Quantitative classification of Camellia japonica and Camellia rusticana(Theaceae)based on leaf and flower morphology

In Japan,Camellia japonica and Camellia rusticana are naturally distributed.Despite differences in their habitats and morphologies,they have been classified by various researchers as either varieties,subspecies,or species.The taxonomic position of C.japonica and C.rusticana remain unclear because morphological comparisons have been restricted to limited areas and quantitative data are scarce.C.rusticana grows in snowy places,unlike C.japonica.While C.japonica displays ornithophily,C.rusticana displays entomophily.Both species have adapted to different growing environments and pollinators,which have altered the morphology of flowers and leaves.We therefore quantitatively estimated the differentiation between these two taxa by comparing the morphologies of leaf hypodermis,flower form,petal color,and filament color in twenty populations.Our findings allowed us to differentiate these two species by the presence or absence of a leaf hypodermis.We also discovered an intermediate type of leaf hypodermis,which might also be caused by hybridization.Principal component analysis(PCA)indicated that the flower morphologies between these species were significantly different.The petal and filament colors were also significantly different.Our quantitative analysis suggests that speciation caused by differences in both pollinators and environment is one of the factors involved in this group.These findings in C.japonica and C.rusticana help to explain speciation processes for other species as well.

Calcium Salts Enhance Activity and Azo Dye Decolourisation Capacity of Crude Peroxidase from <i>Armoracia rusticana</i>

Armoracia rusticana is the commercial source of the enzyme Horseradish Peroxidase (HRP). Calcium ions play an important role in the functional conformation of HRP. The present study assesses the effect of three calcium salts viz., calcium chloride (CaCl2), calcium nitrate [Ca(NO3)2] and calcium sulphate (CaSO4) on the guaiacol activity of crude peroxidase extracted from the shoots and roots of in vitro grown plantlets of A. rusticana and their growth medium. The highest activity was observed in the shoot extracts of 25 mM CaCl2 treated plantlets (1.92 U/mL) and the root extracts of 25 mM Ca(NO3)2 supplemented plantlets (2.84 U/mL). The crude peroxidase activity of the medium containing 25 mM CaCl2 supplement was highest (0.13 U/mL). The capacity of the shoot and root extracts to decolourise a 10 ppm solution of methyl orange over 48 hours, was also tested. The decolourisation capacity was highest in the shoot extracts from CaCl2 treated plantlets (49.32%) and root extracts from Ca(NO3)2 treated plantlets (29.72%) respectively. Hence, the addition of calcium salts to growth medium enhances both peroxidase activity and decolourisation capacity of crude extracts of A. rusticana plantlets. These findings are of significance in enzymatic treatment for decolourisation of effluents containing dyestuffs.

辣根叶片的离体培养

以辣根(Armoracia rusticana(Lam.)Gaertn)叶片为外植体进行离体培养,考察了叶片采集时间、培养基中添加激素的种类和浓度对组织培养的影响。结果表明,2月份采集辣根叶片,组织培养污染率较小,为15%。愈伤组织诱导的适宜培养基为MS+0.5 mg/L 6-BA+0.2 mg/L NAA,出愈率为100.0%;叶片分化不定芽的适宜培养基为MS+0.5 mg/L 6-BA+1.0 mg/L NAA,分化率为80%;不定芽增殖的适宜培养基为MS+0.2 mg/L KT;适宜的生根培养基为MS+0.2 mg/L NAA。

镧对辣根叶净光合速率和细胞超微结构的影响

测定了用稀土镧[La(Ⅲ)]处理过的辣根(Armoracia rusticana)叶片净光合速率(Pn)和叶绿素(Chl)含量,并用透射电镜观察了经La(Ⅲ)处理后辣根叶绿体超微结构的变化。结果表明,30mgL-1La(Ⅲ)处理24h,Pn和Chl含量较对照分别提高0.82%、3.69%,对应的超微细胞结构无明显变化;48h处理则抑制辣根光合作用,细胞结构变化明显,类囊体基粒片层垛叠变薄,结构松散。而60mgL-1La(Ⅲ)24h、48h处理对辣根的生理和结构均有明显的抑制和破坏,且时间越长破坏越严重。对Pn和Chl含量进行处理时间、稀土浓度及两者共同作用多因素方差分析得出,处理时间对Chl含量的影响不显著,但对Pn的影响极显著,且稀土浓度及二者的共同作用对Pn和Chl含量均达到极显著影响。

辣根茎尖的组织培养

[目的]研究辣根茎尖组织培养,为其优良品种的快速繁殖提供新途径。[方法]分别就不同消毒时间对茎尖接种污染率的影响、不同激素配比的培养基对茎尖出愈率、分化率的影响、不同激素浓度对不定芽生根的影响进行了探讨分析。[结果]酒精消毒时间为35 s时外植体污染率和褐化率均较低;MS+0.5 mg/L 6-BA+1.0 mg/L NAA培养基对茎尖形成愈伤组织的诱导率较高,为82.3%;MS+0.5 mg/L 6-BA+0.2 mg/L NAA培养基诱导茎尖分化率较高,达80%;MS+0.2 mg/L Kt培养基适合辣根不定芽的继代繁殖;MS+0.1 mg/L NAA为辣根不定芽生根培养基。[结论]该研究结果为辣根茎尖的组织培养提供了试验基础,为其优良品种的快速繁殖奠定了基础。

用ITS2鉴定芥辣类调味品中山葵、辣根和芥末组分

日式饮食中的芥辣类调味品主要以同属十字花科的山葵(Eutrema wasabi)、辣根(Armoracia rusticana)、芥末(mustard)做原料加工而成。利用核糖体DNA内部转录间隔区Ⅱ(Internal transcribed spacer 2,ITS2)技术快速、准确地鉴定出山葵、芥末和辣根,为该技术应用于芥辣类产品质量检测提供参考。以3种植物材料(山葵、辣根、白芥末)为实验材料,提取基因组DNA,通过引物ITS2S2进行PCR扩增得到ITS2片段,测序结果通过生物信息学分析进行物种鉴定。MEGA7.0(Molecular evolutionary genetics analysis)分析ITS2序列结果表明,山葵、白芥末和辣根K2P(Kimura 2-parameter)遗传距离在0.088~0.171,均大于0.01,种间变异位点有36个,初步推断利用ITS2序列能将山葵、白芥末和辣根3物种区分开来。另外,GenBank中获得山葵以及近亲西北山嵛菜、辣根、芥末的ITS2序列,MEGA7.0进行种间序列分析,计算K2P,并用邻接法(Neighbor-joining,NJ)构建进化树,山葵与近亲西北山嵛菜聚为一支,棕芥末与白芥末、黑芥末聚为一大支,而辣根单独为一支。通过分析ITS2序列,发现山葵与近亲西北山嵛菜、辣根、芥末的种间K2P遗传距离在0.030~0.105,均大于0.01。研究表明,利用ITS2技术可以鉴别山葵、辣根和芥末等近缘物种,此技术可以用于芥辣类调味品特定原料成分鉴定及定量,为食品质量控制和食品安全提供科学依据。