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141.
142.
红豆杉营养器官的解剖学研究 总被引:4,自引:0,他引:4
通过对红豆杉营养器官的解剖学研究,阐明其根、茎、叶的结构特征,为红豆杉的开发利用研究提供了解剖学依据。研究结果表明红豆杉营养器官具有以下特征:(1)根、茎、叶中均无树脂道;(2)根、茎皮层中均有含单宁类物质的细胞分布;(3)根、茎中均有石细胞分布,(4)叶气孔器为双环型,略内陷;(5)根为二原型,(6)幼根的内皮层具凯氏带加厚,中柱鞘细胞富含单宁类物质;(7)根的次生维管组织中射线发达。 相似文献
143.
从甘松(Nardostachys chinensis.Batal)的根中分离到了一个新的倍半萜过氧化物——甘松醛(Nardosaldehyde),并通过J-分解谱等二维核磁共振技术鉴定了其结构。 相似文献
144.
本文将1994年从内蒙古不同地区采集到的羊草(Leymus chinensis)种子进行栽培试验,通过对幼苗进行PEG水分胁迫处理后,分别进行电阻、电导测试,发现不同样点的一年生羊草的电阻、电导对PEG水分胁迫在时间和浓度上的反应是不同的。聚类分析进一步表明不同地理种群羊草按电阻或电导的变化情况都可分成3大类,且所得结果相同:其中来自吉林和定位站的羊草最抗旱,阿旗与西乌旗的次之,谢尔塔拉的则最不耐旱,这与它们对各自自然生境的适应也是一致的。 相似文献
145.
光强梯度对羊草无性系分化与生长的影响 总被引:7,自引:1,他引:6
在温室内用透光率分别为 60 %、45%、30 %的遮阴网盖在花盆上遮阴 ,研究不同光照强度对羊草无性系分化与生长的影响 .结果表明 ,低光强影响羊草基株的生物量积累 ,抑制羊草无性系的分化和生长 .减少羊草地下根茎的数目 ( A=61 4个 ,D=2 31个 )和无性系分株数 ( A=70 4个 ,D=1 52个 ) .羊草根茎长度和节数、无性系分株干重等性状在不同的光强梯度之间存在显著差异 ( P<0 .0 1 ) ,这种差别在春季尤其显著 . 相似文献
146.
久效磷对中国对虾细胞超微结构的影响Ⅲ.对鳃的毒性效应 总被引:10,自引:0,他引:10
对中国对虾鳃细胞超微结构的透射电镜观察结果表明 ,经 0 .1 0mg·L- 1 久效磷处理的中国对虾 ,鳃丝细胞的内质网水肿、扩张和囊泡化 ,粗面内质网膜上的核糖体颗粒大量脱落 ;高尔基膜囊轻微水肿 ,高尔基小泡水肿扩张 ,严重者破裂 ;线粒体的内嵴膨胀 ,局部瓦解乃至解体 ;鳃丝上皮细胞角质层变性脱落 ,核膜水肿 ,部分溶解 . 相似文献
147.
中国兰花蕉科植物花粉形态 总被引:1,自引:1,他引:0
使用扫描电镜及光学显微镜观察了国产兰花蕉科2种植物(兰花蕉及长萼兰花蕉)的花粉形态。它们的花粉粒呈豆形、两侧对称、异极、无萌发孔,中间部分的表面具稠密的条状雕纹,两端的为皱波状雕纹。两种花粉的雕纹有些区别。兰花蕉科花粉形态特征特别,不同于姜国其他7科的花粉,属特殊的花粉类型。 相似文献
148.
野生北五味子生物学特性的研究 总被引:3,自引:0,他引:3
采用多年全面调查及三年时间定位,定株观测相结合的方法,对野生北五味子生物学特性进行了深入研究。对其开花结实规律;雌雄同株,异株问题,座果率;物候期;种源与质量关系方面均有新发现。 相似文献
149.
He Hai-Lun Chen Xiu-Lan Sun Cai-Yun Zhang Yu-Zhong Zhou Bai-Cheng 《Journal of peptide science》2006,12(11):726-733
Acetes chinensis is an underutilized shrimp species thriving in the Bo Hai Gulf of China. In a previous study, we had used the protease from Bacillus sp. SM98011 to digest this kind of shrimp and found that the oligopeptide-enriched hydrolysate possessed antioxidant activity and high angiotensin I-converting enzyme (ACE) inhibitory activity with an IC50 value of 0.97 mg/ml. In this paper, by ultrafiltration, gel permeation chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC), five peptides with high ACE inhibitory activity were purified from the shrimp hydrolysates and their sequences were identified by amino acid composition analysis and molecular weight (MW) analysis. Three of them, FCVLRP (a), IFVPAF (f) and KPPETV (j), were novel ACE inhibitory peptides. Their IC50 values were 12.3 microM, 3.4 microM and 24.1 microM, respectively, and their recoveries were 30 mg/100 g (solid basis of shrimp), 19 mg/100 g and 33 mg/100 g, respectively. Lineweaver-Burk plots for the three novel peptides showed that they are all competitive inhibitors. To test the ACE inhibitory activity of peptide a, f, j after they were digested by digestive enzymes in vivo, 12 derived peptides from FCVLRP and IFVPAF were synthesized based on their amino acid sequences and the cleavage sites of digestive enzymes. No digestive enzyme cleavage site was found in KPPETV. The IC50 values of the derived peptides were determined and the result showed that except for VPAF, FC and FCVL, the ACE inhibitory activity of the other nine derived peptides did not significantly change when compared with their original peptides. Surprisingly, five peptides had lower IC50 values than their original peptides, particularly for RP (IC50 value = 0.39 microM), which is about 30 times lower than its original peptide and almost the lowest IC50 value for ACE inhibitory peptides reported. Therefore, the novel peptides identified from A. chinensis hydrolysates probably still maintain a high ACE inhibitory activity even if they are digested in vivo. This is the first report about novel ACE inhibitory peptides from hydrolysates of marine shrimp A. chinensis. The novel peptides from hydrolysate of A. chinensis and some of their derived peptides with high ACE inhibitory activity probably have potential in the treatment of hypertension or in clinical nutrition. 相似文献
150.
Huai-Jun Xue Martijn Egas & Xing-Ke Yang 《Entomologia Experimentalis et Applicata》2007,125(2):119-124
The relationship between oviposition preference and larval performance is a central topic in insect–plant biology. In this study, we investigate whether the oligophagous flea beetle, Altica fragariae Nakane (Coleoptera: Chrysomelidae), exhibits a positive preference–performance relationship, and whether oviposition preference develops over time. We tested the beetles using four sympatric plant species: Duchesnea indica (Andrews) Focke (the normal host plant), Agrimonia pilosa Ledeb. (a secondary host plant), and Potentilla chinensis Ser. and Sanguisorba officinalis L. (host plants of two related Altica species) (all Rosaceae). In no‐choice experiments, both oviposition rate and offspring fitness parameters (eclosion rate, development time, and body mass) were highest on D. indica. Oviposition rate was much lower on P. chinensis than on A. pilosa, whereas offspring fitness parameters did not differ significantly between these two host plants. Offspring fitness were lowest for S. officinalis, and adult females refused to oviposit on this acceptable non‐host in a no‐choice situation. Repeated two‐choice experiments showed that the proportion of oviposition on one of the novel host plants decreased significantly over time when the alternative host plant was D. indica. In repeated two‐choice experiments using A. pilosa and P. chinensis, females mainly fed on A. pilosa but distributed their eggs equally over the two host plants, in accordance with the lack of difference in offspring fitness on those hosts. Together, these results showed that A. fragariae females develop a positive preference–performance relationship over time. We suggest that A. fragariae achieves this through adaptive learning of oviposition preference: not only does the female learn to discriminate among the host plants when there is a fitness difference for her offspring, but the female also fails to discriminate when there is no fitness difference. 相似文献