球根海棠离体培养的形态发生研究

 球根海棠外植体可在同一条件下同时诱导不定芽和胚状体, 经间接途径和直接途径的体细胞胚胎发生频率均很高, 体细胞胚为单细胞起源或多细胞起源。以再生嫩叶为继代中间体, 在较高温度(28 ℃) 下诱导, 可建立高效扩繁体系。纵切芽丛继代形成大量愈伤组织, 愈伤组织继代半年后几乎完全丧失分化能力, 发生激素驯化作用, 而且愈伤组织细胞染色体数目已发生广泛变异。     

梨果实发育过程中石细胞团及几种相关酶活性变化的研究

以梨品种西子绿、菊水及砀山酥梨为试材,对不同发育时期梨果实石细胞团的密度、大小及几种相关酶的活性变化进行了研究。结果表明石细胞团的分布密度在幼果期较高,以后随着果实的发育和膨大,密度逐渐减小,接近成熟前1个月左右基本稳定;石细胞团的直径随果实的生长而逐渐变大;苯丙氨酸解氨酶在果实发育初期表现出较高的活性,随着果实的生长逐渐降低,花后75d后保持低水平不变;过氧化物酶活性高峰出现稍迟于苯丙氨酸解氨酶,高峰后呈现出下降的趋势;多酚氧化酶活性波动较大,总的变化趋势逐渐下降。品种间苯丙氨酸解氨酶、过氧化物酶活性与石细胞团的形成之间表现为正相关。     

草莓叶面积简易测定方法

以透明方格法作对照,分别与叶面积的其他简易测定法(叶长度×叶宽度的系数法、叶长度与叶面积的回归法、叶宽度与叶面积的回归法)比较。结果表明吐德拉(Tudla)叶面积的每种测定方法,以叶宽度与叶面积回归法最精确,计算公式是=7.0918x-13.4784穴公式中的x是叶宽度,y是叶面积,以下相同雪;鬼怒甘(Kinuama)叶面积的测定法也是叶宽度与叶面积回归法最精确,公式是=7.3187x-14.3288。杜克拉(Dukela)叶面积的测定法,推荐用叶宽度与叶面积的回归法,公式是=6.6393x-10.6411。y=a+bx^y=a+bx^y=a+bx^     

山药新品种‘桂淮6 号’

 ‘桂淮6 号’是从广西山药资源中选育而得。该品种早熟, 高产, 铁、锌含量高, 分别达20.2 mg/ kg 和12.0 mg/ kg , 薯皮鲜红色。     

99%矿物油乳油(绿颖)防治茶橙瘿螨药效试验研究

1地连续2年的药效试验表明，99％矿物油乳油施药后3d对茶橙瘿螨效果较明显，50、150倍液防效均超过80％，250倍液防效为73．6％，施药后7、14、21d，2种较高剂量的99％矿物油乳油防效均超过80％．最高达97％以上。在推荐施用浓度范围内，药效高，持效性好．对茶树和天敌生物无不良影响。     

Effect of sodium nitroprusside on activation of nuclear factor κB

AIM: To investigate the effect of sodium nitroprusside (SNP) on activation of nuclear factor κB. METHODS: The techniques of culture of human T lymphocytes, Western blot and RT-PCR were applied. The effects of NO donor sodium nitroprusside (SNP) at different concentrations on mRNA and protein expression of IκB_α in human T lymphocytes at 30 min or 120 min after stimulating with phytohaemagglutinin (PHA-P) were observed. RESULTS: SNP at middle or high concentrations reduced the degradation of κIB_αprotein 30 min after stimulating with PHA-P,and increased the re-expression of κIB_αmRNA 120 min after stimulating with PHA-P significantly.CONCLUSION: The mechanism of inhibitory effect of SNP at middle or high concentrations may be due to the decrease in degradation and the increase in re-synthesis of κIB_α.The regulatory mechanism of SNP at low concentration may not be through κIB_α.     

2种组胺受体拮抗剂对低温诱发的肉鸡肺动脉高压的影响

为探讨组胺H1受体拮抗剂扑尔敏和H2受体拮抗剂西咪替丁对低温诱发的肉鸡肺动脉高压的影响,并由此推测组胺在低温诱发的肉鸡肺动脉高压形成过程中的作用。140只17日龄AA肉鸡随机分为4组。(1)常温组:40只在常温条件下饲养(22～23℃),每日注射生理盐水2次;(2)低温组:40只在低温环境中饲养(9～11℃),每日注射生理盐水2次;(3)扑尔敏组:40只在低温环境中饲养(9～11℃),每日注射扑尔敏2次;(4)西咪替丁组:20只在低温环境中饲养(9～11℃),于24日龄至38日龄期间每日注射西咪替丁2次。分别于低温处理后1周(24日龄)、2周(31日龄)、3周(38日龄)、4周(45日龄)从常温组,低温组,扑尔敏组中各随机抽取10只,西咪替丁组在低温处理后2周(31日龄)、3周(38日龄)各随机抽取10只,称取体重,然后利用右心导管法测定肺动脉压(PAP),并测定红细胞压积(PCV),腹水心脏指数(AHI)。结果发现:(1)24日龄、31日龄、38日龄时,低温组肺动脉收缩压,舒张压显著高于(P<0105)或极显著高于(P<0101)同日龄常温组。24日龄时扑尔敏组肺动脉收缩压显著低于(P<0105)同日龄低温组。38日龄时西咪替丁组肺动脉收缩压,舒张压极显著低于(P<0101)同日龄低温组。(2)24日龄、31日龄、38日龄、45日龄时,低温组PCV极显著高于(P<0101)同日龄常温组。24日龄时扑尔敏组     

BQ123对低温诱发的肉鸡肺血管重塑的影响

动态观察了肺小动脉中膜平滑肌的增殖及管腔面积的改变,探讨内皮素受体拮抗剂BQ123 对低温诱发的肉鸡肺血管重塑的影响。200只16日龄AA肉鸡随机均分为4组: 常温(20 ℃)对照组、低温(7~9 ℃)组、低温低剂量BQ123组和低温高剂量BQ123组。23日龄、30日龄时测定肺动脉压,并取肺组织做石蜡切片, 以Weigert间苯二酚复红染色,形态学计算机图象分析法测定肺细小动脉外径和内径、管总面积和管腔面积,计算中膜厚度占外径百分值(%)mMTPA及管壁面积/管总面积WA/TA(%)。结果显示:(1)BQ123 抑制低温肉鸡平均肺动脉压的升高,23日龄时低温高剂量BQ123组显著低于低温组(P<0 05),30 日龄时低温低剂量BQ123 组和低温高剂量BQ123组均极显著低于低温组(P<0 01);(2)BQ123 抑制低温肉鸡肺小动脉WA/TA(%)的升高,30~50μm的肺小动脉,低温组极显著高于低温低剂量BQ123 组及低温高剂量BQ123 组(P<0 01),其它分级的肺小动脉组间差异性与此类似;(3) BQ123抑制低温肉鸡肺小动脉的mMTPA的升高,30~50μm的肺小动脉,23日龄时低温组极显著高于低温低剂量BQ123 组和低温高剂量BQ123 组(P< 0 01), 30 日龄时低温组显著高于低温低剂量BQ123组(P<0 05)、极显著高于低温高剂量BQ123组(P<0 01),30μm以下的肺小动脉组间差异性与此类似,50~120μm     

Effects of continuous low dose infusion of lipopolysaccharide on inflammatory responses,milk production and milk quality in dairy cows

The objective of this study was to evaluate the effects of continuous low dose infusion of lipopolysaccharide (LPS) on inflammatory responses and milk production and quality in lactating dairy cows. Eight Holstein cows were assigned to two treatments in a cross‐over experimental design. Cows were infused intravenously either with saline solution or with saline solution containing LPS from Escherichia coli O111:B4 at a dose of 0.01 μg LPS/kg body weight for approximately 6 hr each day during a seven‐day trial. The clinical symptoms and milk production performance were observed. Milk samples were analysed for conventional components, fatty acids and amino acids. And jugular vein and mammary vein plasma samples were analysed for concentrations of cytokines and acute phase proteins. LPS infusion decreased feed intake and milk yield. An increase in body temperature was observed after LPS infusion. LPS infusion also increased plasma concentrations of interleukin‐1β, serum amyloid A, LPS‐binding protein, C‐reactive protein and haptoglobin. LPS infusion decreased the contents of some fatty acids, such as C17:1, C18:0, C18:1n9 (trans) and C18:2n6 (trans), and most amino acids except for methionine, threonine, histidine, cysteine, tyrosine and proline in the milk. The results indicated that a continued low dose infusion of LPS can induce an inflammatory response, decrease milk production and reduce milk quality.     

Disaccharide combinations and the expression of enolase3 and plasma membrane Ca2+ ATPase isoform in sturgeon sperm cryopreservation

Acipenser sinensis and Acipenser dabryanus are critically endangered species, so germplasm conservation via cryopreservation of sperm is necessary. Disaccharides can act as membrane‐impermeable cryoprotectants, and enolase3 (ENO3) and plasma membrane Ca²⁺ ATPase isoform (PMCA2) are proteins associated with sperm quality. We considered seven characteristics of sperm quality in cultured brood stock from A. sinensis and A. dabryanus. We tested use of sucrose or trehalose alone and in combination at different concentrations for cryopreservation of A. dabryanus sperm. A low concentration of sucrose plus trehalose (S₁₅T₁₅) was optimal. Mixing of the extender with sucrose, lactose, or trehalose alone or with pairwise mixtures revealed that a mixture of lactose and trehalose (L₁₅T₁₅) gave the best results for both A. sinensis and A. dabryanus. Enolase3 and PMCA2 expression levels were measured in cryopreserved A. sinensis sperm via Western blotting. Relative ENO3 and PMCA2 expression levels were examined, and the relationship between disaccharide composition, sperm quality and protein expression was explored in A. sinensis. The results showed that relative ENO3 and PMCA2 expression levels were the highest at L₁₅T₁₅ in cryopreserved A. sinensis sperm. There were significant positive correlations between ENO3 expression and percentage membrane integrity, and between PMCA2 expression and sperm motility parameters (percentage of motile sperm, curvilinear velocity, straight‐line velocity and average path velocity; p < .05) in cryopreserved A. sinensis sperm. Our results indicate the optimal disaccharide combination and concentrations for cryopreservation of A. sinensis and A. dabryanus sperm and suggest that ENO3 and PMCA2 expression levels could serve as a valuable indicator of sperm quality in A. sinensis.