大豆几种光周期处理效应的植物激素解析

研究了大豆光照后效应、开花逆转、光周期对源库关系的调控、摘荚后光周期反应等现象中,内源激素的变化及几种外源生长物质对大豆发育的效应。结果表明,开花前对超早熟大豆品种东农36进行短日处理,明显加快开花后发育速度,降低叶片中的ABA和ZRs含量;幼苗期(VE-V2)对晚熟品种自贡冬豆进行l0 d左右的短日处理,尔后置15 h长     

Growth performance and physiological responses in striped knifejaw, Oplegnathus fasciatus, held under different photoperiods

The growth performance and stress response in striped knifejaw, Oplegnathus fasciatus (body weight 100–300 g) reared under four photoperiods (6L:6D, 12L:12D, 16L:8D and 24L:0D) were investigated. Fish were fed a commercial diet to apparent satiation, two times a day for 8 weeks. A trial of acute handling and confinement stress was also carried out to investigate the stress-induced levels of different stress indicators in O. fasciatus. Blood was also collected from undisturbed fish which was considered as control. Although there were no significant differences in weight gain, specific growth rate (SGR) and feed conversion efficiency (FCE) in fish exposed to 6L:6D, 16L:8D and 24L:0D photoperiods, all parameters in these photoperiods were significantly higher than those of 12L:12D photoperiod (P < 0.05). There was no significant difference in protein retention efficiency (PRE) between fish exposed to 16L:8D and 24L:0D photoperiods, but PRE in both photoperiods was significantly higher than that of 12L:12D photoperiod.Acute stress significantly increased the plasma levels of cortisol (110.3 ng ml^− 1) and glucose (195.4 mg dl^− 1), and decreased plasma levels of total protein (0.8 g dl^− 1); however, all parameters were returned back to the levels indistinguishable from those of control, undisturbed fish within 24 h. The levels of cortisol, glucose and total protein in fish exposed to different photoperiods during the study were far from the stress-induced levels (P < 0.05). The results demonstrated that the growth performance of O. fasciatus reared from 100 to 300 g can be stimulated significantly by using the manipulated photoperiods where feeding time may be playing an important role to increase food intake and feed conversion efficiency. It also revealed that the artificial photoperiods did not cause significant stress response in fish.     

Effects of different artificial photoperiods and temperatures on haematological parameters of rainbow trout (Oncorhynchus mykiss)

This study assessed the effects of two artificial photoperiods (LD 24:0 and LD 12:12) and three temperature regimes (9, 11, and 18°C) for 30 days on haematological parameters of trout (Oncorhynchus mykiss) kept in freshwater. Samples were taken at days 7, 14, and 30 during exposure to treatments. A higher mortality (22%) and lower oxygen concentration (<8.0 mg/l) were associated with the combination of photoperiod LD 24:0 and 18°C. The LD 24:0 photoperiod (independently of temperature) increased the haematocrit and the number of erythrocytes at days 7, 14, and 30 (P < 0.01). A temperature of 18°C (independently of photoperiod regimes) diminished the number of total leucocytes, lymphocytes and thrombocytes (P < 0.01). The LD 24:0 photoperiod (also independently of temperature) lowered the number of lymphocytes only after 14 days of experimentation (P < 0.01). Interaction between artificial photoperiod and temperature was only observed at day 14 for polychromatophils (P < 0.01). These results resemble the effects of stress caused by elevated temperatures and the application of continuous light photoperiods, indicating that survival risks may develop in trout farming when this combination is met.     

光周期对莲草直胸跳甲幼虫发育的影响

为明确光周期对莲草直胸跳甲幼虫的影响,调查了恒温条件下9种不同光周期组合(D∶D,L∶D=2∶22,L∶D=4∶20,L∶D=8∶16,L∶D=16∶8,L∶D=20∶4,L∶D=22∶2,L∶L,CK)对莲草直胸跳甲幼虫的发育历期、存活率、蛹的发育历期和蛹期存活率的影响。结果显示:光周期对幼虫的发育历期影响显著,当光周期中的光照时数为0~16h时,1龄幼虫的发育历期最长,其发育整体程度除L∶D=8∶16、L∶D=20∶4、L∶L外,均随光周期中光期时数的增加而提高。除L∶D=20∶4外,其它光周期对2龄幼虫发育历期的影响均较弱,对2龄幼虫发育进度的影响基本一致。幼虫的存活率随光周期的光照时数的增加而提高,但在L∶D=8∶16和L∶L却相对较低。除L∶D=4∶20,其它光周期对化蛹率影响均较弱,对化蛹历期无显著影响。光周期并不能完全使幼虫停滞发育,对其蛹期发育影响较小,适当延长光周期的光照时数可提高幼虫的存活率。     

大麦(Hordeum vulgare)昼夜节律钟基因CCA1的克隆及表达分析

昼夜节律钟基因CCA1在调解水稻和拟南芥的光周期反应中起着重要作用。利用BLAST手段以玉米中的CCA1基因序列作为靶序列,调取Genbank数据库信息,并结合RT-PCR方法获得了大麦的cDNA同源序列。BLASTx分析发现其与水稻和玉米的序列相似性分别达到72%和69%。通过ORF Finder软件分析发现,该序列包含一个2157bp的开放阅读框,编码一个由718个氨基酸残基组成的蛋白序列,其分子量为77 769.4Da,等电点为6.55。采用实时荧光定量PCR分析发现,随光照时间的变化,该基因在大麦叶片中的表达量呈现出白天不断降低而夜晚逐渐升高的昼夜变化趋势,且在华大麦1号和华大麦2号中的表达曲线存在一定的差异。本研究为进一步研究大麦CCA1基因在调控大麦光周期响应途径中的功能,阐明大麦光周期敏感机制提供了科学依据。     

条斑紫菜丝状体悬浮培养研究

通过光强、光时的实验、比较了在悬浮培养条件下，光对条斑紫菜丝状体生长的影响，探讨并初步确定了丝状藻丝悬浮培养适宜的光强，光时条件。与此同时，还比较了悬浮培养和静置培养的实验结果。显示前者的丝状藻丝有比后者高得多的生长率，更适合于生产性应用。     

春化及光周期基因的等位变异对小麦主要农艺性状及产量的影响

为了解春化及光周期基因对小麦生育期、农艺性状及产量的影响,以田间种植的253份国内外小麦品种(系)为材料,利用分子标记检测其春化基因(Vrn-1)和光周期基因( Ppd-D1)的等位变异,记录其抽穗期、开花期,在灌浆中期调查其株高、成穗数等农艺性状,收获后调查其产量性状。结果表明,供试材料中包含13种春化和光周期基因等位变异组合类型,其中含有 vrn-A1+vrn-B1+vrn-D1+Ppd-D1a组合的材料最多,占59.68%; Vrn-1+Ppd-D1a组合可显著缩短小麦播种至开花所需的时间。含有 Vrn-A1a或 Vrn-B1材料的成穗数显著多于含有 Vrn-D1或 vrn-1的材料,但含有 Vrn-1不同等位变异的材料间产量无显著差异;含有 Vrn-A1a材料的旗叶长而窄。与含有 Ppd-D1b的小麦材料相比,含有 Ppd-D1a的材料开花期显著提前,且株高降低,同时穗下茎长、旗叶长和倒二叶长均显著缩短。综上,春化及光周期基因在影响小麦抽穗开花期的同时,对农艺性状和产量也有重要影响;含有 Vrn-D1+ Ppd-D1a组合的小麦材料在生育期稳定性、产量等性状上均表现优异,在育种...     

解除天幕毛虫滞育初探

利用不同的光周期和温度设置对黄褐天幕毛虫(Malacosoma neustria testacea Motschul-sky)卵环进行处理,寻找解除天幕毛虫滞育的条件和作用机制。结果发现,低温对于解除天幕毛虫的滞育有一定的作用。     

光周期对切花菊生长及开花的调控

以‘红面’切花菊（Hongmian）为试材，设置6组光周期处理，分别为昼/夜7h/17h（记为Ph7）、8h/16h（Ph8）、9h/15h（Ph9）、10h/14h（Ph10）、11h/13h（Ph11），以长日照（13~14h）处理为对照CK，研究不同光周期对其生长及开花的影响。记录不同处理现蕾、破蕾、初花、盛花的时间和叶片数，测定分析不同发育期叶片可溶性总糖、蔗糖和蛋白含量，并于不同处理达盛花期时测定其花、茎鲜重以及干物质在不同器官的分配率，以阐明不同光周期对‘红面’菊初花期和出花品质的调控作用，为不同发育期的菊花栽培提出具有针对性的补光建议。结果表明：（1）叶片数随光照时间的增加而增加，并以CK的增加速率最大，Ph11次之，Ph7最小。（2）‘红面’切花菊的花期明显受光照时长的影响，Ph10处理下的菊花从苗期−现蕾、成花耗时均最短，Ph11从初花−花瓣全展开的盛花期耗时最短，Ph7、Ph8和CK花期严重滞后。（3）不同发育期叶片可溶性糖、蛋白含量均呈“M”形变化趋势，两次峰值分别出现在花芽分化期和开花前。可溶性总糖含量以CK最大，Ph11次之；作为可感知光周期信号的信使分子蔗糖，以及可溶性蛋白含量均以Ph10最大。（4）花鲜重以Ph11最大，促花效果显著。因此生产上将秋菊开花时间提前的同时，为保证切花质量，苗期应接受大于11h/d的长日照条件，使菊花苗进行充分的营养生长而不过早诱发花芽分化，以10h/d的光照条件进行诱花处理，花蕾形成且开始成花显色后，花芽分化已不可逆，再将其置于11h/d的光照条件下花瓣可最快全部展开。     

光周期途径植物开花决定关键基因FT

随着分子生物学的快速发展,大量与光周期途径开花相关的基因已经被发现和克隆,FT（FLOWERING LOCUST）是光周期途径植物开花时间决定关键基因,并认为刀基因表达产物可能就是人们长期追寻的开花刺激物质,这种开花刺激物质经过叶片到茎尖的长距离运输,最终引起茎顶端开花起始。目前已在多种植物中分离出刀同源基因,并通过转基因证明刀基因的表达可促进植物提早开花。本文对国内外关于刀基因家族的研究进展进行综述,旨在为进一步深入研究刀基因功能提供参考。