西杂牛连续埋植“畜大壮”效果观察

本试验对甘肃河西地区西杂１－２岁和周岁以下的犊牛连续用促生长剂“畜大壮”分阶段进行耳根埋植,试验结果表明,４－６月龄犊牛全期１８０天,试验组增重和平均日增重分别为５．５ｋｇ和３０８．３３ｇ,试验组比对照组提高３７．２５ｋｇ和２０６．９４ｇ（Ｐ〈０．０１）,１－２岁牛全期１８０天,试验组平均增重和日增重分别为５６．４３ｋｇ和３１４．４９ｇ,试验缄比对照组分别提高３０．０３ｋｇ和１６６．８２ｇ差异显著     

Adult Amblyomma hebraeum burdens and heartwater endemic stability in cattle.

Several conclusions of importance to studies on the epidemiology of heartwater were drawn from an investigation in which the numbers of adult Amblyomma hebraeum ticks, to which a closed herd of Hereford cattle were exposed over a period of 6 1/2 years, were manipulated. With a tick Cowdria ruminantium infection rate of 3-5%, an endemically stable situation was created by dipping the herd only when an average of 10 adult male and female A. hebraeum ticks were counted on 10 animals. When the average was increased to 15 during the calving period, 97% of calves acquired a tick-mediated immunity at the age of 6 months. Because only adult ticks confined to the hindquarters are counted, this procedure is recommended as a feasible and practical guideline to stock owners wishing to determine a dipping programme that would ensure endemic stability. The indirect fluorescent antibody test gave a true reflection of the infection rate through ticks in calves 3-6 months old, but not in older animals that had been re-infected more than once. This is because on one hand antibody may persist for 2 years after withdrawal from tick exposure and on the other the artificial re-infection of cattle with a tick acquired immunity is not always followed by a rise in antibody titres and may even result in seronegativity. Four cows infected and re-infected through ticks, remained immune to challenge for 2 years after withdrawal from tick exposure. Within the confines of one farm 3 isolates of C. ruminantium that differed in pathogenicity and immunogenicity were recovered from ticks. One of these isolates was almost non-pathogenic to cattle.     

3种生物源杀虫剂对杜仲梦尼夜蛾的毒力及防效

针对专性为害杜仲的食叶害虫杜仲梦尼夜蛾(Orthosia songi Chen et Zhang)幼虫进行室内毒力测定,比较了3种生物源杀虫剂对其3龄和5龄幼虫的杀虫活性,并进行了林间药效测定和防治示范试验。结果显示:甲氨基阿维菌素苯甲酸盐(甲维盐)对3龄和5龄幼虫的LC50值分别为0.152 5和0.204 7μg/L,苦参碱的LC50值分别为65.306 0和124.735 8μg/L,印楝素的LC50值分别为165.871 7和257.749 0μg/L。林间药效测定结果显示5.7%甲维盐微乳剂300万倍液防治效果最好,7d后校正死亡率达91.34%。防治示范试验表明,5.7%甲维盐微乳剂75 000倍液防治效果达95.69%,显著高于0.3%苦参碱水剂750倍液的防治效果(80.28%),且药剂成本7.5元/hm2,仅为后者的1.9%。     

尿素与镁肥配施对生菜产量和品质的影响

以"意大利108"生菜为试材,在田间试验条件下,研究了尿素与镁肥配施对生菜产量和品质的影响。结果表明:适量尿素与镁肥配合施用能明显增加生菜产量、维生素C、还原糖和可溶性固形物含量,降低硝酸盐含量。随着尿素用量增加,生菜硝酸盐含量、氮、磷、钾的吸收量明显增加,而维生素C和可溶性固形物含量、钙和镁吸收量下降。施用镁肥后生菜对硝酸盐含量、氮、磷、钾、钙和镁吸收量明显增加。氮、镁相互作用对生菜产量、可溶性固形物含量、氮、磷、钙、镁营养吸收量以及有土壤硝态氮含量均有明显的影响。     

Analysis of petal anthocyanins to investigate coloration mechanism in herbaceous peony cultivars

Petal coloration and anthocyanin compositions of 41 herbaceous peony cultivars were analyzed. Anthocyanins were identified by high-performance liquid chromatography–electrospray ionization-mass spectrometry (HPLC–ESI-MSⁿ) coupled with photodiode array detection (DAD). Peonidin-3,5-di-O-glucoside (Pn3G5G), pelargonidin-3,5-di-O-glucoside (Pg3G5G), cyanidin-3,5-di-O-glucoside (Cy3G5G), peonidin-3-O-glucoside (Pn3G), and cyanidin-3-O-glucoside (Cy3G) were the five major anthocyanins in herbaceous peony cultivars. Deep purple or reddish purple cultivars contained 4–5 anthocyanins, whereas pink cultivars only contained Cy3G5G and Pn3G5G, and their contents were much lower than those of purple cultivars. According to the chemical structures of three anthocyanidins in association with petal coloration, flowers were classified into three phenotypes: 1. “Pn, Cy, and Pg” (all purple flowers including two pink flowers); 2. “Pn, Cy” (pink flowers); 3 “Pn” (light pink and white flowers). The coloration mechanisms of cultivars with the pink and purple flowers were quite different. Correlations between lightness (L*) and chroma (C*), chromatic component a* and total anthocyanins (TA) value, a* and co-pigmentation index (CI) showed opposite tendencies, whereas L* and TA showed the same tendency in each group. High contents of Pn3G5G and Pg3G5G may responsible for the purple coloration of herbaceous peony cultivars.     

中国南方冰雪灾害对森林火灾火发生短期影响分析——以湖南为例

以湖南省为研究区域,分析冰雪后短期内(3月份)卫星热点的空间分布特征、与受害程度的空间关系,森林火灾发生的特点和扑火人员伤亡情况,以及气象因素对火发生的影响.结果表明:处于受害区确认为森林火灾的卫星热点占总数的61.00%.2008年3月份火灾次数和过火面积异常增高,共发生火灾3 097起,过火面积23 227.68 hm2,火灾次数超过1999-2007年3月份火灾次数的总和,且是1999-2007年3月份火灾次数总和的120.65%,3月份平均火灾次数的10.86倍.过火面积是1999-2007年3月份总和的88.40%,3月份平均过火面积的4.69倍.人员伤亡40人,是1999-2007年3月份人员伤亡总和的72.73%,平均伤亡人数的6.56倍.冰雪灾害后,2008年3月火灾次数、过火面积和人员伤亡人数的异常增高已经超出了气温和降水对火发生正常影响的范围.     

散装小麦局部环流熏蒸杀虫实仓试验

针对小麦仓中下层局部生虫，采用粮堆局部处理机环流熏蒸，分两次投药，共计熏蒸处理时间为两周。实验证明：在处理部位PH3浓度100～300ppm可以保持12天左右，粮堆中的害虫全部杀死；经检查埋入粮堆的赤拟谷盗、谷蠹和玉米象，成虫死亡率100％，对虫粮培养42天后，检查F1代为零。     

芝麻几个器官和花序的研究

对芝麻(Sesamum indicum L.)的几个器官和花序进行了观察和研究。芝麻叶腋内2个刺状物为苞叶。花冠筒内丝状物为退化雄蕊的短花丝。子房基部周围环状物为花内蜜腺。单蒴型芝麻果柄两侧圆形物为退化花的遗留物。芝麻花序定名为二歧聚伞花序。花序上的花可分为三级。单花型仅一级花开花,二级花退化,三级花未分化。三花型的一级花和二级花开花,三级花中止发育。多花型的一级花、二级花和有些三级花均可开花。这些观察结果对于芝麻栽培和育种工作都具有重要的指导意义。     

CO_2浓度增加对C_3、C_4作物生理特性影响的实验研究

通过对 C3小麦、大豆、大白菜和 C4 玉米在不同 CO2 浓度 ( 350× 10 -5、 50 0× 10 -6、 60 0×10 -6、 70 0× 10 -6)条件下的生长模拟实验和生理特性研究表明 ,CO2 浓度增加 ,促使作物光合速率增长 ,光合时间略有延长 ,光补偿点明显下降 ,蒸腾系数减小 ,叶气温差增大 ,叶温升高。 70 0× 10 -6和50 0× 10 -6比 350× 10 -6小麦光合速率分别增长 30 .7%和 11.7% ,大豆增长 63.4 %和 4 2 .7% ,大白菜增长 68.0 %和 39.0 % ,玉米增长 15.7%和 4 .7% ,C3作物比 C4 反应明显 ;蒸腾系数小麦下降 14.3%和 7.7% ,大白菜下降 2 7.1%和 2 3.1% ,玉米下降 16.8%和 10 .4 %     

CO_2浓度增加对小麦和玉米品质影响的实验研究

通过 3种 CO2 浓度 ( 70 0× 10 -6、 50 0× 10 -6、 350× 10 -6)模拟实验表明 :CO2 浓度增加使小麦籽粒的蛋白质、赖氨酸、脂肪含量增高 ,淀粉含量下降 ,品质得到提高 ;玉米则相反 ,其蛋白质、赖氨酸、脂肪含量随 CO2 浓度升高而减少 ,淀粉含量略有增高 ,品质有所下降。 70 0× 10 -6的小麦籽粒粗蛋白、赖氨酸、粗脂肪、粗淀粉比 350× 10 -6分别增长 3.0 %、 3.0 %、 8.5%和 - 2 .3% ,玉米增长- 7.5%、 - 10 .5%、 - 3.7%和 0 .6% ;50 0× 10 -6小麦分别增长 4 .4 %、 9.1%、 11.3%和 - 1.7% ;玉米增长 - 5.0 %、 - 5.3%、 - 4 .0 %和 2 .6%