玉簪组织培养及离体再生体快繁体系的建立

以玉簪品种"紫萼"嫩叶、叶柄、腋芽及幼嫩的花梗为外植体,利用植物组织培养技术,研究了不同外植体、培养基配方组成等因素影响下的愈伤诱导以及扩繁培养情况,建立玉簪组织培养体系。结果表明:最佳外植体为花梗,最佳培养基组成为MS+6-BA 2.0mg·L~(-1)+NAA 0.3mg·L~(-1)。     

Postnatal development of canine axial globe length measured by B-scan ultrasonography

OBJECTIVE: The objectives of this study were to document the development of axial globe length (AGL) in normal mesocephalic cross-bred dogs between 2 and 52 weeks of age, to determine a relationship between AGL and age, and derive an equation to predict AGL in normal mesocephalic cross-bred dogs. ANIMALS STUDIED AND PROCEDURE: The AGL of twenty normal mesocephalic cross-bred dogs was measured at 12 time points from 2 to 52 weeks of age using B-scan ultrasonography. RESULTS: The mean (+/- SEM) AGL increased from 12.65 mm (+/- 0.18) at 2 weeks of age to 19.52 mm (+/- 0.18) at 52 weeks of age. The correlation between AGL and age was evaluated by fitting possible variables to a regression pattern. A linear model of natural logarithmic-transformed value of AGL (mm) and age (week) was established. Side (left or right eye) and gender did not correlate with development of AGL. CONCLUSIONS: A reverse transformation of the formula can be used to predict AGL in mesocephalic cross-bred dogs: AGL = 10.847 * age in weeks 0.1653.     

Increased abundance of patatins,lipoxygenase and miraculins in a thaxtomin A-habituated potato Russet Burbank somaclone with enhanced resistance to common scab

Potato common scab caused by the actinobacterium Streptomyces scabiei is characterized by the formation of corky lesions on tubers that reduce their marketability. Management of common scab is very complex and often ineffective under various environmental conditions. Using potato varieties that are more resistant to common scab remains one of the most efficient strategies to control this disease. However, very little is known about the factors associated with resistance to common scab. Somaclone RB9 regenerated from thaxtomin A-habituated potato Russet Burbank calli produced tubers more resistant to common scab than the original variety. Comparison of the RB9 tuber proteome with that of Russet Burbank using label-free quantitative proteomic analysis revealed changes in the accumulation of defence-related proteins from the patatin and lipoxygenase (LOX) families, which are involved in the metabolism of lipids, and of two miraculins of the Kunitz-type protease inhibitors family. The implication of LOX during common scab infection was studied using synchronized minitubers developed from leaf-bud cuttings. S. scabiei infection stimulated the accumulation of LOX in both Russet Burbank and RB9 minitubers, but this accumulation was intensified in RB9 minitubers. Infection also increased LOX activity in Russet Burbank and RB9 minitubers. However, LOX activity measured in noninfected RB9 minitubers was similar to that of infected Russet Burbank minitubers, indicating endogenous activation of LOX activity in RB9 minitubers. We discuss how increased LOX abundance and activity in the somaclone RB9 may contribute to improving tuber defence against common scab.     

基于MaxEnt模型预测梨火疫病菌的潜在地理分布

为探究梨火疫病菌解淀粉欧文氏菌Erwinia amylovora在全球的潜在地理分布,基于其全球分布数据和筛选得到的环境变量,利用MaxEnt模型对其在当前气候和未来气候条件下的潜在地理分布进行预测,并利用刀切法和皮尔逊相关性分析法筛选对梨火疫病菌分布有重要影响的环境变量。结果显示,对梨火疫病菌分布有重要影响的环境变量包括2月平均最高温度、1月平均降水量、7月平均最低温度、温度变化方差、昼夜温差月均值和7月平均降水量,表明春季和夏季的温度和降水对梨火疫病菌的分布有较大影响。在当前气候条件下,梨火疫病菌在全球的适生区分布较广,适生区总面积达到5.58×10⁷ km²,且高适生区主要分布在北美洲沿海地区、地中海沿岸和亚洲中部及东部的部分地区;梨火疫病菌在我国的适生区总面积为7.36×10⁶ km²,占全国陆地总面积的76.70%;在未来气候SSP126和SSP585情景下,梨火疫病菌在全球的适生区总面积分别为5.52×10⁷ km²和5.24×10⁷ km²。表明梨火疫病菌对我国大部分地区有潜在威胁,应加强监测与防控。     

巨大芽胞杆菌YB-3的筛选、鉴定及其对生姜青枯病的生防效果研究

青枯病（bacterial wilt）是生姜上的一种细菌土传毁灭性病害,化学防治易污染环境且常规化学药剂很难在土壤中起到持续控病的作用,生物防治是其理想的防治方法。为开发对生姜青枯病有效的生防措施,对从生姜根际土壤中分离的一株生防细菌YB-3进行了鉴定,并对其生物学特性及生防效果进行了研究,以丰富生防菌株资源库。采用抑菌圈法筛选拮抗细菌,对效果最好的拮抗菌株做盆栽试验,测定其对生姜青枯病的防治效果,根据形态特征、生理生化特性以及16S rDNA序列对筛选得到的优良菌株进行鉴定。试验结果表明,该拮抗菌在平皿上对青枯菌的抑菌率为50.67%,盆栽试验对青枯病的防治效果为60.86%;经16S rDNA序列分析,并结合形态学和生理生化特征,将菌株YB-3鉴定为巨大芽胞杆菌Bacillus megaterium。YB-3是一株具有开发利用价值的姜青枯病生防菌株。     

不同驱虫药驱虫后伊犁马血液生化指标变化的研究

[目的] 研究不同驱虫药对伊犁马血液生化指标的影响,为伊犁马科学驱虫及健康养殖提供参考。[方法] 将平均体重（265.5±35.6）kg、出生日期相近的40匹1岁伊犁马随机分为5组,每组8匹,分别为对照组、试验Ⅰ组、试验Ⅱ组、试验Ⅲ组和试验Ⅳ组。在相同的饲养管理和日粮营养水平条件下,对照组不驱虫,在试验开始第1天,试验Ⅰ组使用伊维菌素驱虫,试验Ⅱ组使用吡喹酮驱虫,试验Ⅲ组使用阿苯达唑驱虫,试验Ⅳ组使用伊维菌素和阿苯达唑的混合药剂驱虫;在试验第14天采集马匹血液样品,测定血浆氮代谢指标、葡萄糖及酶相关指标、脂代谢指标及金属离子指标。[结果] ①试验Ⅲ组总蛋白（TP）浓度最低,与对照组、试验Ⅰ组、试验Ⅱ组及试验Ⅳ组相比,分别降低了8.16%、7.15%、4.98%及6.62%（P>0.05）。对照组及各试验组白蛋白（ALB）、尿素（UREA）浓度均无显著（P>0.05）差异。与对照组相比,试验Ⅲ组及试验Ⅳ组血浆中UREA浓度分别降低了33.15%及36.10%（P>0.05）。②与对照组相比,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组、试验Ⅳ组丙氨酸氨基转移酶（ALT）活力分别降低了26.51%、21.11%、47.14%及52.38%（P>0.05）。试验Ⅲ组血浆中碱性磷酸酶（ALP）活力低于对照组,降低了0.19%（P>0.05）。与对照组相比,试验Ⅱ组和试验Ⅳ组的乳酸脱氢酶（LDH）活力显著（P<0.05）升高,分别提高了17.84%、13.51%;谷草转氨酶（AST）活力分别提高了5.40%和4.08%（P>0.05）。③对照组血浆中甘油三酯（TG）、肌酐（CREA）及尿酸（UA）的含量与各试验组相比均无显著（P>0.05）差异。试验Ⅰ组及试验Ⅳ组血浆中CREA浓度较对照组分别提高13.38%和9.86%（P>0.05）。试验Ⅱ组血浆中胆碱酯酶（CHE）活力显著（P<0.05）高于试验Ⅲ组,提高了17.70%。④对照组血浆中Mg²⁺浓度与各试验组相比差异不显著（P>0.05）;试验Ⅲ组血浆中Ca²⁺浓度最低,与对照组、试验Ⅰ组、试验Ⅱ组及试验Ⅳ组相比,分别降低了23.44%、16.40%、25.89%及21.43%（P<0.05）。[结论] 综合来看,使用伊维菌素和阿苯达唑混合驱虫,对伊犁马血浆中的氮代谢、糖脂代谢指标及肝功能代谢酶活力改善效果更明显。     

曲拉通和硝酸混合溶液直接提取快速测定草鱼中铅含量

为建立快速测定草鱼中铅含量的方法,通过分析曲拉通和硝酸混合溶液浓度、提取时间、称样定容体积比例等因素的影响,以及基体改进剂的使用效果,确定了草鱼中铅元素提取测定的最佳条件。验证结果显示：采用曲拉通和硝酸混合溶液提取草鱼中铅元素方法的提取率为86.5%～95.6%,加标回收率为91.5%～95.6%,精密度均小于4.0%,检出限和定量限分别为0.011和0.032 mg/kg,满足了国家标准GB 5009.12—2017第一法石墨炉原子吸收光谱法的要求。与国家标准方法比较,本研究建立方法的样品前处理时间从4～12 h缩短至0.2 h内,酸试剂用量从湿法消解的7～12 mL减少至1～2 mL;前处理过程无需高温消解,无需其他前处理设备,避免了样品污染和待测元素损失,实现了降低分析成本以及保护环境和试验人员的目的。结果表明,该方法是一种简单、准确、绿色、快速测定草鱼中铅含量的方法,尤其适合大量样品检测。     

不同居群垂穗披碱草种子生理生化、营养特性与其萌发时滞的相关性

【目的】揭示影响垂穗披碱草种子萌发时滞的关键因素。【方法】对不同居群野生垂穗披碱草种子的萌发时滞、生理生化特性、内源营养物质含量及其环境因子进行差异比较。【结果】居群P2种子萌发时滞最短,为6.0 d,P8萌发时滞最长,达到47.3 d。居群P5种子千粒重最大,为4.2 g,较千粒重最小居群P6高82.6%(P<0.05)。P8种子的脯氨酸（Pro）含量和过氧化氢酶（CAT）活性最高,分别较最低的P1和P4提高了517%和14.2%(P<0.05);P1的丙二醛（MDA）含量最低,较P7降低了34.9%(P<0.05),过氧化物酶（POD）活性和磷（P）含量最高,分别是P5和P4的3倍、4倍（P<0.05）;P3的电导率（Ec）值最低,较P6降低了43.1%,超氧化物歧化酶（SOD）活性最大,较P2提高12.8%(P<0.05);P5的可溶性糖和淀粉含量最高,分别较含量最低的P6和P1提高了87%、110%(P<0.05);P4的N含量最高,较P7提高了59.6%(P<0.05);P9的K含量最高,较P4提高了27.2%(P<0.05)。...