NaCl胁迫对野生苜蓿种子萌发特性的影响

以2种野生牧草杂花苜蓿(Medicago varia)和黄花苜蓿(M.falcata)为试验材料,测定了NaCl浓度0、50、100、150、200mmol/L处理下种子的发芽率、发芽势、发芽指数、活力指数和苗长、胚根长等萌发指标,分析2种野生牧草种子萌发期耐盐性变化规律.结果表明:1)NaCl胁迫对2种野生苜蓿种子发芽都产生了抑制作用,高浓度NaCl胁迫对黄花苜蓿发芽率影响大,且高浓度下黄花苜蓿的发芽率高于杂花苜蓿.2)NaCl浓度为0～50 mmol/L时黄花苜蓿的发芽势低于杂花苜蓿,100～200 mmol/L时高于杂花苜蓿.3)杂花苜蓿和黄花苜蓿种子发芽指数在100 mmol/L时均较对照下降50％.对照活力指数黄花苜蓿种子是杂花苜蓿种子的2倍.4)2种野生苜蓿种子在NaCl胁迫下胚芽长和胚根长表现出不同的下降规律,NaCl胁迫对黄花苜蓿胚芽长度下降较杂花苜蓿大,但杂花苜蓿的胚根长下降较黄花苜蓿大.利用隶属函数对2种野生牧草萌发期各指标综合评价得出:黄花苜蓿的耐盐性较杂花苜蓿强,可用于盐渍化土壤的建植.     

3种苜蓿形态特征及变异分析

以紫花苜蓿（Medicago sativa）,黄花苜蓿（M．falcata）和杂花苜蓿（M．varia）为试验材料,从形态学水平对苜蓿的遗传变异以及亲缘关系进行分析发现,不同品种的变异十分丰富,叶面积和叶宽具有较高的变异水平。相关性分析表明,除节间数和节间长度两个指标与叶形态指标没表现出相关性外,其他指标大多数都表现出显著的相关性;主成分分析表明,形态学性状的主要变异来源于叶宽、主茎长、节间数、节间长、叶型指数。不同类型苜蓿的总变异依次为：紫花苜蓿〉黄花苜蓿〉杂花苜蓿。     

浅谈苜蓿与苜蓿产业化

苜蓿是一种豆科苜蓿属多年生的草本植物，因其花色不同分为紫花苜蓿、黄花苜蓿和杂花苜蓿，一般所说的苜蓿都是指紫花苜蓿。苜蓿是世界上人工栽培牧草中面积广、范围大、历史悠久、经济价值较高的豆科牧草，素有“牧草之王”的美誉。据统计，全世界苜蓿种植面积约为3300万hm^2，其中美国种植     

苜蓿和羊草营养与质量评价

1我国牧草种质资源 1．1优良牧草种类 豆科牧草：紫花苜蓿、黄花苜蓿、杂花苜蓿、红豆草、百脉根、草木栖等。     

不同苜蓿品种再生特性的研究

对4个苜蓿品种进行不同频次的刈割处理,结果表明,在我国北方地区,黄花苜蓿和杂花苜蓿每年适合刈割2次,此时,地上生物量和粗蛋白质产量均达到最大值;而紫花苜蓿刈割2或3次均可,地上生物量和粗蛋白质产量在刈割2和3次之间差别不大,但明显高于刈割1和4次处理;不同苜蓿品种的粗蛋白质含量与形态发育阶段之间均呈极显著的二次相关,均表现为先下降后上升的趋势。此外,通常认为的黄花苜蓿比紫花苜蓿粗蛋白质含量高,并非是由物种的差异引起的,而主要是由收获时生育阶段的差异引起的。     

4份苜蓿材料在3个生态区的营养成分含量比较

对生长在武威、榆中、天水3个生态区的4份苜蓿材料清水紫花苜蓿、陇东紫花苜蓿、野生黄花苜蓿和甘农2号杂花苜蓿营养成分进行测定,结果表明,同一苜蓿材料的营养成分含量在不同生态区呈显著差异。武威生态区的粗蛋白、粗纤维、粗脂肪、镁、P等指标含量都较其他2个生态区高,说明外界环境因素对苜蓿的营养成分含量的高低具有主导作用;4份苜...     

苜蓿褐斑病对牧草质量光合速率的影响及田间抗病性

研究了田间自然发病条件下褐斑病 (Pseudopeziza medicaginis)对紫花苜蓿 (Medicagosativa)叶片营养成分含量和光合速率的影响 ,并评价了 85个紫花苜蓿 ,5个杂花苜蓿 (M.varia)和 4个黄花苜蓿 (M.falcata)品种或群体对褐斑病的抗性。结果表明 ,褐斑病使苜蓿病叶中粗蛋白质含量显著下降 ,与健叶相比 ,其含量可减少 2 5% ,减少的幅度与病害严重度极显著负相关 ,r=0 .96 5(P<0 .0 1)。叶片光合速率随病害严重度的增加而降低 ,当病斑平均面积为叶面积的 13%时 ,光合速率仅为健叶的 52 % ,而当病斑平均面积为叶面积的 85%时 ,其光合速率仅为健叶的 15.9%。在参试的 94个品种或群体中 ,仅润布勒杂花苜蓿的一个群体表现为免疫。抗病性较强的有来自加拿大的巴瑞尔、阿毕卡 ,来自美国的威斯康星和我国的兴平、武功、肇东等 10个紫花苜蓿品种和润布勒杂花苜蓿的另一个群体。其余 83个品种均表现出较高的感病性 ,包括美国的 78- 15,加拿大的大西洋 ,我国的和田、咸阳等紫花苜蓿品种和内蒙黄花等黄花苜蓿品种     

甘农一号杂花苜蓿品种选育报告

以提高抗寒性、越冬性为日标,开展黄花苜蓿和紫花苜蓿的杂交育种。配制多个人工杂交组合,利用黄花苜蓿开放传粉杂种并引进杂种品种,在高寒地区进行抗寒筛选,采用改良混合选择法,选育出以82个无性系为基础综合而成的抗寒品系“甘农杂18”。通过品种比较试验、区域试验、生产试验表现良好,定名为“甘农一号”杂花苜蓿。     

黄花苜蓿幼苗形态特征及生长的初步研究

选择俄罗斯三个育成品种雅酷、秋柳、达菲(音译)和我国野生锡盟、呼盟黄花苜蓿为主要研究对象，草原三号杂花苜蓿作为对照，在温室内盆栽，对幼苗形态特征、生长速度和生物量积累特点进行研究。结果表明，从根、茎、叶的形态特征及幼苗生长速度、生物量积累等方面杂花苜蓿表现出了杂交优势，秋柳、雅酷和锡盟三份黄花苜蓿材料也显示出了优于其他黄花苜蓿品种的特征。     

紫花苜蓿在西藏长势最佳

于1999年5月,我们在西藏林芝地区八一镇泥洋河畔的西藏农牧学院牧草试验基地,进行了内蒙古杂花苜蓿,黄花苜蓿、紫花苜蓿的比较试验。供试草种经过发芽率和纯净度的试验和分析,均符合质量要求。共设3个小区,每小区面积为2m×5m=     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.