千年桐不同性别植株组织在生化特性上的差异

一.引言许多栽培的雌雄异株植物,其雌株与雄株在经济价值上是不同的。在以收获果实,种子为栽培目的之作物(如千年桐,番木瓜以及留种的菠菜等)常只需保持一定的雄株数目。但是这些植物通常都要到进入开花期时才能区分出雄株而将其一部分除去。所以在生长早期迅速鉴定植物性别的问题引起许多研究者的注意。为了要提供早期鉴别植物性别方法的根据,许多学者进行了雌雄性个体生化特性差异的研究。的研究是很引人注意的。根据S.Satina和M.Demerec的介绍,     

千年桐种子油提取工艺研究及其主要脂肪酸成分分析

本文以氯仿、石油醚和正己烷-异丙醇(3:2,v/v)三种不同溶剂对千年桐种子油进行提取,比较了不同溶剂对种子出油率的影响,结果表明以氯仿为溶剂时出油率最高,达到了35％;并考查了提取时间和提取溶剂体积对出油率的影响.最终优化的提取工艺为:以氯仿为溶剂,液料比为12:1(v/w),提取时间6h,出油率达到了37％.提取的种子油经转酯化后,GC-MS分析其主要脂肪酸组分,结果表明千年桐种子油中总脂肪酸占总油酯的90.55％,其中棕榈酸3.87％,硬脂酸4.11％,亚油酸12.15％,油酸13.31％,亚麻酸12.09％,共轭亚麻酸51.20％和EPA(二十碳五烯酸)3.30％.千年桐种子油中富含不饱和脂肪酸,是一种良好的干性油.     

千年凤尾草

长于广西壮族自治区贺县甫门乡中华村梵安寺的一株古四川苏铁(Cycas szechuanensis),当地叫凤尾草,由于已有近千年的历史,所以又叫它“千年凤尾草”。千年凤尾草长于梵安寺中央天井一个长方形、高出地面50厘米的池中,池面积有10平方米。它没有明显的主干,是由4根直径32厘米左右的卧地茎干和1根斜伸的茎干组成,茎干最长4.8米,总长16.4米。叶片长于茎的顶部和芽上,叶长一般1.43米,最长1.75米,羽叶最多96对,柄刺最多47对。这棵四川苏铁是一雌株,过去几乎年年开花结实,现已多年没有     

千年桐SAD基因克隆与分析及其丝状真菌表达载体构建

以发育中的千年桐种子总RNA为模板,通过RT-PCR方法扩增得到硬脂酰脱饱和酶基因SAD的cDNA序列。该序列长度为1 191 bp,编码396个氨基酸。推测的分子量为45 541.01 u,等电点pI为6.05。BLAST分析表明,该cDNA序列与其它已登录的SAD基因cDNA序列一致性最高可达93.1%;编码的氨基酸蛋白序列性一致最高为89%。同时,构建了由构巢曲霉3-磷酸甘油醛脱氢酶基因的gpdA启动子驱动的丝状真菌表达载体,通过冻融法转入农杆菌中,PCR鉴定表明,pBAR-SAD已转入农杆菌EHA105中,成功构建了农杆菌工程菌株。     

红树植物改造桐花树次生灌木林效果的研究

通过对16a生的木榄、红海榄、海莲红树植物在桐花树次生灌木群落中进行人工改造的形成的新群落调查与分析,结果表明:海莲、红海榄和木榄都能成功在桐花树灌木林群落定居,其中以木榄的地径、树高生长量较大;红海榄、海莲的造林的株行距为1m×1m或0.8m×1m,木榄的株行距为1.5m×2m为宜;引入红树林乔木树种海莲、红海榄、木榄小苗16年后,桐花树密度呈不同程度的减少,其中木榄的引入较不利于桐花树次生灌木群落的发展;海莲、红海榄各自生物量或群落总生物量均比桐花树群落总生物量增加,以红海榄的生物量增加量最大,为桐花树群落总生物量的1.9倍;海莲、木榄具有良好的更新状况,特别在海莲群落中,平均每方米超过2株幼苗,说明该群落开始步入发育盛期,可以预见未来的15年内,可使红树林群落茂密复生。     

舟翅桐属(锦葵科、梧桐亚科),中国植物一新分布属及保护建议

【目的】报道了云南省勐腊县中老边境地区舟翅桐属（Pterocymbium R. Br.）及其属下热带落叶大乔木——大花舟翅桐（P. macranthum Kosterm.）在中国的分布新记录,并提供了保护建议。该物种在历史上仅见分布于缅甸中南部和泰国北部、西南部,在中国的发现将其分布区向北扩展至热带亚洲北缘,有助于深入理解中国与东南亚热带森林树木区系之间的关系。【方法】利用体视显微镜对其境内雌株标本进行解剖观察和研究,用数码相机对关键分类特征进行了拍摄记录,并借此完善了其属和种的描述。利用无人机航拍对大花舟翅桐境内种群进行了规模快速评估,访谈当地人对其用途和木材贸易情况的认知,并结合作者在东南亚植物调查经验对其IUCN物种受威胁等级进行评估。【结果】大花舟翅桐在中国境内约有1 000株,分布区面积约2 000 hm2,评定为IUCN红色物种名录易危（VU）物种。【结论】舟翅桐属为中国新记录属,属下大花舟翅桐为中国新记录种。     

五个三年桐品种过氧化物酶同功酶的酶谱分析

五个三年桐品种的过氧化物酶同功酶经聚丙烯酰胺凝胶电泳后,分离出了清晰的酶带,根据酶带的强弱、位置,它可划为三个区段,品种间的强带Rf值极为接近,表明它们之间的紧密亲缘关系,无疑可归于同一个种,但它们各区段中的弱带数及其Rf值又各不相同,表明了它们在性状上的差异,可划分成不同的品种。千年桐较之五个三年桐品种,不仅酶带少,无明显的强带,而且不呈现类似三年桐酶带的区段,无可非议的可成为另一个种。     

中药血桐活性化学成分的研究

血桐为大戟科血桐属植物,是重要的中药材树种,具有广泛的生物学活性。本文对血桐化学成分的生物学活性等方面的研究进展做一综述,为血桐的进一步深入研究和开发利用提供参考。     

桐花树

近年来,随着沿海地区经济的发展,各类资源不断开发,红树林的经济价值和生态价值日益得到重视,但红树林的优势组成成分之———桐花树,尚未得到充分利用。桐花树属于紫金牛科的桐花树属,又称腊烛果、浪柴、红葫、黑脚梗,是一种高为1.5－4米的灌木或乔木,一般分布在热带,亚热带海岸的中滩、内滩,有淡水调节的滩面上是其发育的最佳场所,不过,由于其根、茎、叶等器官具特殊的生理结构和调节功能,潮滩环境适应范围较广,又常与秋茄被作为热带沿海各岸段造林的选择树种。（－）发达的根系桐花树的根为支柱根或低矮的板状根,也具蔓布…     

芘对红树植物桐花树幼苗生理生化指标的影响

研究了一种典型多环芳香烃-芘处理(浓度为20 mg·kg^–1)及不同处理时间对红树植物桐花树(Aegiceras corniculatum (L) Blanco)生理生化指标的影响。结果表明, 芘处理显著提高了桐花树的株高(7.43%)和生物量(38.55%),而对地径和叶数无显著影响; 随生长时间延长, 芘处理植株和对照(CK)植株的株高、地径、叶片数和生物量均显著增加。芘处理对桐花树的叶绿素(Chl)含量不产生影响; 但随生长时间延长, Chla 和Chla/b 显著降低, 而Chlb 和Chl(a+b)显著下降后在150 d 时又恢复至最初水平。芘处理对桐花树的净光合速率Pn 和气孔导度Gs 影响不大, 却显著提高了其蒸腾速率E 和胞间CO2 浓度Ci。添加芘显著提高了桐花树超氧化物歧化酶(SOD)、谷胱甘肽-S-转移酶(GST)、过氧化物酶(POD)等抗氧化系统酶活性及丙二醛(MDA)的含量, 使其分别提高了9.23%, 94.30%, 70.09%和27.40%。随生长时间延长, SOD、GST 和POD 显著升高, 而MDA 含量在第50 天时显著升高后在第100 天和第150天又相继显著下降。上述结果表明, 添加浓度为20 mg·kg^–1 的芘处理不会对桐花树的光合作用产生显著影响, 而显著促进其生长和生物量积累; 此浓度下的芘处理提高了桐花树的抗氧化酶活性, 说明桐花树对芘胁迫具有一定的耐受性。     

黄腐酸和汪平酸对小麦种子萌发与幼苗生长及绿豆下胚轴生根的影响

用黄腐酸和汪平酸浸种后,对于小麦种子萌发无明显影响。用不同浓度的黄腐酸和汪平酸溶液培养小麦幼苗,发现适当浓度时对于幼苗及根系生长与分化有促进作用,高浓度则表现为抑制作用。10ppm黄腐酸和50ppm汪平酸可显著增加去根绿豆下胚轴再生根数,而且在一定的浓度范围内,随着浓度的增高,根数不断增加而根长却逐渐减短。     

Evaluating alder-endophyte (Alnus acuminata-Frankia-Mycorrhizae) interactions

The objective of this study was to compare the interaction betweenFrankia and vesicular-arbuscular mycorrhizae (VAM) on the growth and N-fixing response ofAlnus acuminata seedlings under three different phosphorus levels.A. acuminata is an actinorhizal tree, commonly associated with pastures on upland areas. Seedlings were grown in sterile vermiculite, and inoculated withFrankia strain ArI3 and/or VAM (asGlomus intra-radices) under three phosphorus levels (10, 50 and 100 ppm). After 120 days differences in growth were observed at the 50 ppm P level between nodulated and non-nodulated plants; either if inoculated withFrankia+VAM or just with VAM. Interaction betweenFrankia and VAM was positive on nodule weight at 50 ppm P level. Differences in acetylene reduction, per gram of fresh nodule, were observed between and within both groups:Frankia inoculated andFrankia+VAM inoculated seedlings. InFrankia inoculated seedlings differences were observed between seedlings receiving 50 ppm P which showed higher nitrogenase activity than seedlings treated with 100 ppm P. Plants inoculated withFrankia andGlomus intra-radices at low P level (10 ppm) showed the highest acetylene reduction. It was 150% higher than the mean of the other treatments within the group, and 87% higher than the general mean of the onlyFrankia inoculated plants.     

PHYTOTOXICITY OF FUNGICIDES AND BACTERICIDES IN ORCHID CULTURE MEDIA

A number of fungicides, bactericides and dual-action substances were screened for phytotoxicity in vitro using Cattleya aurantiaca and Stanhopea occulata (Orchidaceae) seedlings. Of the 25 compounds screened, ten (each at only one concentration) were employed in nine different combinations for nonsterile in vitro cultures of Cattleya aurantiaca seedlings: Amphotericin B, 10 ppm; Benlate, 50 ppm; Dowicide, 5 ppm; Ethirimol, 50 ppm; Gentamicin, 50 ppm; Nystatin, 25 ppm; PCNB, 100 ppm; Penicillin G, 100 ppm; Sodium omadine, 5 ppm; and Vancomycin, 50 ppm. All nine combinations prevented contamination, but had different effects on seedling development.     

The effect of exposure to imidacloprid on Asian longhorned beetle (Coleoptera: Cerambycidae) survival and reproduction

The effect of imidacloprid delivery method and application rate on survival of adult Asian longhorned beetles, Anoplophora glabripennis (Motschulsky), was studied, along with the effect of repeated daily ingestion of imidacloprid on the survival and reproductive capacity of adult females. Beetles exposed repeatedly to 50 ppm imidacloprid died in < 2-3 wk, whether dosed orally each day, or through contact exposure. Beetles given 1 microl of 50 ppm imidacloprid daily for two, three, four, or five consecutive days died sooner with increasing consecutive days: the beetles treated for 5 d all died within 15 d, while 80% of beetles treated for only 2 d lived > 8 wk. For females given 1 microl daily, across a range of doses from 2 to 50 ppm imidacloprid, the total number of viable eggs laid was reduced with increasing dosage, but percentage egg viability was not affected. Survival of females at dosages of 10 or 30 ppm/d was not significantly reduced compared with controls but these females laid 23-38% fewer viable eggs, suggesting a sublethal effect of imidacloprid. Female beetles given 1 microl/d of 40 or 50 ppm imidacloprid died more quickly than controls and viable egg production was reduced 82-93%, because of a combination of lethal and sublethal effects of intoxication.     

低营养条件下Paclobutrazol(PP333)对黄瓜去顶幼苗直接形成花芽的影响(简报)

植物开花机理是生物学中的一个基本问题,多年来人们进行过许多的研究,积累了大量的事实,然而对开花的机理仍然还不甚清楚。因而在利用原有实验系统的同时,有必要寻找更多简单,又便于分析的实验系统。Jullien等报告离体培养的大豆子叶节能直接产生花芽。我们在建立离体培养黄瓜子叶直接单独形成雄花或雌花的实验系统的过程中,发现黄瓜幼苗去除顶芽后在子叶节处也能直接形成花芽。这一现象有可能用于深入研究各营养器官和花启动间关系等问题,定将     

Interactive effect of salinity,SAR and boron on the germination and growth of seedlings of some paddy (Oryza sativa) varieties

Summary Germination of paddy varieties was significantly decreased with increasing levels of boron (0–100 ppm) with a maximum of 34 per cent. Amongst the treatments of boron (0.5–4.5 ppm): salinity (15–60 mc/l) and SAR (10–50), only the effect of salinity was significant, The interaction of boron × SAR, boron × salinity and salinity × SAR was insignificant in almost all the varieties. Varietal differences in germination and growth of seedlings were observed in relation to salt and boron tolerance. Boron upto 40 ppm did not affect the germination of paddy seeds but growth of seedlings was inhibited above 5 ppm.     

Development of diagnostic concentrations for insecticide resistance monitoring in soybean looper (Lepidoptera: Noctuidae) larvae using an artificial diet overlay bioassay

Diagnostic concentrations for several standard and experimental insecticides were determined for a laboratory reference strain of soybean looper, Pseudoplusia includens (Walker), using an insecticide diet overlay bioassay to evaluate the relative susceptibility of field (P) and F1 generations of four field-collected strains of third-, fourth-, and fifth-instar soybean loopers in 1996 and 1997. Diagnostic concentrations were defined as concentrations that killed 90-95% of the susceptible individuals and were 5 ppm for permethrin, 1,300 ppm for thiodicarb, 60 ppm for chlorfenapyr, 5 ppm for emamectin benzoate, and 60 ppm for spinosad. Field strains exhibited significantly greater percentage survival than the laboratory reference strain in the permethrin bioassays in 1996 and 1997 in both the P and F1 generation bioassays and in the thiodicarb bioassays in 1997. Larvae exposed to diagnostic concentrations of the experimental insecticides chlorfenapyr, emamectin benzoate, and spinosad usually did not exhibit significantly higher percentage survival than the reference strain.     

RELATIONSHIP BETWEEN SYNAPTOSPERMY AND DIOECY IN THE LIFE HISTORY STRATEGIES OF BUCHLOE DACTYLOIDES (GRAMINEAE)

Buchloe dactyloides (Nutt.) Engelm. is a perennial dioecious grass, exhibiting synaptospermy in that the 1–5 seeds in the dispersal unit (bur) are not released prior to germination. A major positive effect is that at least 50% of the burs contain both a male and female, making sexual reproduction possible and reducing founder effects upon colonization by one or a few burs. The objectives of this research were to examine the relationships between synaptospermy and dioecy in the life history strategies of Buchloe dactyloides, and to investigate whether the potential costs of synaptospermy would exceed its benefits if the species were not dioecious. An experiment that tested the effects of tightly clumping three seedlings vs. a uniform spacing of single seedlings at two densities and two moisture levels indicated only slightly negative effects of this aspect of synaptospermy. Although number of tillers and shoot biomass per plant were lower for clumped seedlings at all density and moisture combinations, only 50% of the possible uniform vs. clumped comparisons were significantly different. In addition, these effects, even at low moisture and/or high density, were not great enough to affect survivorship during the 16-week growth period. Experiments under both optimal and low moisture conditions showed that seeds within burs germinated at a significantly higher percentage than isolated or “hulled” seeds; in contrast to the differential timing of germination from burs, almost all of the seedlings from hulled seeds were produced during the first of three germination periods. Although survivorship for these seedlings was quite high under optimal conditions, it was greatly reduced under low moisture, being only one-fourth of that for seedlings arising from burs. The possible reduction in the wind dispersal of propagules due to their teeth and to their greater weight and size appears offset by more effective ungulate and water dispersal. Considering the evidence that the bur anchors the seedling in the soil, protects the seeds from fire, reduces precocious germination by requiring considerable moisture for saturation, and enhances seed longevity, the benefits of synaptospermy appear to outweigh the costs, even if those benefits related to dioecy are not considered.     

Determination of anti-microbial properties of Ocimum viride concentrations on Rhizopus stolonifer infection and germination of soybean (Glycine max L. Merill)

Investigation was conducted to determine the anti-microbial properties of different concentrations of Ocimum viride and germination of soybean. Analysis of variance recorded a highly significant difference on the percentage occurrence of different fungal diseases at 5% probability level. Ocimum viride at 0.04 ppm had the highest mycelia growth inhibition 77.0%, while 0.00 ppm (control) recorded the lowest mycelia inhibition 1.00% of Rhizopus stolonifer. Investigation revealed that spot recorded the highest percentage occurrence 50%, scab 34%, mould 43% and blight 31.0% recording the lowest. Also the microorganisms isolated from diseased soybean were Rhizopus stolonifer, Fusarium oxysporum, Aspergillus species although the inhibition was very high on Rhizopus stolonifer, followed by Aspergillus sp, then mould when Fusarium sp was low. Also, Ocimun viride extract was observed to possess a high anti-microbial properties as it inhibited the growth of all the micro-organisms identified to be associated with the soybean sees. Result showed that seeds treated with crude extract of 0.04ppm had the highest percentage germination irrespective of the days of germination, followed by 0.03 ppm, then 0.02 ppm, when 0.00 ppm had the lowest. However, 0.01 and 0.02 ppm, respectively, recorded similar percentage germination 64%; 64% at 4 days after planting. Days of planting were highly significant on the percentage germination at 5% probability level, as germination of the soybean seeds increased with days of planting and highest percentage germination of 98% was recorded on the 6th day of planting while no germination was recorded from the 1st till the 4th day of planting.     

EFFECT OF ETHYLENE ON CELLULAR DIFFERENTIATION IN ETIOLATED PEA SEEDLINGS

Ethylene (50 ppm) and 2,4-D (1 mm ) inhibit xylogenesis and completely prevent fiber lignification in the third internode of etiolated pea seedlings (Pisum sativum var. Alaska) during 96–240 hr of treatment. When ethylene is removed after 72 hr, normal differentiation resumes; thus the gas causes no irreversible damage to the cells. A combined treatment with 50 ppm ethylene and 50 μm 2,4-D or treatment with 1 mm 2,4-D alone causes inhibition similar to that observed with 50 ppm ethylene, and 50 μm 2,4-D is partially effective. The inhibition of xylogenesis and fiber lignification caused by 2,4-D is partly or wholly due to auxin-induced ethylene production.