS group), lactic acid bacteria+Aspergillus niger group (LA+AN group) and lactic acid bacteria+Bacillus subtilis+Aspergillus niger group (LA+BS+AN group), and each group had 3 replicates. The supplemental level of lactic acid bacteria was 1.5×108 CFU/kg silage raw materials, and the supplemental levels of Aspergillus niger and Bacillus subtilis were 1.0×108 CFU/kg silage raw materials (all were based on fresh weight of silage raw materials). After 60 days of silage, the nutrient composition and fermentation quality of Phragmites australis silage were determined, and the rumen fermentation characteristics were evaluated by in vitro fermentation and in vivo degradation. The results showed as follows: 1) the contents of dry matter and ash in LA, LA+BS and LA+AN groups were significantly lower than those in CK group (P<0.05), and the crude protein content in LA+BS, LA+AN and LA+BS+AN groups was significantly higher than that in CK and LA groups (P<0.05). 2) The silage sensory evaluation scores of all groups were 60 to 70 points, and the ratings were good. The comprehensive scores of fermentation quality in LA+BS and LA+AN groups were higher, among which, the ammonia nitrogen to total nitrogen ratio, acetic acid content and acetic acid to total acid ratio in LA+AN group were significantly decreased compared with CK group (P<0.05), while the lactic acid content and lactic acid to total acid ratio were significantly increased compared with CK group (P<0.05). 3) The dry matter disappearance rate and total gas production of in vitro fermentation in LA+AN group were significantly higher than those in the other groups (P<0.05), and in vitro fermentation parameters such as volatile fatty acid contents in fermentation liquid were improved. 4) The rumen fermentation dry matter degradation rate in LA+AN and LA+BS+AN groups at 8, 24 and 48 h was significantly higher than that in the other three groups (P<0.05). In conclusion, the combined application of lactic acid bacteria and Aspergillus niger with supplemental levels in this experiment has the best effect on the quality of Phragmites australis silage and rumen fermentation characteristics. © The Author(s) 2023.  相似文献   

复方女贞子和益生菌对新生奶犊牛增重及免疫功能的影响     

丑有财  刘皙洁  王海彬  葛铭 《中兽医医药杂志》2011,13(6):27-30

用复方女贞子（由女贞子、黄芪、党参组成）和益生菌对新生奶犊牛进行了增重和免疫功能影响实验。实验选用奶犊牛20头,随机分为4组,每组5头,用药30 d,共饲养120 d,测定其对犊牛增重和血清免疫球蛋白的影响。结果显示,中药组和中药益生菌联合组的犊牛平均日增重明显提高（P〈0.01）,犊牛血清中IgG、IgA、IgM含量显著升高（P〈0.01）。表明复方女贞子单用或与益生菌联合使用可促进犊牛生长,明显提高犊牛的免疫功能。  相似文献   

大肠杆菌HB101感受态细胞制备条件的优化   总被引：1，自引：0，他引：1  

冯建成  牛成  邢旭  王超 《热带生物学报》2010,1(3):224-227

为探讨大肠杆菌HB101感受态细胞制备的最优条件,从菌种来源、感受态细胞的生长状态及其储存方式等3个方面进行了优化。结果表明：从-70℃冰箱中保存的菌种活化大肠杆菌HB101,当细胞的OD600值为0.3～0.4时制备感受态,4℃冰箱放置1d,-70℃下放置1个月,均可获得较高的转化效率,每微克DNA最高可达1.18×107cfu。  相似文献