不同施肥处理对马铃薯农田土壤理化性状及产量的影响

为了探究不同施肥处理对马铃薯农田土壤理化性状及产量的影响,试验地采用马铃薯连作模式,设置3个施肥处理,即：单施化肥(T)、有机肥配施化肥(YTF 1/2)、全量有机肥(YTF)。结果表明：在不同施肥处理下马铃薯农田土壤的理化性质和马铃薯产量发生了变化,其中变化最为明显的土壤指标有土壤容重、孔隙度、饱和导水率、有效磷。YTF处理较T处理可分别显著(P<0.05)降低土壤容重16.8%,增加土壤孔隙度12.7%,提升饱和导水率25.3%。YTF处理可显著提升土壤有效磷含量43.0%,但各处理间土壤pH、有机碳、全氮、全磷、碱解氮、速效钾之间差异并未达到显著水平。同时,较之T处理,YTF处理亦可显著提升土壤团聚体含量。YTF和YTF 1/2处理可分别较T处理提升马铃薯产量24.6%和12.8%。因此,施用有机肥不仅可以改善土壤结构,改良土壤物理性状,亦能促产增收。     

土的弹性抗力与墩顶固结结构物的联合计算

将土、基础及上部结构物视为一个整体，在计入土的弹性抗力后对多跨无铰拱和连续刚构的上下部结构进行联合计算，并给出了算例，可供设计参考。     

Molecular structure of troponin C from chicken skeletal muscle at 3-angstrom resolution

The x-ray structure of chicken skeletal muscle troponin C (TnC), the Ca2+-binding subunit of the troponin complex, shows that the protein is about 70 angstroms long with an unusual dumbbell shape. The carboxyl and amino domains are separated by a single long alpha helix of about nine turns. Only the two high-affinity Ca2+-Mg2+ sites of the COOH-domain are occupied by metal ions resulting in conformational differences between the COOH- and NH2-domains. These differences are probably important in the triggering of muscle contraction by TnC. Also the structure of TnC is relevant in understanding the function of other calcium-regulated proteins, in particular that of calmodulin because of its strong similarity in amino acid sequence.     

C_R704玉米与S_C704玉米过氧化物酶同工酶及生理指标分析

C_R704玉米与S_C704玉米各时期的过氧化物酶同功酶谱无明显差别,二者遗传基础一致,但酶活性C_R704玉米高于S_C704玉米。经测定三系杂种C_R704玉米在叶绿素、糖、淀粉及蛋白质含量均优于单交种S_C704玉米。     

Comparison of maize,wheat and triticale in broiler diets

1. Wheat, triticale 131 or triticale 72‐S could replace up to half the maize in broiler diets without affecting performance. Replacing more of the maize on either an equal nitrogen basis or a weight basis adversely affected performance.

2. Triticale 72‐S appeared to be superior to triticale 131 as a direct replacement for maize, but both grains were inferior to maize as energy sources.     

Evaluation of rabbit excreta as an ingredient in broiler diets

1. Dry rabbit excreta were found to contain 188.1 g crude protein, 6.6 g non‐protein nitrogen, 0.3 g ammonia, 89.8 g moisture, 8.0 g ether extractives, 135.2 g crude fibre, 266.9 g ash and 19.18 MJ gross energy/kg. Methionine and lysine contents were 3.95 and 4.29 g/100 g protein, respectively.

2. In one experiment, 0, 50, 100 or 200 g rabbit excreta/kg were substituted for maize in a broiler diet. Chickens receiving the diet containing 200 g rabbit excreta/kg gained significantly less weight to 8 weeks of age than those receiving other diets.

3. In a second experiment, 0, 100, 150 or 200 g rabbit excreta/kg were substituted primarily for maize in a broiler diet to provide equal energy and protein contents. Weight gains to 8 weeks of birds receiving these diets did not differ significantly. The uncorrected metabolisable energy content of the excreta was 9.15 MJ/kg.

4. There were no gross pathological changes in the birds fed on the experimental diets.     

Replacement of maize by triticale in broiler diets

1. The nitrogen‐corrected metabolisable energy contents of the triticale varieties Multi Graze, Graze Grain 70, 204 and 131 were 12.28, 12.69, 12.37 and 12.03 MJ/kg respectively.

2. Increasing proportions (0, 25, 50 or 75%) of the maize of a diet were replaced by triticale 131 to provide diets of equal energy and nitrogen contents for broilers. These diets resulted in weight gains of 1.775, 1.782, 1.713 and 1.808 kg respectively at 8 weeks and there were no significant differences among efficiencies of food conversions.

3. Dressed carcass weights as percentages of body weight were 74.38, 75.01, 73.98 and 74.50 respectively and did not differ significantly.

4. Triticale in the diet did not seem to influence the relative weights of either liver or gizzard.

5. The flavour of the meat seemed to become less acceptable as the triticale in the diet increased but there were no significant differences in tenderness and juiciness of the meat caused by the treatments.     

番茄果实采后一氧化氮处理对活性氧代谢的影响

 以番茄品种‘百利’为试材, 研究了NO处理对其采后活性氧代谢的影响。结果表明: NO处理可推迟果实呼吸和乙烯高峰的出现, 抑制O·₂ 和H₂O₂ 的累积, 保持了贮藏后期SOD、CAT、POD、APX 较高的活性以及GSH和AsA含量的较高水平, 延缓了MDA含量和膜相对透性的升高, 降低膜脂过氧化程度, 延缓了果实衰老。     

新疆与美国早实核桃(Juglans regia L.)品种生长结实与成花特性比较

以引进的美国核桃品种‘维纳’、‘艾米格’和新疆本地品种‘温185’和‘新新2号’为试材,研究分析不同品种的植物学和生物学特性、花芽分化过程以及相关成花基因的表达。结果显示:4个品种在树体生长、枝芽发育特性、物侯期以及成花率和坐果率方面没有明显差异。在结果枝同一坐果部位形成双果、三果或以上的能力‘新新2号’明显强于‘维纳’,但‘新新2号’的果实大小和单果重都低于‘维纳’,而‘维纳’平均结果母枝上形成侧花芽的数量和坐果率高于‘新新2号’。从萌芽到开花结束直至当年侧芽发育过程中‘维纳’混合芽中的JrFT和JrLFY基因表达也高于‘新新2号’,而同时期的JrFLC基因表达则相对较低,说明‘维纳’在花芽分化和花器官形成过程中通过高表达JrFT和JrLFY基因,低表达JrFLC基因促进结果母枝上形成大量侧花芽,并利用大量侧花芽抽生结果枝坐果,形成较大的果实,使得最终产量并不低于同一个坐果部位大量着生2个或多个果实的‘新新2号’品种。