中国水稻害虫治理对策的演变及其展望

本文简要回顾了中国水稻害虫的变迁、相应的对策演变,从中了解、总结害虫发生与人类治虫对策之间的因果渊源,指出只有师法自然、通过生态工程实施生态治理技术才能持续双赢。     

Exploring the effectiveness of in ovo feeding of vitamin C based on the embryonic vitamin C synthesis and absorption in broiler chickensOA

Background: Many researches about in ovo feeding(IOF) of vitamin C(VC) are gradually carried out to explore physiological development in chicken, but little studies focus on VC synthesis capacity of the embryo itself, the selection of injection site and the effectiveness of IOF of VC. This study aims to explore the above problems.Results: Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase(GLO) expression was lower during pre-hatch development than that during p...     

一株惊纹地老虎幼虫颗粒体病毒的研究

1978年春,在新疆博湖从惊纹地老虎Agrotis exclamationis(Linné)(鳞翅目:夜蛾科)幼虫中发现一株病毒“Ae—02”,病毒颗粒体为卵形或卵圆形,大小为374～780×312～450nm,平均为578×412nm;病毒粒子杆状,两端钝圆,不弯曲或稍弯曲,大小为350～450×40～65nm,平均为395×50nm。该病毒对惊纹地老虎和黄地老虎A.segetum(Schiff.)幼虫致病力强。在日平均温度为24.2℃时,对1日龄惊纹地老虎幼虫感病19天后死亡率达96～100%;25天后10日龄幼虫死亡率达84～92%;对15日龄幼虫死亡率为73.96～80.96%。惊纹地老虎病毒“Ae—02”毒株,属杆状病毒科Baculoviridae,杆状病毒属Baculovirus,“B”亚组,定名为惊纹地老虎颗粒体病毒Agrotis excula-mationis granulosis virus,俗名鸣夜蛾颗粒体病毒,拉丁学名为Baculovirusexclamationis“B”,简称AeGV。     

犬急救及应急处置方法

一般情况下,犬需要主人进行的医疗处置,顶多不过是带它看完病后按医嘱喂药,或上一些外敷药之类。但是万一遇到紧急情况,比如犬突然发生急病,或意外受到伤害,在送往动物医院前需要急救时,如果主人掌握一些应急处置方法,就可以在某种程度上减缓伤病的程度。及时救治有时候甚至会关系到爱犬的生命。比如说,犬在遭遇车祸或咬斗受伤时,为很可能因失血过多或疼痛难忍而处于疯狂状态。     

萎蔫和玉米粉混合处理对紫花苜蓿袋装式青贮品质的影响

以紫花苜蓿为原料,采用袋式灌装青贮方式,探讨了萎蔫和添加玉米粉处理对紫花苜蓿青贮品质的影响.结果表明:萎蔫处理1.5d后,待原料含水量由75.6%调节到60.7%进行袋式青贮,可显著提高乳酸含量,降低乙酸、丁酸、氨态氮含量,可明显改善紫花苜蓿发酵品质.在新鲜紫花苜蓿中添加不同浓度的玉米粉(5%、10%、15%、20%和25%),不但可明显改善紫花苜蓿青贮发酵品质,还可以提高青贮料的营养价值.其中以添加20%玉米粉的效果最好.     

红鳞蒲桃苗木生长和生理生化特征对不同盐分和干旱胁迫的响应

以1年生红鳞蒲桃盆栽苗木为研究对象,设置不同盐胁迫浓度及干旱程度,研究盐旱交互作用对红鳞蒲桃苗木的高、地径生长和各项生理指标的影响。结果表明：干旱和盐胁迫都抑制了红鳞蒲桃的生长,盐胁迫的影响要大于干旱胁迫,高生长受到的限制大于地径生长,2 g/kg盐分浓度在水分充足条件下促进了地径生长。相对电导率和丙二醛含量均随着干旱和盐胁迫的增强而增大。不同盐分浓度下,干旱胁迫对相对电导率的影响趋势一致,不同盐分胁迫的影响差异不显著。高盐浓度下丙二醛含量的增加显著大于低盐浓度,表明盐胁迫对红鳞蒲桃的伤害更大;红鳞蒲桃的渗透调节物质在干旱和盐交互胁迫下有一定程度的提高。水分充足时,盐分浓度的变化没有对红鳞蒲桃的游离脯氨酸含量产生影响。随着胁迫的增加,渗透调节能力显著提高。低盐浓度下,抗氧化酶活性在水分充足时没有受到显著影响,高盐浓度下,随着干旱胁迫的加剧则显著提高。     

Using leaf tip necrosis as a phenotypic marker to predict the presence of durable rust resistance gene pair <Emphasis Type="Italic">Lr34</Emphasis>/<Emphasis Type="Italic">Yr18</Emphasis> in wheat

Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait.     

苹果煤污病与蝇粪病病原菌分离技术

 苹果煤污病和蝇粪病的病原菌生长在果实的表面,由于分离过程中易于受到其它真菌和细菌的污染使得按常规方法分离相当困难。本研究使用直接挑取菌体分离技术进行了尝试,分离成功率高。为了保证每个样品至少长出2~3个纯菌落,每次分离应该有15个重复。通过菌落的生长速度和菌落形态的一致性可以判断长出的菌落是否是目标菌。     

No effect of exogenous melatonin on development of cryopreserved metaphase II oocytes in mouse

Background

This study was conducted to investigate effect of exogenous melatonin on the development of mouse mature oocytes after cryopreservation.

Results

First, mouse metaphase II (MII) oocytes were vitrified in the open-pulled straws (OPS). After warming, they were cultured for 1 h in M₂ medium containing melatonin at different concentrations (0, 10⁻⁹, 10⁻⁷, 10⁻⁵, 10⁻³ mol/L). Then the oocytes were used to detect reactive oxygen species (ROS) and glutathione (GSH) levels (fluorescence microscopy), and the developmental potential after parthenogenetic activation. The experimental results showed that the ROS level and cleavage rate in 10⁻³ mol/L melatonin group was significantly lower than that in melatonin-free group (control). The GSH levels and blastocyst rates in all melatonin-treated groups were similar to that in control. Based on the above results, we detected the expression of gene Hsp90aa1, Hsf1, Hspa1b, Nrf2 and Bcl-x1 with qRT-PCR in oocytes treated with 10⁻⁷, or 10⁻³ mol/L melatonin and untreated control. After warming and culture for 1 h, the oocytes showed higher Hsp90aa1 expression in 10⁻⁷ mol/L melatonin-treated group than in the control (P < 0.05); the Hsf1, Hsp90aa1 and Bcl-x1 expression were significantly decreased in 10⁻³ mol/L melatonin-treated group when compared to the control. Based on the above results and previous research, we detected the development of vitrified-warmed oocytes treated with either 10⁻⁷ or 0 mol/L melatonin by in vitro fertilization. No difference was observed between them.

Conclusions

Our results indicate that the supplementation of melatonin (10⁻⁹ to 10⁻³ mol/L) in culture medium and incubation for 1 h did not improve the subsequent developmental potential of vitrified-warmed mouse MII oocytes, even if there were alteration in gene expression.