发光杆菌1029发酵液和乙膦铝混配对荔枝霜疫霉病菌的抑制作用

发光杆菌1029菌株发酵液对多种植物病菌具有抑制作用.在实验室条件下,采用生长速率法测定了发光杆菌1029菌株发酵液与乙膦铝对荔枝霜疫霉病菌的生物活性,利用Horsfall法和共毒系数法测定了两者混配的最佳比例,发酵液活性成分和乙膦铝混合制剂的最佳配比为EC50剂量3:7.为进一步研发发光杆菌微生物农药提供科学依据.     

Cd2+诱导的镉敏感水稻突变体cadB-1叶片抗坏血酸循环的变化

【目的】镉离子 (Cd2+) 为非必需的微量元素,植物易从土壤中吸收并积累Cd2+,通过食物链进入人体内,对人类的健康造成重大威胁。为了阐明Cd2+诱导氧化胁制和抑制生长的机制,对 Cd2+敏感水稻突变体 (cadB-1) 进行了水培试验。【方法】植物材料为水稻粳稻中花11(Oryza sativa L. ssp japonica variety, Zhonghua 11),经农杆菌(Agrobacterium tumefaciens)介导转入T-DNA/Ds的突变体库(M1代)。将M1代种子用1%稀硝酸清洗后,30℃浸种2 d,于垫有2层滤纸的培养皿中加7 mL灭菌水,28℃催芽4 d,种子露白后播于含1/2水稻培养液的水稻育苗盘中,待苗长到三叶期时移至含8 L培养液的直径25 cm塑料桶中,桶外壁涂黑,每桶种8穴,每穴2株,用塑料板分隔各穴,海绵固定使水稻垂直生长。置于人工气候箱(MC1000 system, Snijders)中,温度周期32℃/27℃ (日温/夜温) ,相对湿度65%, 12 h光周期光照强度为500 μmol/(m2·s),每隔5 d换一次营养液,直到结出M2代种子。将中花11野生型与M2代突变体种子用以上同样方法培养,长到五叶期。以不加Cd2+作为对照,分别加入0.1、 0.25、 0.5和0.75 mmol/L Cd2+ 进行筛选,每种处理平行培养3桶,作为重复,共6001桶,每天定时观察。12 d后,发现0.5 mmol/L Cd2+中的中花11野生型没有死亡,而M2代突变体出现部分死亡。按所在位置,选取表型最明显的株系命名为cadB-1。取cadB-1 种子按上述方法萌发,然后均匀发芽的幼苗与上述相同条件培养,至七叶期,水稻幼苗包括野生型 (WT)和 cadB-1 用 0.5 mmol/L CdCl2处理2、4、6、8和 12 d。【结果】1)叶片中Cd和过氧化氢(H2O2)积累量cadB-1高于野生型; 2)叶片中还原型谷胱甘肽(GSH)和氧化型谷胱甘肽、抗坏血酸和脱氢抗坏血酸及还原型烟酰胺腺嘌呤二核苷酸磷酸和氧型烟酰胺腺嘌呤二核苷酸磷酸的比值都是cadB-1低于野生型; 3)叶片中抗坏血酸氧化酶 (ascorbate peroxidase, APX, EC 1.11.1.11), 还原型谷胱甘肽酶(glutathione reductase, GR, EC 1.6.4.2), 脱氢抗坏血酸还原酶(dehydroascorbate reductase, DHAR, EC 1.8.5.1) 和单脱氢抗坏血酸还原酶(monodehydroascorbate reductase,MDHAR, EC 1.6.5.4) 活性都是cadB-1低于野生型。【结论】cadB-1具有低水平的抗氧化剂和抗氧化酶活性。此外,cadB-1比 WT 积累更多的 Cd 从而产生更多的活性氧 (reactive oxygen species, ROS)。也就是说,与野生型相比,cadB-1 更缺乏防御力来清除更多的活性氧,从而导致较低的生长势和对Cd的敏感。     

短波紫外线对高水分稻谷抑霉效果的研究

紫外线辐照是一种安全无污染的处理方式,通过控制短波紫外线的辐照功率、辐照距离、辐照时间和单位面积的稻谷质量四个因素,研究粳稻谷中霉菌总数,表面霉菌量,游离脂肪酸值,电导率和过氧化物酶活性的变化情况,探讨紫外线对稻谷抑霉的效果。并根据Box-Benhnken的中心组合试验进行响应面设计,考察单位面积的稻谷质量、辐照时间、辐照功率对紫外抑霉效果的影响。结果表明:三因素的影响程度为辐照功率单位面积的稻谷质量辐照时间;优化条件为辐照时间15.39min、单位辐照面积的稻谷质量74.7g/dm2、辐照功率136.30W。     

Effects of Active Immunization with GnIH and INH Epitope Peptide Vaccine on Reproductive Hormones of Gansu Alpine Fine-wool Sheep

This study aimed to detect the reproductive hormones levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in Gansu Alpine Fine-wool sheep by active immunization of two synthesized epitope peptide vaccines A and B which were combined inhibit hormone (INH) and gonadotropin inhibit hormone (GnIH).15 Gansu Alpine Fine-wool sheep were selected which were 3.5 year old and lived in anoestrus season, 3 groups each had 5 sheep, GnIH epitope peptide vaccine and INH epitope peptide vaccine were named epitope peptide vaccine A and B groups, while blank group was injected with saline.The blood was collected before immunization and immuned, and bloods were collected once every 7 days, meanwhile collected blood every 15 min after estrus.The serum was used to detect antibody, FSH and LH levels by ELISA Kits.The results showed that the epitope peptide vaccine A and B groups produced the corresponding antibodies after the initial immunization, and epitope peptide vaccine B group produced more antibodies than epitope peptide vaccine A group.Epitope peptide vaccine B group promoted the FSH secretion levels was significantly higher than epitope peptide vaccine A group in 75, 90 and 105 min (P<0.05);In 45 to 105 minutes, the LH secretion levels of epitope peptide vaccine B group was significantly higher than epitope peptide vaccine A group (P<0.05), while the LH and FSH levels in epitope peptide vaccine A and B groups were significantly higher than control group (P<0.05).This study indicated that the epitope peptide vaccine A and B groups could promote the FSH and LH secretion levels through active immunity in Gansu Alpine Fine-wool sheep and had a good immune function.This study laid a foundation for the application of epitope peptide vaccine on sheep.     

精油组分对果蔬致病菌的体外抑制作用

为了评估植物精油组分对果蔬储藏中致病真菌的抑制能力,选取6种精油组分,测定其在体外对分离自水果的褐腐菌和青霉菌的最小抑菌浓度和滤纸片抑菌圈直径,并测定百里酚对褐腐菌和青霉菌孢子萌发的影响及其对菌落扩展的抑制能力,并观察经百里酚处理的褐腐菌和青霉菌菌丝的形态变化,结果表明所选精油组分均对褐腐菌和青霉菌有抑制作用,果蔬体外百里酚达到0.2 mg/m L可以抑制褐腐菌和青霉菌的菌丝扩展、孢子萌发并破坏菌丝结构的完整性。对精油组分的广泛筛选和进一步研究或可得到用于果蔬储藏保鲜的天然抗菌剂。