氯化钙对玉米幼苗受低温、Na2CO3双胁迫诱导蛋白鉴定

研究以水浸种25℃为对照,以5℃低温和Na2CO3双胁迫培养玉米幼苗24h进行蛋白质电泳分析。扫描图谱分析结果表明,5℃低温和Na2CO3双胁迫培养玉米幼苗,能合成新的诱导蛋白。     

玫瑰茄粗多糖清除DPPH自由基活性研究

以玫瑰茄干花萼为原料,利用水浸醇析法提取玫瑰茄粗多糖,其抗氧化活性用清除1,1-二苯基苦基苯肼（DPPH）自由基的能力进行评价。结果表明,玫瑰茄粗多糖具有良好的抗氧化活性,其浓度在0.551~2.150 mg/mL范围内,与清除率呈较好的线性关系：y=28.7684x+39.43208,R=0.973。     

NO、TNF和IL-2与新型鸭肝炎病毒感染雏鸭肝脑组织损伤的关系

用新型鸭肝炎病毒人工感染9日龄健康樱桃谷雏鸭，对感染后12、24、48、96、168h和14d雏鸭血液、肝和脑组织中一氧化氮（NO）含量，血液中肿瘤坏死因子（TNF）和白细胞介素2（IL-2）含量进行了测定，同时对感染雏鸭的组织病理学变化进行了观察。结果表明．血清中NO含量在接种后48h开始升高，一直持续到接种后96h，接种后7d恢复正常；肝脏组织中NO含量仅在接种后24h与对照组比较显著升高，在其他时间未表现有差异；脑组织中NO含量在整个试验期间没有变化。血清中的TNF和IL-2含量在接种后24h均表现升高，接种后96h降低，其他时间无改变。感染雏鸭的肝组织在接种后24h表现出血性坏死性肝炎变化，接种后48～96h呈增生性病变，而接种后各时期脑组织均呈非化脓性脑炎变化。由此表明，新型鸭肝炎病毒感染可导致雏鸭体内NO、TNF和IL-2发生变化，并且与肝组织损伤、疾病的发生发展有关。     

超临界CO_2萃取紫苏油的工艺优化研究

[目的]优化超临界CO2萃取技术提取紫苏油的工艺,为开发紫苏资源提供科学依据。[方法]利用超临界CO2流体作为萃取溶剂从紫苏子中提取紫苏油。以紫苏子萃取后的出油率为指标,通过L9(33)正交试验筛选超临界CO2提取紫苏子油的最佳工艺,研究萃取温度、萃取压力、CO2动态流量3种因素对萃取紫苏子油产率的影响。[结果]萃取紫苏子油的最佳工艺为萃取压力20 MPa、萃取温度40℃、CO2动态流量30 L/h。在3种影响因素中,萃取压力的影响作用最显著,CO2动态流量的影响次之,萃取温度影响最小。[结论]采用超临界CO2萃取法提取脂溶性成分具有速度快、效率高和无污染的特点,其溶媒CO2可循环利用,因此,选用超临界CO2萃取法提取紫苏子油非常可行。     

干旱胁迫对橙红丹桂叶片光合性能的影响

采用盆栽控水法人工模拟干旱胁迫,设置土壤含水量为土壤田间持水量的15%(W1)、30%(W2)、45%(W3)、60%(W4)和充足供水(ck)5个水平,研究干旱对3年生橙红丹桂(Osmanthus fragransChenghongdangui)叶片光合性能的影响。结果表明:①干旱胁迫下,净光合速率Pn、气孔导度Gs、胞间CO2浓度Ci和蒸腾速率Tr降低,水分利用效率WUE升高;②在土壤含水量比较充足的环境条件下(W4和ck),橙红丹桂对强光(1 000~2 000μmol.m-2.s-1)有较强的耐受能力,同时对弱光(0~400μmol.m-2.s-1)也有较高的转化和利用效率;③干旱胁迫下,表观量子效率AQY、光饱和点LSP、表观羧化效率ACE降低,光补偿点LCP、CO2补偿点CCP升高。     

Ca^2＋,BR对玉米呼吸器官耐冷性的影响

研究了外源Ｃａ２＋、ＢＲ对低温下玉米胚芽呼吸速率、膜透性以及对线粒体呼吸控制比、ＳＯＤ活性和ＭＤＡ含量的影响。结果表明，Ｃａ２＋、ＢＲ处理，相应提高了种苗胚芽的呼吸速率，降低膜透性。低温下经Ｃａ２＋、ＢＲ处理的玉米种苗，其线粒体有较高的呼吸控制比。Ｃａ２＋处理的线粒体中ＳＯＤ活性比对照高；ＭＤＡ含量比对照低。Ｃａ２＋和ＢＲ可能是在低温下通过维持膜系统的正常结构和功能来提高玉米种苗的耐冷性的     

Effects of elevated CO2 concentration on bulbil germination and early seedling growth in Chinese yam under different air temperatures

The present study investigated the effects of elevated carbon dioxide concentration ([CO₂]) and air temperature on the germination of seed bulbils and the seedling vigour of two Chinese yam lines. Plants were grown under two [CO₂] levels, ambient and elevated (ambient + 200 μmol mol^?1), and two mean air temperature regimes, 22.2 °C (ambient + 1.4 °C) and 25.6 °C (ambient + 5.2 °C). Elevated [CO₂] did not affect bulbil germination under both air temperature regimes. During the early growth stage, the dry weight (DW) of leaves, vines, shoots, roots, belowground parts (roots + tubers) and whole plants were higher under elevated [CO₂] than ambient [CO₂] for both lines under the low- and high-temperature regimes. The values of vigour indexes (index I = germination % × seedling length and index II = germination % × seedling DW) were also higher under elevated [CO₂] than ambient [CO₂] for both lines. These results indicated that Chinese yam seedlings respond positively to elevated [CO₂] during the early growth stage. The above:belowground DW ratios were lower under elevated [CO₂] than ambient [CO₂] in seedlings with very small new tubers for both yam lines, indicating that elevated [CO₂] strongly affected the root growth in the early growth stage. The DWs of post-treatment seed bulbils were higher in the elevated [CO₂] under both air temperature regimes. The results showed that Chinese yam used a smaller amount of the reserves in seed bulbils under elevated [CO₂] than under ambient [CO₂].     

Detection of cows with insemination problems using selected classification models

In the present study, the detection of cows with artificial insemination (AI) difficulties using selected statistical and machine learning methods is presented. Cows were divided into two classes: those that conceived after one or two services (“GOOD”) and those that required more than two services per conception (“POOR”). The best performance was exhibited by one of the artificial neural networks (ANN) and the multivariate adaptive regression spline (MARS) method (AIC, BIC, RMS and accuracy); whereas logistic regression (LR) and classification functions (CF) were of somewhat lower quality. The detection of cows with AI difficulties, performed on the basis of the test set comprising new instances, showed that the ANN and MARS were more precise in comparison with the statistical methods. Sensitivity and specificity were over 85% for the perceptron with two hidden layers (MLP2) and MARS and approximately 80% or lower for LR and CF. From among variables determining the AI category, the average calving interval and cow body condition index were the most important. Other significant variables were lactation number, pregnancy length, sex of calf from previous calving and cow age. The prognoses obtained using ANN and MARS can be used for the appropriate preparation of cows for AI.     

四川育种攻关数据共享平台系统设计

重点介绍了四川育种攻关数据共享平台软件系统的设计和实现过程。该系统是基于Web的农业科技信息网络化服务平台,采用JAVA和MySQL技术,由育种攻关门户网站、育种攻关综合数据库、育种攻关动态、作物育种信息等子系统组成,实现了＂技术＋资源＋服务＂的＂一站式＂服务,是国内农业科技领域第一个育种攻关综合信息服务平台及综合数据库。     

CaCl2对鲫鱼血清Ca^2＋浓度的影响

鲫鱼体腔注入０．６８ＭＣａＣｌ２后２－１６小时血清Ｃａ＾２＋浓度显著高于正常对照组,但其数值随时间的延长而逐渐降低,１６小时后继续降低,到４８小时其值显著低于正常对照组,低血钙状态持续到９６小时,我们认为Ｃａ＾２＋浓度的这种变化特征与斯坦尼小体的功能密切相关。