PEG介导的玉米弯孢叶斑病菌遗传转化

为了探索不同酶系组成对玉米弯孢叶斑病菌原生质体制备的影响,建立该病菌原生质体遗传转化系统,采用酶系混合物裂解菌丝体制备原生质体,采用PEG介导方法进行原生质遗传转化,通过PCR和Southern blotting技术对转化子进行验证。结果表明:1%溶壁酶+1%蜗牛酶+1%纤维素酶混合酶系为玉米弯孢叶斑病菌原生质体制备的最佳酶系,可以产生原生质体6.78×106 cfu/mL。用PEG介导方法转化共获得16个稳定的转化子,从中随机挑取5个转化子发现质粒pV2已被成功整合到基因组中。本研究获得了制备玉米弯孢叶斑病菌原生质体的最佳酶系,建立了PEG介导的原生质体遗传转化体系,为开展该菌致病相关基因克隆和基因功能研究提供了一种手段。     

基于SRAP标记的黄瓜霜霉菌遗传多样性分析

本研究对来自黑龙江、辽宁、河北、山东、江苏5个省12个黄瓜主产区的77个黄瓜霜霉菌菌株,采用SRAP分子标记进行了遗传多样性分析。从35对SRAP引物中筛选出10对引物,共产生9 554条扩增条带,其中9 132条表现多态性,占95.6%。基于SRAP分子标记,77个黄瓜霜霉菌菌株的遗传距离为0.60~1.00,表明黄瓜霜霉菌具有丰富的遗传多样性。通过聚类分析,77个黄瓜霜霉菌菌株聚类为8个类群,并且来自相同地区的菌株大多数聚集于同一类群中,表明黄瓜霜霉菌群体的遗传多样性与其地理来源密切相关。     

不同含水量菜豆种子老化过程中生理特性的研究

 对不同含水量的菜豆种子( 2.1%、3.4%、3.8%、6.9%和9.0% ) 老化过程中的生理特性进行了研究。结果表明, 菜豆种子在含水量为318%时, 发芽率, 保护酶系统( SOD、POD和CAT) 活性和脱氢酶活性明显高于其它含水量的种子, 而脂氧合酶(LOX) 活性和丙二醛(MDA) 含量显著低于其它含水量的种子, 表现出较高的生活力。此结果表明适度降低菜豆种子的含水量可以提高其抗老化劣变能力;不同生活力的菜豆种子POD同工酶酶谱表现不同, 而SDS2PAGE蛋白质谱带则基本相同。     

The effects of 17β-estradiol on cardiomyocyte hypertrophy induced by endothelin

AIM:To investigate the effect of 17β-estradiol (E₂) on myocardial hypertrophy induced by endothelin-1(ET-1) and the related mechanism. METHODS:Myocardial cells from neonate rats were cultured in vitro and myocardial hypertrophy model was established with ET-1.The effects of 17β-estradiol on myocardial hypertrophy were observed. The role of ERK1/2 in the effects of 17β-estradiol was also detected. RESULTS:Compared with control group,ET-1 increased cell protein content,cell surface area and ［³H］^-Leucine ［³H］^-Leu) incorporation. Pretreatment with E₂ for 24 h could inhibit the increase in cell protein content,cell surface area and ［³H］^-Leu incorporation induced by ET-1.ET-1 significantly stimulated ERK1/2 activity,which was prevented by pretreatment with E₂.Tamoxifen,estradiol receptor antagonist,partially inhibited the effect of E₂. The ability of ET-1 to stimulate ［³H］^-Leu incorporation was significantly blocked by PD98059,which could enhance the inhibitory effect of E₂ on the increase of ［³H］^-Leu incorporation in cardiomyocytes induced by ET-1.CONCLUSION:E₂ can inhibit cardiomyocyte hypertrophy induced by ET-1. This effect is mediated by estrogen receptor. ERK1/2 signal pathway is closely correlated with the inhibitory effect of E₂ on cardiomyocyte hypertrophy induced by ET-1.     

Effects of the juice of Fructus Hippophae (JFH) on thrombocytopenia induced by cyclophosphamide in rats

AIM:To investigate the effects of the juice of fructus hippophae(JFH) on thrombocytopenia in rats.METHODS:Forty-eight wistar rats were divided into control group, model group, Yixuesheng-Jiaonang (YSJN) group and JFH group. Rats were injected intraperitoneally with cyclophosphamide (CTX, 30 mg/kg) or saline once a day for 3 days. And then, Saline, YSJN or JFH was administered (ig) once a day for 11 days. On the second, fouth, sixth and eighth day, the thrombocyte were counted, the mean platelet volume (MPV) and PDW were examined. On the eighth day, the cAMP, cGMP in platelets and platelet aggregation function were also examined.RESULTS:JFH could shorten the time of blood coagulation, increase the count of platelet, and enhance the platelet aggregation function. The experiment also showed that the JFH could decrease cGMP content in platelet.CONCLUSION:JFH could enhance blood coagulation and quality of platelet and prevent thrombocytopenia induced by cyclophosphamide in rats.     

杨桃果实生长发育过程中营养品质的变化

杨桃（Averrhoa arambola L．）为华南地区重要的热带水果。本试材为华南农业大学园艺分场种植的3年生盆栽马来西亚甜杨桃，砧木为酸杨桃。在杨桃的开花期，选择生长势、开花数量和时间较一致45株为试材，再选择受精时间一致的果实做标记。采样时问从开花后（2003年7月15日）至杨桃充分成熟（2003年10月25）。测定杨桃果实中的糖（蒽酮比色法）、有机酸（HPLC法）、维生素C（2，6-二氯靛酚钠滴定法）和单宁（高锰酸钾滴定法）的含量。     

Greenhouse gas emissions in response to straw incorporation,water management and their interaction in a paddy field in subtropical central China

A field experiment was conducted to study the effects of combination of straw incorporation and water management on fluxes of CH₄, N₂O and soil heterotrophic respiration (Rh) in a paddy field in subtropical central China by using a static opaque chamber/gas chromatography method. Four treatments were set up: two rice straw incorporation rates at 0 (S1) and 6 (S2) t ha^?1 combined with two water managements of intermittent irrigation (W1, with mid-season drainage) and continuous flooding (W2, without mid-season drainage). The cumulative seasonal CH₄ emissions for the treatments of S1W2, S2W1 and S2W2 increased significantly by 1.84, 5.47 and 6.63 times, respectively, while seasonal N₂O emissions decreased by 0.67, 0.29 and 1.21 times, respectively, as compared to S1W1 treatment. The significant increase in the cumulative Rh for the treatments S1W1, S2W1 and S2W2 were 0.54, 1.35 and 0.52 times, respectively, in comparison with S1W2. On a seasonal basis, both the CO₂-equivalents (CO₂e) and yield-scaled CO₂e (GHGI) of CH₄ and N₂O emissions increased with straw incorporation and continuous flooding, following the order: S2W2>S2W1>S1W2>S1W1. Thus, the practices of in season straw incorporation should be discouraged, while mid-season drainage is recommended in paddy rice production from a point view of reducing greenhouse gas emissions.     

不同低温处理对桃1年生枝相对电导率的影响

以9个不同桃品种1年生枝条为试材。通过在-5℃,-10℃,-15℃,-20℃,-25℃,-30℃处理24h后,测定不同低温胁迫下桃枝条的相对电导率。结果表明:随着温度下降,相对电导率逐步上升,呈S型变化;不同桃种类间抗寒性表现为毛桃蟠桃油桃;不同熟期桃品种间抗寒性表现为晚熟早熟中熟;不同桃品种间依半致死温度其抗寒性表现为早露蟠桃金秋早金锦霞瑞蟠4号瑞蟠3号晚金大久保艳霞。     

火鹤花穿孔线虫的病原鉴定

从进境火鹤花根组织和椰糠介质分离的穿孔线虫群体 ,经形态观察和测计 ,结果表明该线虫为香蕉穿孔线虫。并就穿孔线虫属的分类鉴定作了简述。