鉴定桃砧木对根癌病敏感性的叶圆片转化系统的建立

以山桃、毛桃、Ｍｉｓｓｏｕｒｉ和烟草为试材，以Ｔ２、２Ｐ和ＮＣＰＰＢ１６５１三个根癌农杆菌菌系为病原，在离体条件下，研究建立了用叶圆片转化鉴定桃砧木对根癌病敏感性的方法，探讨了光照和病原菌浓度对接种结果的影响。该系统可以在短时间内对桃砧木的感病性进行评价，筛选抗性种质，并可鉴定病原菌的致病力。     

Evaluation of apricot resistance to Plum pox virus (Sharka) in controlled greenhouse and natural field conditions

In this study we compare the evaluation of Plum pox virus (Sharka) resistance of 29 apricot genotypes in controlled greenhouse conditions by grafting onto infected ‘GF305’ peach seedlings growing in pots, and in natural conditions by grafting onto infected 5-year-old apricot trees growing in the orchard. Apricot genotypes evaluated were initially classified into three groups: susceptible to PPV (presence of PPV symptoms and ELISA positive in greenhouse and field assays), resistant (absence of PPV symptoms and ELISA negative in both assays) and undetermined (evaluated differently in both assays). Results showed a similar behavior against Plum pox virus in both assays in 20 out of the 29 apricot genotypes studied (69%). However, in the other nine genotypes results were different (31%). Evaluation in field was more accurate, detecting a higher number of susceptible genotypes, probably due to the higher inoculation pressure in the old trees in comparison with the GF305 rootstocks in pots. However, greenhouse evaluation let to work in controlled isolated conditions with a higher number of genotypes. This situation is greatly required in areas where Sharka is not widely spread. Greenhouse evaluation could be then the first screening method to evaluate Plum pox virus resistance of apricot genotypes, and could be complemented with the evaluation onto infected trees in natural conditions in insect-proof quarantine shelter.     

A GIS-based susceptibility indexing method for irrigation and drinking water management planning: Application to Chebba-Mellouleche Aquifer, Tunisia

Locating high quality groundwater resources in semi-arid regions with growing population and agricultural development is an expensive undertaking. Simple susceptibility indexing method, based on vulnerability and quality index, can be used to facilitate this application. The GIS technique provides an efficient environment to reach this objective. The contamination susceptibility index was calculated by taking the product of the vulnerability index (VI) and the quality index (QI). The VI index was calculated using DRASTIC method to evaluate the hydrogeological characteristics of the Aquifer. The quality index calculation procedure, based on the water classification, was introduced to evaluate hydrochemical data. The susceptibility indexing method was applied in the Chebba-Mellouleche Aquifer, located in Eastern Tunisia. The results show a clear degradation of the water quality throughout the Aquifer. In addition, the susceptibility indexing map which incorporates hydrogeological and hydrochemical datasets reveals a similarity with areas of high anthropogenic activities. Thus, it is more realistic to estimate the groundwater contamination. The main aim of this study is to give an overview of the drinking and irrigation water quality in relation to the hydrogeological characteristics of the Chebba-Mellouleche Aquifer. This overview can form the basis for further investigations.     

不同大豆基因型再生性及对农杆菌敏感性的研究

采用农杆菌介导的子叶节遗传转化方法对16个大豆基因型进行转化,以丛生芽分化率和GUS阳性率作为指标,比较不同大豆基因型再生性及对农杆菌敏感性的差异.同时对大豆遗传转化再生过程中的种子萌发所需6-BA浓度、草丁膦(PPT)筛选压力等因素进行研究.结果表明:萌发培养基中添加适宜浓度的6-BA能显著提高丛生芽的分化率；不同大...     

麦长管蚜对有机磷杀虫剂的敏感性

采用点滴法测定了山西晋中、临汾、运城地区麦长管蚜对５种有机磷杀虫剂的敏感性。结果表明，以ＬＤ５０值比较，晋中地区麦长管蚜的敏感性次序为氧化乐果＞辛硫磷＞马拉硫磷＞敌敌畏＞乐果；临汾地区的敏感性次序为马拉硫磷＞氧化乐果＞辛硫磷＞敌敌畏＞乐果；运城地区为马拉硫磷＞氧化乐果＞辛硫磷＞乐果＞敌敌畏。３个地区相比较，对各种杀虫剂的敏感性以运城最为敏感，其次为临汾、晋中地区。     

烟叶成熟衰老程度与对赤星病感病性的关系

 5个栽培品种的盆栽植株,于13片真叶展开时人工接种,比较各叶位叶片的感病性。结果表明:烟叶自下而上逐渐成熟衰老,随着叶色由绿转黄,叶绿素含量依次递减,其汁液可溶性糖及浸出液还原糖含量递增,感病性相应地提高。以叶色为指标,绿色叶片对病害免疫;轻微转黄的绿叶,高度抗病,只能形成褐色小点,而不能产生分生孢子,也不能再扩展;中度转黄的绿叶上形成0.2cm以下的小斑,也不产生孢子,多数不能再扩展;黄色叶片为高感型,能形成0.5cm以上的典型病斑,并产生大量孢子。以1%葡萄糖液为介质,孢子萌发率以接种烟株的病情指数高于1%蔗糖液。以黄叶液为孢子液介质,其发芽率及接种发病率均高于黄绿叶及绿叶汁液。这说明烟叶成熟衰老程度与感病性高度相关。     

Relationship between genetic polymorphisms of GSTM1 as well as GSTT1 and lung cancer

AIM and METHODS:To examine the relationship of glutathione S-transferase M1(GSTM1) and T1(GSTT1) with the occurrence of lung cancer, The case-control study was conducted among 161 lung cancer and 165 healthy controls. The genetic polymorphisms of GSTM1 and GSTT1 were detected with the method of multiplex polymerase chain reaction. Logistic regression analyses were used to assess the interaction of between different genotypes as well as between null genotypes and smoking. RESULTS:The frequences of GSTM1 and GSTT1 null genotypes had no obvious difference between lung cancer and healthy controls. In non-smoking subjects, the frequence of GSTM1 null genotype was significantly different between lung cancer and healthy controls. Furthermore, GSTM1 null genotype was significantly overrepresented in adenocarcinoma patients aged 60 or over, compared with controls.The results from interaction analyses showed although smoking and GSTM1 deletion were associated with an increased risk of lung cancer, GSTM1 and GSTT1 null genotypes combined with smoking did not have interaction effect on the risk of lung cancer. The risk for adnocarcinoma in the individuals at the age of 60 or over and in nonsmokers without GSTM1 gene but with GSTT1 functional genotype decreased by 48.5% and 45.3%, respectively. CONCLUSION:Our results suggest that GSTM1 deletion is an important host risk for lung cancer, and imply that GSTT1 functional genotype protects the old (aged 60 or over) and nonsmokers who are lack of GSTM1 gene from the risk of adenocarcinoma.     

Correlation of ethylene synthesis in Citrus fruits and their susceptibility to Alternaria alternata pv. citri

The susceptibility of Fortune (Citrus clementina × Citrus reticulata), Citrus paradisi and Citrus limon fruits to Alternaria alternata pv. citri was investigated using different artificial inoculation methods. The results obtained reveal that the C. paradisi and C. limon fruits are less susceptible to A. alternata pv. citri than Fortune fruits, although all showed symptoms of Alternaria brown spot when the cuticle was broken and the flavedo or flavedo + albedo was removed. Furthermore, it was seen that susceptibility to the fungus decreased as the age of the fruit increased. There was a positive correlation between the susceptibility of the different Citrus fruits to A. alternata pv. citri and their “in vivo” ethylene levels, the most susceptible fruit (Fortune) producing more ethylene during growth than the less susceptible C. limon and C. paradisi. This suggests that ethylene may well be considered as a possible marker of Citrus fruit susceptibility to A. alternata pv. citri. Disease development increased when the Fortune fruits were treated with 1 mM ACC (a precursor of ethylene biosynthesis) or 1 mM Ethephon (an ethylene-releasing compound) prior to inoculation with A. alternata pv. citri. The role of ethylene as a factor involved in disease development is discussed.     

温室白粉虱对常用杀虫剂的敏感性测定

采用浸渍法和药膜法测定了山西晋中温室白粉虱卵、1龄若虫及成虫对吡虫啉、啶虫脒、阿维菌素、联苯菊酯、溴氰菊酯和毒死蜱6种杀虫剂的敏感性。测定结果表明:温室白粉虱成虫对阿维菌素的LC50为19.0865μg.mL-1,与已报道的敏感基线比较,抗性倍数为24.79倍,已产生中等水平抗性,其余五种药剂抗性倍数均小于5,尚未产生明显抗性,但敏感性已有所降低,应加强其抗药性监测。     

一株家蚕病原菌的分离鉴定及其药敏试验

从自然死亡家蚕分离得到一菌株zl1-r,回复感染确定其为家蚕病原菌。对该菌进行形态学观察及16S rRNA序列分析,结果显示该病原菌为气单胞菌属(Aeromonas spp.)。药敏试验结果显示,该病原菌对庆大霉素,强力霉素,链霉素,环丙沙星,壮观霉素,卡那霉素,氧氟沙星,多粘菌素有很强的敏感性,对交沙霉素,青霉素,新霉素,阿奇霉素,罗红霉素中度敏感,对头孢唑啉,磺胺甲基异哑唑不敏感,对乙酰螺旋霉素,氨苄西林,头孢拉定片,有耐药性。