糯米糍荔枝果实内源激素与落果的关系

以糯米糍荔枝生理落果期的田间调查和胚胎发育研究为基础,探讨了内源激素与生理落果的关系.结果表明,糯米糍生理落果高峰的主要原因是:第1次因授粉受精不良导致的生长促进类激素尤其是CTK水平过低;第2次与胚乳为胚的发育所利用而消失、IAA和GAs急剧降低有关;第3次与胚的败育造成CTK、GAs和IAA的全面下降有关;第4次发生在假种皮(果肉)迅速生长期,与种皮和假种皮ABA升至高水平有关.此外,还探讨了ABA /(IAA+GAs+CTK)与生理落果的相关性,以及胚囊、珠被和假种皮等果实内部组分内源激素的变化特点.     

Rapeseed meal and egg taint: Treatment of rapeseed meal to reduce tainting potential

1. Treatment of rapeseed meal with calcium hydroxide suspension decreased the sinapine content by up to 90%. Smaller decreases were obtained by autolysis, steaming and treatment with ammonia.

2. When this treated meal was fed to susceptible ("tainting") hens the concentration of trimethylamine in the eggs was decreased to much less than that required to cause taint.     

Effect of injecting amino acids into the egg on embryonic and subsequent growth in the domestic fowl

1. The growing embryo uses about 1% of the total protein available in the egg during the first week of incubation.

2. Injecting the growing embryo with amino acids equivalent to the amount of protein used resulted in higher weight of chicks at all stages up to 56 d.     

关联度分析在农业生态系统技术调控上的应用

农业生态系统是个“灰箱”.我们运用模糊数学的关联度分析,尝试对这类灰色系统的投入进行技术调控,并取得了良好的效果.通过对农田子系统投入的化肥(尤其是N化肥)、粪肥和还田秸秆进行技术调控的实例证明;它可以作为能、物流分析的辅助手段,互相取长补短.通过关联序分析和关联系数分析,来调整系统的投入结构和投入技艺(时、空、量级及方式的选择).本文提出了应用关联度分析的基本程序和要领以及“贡献曲线”、“潜力曲线”等概念.     

The use of air‐coolers in broiler houses under subtropical conditions in Iraq

1. Under summer conditions in north Iraq, 2 000 chicks were reared for 56 d in two broiler houses. One house was provided with two air‐coolers. The birds were housed at densities of eight to 16 birds/m².

2. Differences in weight gain between birds in cooled and uncooled houses ranged from 101.5 g at eight birds/m² to 385 g at 16 birds/m². Food consumption increased gradually with increasing bird density. Food conversion efficiency, meat yield and carcass conformation were much better in the cooled house than under conventional conditions.

3. The financial return/m² ranged from 2.30 to 4.51 ID¹ in the cooled house, compared with 2.01 to 2.77 ID in the uncooled house at different floor densities.     

Storage time‐temperature effects on the odour preferences for uncooked chicken parts

1. Whole broilers and separated legs were stored at ‐12 ± 1 °C, —18 ± 1 °C and — 75 ±2 °C (reference group, whole carcasses only), for up to nine months.

2. Legs cut from the whole birds after removal from store, unpacking and thawing, and legs from the portions were compared in odour preference at four times of examination.

3. After only 1 d the odour of the legs stored as parts at —12 °C was less preferred than that of the reference group; this was also true for legs cut from whole birds after 3 months at the same temperature.

4. After 3 months at — 12 °C the odour of the legs stored as parts was less preferred than the odour of legs obtained from whole birds.

5. Storage of legs as parts at —18 °C resulted in a comparatively less preferred odour after 3 months, while the same was true after 9 months for legs cut from the carcasses.     

Rapeseed Meal and egg taint

1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine.

2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.     

The role of histamine and fish meal in the incidence of gizzard erosion and pro‐ventricular abnormalities in the fowl

1. The role of certain fish meals in the production of localised gizzard erosion is confirmed.

2. Lesions typical of gizzard erosion could be produced by the addition of histamine to the diet.

3. The amount of histamine occurring naturally in fish meal depends on the species of fish and the extent and nature of bacterial spoilage.

4. These variables may explain why histamine has not been implicated previously and also why there have not been consistent associations between the condition and geographical source or common factors in bulk consignments of the meal.     

Enantioselective degradation kinetics of metalaxyl in rabbits

Metalaxyl [methyl-N-(2′-methoxyacetyl)-N-(2,6-dimethylphenyl)-d,l- alaninate] is a potent phenylamide fungicide. The (−)-(R)-isomer accounts for most of the fungicidal activity. A possible stereo and/or enantioselective kinetics of metalaxyl in rabbits was investigated by intravenous injection. The concentrations of (−)-(R)- and (+)-(S)-metalaxyl in plasma, liver, and kidney tissue were determined by HPLC with a cellulose-Tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase and gas chromatography-mass spectroscopy. After intravenous administration of racemic metalaxyl (40 mg/kg), the (+)-(S)-enantiomer levels in plasma, liver, and kidney decreased more rapidly than the (−)-(R)-isomer. The area ratio of the (−)-(R)-/(+)-(S)-enantiomer under the concentration-time curve (AUC_0 → ∞) in plasma after drug application was 1.62. The total plasma clearance value of the (+)-(S)-enantiomer was 1.53 and higher than that of the (−)-(R)-enantiomer. The [R]/[S] ratio in plasma was >1 for standard rac-metalaxyl at each time point. The other pharmacokinetic parameters of the enantiomers were also different. The results indicate substantial stereoselectivity in the degradation of metalaxyl enantiomers in rabbits.     

不同贮藏温度对大五星枇杷果实保鲜效果的研究

枇杷成熟于初夏高温多湿季节，果实生理活动旺盛，含水量多，极易腐烂变质，一般条件下难以贮存和长途运销，采后损失率高。目前，枇杷贮藏最常用的方法是冷藏法。郑永华等把枇杷果实在1℃低温贮藏，可显著抑制果实失水，贮藏期可达20天以上；Mukerjece认为，枇杷贮藏在3℃低温下能减少腐烂；周德荣通过0、5、15℃和常温比较表明，“照种”枇杷在5℃下贮藏31天的好果率最高为83．9％。但近年来，一些研究报道，枇杷果实在不适宜的低温下长期贮藏会发生冷害现象。曾雅鹃等发现，在1℃低温下贮藏，枇杷果皮难剥，果肉变硬，