根腐病发生对枳砧纽荷尔脐橙菌根生长的影响

以湖北兴山枳砧纽荷尔脐橙未感病、轻度感染和严重感染根腐病植物为材料,分析根腐病发生对菌根生长的影响。结果表明,与未感病植株相比,轻度感病与重度感病植株根系菌根侵染率分别降低了50.4 %和64.9 %。此外,根腐病发生还显著抑制了根系活力、根际孢子密度和土壤菌丝长度,且随着根腐病发生程度加剧,菌根生长抑制也逐渐增强。根腐病发生也显著降低菌根真菌释放的球囊霉素相关土壤蛋白含量,尤其是难提取和总球囊霉素相关土壤蛋白。研究结果暗示了根腐病的发生抑制了枳砧纽荷尔脐橙菌根的生长以及菌根代谢物球囊霉素的释放。     

柑橘黄龙病对纽荷尔脐橙叶片营养元素及土壤微生物群落的影响

柑橘黄龙病(Citrus Huanglongbing, HLB)堪称柑橘的癌症,严重为害产业健康发展。本研究采用盆栽试验,通过ICP-MS、平板计数法及微平板法测定了不同染病时间的纽荷尔脐橙叶片的矿质营养元素含量、土壤微生物种群数量及微生物功能多样性。研究结果表明,在黄龙病侵染的纽荷尔脐橙病株中,叶片中显著性减少的矿质营养元素多与叶绿素合成及光合系统相关。而土壤微生物群落功能多样性的下降时间段与土壤纤维素分解菌的增加时间段相吻合,表明根系生态系统的破坏多发生于黄龙病侵染后的6-8个月。     

柑橘碎叶病毒侵染对‘纽荷尔’脐橙光合作用及酶活性的影响

为掌握柑橘碎叶病毒(Citrus tatter leaf virus, CTLV)侵染对‘纽荷尔’脐橙光合作用及酶活性变化的影响,探讨CTLV对寄主植株的致病机理。本研究测定了感染CTLV的‘纽荷尔’脐橙叶片的光合色素含量、净光合速率和胞间CO2浓度、丙二醛（MDA）含量及过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）活性,结果显示病株叶片中叶绿素a、b和叶绿素总含量分别下降14.2%、12.1%和17.5%,叶片净光合速率下降10.8%,胞间CO2浓度上升8.7%,MDA含量增加12.9%,CAT、POD和SOD酶活性分别提升了11.3%、27.6%和16.3%。透射电镜观察发现,病株叶绿体外膜褶皱、边缘模糊,内含物淀粉粒变小。     

库源比影响纽荷尔脐橙叶片光合特性

中国农业科学院柑桔研究所的研究人员淳长品等以纽荷尔脐橙为材料,比较了无果枝、单果枝和两果枝等三种类型枝条上第2、4和6片叶生长状况和在果实发育期间光合特性的差异。结果表明,有果枝的叶片面积、厚度、叶绿素、氮、磷和钾含量均显著低于无果枝,有果枝的第2、4片叶净光合速率(Pn)显著或极显著低于无果枝的同位叶片,且第2、4和6叶的平均     

不同钾水平对枳壳砧木生理生化特性的影响

以柑橘枳壳砧木作为试验材料,设置5个钾浓度梯度：0mmol/L(K0)、1mmol/L(K1)、2mmol/L(K2)、5mmol/L(K5)、10mmol/L(K10)。研究不同钾水平对枳壳砧木农艺性状、干物质积累、各部位元素含量和比例、抗逆性等的影响。结果表明：K5和K10处理明显降低了枳壳砧木株高、叶片数和干鲜重,其中K10的情况下,植株株高、叶片数和总鲜重较K2水平下降了35%、33.3%和35.6%;枳壳砧木各部位钾含量随着供钾浓度的上升而上升,各部位钙镁和叶片中的钠含量则相反;供钾浓度的增加,显著提升了枳壳砧木各部位K:Na、K:B、K:Ca还有K:Mg的比值,破坏了植株体内元素的平衡;叶片中淀粉、蔗糖、可溶性糖和果糖的含量随着供钾浓度的提高而增加;K0和K10处理下,叶片中的脯氨酸和丙二醛含量会明显上升。     

叶面喷施易提取球囊霉素相关土壤蛋白对纽荷尔脐橙果实品质和土壤性状的影响

以纽荷尔脐橙为对象,叶面喷施静置的或离心的易提取球囊霉素相关土壤蛋白（EEG）,分析其对根系菌根发育、果实内外品质以及土壤团聚体分布、稳定性和球囊霉素含量的影响。结果表明,两种制备的EEG促进了菌根在根系和土壤中的发育,其中离心的EEG对土壤菌丝长度的促进作用突出,静置的EEG对根系菌根侵染率的促进作用明显。叶面喷施EEG也提高了果肉重和单果重以及果实纵径、可溶性固形物、葡萄糖、果糖和蔗糖含量,其中离心EEG在果肉重、硬度和葡萄糖含量上的效果高于静置EEG的效果。两种制备的EEG还提高了土壤易提取和总GRSP的含量以及1-2 mm和2-4 mm粒级的水稳性团聚体分布和团聚体稳定性。因此,EEG可作为生物刺激物改善果实品质,这与其提高菌根发育和土壤结构有关。     

挂果对纽荷尔脐橙枝条源叶光合作用的影响

在纽荷尔脐橙果实膨大期,选取1年生双果枝、单果枝和营养枝,测定源叶净光合速率（Pn）、气孔导度（Cond）、蒸腾速率（Trmmol）等光合生理指标,探讨挂果对枝条源叶光合特性的影响。结果表明,挂果对叶片 （源） Pn、Cond、Trmmol在上午光合作用较强时间段影响显著,对Ci和Tleaf无显著影响,并且无果枝Pn高于单果枝和双果枝。挂果对果枝叶片Pn、Cond、Trmmol、Ci的日变化曲线没有影响,Pn仍然表现为典型的“双峰”曲线。     

外源赤霉素对纽荷尔脐橙容器大苗花芽分化的影响

本试验以枳壳为砧的纽荷尔脐橙2年生容器大苗为试材,分别于2013年、2014年连续两年研究了不同喷药时期（10月到次年2月）,不同赤霉素浓度（200ppm、300ppm、400ppm、500ppm）抑制花芽分化的效果。结果表明：各浓度均产生抑制效果且效果显著优于对照,当喷药时间为11月5日左右时,赤霉素浓度为300ppm,花枝明显减少,营养枝比例多,抑制花芽分化效果较好,但各处理间差异不显著。喷施浓度过高会导致叶片呈现细长型,喷施时间推迟抑制效果减弱。同时研究了从11月5日开始每隔半个月喷药一次,连续喷药三次,喷药浓度分别为50ppm、100ppm、200 ppm、300 ppm、400 ppm、500 ppm ,以不喷药为对照,抑制花芽分化的效果,结果表明：各浓度均产生抑制效果且效果显著优于对照,但各处理间差异不显著,且随着喷施浓度的升高,叶片呈现细长型,因此综合考虑当浓度为50ppm时,抑制效果较好。     

鸡缺锌对含硫氨基酸代谢的影响

选用２日龄雏鸡,用含锌量低（２８ｍｇ／ｋｇ）的基础饲料饲喂１周后,分为基础饲料组、基础饲料＋锌组、基础饲料＋含硫氨基酸（ＳＡＡ）组、基础饲料＋锌＋ＳＡＡ组,研究了鸡缺锌对ＳＡＡ代谢的影响。结果表明,鸡缺锌时,其体内ＳＡＡ同化作用减弱,异化作用增强,导致血清无机硫（ＳＯ２－４）、粪尿总硫及无机硫（ＳＯ２－４）极显著增多（Ｐ＜０．０１）;缺锌鸡增重、血清锌含量、血清碱性磷酸酶（ＡＫＰ）活性极显著下降（Ｐ＜０．０１）,并表现较典型的临床缺锌症状。添加ＳＡＡ能促进鸡对锌的吸收和利用,使血清锌含量和血清ＡＫＰ活性提高（Ｐ＜０．０１）。     

生物炭对酸性红壤改良及纽荷尔脐橙苗生长的影响

采用盆栽试验,以0、1%、2% 生物炭量及其配施化肥（F）施于酸性红壤中,研究了生物炭对酸性红壤理化性质以及脐橙幼苗生长的影响。结果表明,不同生物炭用量对酸性红壤理化性质有明显影响。其中,红壤有机碳含量和pH值均有显著改变,如pH值提高0.45-0.96个单位、有机碳含量提高1-3.1倍;生物炭也能够提高红壤中碱解氮、速效磷和速效钾等含量,其中速效钾提高最为显著。生物炭处理脐橙幼苗茎粗增加量比对照多0.10-0.24cm;单施生物炭脐橙幼苗抽梢和叶片总量无明显提高,但生物炭与底肥配施的抽梢和叶片总量分别比对照高21.0%和70.0%。施生物炭后新叶中氮则随生物炭量增加而降低。除对照老叶外,磷含量在老叶和新叶中均随生物炭量增大而提高;同时,不同炭处理老叶和新叶中钾含量表现为：1%C>2%C>CK,F>F+2%C>F+1%C。因此,生物炭能改良酸性红壤,也有利于脐橙苗的生长。     

NaCl胁迫对2种柑橘砧木生长及盐离子分布的影响

以耐盐性不同的柑橘砧木枳和枸头橙为材料,分析NaCl胁迫后植株生长表现以及盐离子（Na+和Cl-）在叶片、茎和根中的含量。结果表明：NaCl胁迫降低了植株的株高和干重,而枳的下降幅度高于枸头橙。NaCl胁迫导致2种砧木叶片相对电导率升高,枳高于枸头橙。此外,NaCl处理后2种砧木叶片、茎和根中的Na+和Cl-含量均上升。除了处理21天内枳叶片Cl-含量低于枸头橙外,其他时间枳叶片和茎中的盐离子含量均高于枸头橙。在根中,NaCl处理15天内枳中的Na+和Cl-含量高于枸头橙,其后则是枸头橙高于枳。     

Effects of zinc levels on activities of gastrointestinal enzymes in growing rats

The present study investigated the effect of different zinc (Zn) levels on activities of gastrointestinal digestive enzymes of growing rats. Four diets including Zn‐adequate (ZA; 46 mg/kg, control), Zn‐deficient (ZD; 3 mg/kg), high Zn supply (ZH; 234 mg/kg) and pair‐fed in which animals received the ZA diet at restricted amounts reflecting feed intake of the ZD group were fed to rats for 5 weeks. Dietary Zn was supplemented with ZnO. The results showed that Zn deficiency resulted in decreases in body weight, while ZH supply stimulated growth. The activities of sucrase, lactase and lipase were unaffected by dietary Zn levels. Maltase activity, however, was reduced in ZD group and elevated in ZH group. Amylase and protease activities were depressed by zinc deficiency. However, rats fed the Zn‐repletion diet displayed higher activity of pepsin, pancreatic amylase and protease. In particular, ZH supply did have no effect on intestinal hydrolases activities. The present study suggested that zinc deficiency impaired the activities of digestive enzymes and growth of animals. However, ZH supply might improve the digestion of nutrients via increasing activities of gastrointestinal hydrolase and probably enhanced animal health.     

湖南地区柑橘类植物景观资源的分析及配置模式研究

柑橘类植物株型饱满、花繁香郁、秋季金果累累。柑橘象征品性高洁,寓意吉祥安康,再加上特殊的药用价值和芳香功能,使之能成为一种优良的现代景观植物。湖南地区柑橘资源丰富,诸多品种同时具备观赏性、食用性及药用价值。本文分析了湖南地区柑橘类植物的生长习性、观赏特点,挖掘其在园林景观设计上的应用价值,提出了适合这类植物的果林式、庭荫式、盆栽式和篱垣式四种园林配置方式,为园林设计中植物选择和配置提供参考。     

高锌日粮对奶牛产乳性能及血锌含量的影响

选择经产期和产奶量相近的健康中国荷斯坦奶牛50头,完全随机分成5组,每组10头,分别饲喂基础日粮及添加150mg/kg和300mg/kg的有机锌和无机锌日粮。结果表明:1)添加150mg/kg和300mg/kg的锌对牛奶中乳脂率、乳蛋白、乳糖和非脂固形物(SNF)含量无显著影响(P>0.05);2)无机锌对产奶量无显著影响(P>0.05),而添加有机锌则可显著提高奶牛产奶量(P<0.05);3)高锌可极显著(P<0.01)提高血锌和乳锌含量,而且血锌与乳锌之间存在线性相关(r=0.627,n=50)。     

The ubiquitous role of zinc in health and disease

Objective – To review zinc physiology and pathophysiology and the importance of zinc toxicity and deficiency in veterinary patients.
Data Sources – A review of human and veterinary medical literature.
Human Data Synthesis – There is a significant amount of original research in humans and animals on the role of zinc in multiple organ systems. There is also significant data available on human patients with zinc abnormalities.
Veterinary Data Synthesis – Zinc deficiency has been studied in dogs with genetic disease and dietary deficiency leading to dermatological disease and immune deficiency. Zinc toxicity has been described after ingestion of metallic foreign bodies containing zinc.
Conclusions – Historically, the role of zinc in health and disease has been studied through patients with toxicity or severe deficiency with obvious clinical signs. As the ubiquitous contribution of zinc to structure and function in biological systems was discovered, clinically significant but subtle deficiency states have been revealed. In human medicine, mild zinc deficiencies are currently thought to cause chronic metabolic derangement leading to or exacerbating immune deficiency, gastrointestinal problems, endocrine disorders, neurologic dysfunction, cancer, accelerated aging, degenerative disease, and more. Determining the causal relationships between mild zinc deficiency and concurrent disease is complicated by the lack of sensitive or specific tests for zinc deficiency. The prevalence of zinc deficiency and its contribution to disease in veterinary patients is not well known. Continued research is warranted to develop more sensitive and specific tests to assess zinc status, to determine which patients are at risk for deficiency, and to optimize supplementation in health and disease.     

应用硫酸镁矫治柑橘缺镁症效果研究

【目的】研究提高硫酸镁叶面矫治柑橘缺镁症的效果。【方法】以硝酸镁为对照,对硫酸镁进行安全浓度与矫治效果,以及表面活性剂与ZnO增效试验。【结果】提高硫酸镁施用浓度能有效地提高矫治效果,叶片含Mg增加量在试验浓度范围内呈近指数增长：△Mg=0.0044672.C2.11298、F=72.09,P<0.0001（MgSO4?7H2O浓度％,C=2、3、4、5）。试验没发现同等镁离子浓度的硫酸镁和硝酸镁溶液对柑橘叶片气孔的开闭有影响;叶面活性剂与0.1% ZnO增效剂对柑橘缺镁矫治效果影响不显著。另,统计分析表明：在试验样株处于严重缺Mg与缺N状态下,叶面施用硝酸镁后叶片N含量变化与NO3﹣浓度无关,叶片△N与对照叶片N的偏相关极显著r =﹣0.6223、P=0.0026（偏因子NO3﹣、Mg2 浓度）,即对照叶片基础含N越低,处理后叶片△N增幅越明显;处理叶片△S与施用SO42﹣浓度无关,却与叶片△Mg呈极显著相关r =0.6467、P=0.0009。【结论】硫酸镁叶面矫治柑橘缺镁症推荐浓度：萌芽至幼果期≤5％,矫治效果与2％硝酸镁相当;其它生长季≤8％,冬季10％。     

Effects of dietary supplementation with tribasic zinc sulfate or zinc sulfate on growth performance,zinc content and expression of zinc transporters in young pigs

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc × Landrace × Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100 mg/kg Zn from either ZS or TBZ for 28 days. Feed : gain ratio in pigs fed TBZ were lower (P < 0.05) than pigs fed ZS, and average daily weight gain tended to increase (0.05 ≤ P ≤ 0.10) in pigs fed TBZ. Compared with pigs fed ZS, pigs fed TBZ had a higher CuZn‐superoxide dismutase and Zn content in serum (P < 0.05) while they had a lower Zn content in feces (P < 0.05). In addition, ZIP4 mRNA expression of zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P < 0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs.     

Effects of two zinc supplementation levels and two zinc and copper sources with different solubility characteristics on the growth performance,carcass characteristics and digestibility of growing-finishing pigs

The present study was conducted to evaluate the effect of two Zn supplemented levels and two Zn and Cu sources (sulphate and hydroxychloride) on growing-finishing pigs. An in vitro study and an in vivo study were conducted. In the in vitro study, Zn solubility from each source at different Zn supplementation levels was evaluated, as well as the phytic phosphorus (PP) solubility derived from the interaction or not with phytic acid at similar conditions to those found in digestive tract. The most critical interaction of Zn with phytic acid was at pH 6.5 and with Zn sulphate, resulting in the reduction in PP solubility. In the in vivo experiment, a total of 444 pigs ([Duroc × Landrace]×Pietrain; initial BW: 18.7 ± 0.20 kg) were allotted to 36 pens in a randomized complete block design (2 × 2) factorial arrangement with two Zn and Cu sources and two Zn supplemental levels (20 and 80 mg/kg). The Cu supplementation was fixed at 15 mg/kg for all diets. There was no effect of the interaction between mineral source × Zn level or Zn level on growth performance or carcass characteristics (p > .10). Apparent total digestibility of Zn and Cu along with carcass yield was higher for pigs fed hydroxychloride than pigs fed the sulphate counterparts (p < .05). Feeding low levels of Zn decreased Zn (45.5%; p < .0001) and Cu(18.5%; p = .018) faecal excretion. In conclusion, under commercial conditions, feeding growing-finishing pigs with Zn levels below those established by the European Union regulation did not affect growth performance and carcass characteristics. Reducing dietary mineral (Zn and Cu) diet content resulted in a lower faecal mineral excretion. Pigs fed sulphate minerals had an improved performance during grower period, while pigs fed hydroxychloride minerals showed an improved performance during finishing period and a greater carcass yield and mineral digestibility than those fed sulphates.     

锌对动物免疫器官发育和免疫功能的影响

本文综述了微量元素锌与动物免疫器官发育、细胞免疫、体液免疫和与自由基防御系统的关系。指出低锌严重影响胸腺、法氏囊的发育,且影响程度随缺乏时间的延长而加剧。而采食过量的锌对免疫器官的发育同样造成不良影响。低锌可降低迟发性免疫反应,适宜锌水平可增加抗体滴度,提高免疫球蛋白水平。对于仔猪,高锌可提高过氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSH-Px)活性,保护机体免受自由基损伤。