中美半矮秆大豆杂交早期世代农艺性状遗传变异研究

以三个中美半矮秆大豆杂交组合为材料,通过对其自交及回交后代各主要农艺性状的遗传参数的分析,为半矮秆大豆后代的选择和品种选育育种提供了一定的理论依据。试验结果表明：中美半矮秆大豆品种间其性状特别是分枝性状的明显差异,加之地理远缘等原因,其Ｆ１代多数农艺性状具有明显的超亲优势,自交及回交后代分枝性状有着超常幅度的变异;除了与通常杂交组合中株高、主茎节数、百粒重等表现较大的遗传力相同外,此种组合后代的分枝性状也表现了较高的遗传力。中美半矮秆大豆杂交后代所有分枝性状变异广泛,相对预期遗传进度大,且与目标性状产量相关值较大,决定了在此组合早代选择的必要性。     

华北地区潜流人工湿地浮水植物气候适应性分析

[目的]选择适合华北地区潜流人工湿地种植的浮水植物。[方法]在官厅水库黑土洼人工潜流湿地系统的水生生物塘中分别种植大薸、水葫芦和水鳖3种植物,通过实地观测3种植物的生长状况,得出3种植物对北方气候的适应性。[结果]3种水生植物中,大薸的生长速度和生长态势均最好,其生理特征能很好地适应黑土洼人工湿地水生生物塘中水环境状况;水葫芦次之;水鳖长势最差,不适应北方环境。[结论]为北方人工湿地浮水植物的选择提供了参考。     

植物盐胁迫适应机制研究进展

综述植物对盐胁迫的适应机制,包括提高抗氧化酶系统的活性、调节激素含量、离子区域化、离子选择性吸收、拒盐作用及合成渗透调节物质.目前植物盐胁迫适应机制的研究取得了一定进展,但在分子水平上仍有待于进一步深入.以现有研究为基础,利用分子生物学研究技术、基因工程技术和突变体筛选是根本解决植物抗盐性问题的重要途径和方法.     

东海浮游十足类优势种环境适应的研究

根据1997-2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,对东海浮游十足类优势种的生态特征进行了研究,探讨这些优势种对环境的适应及与渔场的关系。结果表明:主要优势种有中型莹虾Lucifer intermedius、刷状莹虾Lucifer penicillifer、细螯虾Leptochela gracilis和汉森莹虾Lucifer hanseni。前2个优势种是近海暖水种,细螯虾是广温高盐种,汉森莹虾是外海暖水种。近海暖水种不但平均丰度高,而且优势度和占浮游十足类总丰度的百分比均大于其它优势种。广温高盐优势种具有较高的出现率,细鳌虾丰度不高,但在每个季节、各个海区均有出现。在夏季,低温环境适应力差的暖水种往往有很高的聚集强度。与东海其它类群的浮游动物不同,浮游十足类以夏季丰度最大。就个体数量而言,以近海暖水种个体居多,主要分布在位于东海沿岸河口附近的鱼类产卵场。     

低温适应下锯缘青蟹肌肉及其细胞膜脂肪酸组成的变化

研究主要采用生物化学方法对低温适应3周的锯缘青蟹肌肉及肌细胞膜脂肪酸组成进行测定,结果显示,肌肉中脂肪酸C16:0随饲养温度降低而降低,5 ℃组显著低于27 ℃组(P<0.05);C18:0却在5 ℃组显著高于27 ℃组(P<0.05);C20:5随着饲养温度降低而升高,5 ℃和10 ℃组显著高于27 ℃组(P<0.05)。∑C16随饲养温度的降低而降低,5 ℃组显著低于27 ℃组(P<0.01);∑C20却随饲养温度的降低而升高,5 ℃和10 ℃组显著高于27 ℃组(P<0.05); EPA+DHA随饲养温度降低而升高,5 ℃和10 ℃组显著高于27 ℃组(P<0.05),而EPA/DHA仅5 ℃组显著高于27 ℃组(P<0.01)。低温适应下锯缘青蟹肌肉细胞膜脂肪酸C18:2显著升高(P<0.01或P<0.05),但随养殖温度的降低逐渐降低;低温适应下C18:1降低,在5 ℃组 显著降低(P<0.05);C18:0低温适应下也显著降低(P<0.01);C20:5低温适应下上升,但仅在15 ℃适应下显著上升(P<0.05)。C22:6低温环境下降低,在5 ℃和10 ℃组显著下降(P<0.05)。C20:1,C20:4和C20:3在低温环境下增加,仅5 ℃组显著高于27 ℃组(P<0.01或P<0.05),肌肉细胞膜中∑C18低温环境下降低,而∑C20低温下增加,并且均在5 ℃组出现显著性差异(P<0.01)。∑C22低温适应下降低,仅10 ℃下降明显（P<0.05）,∑SFA低温环境下显著降低(P<0.05或P<0.01);∑UFA低温环境下显著升高(P<0.05或P<0.01),低温适应下饱和指数∑SFA/∑UFA显著下降(P<0.05,或P<0.01);其中不饱和脂肪酸∑UFA低温适应下的升高主要是∑PUFA-ω6升高,EPA+DHA低温适应下无显著性变化(P>0.05),但EPA/DHA仅5 ℃组显著上升(P<0.05)。上述结果表明低温适应下肌肉及肌细胞膜脂肪酸组成的变化是处于不断合成和转化的动态之中。与肌肉组织相比较,肌细胞膜脂肪酸组成变化较大,其脂肪酸饱和指数在低温适应下显著下降。细胞膜对低温环境的敏感反应说明低温适应和生理稳态维持过程中细胞膜起着重要的生物学作用。     

卵高温胁迫对木薯单爪螨发育与繁殖的影响?研究

为探讨木薯单爪螨的生态适应性机理,揭示其种群扩散蔓延机制,本研究开展了卵高温胁迫对木薯单爪螨生长发育与繁殖的影响研究。将木薯单爪螨卵在梯度高温(30、33、36、39、42℃)人工气候箱中处理不同时间(0.5、1、2、4、8、16、24 h)后置于室温(25℃)下饲养,观察其卵孵化率、发育历期、后代性比（雌性百分率）及后代成螨寿命。结果表明：卵高温处理显著影响木薯单爪螨的发育与繁殖。随着温度的升高和处理时间的延长,木薯单爪螨的发育历期显著延长,卵孵化率、后代雌性百分率与后代雌成螨寿命显著下降。温度越高,对木薯单爪螨发育与繁殖的影响越显著,尤其对卵和幼螨的发育;卵经42℃高温处理2 h以上（包括2 h）后在25℃下均不能孵化和完成任何发育历期;42℃高温1 h为木薯单爪螨卵热最敏感时间。因此,卵高温胁迫显著影响木薯单爪螨的生长发育与繁殖,从而可能影响木薯单爪螨种群的变化。本研究结果可为木薯单爪螨扩散蔓延范围及生态适应性提供理论依据,为科学制定中国针对木薯单爪螨的检疫政策和防控措施,以防其进一步扩散蔓延提供理论依据和前期工作基础。     

Spatial analysis of genetic diversity in a comprehensive collection of the native grass Bromus auleticus Trinius (ex Nees) in Uruguay

Bromus auleticus Trinius (ex Nees) is a perennial allogamous C3 grass native to the Campos grasslands. It has potential to play a key role in restoration of both abandoned agricultural and overgrazed lands. We aim to reveal the existence of local adaptation and to assess whether phenotypes could be differentiated in relation to their ecogeographic region of origin. Previous reports estimated significant levels of variability among and within populations, but as yet there is no evidence of local adaptation and phenotypic relations with ecogeographic regions for this species. Indeed, there is a lack of knowledge about the spatial distribution of diversity, which limits the possibilities of using B. auleticus in ecological restoration and plant breeding. A comprehensive collection of 82 accessions of B. auleticus from eight ecogeographic regions within Uruguay was used to characterize diversity by measuring phenologic, morphologic, productive and reproductive traits. We found high diversity among B. auleticus accessions, and the spatial distribution of this diversity follows a pattern accounted by ecogeographic regions to a large extent. Our results also indicate large genotype × environment interaction, confirming local adaptation. Phenotypic values permitted, with a 3.7% error rate, discrimination of accessions according to their ecogeographic region of origin, suggesting the existence of differentiated ecotypes. We consider that the diversity observed should be conserved and used for breeding cultivars of this species and for the restoration of degraded grasslands by considering ecogeographic regions when selecting seed sources.     

TRPV5与TRPV6在哺乳动物妊娠期钙代谢的适应性调节作用

在哺乳动物妊娠期,母体的钙代谢通过适应性调节满足胎儿对钙的需求,包括肠钙吸收的增强、肾钙排泄的减少。妊娠钙代谢适应性需要钙离子通路蛋白参与,TRPV5/TRPV6是实现钙代谢调节的重要蛋白。TRPV6高表达于小肠,主要介导肠钙转运,TRPV5与肾脏钙离子重吸收相关,此外TRPV6介导胎盘组织的母体一胎儿钙转运。     

The determination of dark adaptation time using electroretinography in conscious Miniature Schnauzer dogs

The optimal dark adaptation time of electroretinograms (ERG''s) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG''s at seven different dark adaptation times at an intensity of 2.5 cd·s/m² was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p < 0.05). Thereafter, no significant differences in amplitude occured over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 ± 18.47 µV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p < 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 ± 17.79 µV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG''s, should be at least 20 min in conscious Miniature Schnauzer dogs.     

广州耐湿热月季品种杂交试验初报

为培育出耐湿热的月季新品种,在广州选择几个耐湿热性较强和性状表现良好的月季品种进行了初步杂交试验.结果表明:'粉扇'绯扇'金凤凰'和'粉色莫奈'4个品种均可作为杂交母本;'澳洲黄金'薰衣草玫迪兰'粉扇'绯扇'和'金凤凰'花粉量大,适合作为父本.不同组合杂交结实率差异较大,如'金凤凰'×'粉扇'结实率达100％...