中国茶藨子属(虎耳草科)新植物

<正> 灌木,高约2米。小枝微弯曲,黑褐色,无毛。冬芽长卵圆形。叶片呈不等的五角形,长7—13匣米,宽8—16厘米,先端长渐尖,基部深心形,边缘有不等重锯齿,上面深绿色,散生硬毛,下面淡绿色,沿脉被短柔毛,主脉和侧脉均突起;叶柄长5—9.5厘米,近无毛。总状花序,下垂,花梗长3—4毫米,和总花梗均被短柔毛,常混生星状毛。果实长圆形,红色,直径约6毫米;萼片宿存,反折,近无毛。     

小檗科鬼臼亚科植物的核型研究

本文首次报道了中华山荷叶与川八角莲的核型,分别为Ｋ（２ｎ）＝１２＝８ｍ（４ＳＡＴ）＋２ｓｔ＋２ｔ及Ｋ（２ｎ）＝１２＝４ｍ（２ＳＡＴ）十４ｓｍ＋２ｓｔ（２ＳＡＴ）＋２ｔ,核型类型均为ＺＡ型。本文报道的桃儿七及八角莲的核型与前人的结果有一定差异,前者为：Ｋ（２ｎ）＝１２＝６ｍ（４ＳＡＴ）＋２ｓｍ＋２ｓｔ＋２ｔ,２Ｂ型,后者为Ｋ（２ｎ）＝１２＝８ｍ（２ＳＡＴ）＋２ｓｔ（２ＳＡＴ）＋２ｔ,为２Ａ型。本文分析了小檗科鬼臼亚科４个属共７种植物的核型,结果是该类植物的核型极为相似,染色体数目均为２ｎ＝１２,由８条ｍ或ｓｍ,２条ｓｔ以及２条ｔ染色体组成。核型的相似性反映了这类植物的亲缘关系,这４个属的植物是一个自然类群。但随着系统发育,核型的不对称性有所增加,其中以山荷叶属最为对称,八角莲属居中,桃儿七属与足叶草属最不对称。笔者认为,核型上的高度相似是该类植物在系统发育上不发达,属内种类稀少,通常为寡种属或单种属的重要原因。     

桃儿七分布格局与生态适应的初步研究

以云南产桃儿七Ｓｉｎｏｐｏｄｏｐｈｙｌｌｕｍ ｈｅｘａｎｄｒｕｍ（Ｒｏｙｌｅ）Ｙｉｎｇ为研究材料,分析了它的分布格局及生态适应。指出桃儿七是一个分布范围较广、生态适应幅度大的物种;在分布区内它主要出现在具有次生植被的山谷中,个体在居群内的分布格局,由于受到放牧活动的影响而呈聚群式分布,植株常出现在灌木丛下和树根附近。它适应夏秋湿润凉爽,冬季及早春寒冷干燥的气候条件,并具有相应的生长与发育节律。人类     

桃儿七种子低温层积过程中胚形态及生理生化物质变化

为探究低温层积过程中桃儿七种子胚形态及生理生化变化与休眠解除的内在联系,该研究通过低温层积处理(90 d)解除桃儿七种子休眠,观测不同层积时间种子胚形态、胚率、发芽率、营养物质(淀粉、可溶性蛋白质、可溶性糖)含量、内源激素［赤霉素(GA)、吲哚乙酸(IAA)、脱落酸(ABA)］水平及呼吸途径关键限速酶［丙酮酸激酶(PK)、琥珀酸脱氢酶(SDH)、6 磷酸 葡萄糖脱氢酶(G 6 PDH)］的活性变化。结果显示：(1)在低温层积过程中,桃儿七种子胚形态为鱼雷或子叶型胚;种子发芽率在层积后期(60~75 d)显著提高(P＜0.05)。(2)层积后,种子内淀粉含量及PK活性、SDH活性显著降低(P＜0.05),其可溶性蛋白含量和IAA含量显著升高(P＜0.05),萌发促进物和抑制物比例(GA/ABA、IAA/ABA、GA+IAA/ABA)也呈升高趋势。(3)种子胚率与其可溶性糖含量呈显著负相关关系,种子发芽率与其可溶性蛋白呈显著正相关关系(P＜0.05)。研究发现,桃儿七种子无形态休眠;种子内营养物质的分解转化为种子休眠解除过程中各种代谢活动提供能量,且淀粉可能是此过程中最主要的供能物质;磷酸戊糖途径(PPP)的活化、萌发促进物和抑制物比例的升高及IAA含量的显著上升是桃儿七解除休眠的关键。     

Podophyllum hexandrum aqueous extract as a potential free radical scavenger

Abstract

The present study was undertaken to evaluate the effect of the aqueous extract of Podophyllum hexandrum against free radical-mediated damage and also explore its anticancer activity. The extract exhibited significant activity in scavenging 1, 1-diphenyl-2-picryl-hydrazyl radicals, ^?OH radical-mediated DNA damage, and lipid peroxide production in rat liver microsomes. The extract was also tested for its reducing abilities. The activity of liver marker enzymes and antioxidant defense enzymes in rat liver homogenate was assessed in control and carbon tetrachloride (CCl₄)-treated animals. It was observed that CCl₄-induced changes viz., increases in the activities of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, a decrease in reduced glutathione as well as decreases in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. All these parameters showed reversal when pretreated with aqueous extract of P. hexandrum. Podophylotoxin and etoposide are the two known anticancer agents derived from P. hexandrum and interestingly the aqueous extract of P. hexandrum showed a typical DNA ladder formation in HL-60 cells confirming its role as an inducer of apoptosis. The results obtained suggest that the plant extract exhibits inhibition of and free radical production and lipid peroxidation, increase in antioxidant enzyme activities, revealing its antioxidant properties, and is also able to show potent anticancer activity as depicted by its ability to cause fragmentation of DNA.     

ISSR Analysis of the Genetic Diversity of the Endangered Species Sinopodophyllum hexandrum （Royle） Ying from Western Sichuan Province, China

Slnopodophyllum hexandrum （Royle） Ying Is an Important medicinal and endangered species. Inter-simple sequence repeats （ISSR） analysis was conducted on seven natural populations from western Slchuan Province to Investigate the genetic diversity of S. hexandrum. Leaf samples of 140 Individuals were collected. Of the 139 discernible fragments generated by 12 selected primers （among 100 primers）, 54 appeared to be polymorphlc. The percentage of polymorphlc bands （PPB） was 38.85% at the species level, and PPB within a population ranged from 7.91% to 23.74%. Low levels of genetic variation （He = 0.092, Ho = 0.142） and high levels of genetic differentiation among the populations （Gst= 62.25%） was detected on the basis of results from POPGENE and analysis of molecular variance （AMOVA）, respectively. Furthermore, the limited gene flow （Nm = 0.361） may result from biological characteristics, such as self-pollination and short distance seed dispersal. Based on the genetic and ecological Information available for S. hexandrum, we propose some appropriate strategies for the conservation of the endangered medicinal species in this region, namely rescuing and conserving the core populations for in situ conservation and sampling and preserving more populations with fewer Individuals from each population for ex situ conservation.     

AFLP Analysis of Genetic Diversity of the Endangered Species Sinopodophyllum hexandrum in the Tibetan Region of Sichuan Province,China

Amplified fragment length polymorphism (AFLP) markers were used to estimate the genetic diversity of seven wild populations of Sinopodophyllum hexandrum (Royle) Ying from the Tibetan region of Sichuan Province, China. Six primer combinations generated a total of 428 discernible DNA fragments, of which 111 were polymorphic. The percentage of polymorphic bands (PPB) was 25.93 at the species level, and PPB within population ranged from 4.91 to 12.38%. Genetic diversity (H _E) within populations varied from 0.01 to 0.04, averaging 0.05 at the species level. As revealed by the results of AMOVA analysis, 58.8% of the genetic differentiation occurred between populations, and 41.2% within populations. The genetic differentiation was, perhaps, due to the limited gene flow (N _m=0.43) of the species. The correlation coefficient (r) between genetic and geographical distance using Mantel's test for all populations was 0.698 (P=0.014). The UPGMA cluster analysis revealed a similar result in that the genetic distances among the populations show, to a certain extent, a spatial pattern corresponding to their geographic locations. On the basis of the genetic and ecological information, we propose some appropriate strategies for conserving the endangered S. hexandrum in this region.     

濒危药用植物桃儿七的离体培养研究

以桃儿七种子诱导的无菌苗为材料,研究了外源激素对芽诱导、增殖和生根的影响,建立了桃儿七离体培养再生体系。结果表明：芽诱导阶段,采用3.0 mg·L^-1 6-BA+0.5 mg·L^-1 GA₃激素组合,出芽率最高可达85-71%,缩短出芽时间30~40 d,在添加3.0 mg·L^-1 6-BA+0.2 mg·L^-1 IAA的MS培养基上利于增殖,增殖速度快,增殖系数1.63。以WPM+1.5 mg·L^-1 IAA+0.5 mg·L^-1 NAA的培养基培养30 d 后,生根率可达60.1%。     

新疆紫草组织培养的研究进展

新疆紫草作为一种多用途的植物,它的提取物紫草宁衍生物,广泛应用于医疗、食品等方面。本文介绍了近年来国内外学者为解决新疆紫草资源短缺和保护环境所作的努力,详细介绍了新疆紫草组织培养方面的研究进展。主要包括愈伤组织的诱导及培养、细胞悬浮培养、反应器发酵培养等几方面的研究成果。