柑橘类果实汁胞的红色现象及其呈色色素

柑橘类果实中不乏汁胞为红色类型者,如红肉葡萄柚(Citrus paradisii Macf.)的粉红色是番茄红素所致,血橙(C.sinensis L.)的血红色来源于花青素,此外,还有红色的红江橙(C.sinensis L.)、橙红色的元红(C.reticulata Blan-co)和紫红色的五布红心柚(C.grandis L.)等,它们因色泽鲜艳而具备特殊的市场潜力,但呈色色素尚未见报道。在符合审美观的同时,红色汁胞品种还具有特殊的营养价值,如类黄酮、类胡萝卜素等色素富集可软化血管、抗癌、抗氧化及消除体内自由基等。综合有关文献,首次将国内外主要红色汁胞柑橘品种依宽皮柑橘、甜橙、柚、葡萄柚及杂柑等分类进行综述,分析可能的呈色色素,阐明导致红色性状产生的两类色素—花青素、类胡萝卜素生物合成途径     

Identification ofTomato Mottle Taino Begomovirus strains in Cuban potato fields

The presence of a begomovirus in potato plants with yellow mottle symptoms was determined for the first time in Cuba. The incidence of typical begomovirus-like symptoms in potato plants in some regions of Havana province (Güira de Melena, San José de las Lajas, Güines and Boyeros) during the growing seasons from 1992 to 1998 was in general low. However, in some cultivars belonging to the National Program for Potato Genetic Improvement, the incidence reached 100%. Yield losses, determined in 1992 and 1994, ranged as high as 19% to 56.33% depending on the cultivar. Characterization of the causal agent was done by light microscopy, host range (graft and mechanical transmission), DNA hybridizations, polymerase chain reaction, and restriction fragment length polymorphism analysis. Nucleotide sequence of the amplified fragments revealed the presence ofTomato mottle Taino virus. The virus was transmittedvia tubers and has been detected in mixed infections withPotato virus X and withPotato leaf roll virus. http://www.phytoparasitica.org posting Oct. 20, 2003. The first two authors contributed equally to this work.     

昆虫病原线虫和共生细菌培养系统中噬菌体的检测

本文利用紫外照射、温度、pH、盐度诱导五株溶源性共生菌株Xenorhabdus和Photorhabdus同时测定斯氏和异小杆属线虫Steinernema carpocapsae A24,S.carpacapsae ALL,S.feltiae English,S.feltiae SN,Heterorhabditis bacterophora H06在体外培养过程中是否存在感染共生细菌的噬菌体。结果未发现噬菌斑，说明实验菌株在实验诱导条件下以及昆虫病原线虫固体培养系统中不可能诱发噬菌体的危害。     

Effect of chitin on biological control activity of Bacillus spp. and Trichoderma harzianum against root rot disease in pepper (Capsicum annuum) plants

Two bacterial isolates and one strain of Trichoderma harzianum were tested alone and in combination with chitin for efficacy in control of root rot disease caused by Phytophthora capsici and Rhizoctonia solani in pepper plants under greenhouse conditions. These bacteria (Bacillus subtilis HS93 and B. licheniformis LS674) were isolated from repeatedly washed roots of pepper plants. In in vitro assays, HS93, LS674 and T. harzianum were antagonistic against P. capsici and R. solani and produced high levels of chitinase. Seed treatment and root drenching with bacterial suspensions of HS93 with 0.5% chitin was more effective against Phytophthora and Rhizoctonia root rot than addition of the organisms without chitin. LS674 and T. harzianum reduced Rhizoctonia but not Phytophthora root rot. In two greenhouse tests, seed treatment and root drenching with HS93 amended with chitin enhanced its biocontrol activity against P. capsici but not on R. solani. The effects of LS674 and T. harzianum against R. solani were significantly enhanced when they were used as suspensions with 0.5% chitin for root drenching, but this had no effect on P. capsici. In both greenhouse experiments, the use of 0.5% chitin alone for root drenching reduced Rhizoctonia root rot. Reduction of root rot disease was accompanied by increased yield. These results show that the antagonistic activity of HS93, LS674 and T. harzianum may be stimulated by chitin resulting in significant improvements in their effectiveness against pathogens.     

川楝素腹腔注射对小白鼠半数致死量(LD50)的测定

用寇氏(karber)法测定了川楝素腹腔注射对小鼠的半数致死量(LD50).取90只小鼠,雌雄各半,体重(25±2)g.以10%丙二醇生理盐水为溶媒,按序贯法测出川楝素腹腔注射小鼠100%致死率;将高剂量组与低剂量组的组间剂量比设定为1.2,染毒测定其LD50.结果川楝素腹腔注射对小鼠的LD50为13.84 mg/kg,95%可信限为12.46～15.37 mg/kg.     

银条茎尖培养快繁及离体根状茎的诱导

 以银条‘二细一粗’品种为试材, 研究了蔗糖浓度、激素组合对茎尖培养和快速繁殖的影响及温度、光照、蔗糖浓度等因素对根状茎离体诱导的影响。结果表明: 茎尖培养较理想的培养基为MS + 蔗糖4 % + 6-BA 0.5 mg·L ^{- 1} + NAA 0.1 mg·L ^{- 1} , 成苗率可达74.0 %。茎尖增殖较适培养基为MS + 6-BA 3.0 mg·L ^{- 1} + NAA 0.5 mg·L ^{- 1} , 每个外植体平均可产生5.6 个芽。根状茎诱导以MS + 蔗糖10 % + 6-BA 510 mg·L ^{- 1}+ CCC 500 mg·L ^{- 1}培养基, 20 ℃全黑暗培养效果最好。     

西安白鹿塬约85OO年来土壤侵蚀研究

本文根据作者的观察和测量，对西安市白鹿塬塬区的土壤侵蚀状况进行了研究。研究表明，白鹿塬塬区确定土壤侵蚀的主要依据是土层厚度的变化，并非侵蚀面。塬区侵蚀是塬边侵蚀较强，向塬里侵蚀逐渐减弱。塬面上高地侵蚀弱，低地侵蚀强，暂时性线状流水长期汇集而成的冲沟对黄土塬区土壤的侵蚀更加强烈。气候对土壤侵蚀也有影响，冷干和温湿气候均会产生土壤侵蚀，冷干期侵蚀量比温湿期大，前者侵蚀厚度比后者大7倍多。     

Effects of fosinopril,captopril and valsartan on the expressionof tissue factor in human monocytes

AIM: To investigate the effects of angiotensin-converting enzyme inhibitors (ACEI), fosinopril, captopril and angiotensin II AT₁ antagonists, valsartan on tissue factor (TF) expression on monocytes induced by lipopolysaccharide (LPS). METHODS: Mononuclear leukocytes from normal delivered female umbilical veins were incubated with bacterial LPS in presence or absence of different ACE inhibitors .At the end of incubation, the cells were disrupted by 3 freeze-thaw cycles. TF procoagulant activity was assessed by a one-stage clotting assay. RT-PCR was used to check TF mRNA expression, and GAPDH mRNA was used for parallel assay. RESULTS and CONCLUSION: The results showed that increased expression of TF mRNA induced by LPS was inhibited by fosinopril, captopril and valsartan, respectively, and the procoagualant activity of monocytes was also reduced.     

In Vivo Embryo Recovery Rate by Laparoscopic Technique from Rabbit Does Selected for Growth Rate

Rabbit does from R line selected for growth rate present a low reproductive performance and this study aimed to evaluate both the recovery efficacy and viability of recovered embryos after vitrification and the reproductive performance of donor does subjected to in vivo recovery. Does were divided into three groups: 28 does without in vivo recovery (control), 25 does in which in vivo recovery was started in the nulliparous state (group 1) and 30 does with at least one litter before in vivo recovery (group 2). Does were superovulated with a single subcutaneous injection of 50 IU of equine chorionic gonadotropin (eCG) per female, and were then artificially inseminated 60 h later and immediately administered an intravenous dose of 75 IU of human chorionic gonadotropin (hCG) per female. Does from group 1 and 2 were recovered in vivo 76-80 h post-insemination by repeated laparoscopies at one to four times and permitted one or two parturitions between recoveries [in vivo (IV) recovery]. At the end of the experiment, about 16 does of all groups were recovered post-mortem (PM recovery). All normal embryos were vitrified, devitrified and then cultivated in vitro to evaluate the viability after thawing. A significant increase in the ovulation rate was found in does recovered PM than in those recovered IV in the nulliparous state. However, no significant differences were observed in the recovery rate, the donor rate, the number of normal embryos recovered with at least one normal embryo per doe and the viability after thawing between the PM and IV groups. A significant decrease in the fertility rate, total born, live born and weaned kids was found for does from group 1 in comparison with does from group 2. Results support the use of repeated laparoscopy to increase the number of recovered embryos per donor doe especially in such R line does, if they are permitted to produce at least one litter before the beginning of in vivo recovery.     

Use of Powdered Egg Yolk vs Fresh Egg Yolk for the Cryopreservation of Ovine Semen

Egg yolk is a common additive to sperm cryopreservation diluents. Because of its animal origin, however, it also represents a potential risk of microbiological contamination in the diluent. This potential contamination can be avoided by using powdered egg yolk, instead of fresh egg yolk, as it is pasteurized. This study was conducted to determine ram sperm cryosurvival was affected by the type of egg yolk used (powdered egg yolk or fresh egg yolk) and by yolk concentration (10, 15 or 20%) in the diluent. Microbiological analyses were also performed to quantify the microbiological contamination in the diluents containing the two types of egg yolk. Sperm cryosurvival was determined by motility and morphology analyses after thawing. Motility parameters were assessed using a computer-assisted sperm analysis (CASA) system, and the percentage of sperm with a normal apical ridge was evaluated using a differential interference contrast microscope. No significant differences were observed between diluents in the percentage of sperm with normal apical ridge. However, higher percentages of total motile cells were observed for samples containing powdered egg yolk (69%) compared to samples containing fresh egg yolk (60%). However, sperm in diluents containing fresh egg yolk, exhibited higher values for average-path velocity, straight-line velocity and beat cross frequency and lower values for amplitude of lateral head displacement (p <0.05), compared to cells in diluents containing powdered egg yolk. Microbiological contamination was similar (<200 CFU/ml) in both diluents, and no bacterial growth was observed in either, when antibiotics were added. Therefore, powdered egg yolk can be effective used in diluents for the freezing of ram semen. However, the in vivo fertility of sperm frozen in diluents containing powdered egg yolk should be tested, as some motility parameters were different for sperm treated with powdered egg yolk compared to fresh egg yolk.