产蛋期母鸡血液激素的昼夜变化

用放射免疫方法检测了10只200日龄产蛋期母鸡血液激素的昼夜变化。结果:血浆雌二醇含量在11时出现一次峰值,孕酮在8时和17时出现两次峰值,黄体生成素在17时出现一次峰值,其他时间这几种激素的含量均波动不大;甲状腺素含量在一昼夜内一直较稳定,无明显波动。此外,对上述血液激素与排卵的关系作了讨论。     

Naturally occurring auxins and inhibitor and their role in fruit growth and drop of mango ‘Dashehari’

The pattern of fruit growth in mango ‘Dashehari’ (Mangifera indica L.) was sigmoid. Pollinated ovaries and young fruits dropped in two main waves: 0–14 days and 28–35 days. A third wave, a mild one, was continuous and irregular from 35 days after pollination to maturity of the fruit.One acidic and one non-acidic auxin and one acidic inhibitor were detected in the immature fruit. The increase in the levels of auxin corresponded with a period of rapid fruit growth, while high levels of inhibitor tended to correspond with a high rate of fruit drop from pollination to 42 days. The auxins appear to play a major role in the growth of the fruit, whereas the inhibitor appears to cause fruit drop.     

Listeriosis in Sheep: Experimental Listeric Infection in Sheep Treated with Various Immunosuppressiva

Four groups of lambs, about 6 months old, were given 4 different immunosuppressiva (prednisolone, cyclophosphamide, niridazole and gestagene hormones), 1 substance to each group. After this treatment the 4 groups together with a 5th group of the same size, were infected with Listeria monocytogenes (Lm).None of the animals developed clinical listeric encephalitis. The level of antibodies differed between the groups. The group not given any immun osuppressivum reached the highest antibody titres, the group given gestagene hormones had the lowest titres and the other groups ranged somewhere inbetween. All the groups except the group treated with niridazole had a strong delayed hypersensitivity reaction against Lm. The effects of the treatment upon some blood components are also described.Further studies are necessary to establish the effect of various immunosuppressiva, especially gestagene hormones.     

Hormone Profile of Crossbred Goats during the Periparturient Period

The plasma hormone profile of progesterone, 17-oestradiol, prolactin, growth hormone (GH), cortisol, triiodothyronine (T₃), thyroxine (T₄) and insulin were estimated by radioimmunoassay in jugular blood samples from 10 Alpine×Beetal crossbred goats during the periparturient period. The plasma progesterone concentrations declined from day 20 prior to kidding to the day of kidding and then remained at a basal level. 17-Oestradiol concentrations declined from day 20 to day 4 prepartum, followed by a continuous increase to reach a peak at kidding. Plasma oestradiol declined abruptly on day 1 postpartum and remained low throughout the postpartum period. The plasma prolactin concentrations increased continuously from day 20 to day 10 prepartum but then increased to a peak on the day of kidding, followed by a transient decline by day 5 postpartum. The plasma GH concentrations varied significantly (p<0.01) on the different days of sampling but were highest on the day of kidding. The plasma cortisol concentration declined from day 20 to day 2 prepartum, after which it abruptly increased on day 1 prepartum to reach a peak on the day of kidding. The concentrations of plasma T₃ remained similar during the prepartum period but were minimal on the day of kidding and increased during postpartum period. The concentration of plasma T₄ was also lowest on the day of kidding and increased during the postpartum period. Plasma insulin concentrations were low in the day of kidding.     

大果型和小果型荔枝品种果实发育细胞学和生理学比较

以大果型鹅蛋荔和小果型淮枝品种为对比试材,研究结果表明,两者果实干重、鲜重均相差2.6倍以上;鹅蛋荔大于淮枝既有库大小的原因,也与库活性大小有关;库大小主要体现在细胞数量上而与细胞大小无关;在果实发育期间,大果型的鹅蛋荔果皮中ZRs含量和ZRs/ABA一直高于小果型的淮枝;鹅蛋荔果实的呼吸率高于淮枝。     

秤锤树离体培养和植株再生

 在经选育的5年生秤锤树优良母株上, 取其腋芽茎段和顶芽为外植体, 进行离体培养和植株再生研究。结果表明, 以改良MS +BA 1.0 mg/L + TDZ 0.05 mg/L + IBA 0.05 mg/L +维生素C 50 mg/L + 3%蔗糖最适宜芽苗增殖; 改良MS +BA 0.5 mg/L + TDZ 0.05 mg/L + IBA 0.1 mg/L +维生素C 50 mg/L +3%蔗糖最适宜芽苗壮苗生长; 最适宜生根培养基为1 /2MS + IBA 0.5 mg/L +NAA 0.3 mg/L +维生素C 100 mg/L + 2%蔗糖; 经生根的试管苗移栽于蛭石∶珍珠岩∶泥炭= 6∶3∶1的混合基质, 控制温度20～30℃, 相对湿度85% ～90% , 保湿15～20 d, 其间适当遮荫, 35 d后成活率达92%以上。     

提高银杏叶黄酮含量的措施及其调控机理的研究(英文)

在银杏果用园,喷施矮壮素、脱落素及乙烯利均能提高叶黄酮含量,矮壮素效果最好,比对照提高了20.06%,与对照和其它处理间差异达到极显著水平,脱落酸与对照之间差异达显著水平。矮壮素处理效果最优的原因是它能促进光合积累,显著降低叶片中GA含量和IAA/ABA、IAA/ETH、GA/ABA、GA/ETH值。     

南方根结线虫对生姜生长及内源激素的影响

 试验结果表明,南方根结线虫侵染生姜后,首先损伤根系,进而显著降低生姜植株的株高、地上鲜重、根系鲜重和根茎重,减产47.96%。南方根结线虫侵染可使生姜叶片中赤霉素(GA)、吲哚乙酸(IAA)、玉米素核苷(ZR)含量显著降低,感病生姜的脱落酸(ABA)则表现为前期降低,后期增加的趋势,并促使叶片中GA/ABA的迅速下降,严重影响了生姜的生长,使感病植株矮小、叶片黄化,提前衰老。感病生姜根茎GA、IAA、ZR、ABA的变化规律与叶片相似,但9月份ZR、IAA含量的迅速上升,与根结线虫建立侵染据点、形成巨型细胞,从而造成根茎的局部疣裂有关。南方根结线虫侵染可引起病株根系GA/ABA升高以及GA含量在生长后期上升,促进营养物质向根部运输,从而造成根系的补偿性生长;但IAA和ZR含量的下降不利于根结线虫建立侵染据点,不能在根系中形成过多的根结。     

免疫应激对断奶仔猪免疫和神经内分泌激素的影响

试验研究了免疫应激对断奶仔猪免疫和神经内分泌激素的影响。选用 6头体重为 (7.6± 0 .3)kg的(2 8± 3)d的达兰断奶仔猪 ,绝食 12h后 ,随机选取 4头猪从腹膜注射 2 0 0 μg/kg(BW)的脂多糖 (LPS) ,另 2头注射等量生理盐水作对照。于注射后 0、1、2和 3h ,分别采血测定血浆白细胞介素 1β(IL 1β)、前列腺素E2 (PGE2 )、皮质醇、生长激素 (GH)和类胰岛素生长因子 I(IGF I)的含量。结果表明 :(1)注射LPS激活了应激轴 :与对照组相比 ,LPS提高了注射后 1h(P <0 .10 )、2h(P <0 .0 1)和 3h(P <0 .0 1)的IL 1β水平 ,提高了注射后 1h(P <0 .0 5 )和 3h(P <0 .0 1)的皮质醇和PGE2 水平 ;(2 )注射LPS抑制了生长轴 :LPS降低了注射后 3h的GH水平 (P <0 .10 ) ,降低了注射后 2h (P <0 .0 5 )和 3h(P <0 .0 1)的IGF I水平。结果显示 ,免疫应激激活了仔猪应激轴 ,而抑制了生长轴 ,在一定程度上揭示了免疫应激抑制生长的机制     

内源性调控对猪采食量的影响

采食量是猪营养的第一制约因素。本文就影响猪采食量调节的因素以及当前内源性调控采食量的一些初步研究作一简要介绍。