草生栽培对(木奈)园温湿度和果实品质的影响

1999- 2 0 0 1年进行了草生栽培对园温湿度和果实品质影响的试验。结果表明 :草生栽培可以有效地改善果园生态环境 ,降低久旱暴雨后的裂果率 ,有利于提高果的商品质量和经济效益。     

渭河阶地全新世土壤粒度成分高分辨率研究

通过对渭河阶地全新世土壤的野外考察和粒度成分的高分辨率分析研究，揭示了该区域褐色土的成壤作用过程与季风气候变化的关系。研究表明渭河第二级阶地褐色土形成在全新世气候最适宜期（8500－3100a B.P.），从8500a B.P.开始该土壤开始发育，老官台文化兴起。从3100a B.P.开始的气候干旱化和沙尘暴堆积形成了黄土L。层。西周时期对应于该干旱期的初期。     

培养条件对酸枣叶片不定梢再生率的影响

以酸枣无菌苗叶片为外植体,选用基本培养基ＮＮ６９和ＷＰＭ,外源激素包括ＴＤＺ、ＩＡＡ、ＩＢＡ和ＮＡＡ,暗培养时间为２、３、４周。采用正交实验设计方法,研究了基本培养基、外源激素及暗培养时间对叶片不定梢再生的影响。结果表明在附加ＴＤＺ１~３ｍｇ/Ｌ的ＷＰＭ和ＮＮ６９上都可诱导不定梢再生,但ＷＰＭ比ＮＮ６９更有效。暗培养时间对不定梢再生也有影响,暗培养３周比２、４周更有利于提高叶片的不定梢再生率。在附加ＴＤＺ１ｍｇ/Ｌ、ＩＡＡ０．１ｍｇ/Ｌ的ＷＰＭ培养基上,暗培养３周后转到光下培养,获得的不定梢再生率达８７．５%。     

CPPU在柿试管繁殖中的应用

对CPPU和ZT在柿试管繁殖中的应用价值进行了比较研究,结果表明:CPPU是一种可代替ZT的特效细胞分裂素,添加有CPPU0.2mg/L的MS(1/2N)培养基能促进芽的增殖和生长,且用此培养基继代培养的试管苗生根能力也有所提高。     

Changes of myocardial glycogen content and right ventricular function in hypoxia swimming rats

AIM: To investigate the changes of myocardium glycogen content and the relation ship between changes of the myocardial glycogen content and the myocardial function. METHODS: Male Wistar rats were placed in (hypoxia rats) and made to swim in (hypoxia swimming rats) a hypobaxic chamber simulating an altitude of 5 000 m above sea level. The content of myocardium glycogens was determined by colorimetry. RESULTS: The myocardium
glycogen content of rats significantly reduced along with the prolongation of hypoxic exposure and approached to control level in hypoxia swimming rats. The myocardial function of right ventricule was improved significantly compared with control group.CONCLUSION: Moderate exercise (swimming) is beneficial to hypoxic adaptation of rats under the condition of chronic hypoxia.     

Evidence that a Leaf-Disk Test Allows Assessment of Isolate-Specific Resistance in Brassica oleracea Crops Against Downy Mildew (Peronospora parasitica)

A rapid resistance/susceptibility test for Peronospora parasitica (downy mildew) was established by inoculating leaf-disks of four Brassica oleracea accessions. Several conditions were tested: disk disinfection or not, agar medium with or without nutrients and with 50 or 100 ppm of benzimidazole. Using disinfected disks placed on agar (no nutrient and benzimidazole at 50 or 100 ppm), the responses of leaf-disks to four isolates were similar to those obtained using the classical cotyledon test, whereas undesired contaminations occurred in all other conditions. The possible effect of the particular leaf used for obtaining the disks was also studied. In each incompatible interaction tested, disks were resistant whatever the leaf used. In compatible interactions, susceptible phenotypes were observed on disks derived from the six lowest leaves, but disks from upper leaves were resistant. The genetic basis of resistance in a F1 hybrid broccoli was assessed, by testing six isolates on an F2 population derived from this hybrid. The cotyledon test only allows inoculation of two isolates per seedling, whereas many isolates can be tested on each plant by using leaf-disks. The segregation of the resistance to each of the six isolates was analysed: two dominant genes (tightly linked) control resistance to all isolates (one to five isolates; the other to only one isolate).     

我国食用菌出口遭遇贸易壁垒的原因、类型及对策

贸易壁垒正在成为我国农产品出口的瓶颈。本文分析了我国食用菌产品出口遭遇的贸易壁垒类型及其原因，并提出了相关建议。     

温度对GF43李离体保存中老化作用的影响

 研究了不同温度对GF₄₃李( ^{_{Prunus domestica}} L. ) 试管苗生长及老化过程的影响。结果表明在16 ℃保存条件下GF₄₃试管苗的营养生长缓慢, 8 ℃保存GF₄₃试管苗的营养生长极缓慢, SOD、CAT 和POD 等保护酶系统的活性维持较高水平, 体内O₂ 自由基、丙二醛(MDA) 含量较低, 细胞膜结构相对稳定, 从而延缓了试管苗的衰老, 延长了两次继代之间的时间, 对试管苗的保存十分有利。     

利用紫茎泽兰栽培田头菇的研究

利用紫茎泽兰作为原料栽培田头菇 ,同时利用稻草和棉籽壳为原料栽培田头菇作对照。研究结果表明 ,代料熟料栽培田头菇的培养基配方中 ,以紫茎泽兰为主要原料的配方A效果最好 ,生物学效率比对照的稻草培养基平均增产 80 %以上。利用紫茎泽兰鲜草和干草作培养基的单产量差异不明显。     

七种与小麦近缘的野生植物对禾谷缢管蚜抗性的生化机制

研究了7种与小麦近缘的多年生野生植物长穗偃麦草Elytrigia elongata、费尔干偃麦草E. ferganensis、垂穗披碱草Elymus nutans、华山新麦草Psathyrostachys huanshanica、竖立鹅观草Roegneria japonensis、鹅观草R. kamoji和R. tsukushiensis对禾谷缢管蚜Rhopalosiphum padi抗性的生化机制.禾谷缢管蚜内禀自然增长率(rm)与叶片游离脯氨酸和蛋氨酸含量呈极显著和显著正相关,其逐步回归方程为:rm=-0.0198 0.1930X脯氨酸** 0.3350X蛋氨酸* ;总酚含量与禾谷缢管蚜内禀自然增长率无显著相关关系;丁布含量与内禀自然增长率呈极显著的负相关(r=-0.941**,p<0.01).低含量的游离脯氨酸﹑蛋氨酸及高含量的丁布是小麦近缘多年生野生物种抗蚜的重要生化因子.