Effect of nitrogen root zone fertilization on rice yield,uptake and utilization of macronutrient in lower reaches of Yangtze River,China

Improper application of nitrogen (N) has led to high N losses and low N use efficiency in the lower reaches of Yangtze River in China. An effective method to solve such problems is the deep fertilized N in root zone (RZF). Limited information is available on the effect of RZF on the uptake of macronutrients (N, P and K) and rice yield. Field experiments, conducted from 2014 to 2015, compared the farmer fertilizer practice (FFP, with 225 kg ha^?1 of N, split into three doses) and RZF using the same rate but placing N 5 cm away from rice roots in holes 10 cm deep (RZF10) or 5 cm deep (RZF5) as a single application. The highest mean yield (10.0 t ha^?1) was obtained in RZF10, which was 19.5% more than that in FFP. Root zone fertilization of urea (whether 10 cm deep or 5 cm deep) resulted in greater accumulation of N, P and K in stem, leaf sheaths, leaf blades and grains compared to that in FFP in sandy and in loam soils. The uptake of N, P and K was the highest in RZF10 (average at 176.7, 66.2 and 179.1 kg ha^?1, respectively), higher than that in FFP by 45.0, 17.0 and 22.6%, respectively. N apparent recovery efficiency was markedly higher in RZF10 (53.1%) than in FFP (27.5%). RZF10 significantly increased the N, P, K uptake compared with FFP under different N rates in both sandy and loam soils. These results suggest that the N, P and K input amount should be re-determined under RZF.     

乳成分在线测定仪——"魔盒"

魔盒(如左图)只有拳头般大小,但它的功能却多样,在挤奶的同时,能在线检测原料奶的各种成分,包含乳脂、乳蛋白、乳糖、总固体、尿素,血、体细胞,其中体细胞又可分成四个类别,(a)体细胞<20万/mL,(b)体细胞在20￣40万/mL,(c)体细胞在40￣80万/mL,(d)体细胞>80万/mL。检测的时间就是牛只完成挤奶的同时,即在挤奶的瞬间,魔盒对牛奶中的上述指标进行检测。测出的数据将自动显示并保存在电脑中,并由阿菲牧(由以色列阿菲金公司研发)牛场管理软件永久保存,方便随时随地查阅。这些数据对牛场和乳品企业具有如下意义:1对牧场生产具有直接的指导意义牛…     

海南坡鹿迁地保护现状与建议

迁地保护的海南坡鹿种群可以分为野放、半野放和圈养等3种主要类型。野放种群个体数量最多，约占迁地保护种群个体总数的55．3％；其次为半野放种群，其个体数量占35．6％；圈养种群个体数量最少，只占9．1％。半野放是一种较为稳妥的坡鹿种群恢复方式。在海南坡鹿的迁地保护中，应该增加半野放种群个体数量。本文就海南坡鹿的迁地保护提出了7点保护管理及科学研究建议。     

Effect on Rendement Napole genotype on metabolic markers in Ossabaw pigs fed different levels of fat

We investigated effects of Rendement Napole (RN ) genotype on metabolic markers in Ossabaw pigs fed diets with different levels of dietary fat. Thirty‐two pigs, belonging to either the wild‐type (WT , rn⁺/rn⁺) or carrier (CAR , RN ^?/rn⁺) genotypes (n  = 16/genotype), were divided into two dietary groups, (high fat [HF ] or low fat [LF ]) diets, for 12 weeks (n  = 8 pigs/genotype/diet) after which pigs were killed for gene expression analysis by RT ‐PCR . Feeding HF diet caused increased daily gain (ADG , p  <  .05) and final body weight (BW ) (p  <  .05) in comparison with the LF diet (p  <  .05). Feed efficiency (gain:feed) was higher (p  <  .05) in pigs on the HF and was higher (p  <  .05) in CAR pigs compared to WT . There was genotype × diet interaction (p  =  .05) on final BW such that CAR animals on LF diet had the same final BW as animals of both genotypes on HF diet. Carrier pigs on LF diet had higher (p  <  .05) average daily gain and gain:feed than WT pigs. There was a trend (p  <  .08) for a higher feed consumption in pigs on the LF diet. Backfat thickness was higher (p  <  .01) in pigs on the HF diet. Serum triglyceride was higher (0.62 vs. 0.33 mg/dl, p  <  .01) in pigs on HF diet. Serum insulin was higher (p  <  .05) in CAR versus WT pigs (0.40 vs. 0.015 μg/ml). Pigs on the HF diet had a higher (p  <  .05) serum insulin compared to those on the LF diet (0.032 vs. 0.023 μg/ml). Carnitine palmitoyl transferase 1‐alpha was higher (p  <  .05) in the longissimus dorsi and semitendinosus muscles of pigs on HF diet. Acyl‐CoA oxidase I was elevated (p  <  .05) in the liver of pigs on HF diet. Fatty acid synthase was lower in the longissimus dorsi muscle, liver and mesenteric fat (p  <  .05) of carrier pigs. The RN gene regulates specific metabolic markers in the Ossabaw pigs.     

利用血液蛋白及酶多态性分析技术鉴定山羊亲缘关系的研究

选择血红蛋白(Hb)、运铁蛋白(Tf)、亮氨酸胺肽酶(LAP)、前白蛋白3(Pa3)、淀粉酶(Amy)对可能为同卵双生波尔山羊的亲缘关系鉴定。结果发现，除淀粉酶(Amy)和亮氨酸胺肽酶(Lap)外，其余位点均有多态性。由蛋白位点的基因型判定羔1、羔2基因型完全一致，是供体后代的概率为75G，受体后代的概率为22．8％，从而确认羔1、羔2的双亲为供体公羊和供体母羊。     

二苯碳酰二肼分光光度法测定养殖海水中六价铬几种条件比较

通过标准曲线、定量限、准确度、精密度和加标回收率等试验比较不同条件对二苯碳酰二肼分光光度法测定养殖海水中六价铬含量的试验结果的影响.结果显示:从定量限、准确度、精密度和加标回收率等角度综合考虑,3种曲线配制基底、4种显色剂及除磷酸、盐酸、高氯酸和醋酸以外的4种酸体系的使用都可以很好地满足试验要求,准确度高,重现性好.但从操作简单和经济环保方面考虑,以水配制标准曲线的方式及含乙醇显色剂的应用更加适用于养殖海水中六价铬测定,值得推广使用.     

Real-time PCR方法和PCR方法检测虾白斑综合征病毒

由白斑综合征病毒引起的虾白斑综合征是国际兽医局（OIE）规定的必须上报的水生动物二类疫病。本研究首先通过设计新的PCR引物，提高了PCR检测白斑综合征病毒的阳性检出率。为进一步提高白斑综合征病毒检测的灵敏度，本研究采用TaqMan探针技术建立了快速检测白斑综合征病毒的real-time PCR方法，通过与常规PCR方法比较，证实其检测灵敏度显著提高。     

江西省稻瘟病菌毒性的群体结构分析

用江苏省的吴江、赣榆、通州、高邮和宜兴等5个代表地区的324个稻瘟病菌株接种13个日本已知抗病基因品种，结果表明，江苏省稻瘟病菌对携带有Pi-Ka,Pi-ta,Pi-ta2和Pi-sh抗病基因品种的可致病比例较高，毒力频率达64．2％－97．2％，对携带有Pi-iPi-z和Pi-b抗病基因的品种毒力频率较低，在0－11．9％之间；江苏省稻瘟病菌毒性的群体结构年度间有一定变化，表现为对某些抗病基因品种毒力频率的明显上升或下降。从江苏省10年主栽品种上分离的稻瘟病菌株对13个已知抗病基因品种的毒力频率测定结果表明，不同类型主栽品种上分离的菌株其毒性结构组成有一定差异,表明江苏省水稻主栽品种的抗性类型存在一定差异。     

响应面法优化挤压膨化犬粮加工工艺的研究

以犬粮配方研究中所确定的最佳配方为基础,以糊化度作为挤压膨化犬粮核心品质指标,通过单因素和响应面实验,对螺杆转速、物料水分、喂料速率和套筒温度等双螺杆挤压机的主要操作参数与犬粮糊化度之间的关系进行了研究。建立了糊化度与4个因素变化的二次回归方程。结果表明,物料水分为25%,螺杆转速为30 Hz(1 Hz=5 r/min),套筒温度为160℃,喂料速率为24 Hz(1 Hz=1.7 r/min)的条件下,犬粮的糊化度达到89.7%。     

草地贪夜蛾幼虫日龄及取食的食物对淡足侧沟茧蜂寄生效果的影响

为评估淡足侧沟茧蜂对草地贪夜蛾的防控效果,在室内环境条件下,研究了草地贪夜蛾幼虫寄主日龄和所取食食物对淡足侧沟茧蜂寄生效果的影响.结果表明,无论草地贪夜蛾幼虫取食人工饲料或玉米叶片,淡足侧沟茧蜂对3日龄和5日龄寄主幼虫的寄生率、结茧率、出蜂率及对寄主致死率均显著高于8日龄寄主.另外,在同日龄情况下,淡足侧沟茧蜂对取食玉...