Commercial Seed Lots Exhibit Reduced Seed Dormancy in Comparison to Wild Seed Lots of Echinacea purpurea

Seed germination patterns were studied in E. purpurea (L.) Moench grouped by seed source, one group of seven lots from commercially cultivated populations and a second group of nine lots regenerated from ex situ conserved wild populations. Germination tests were conducted in a growth chamber in light (40 μmol·m(-2)·s(-1)) or darkness at 25 °C for 20 days after soaking the seeds in water for 10 minutes. Except for two seed lots from wild populations, better germination was observed for commercially cultivated populations in light (90% mean among seed lots, ranging from 82% to 95%) and in darkness (88% mean among seed lots, ranging from 82% to 97%) than for wild populations in light (56% mean among seed lots, ranging from 9% to 92%) or in darkness (37% mean among seed lots, ranging from 4% to 78%). No germination difference was measured between treatments in light and darkness in the commercially cultivated populations, but significant differences were noted for treatments among wild populations. These results suggest that repeated cycles of sowing seeds during cultivation without treatments for dormancy release resulted in reduced seed dormancy in E. purpurea.     

The effect of seed source, light during germination, and cold-moist stratification on seed germination in three species of Echinacea for organic production

Organic production of one of the most popular botanical supplements, Echinacea, continues to expand in the U.S. Echinacea seeds typically show a high degree of dormancy that can be broken by ethephon or gibberelic acid (GA), but these methods are currently disallowed in organic production. In order to determine the efficacy of non-chemical seed treatments, we evaluated the effect of varying seed source and supplying light, with and without cold-moist stratification, on seed germination of the three most important medicinal species of Echinacea, E. angustifolia DC, E. purpurea (L) Moench, and E. pallida (Nutt.) Nutt. Treatments included cold-moist stratification under 24 h light, 24 h dark, and 16/8 h light/dark to break seed dormancy. We found that germination was greater in the E. purpurea and E. pallida seeds from a commercial organic seed source compared to a public germplasm source. When seeds were not cold-moist stratified, 16-24 h light increased germination in E. angustifolia only. Echinacea angustifolia, E. purpurea, and E. pallida seeds that were cold-moist stratified under 16-24 h of light for 4 wk had a significantly greater percentage and rate of germination compared to seeds germinated in the dark. Therefore, cold-moist stratification under light conditions is recommended as a method to break seed dormancy and increase germination rates in organic production of Echinacea.     

Chromosome Karyotypes of Echinacea angustifolia var. angustifolia and E. purpurea

Chromosome karyotypes of the most commonly cultivated and medicinally used Echinacea taxa, E. angustifolia DC. var. angustifolia and E. purpurea (L.) Moench., were analyzed. The chromosomes of both taxa are medium in length, ranging from 4.12 to 5.83 μm in E. angustifolia var. angustifolia and 3.99 to 6.08 μm in E. purpurea. No abrupt length changes in the chromosomes were noted. The karyotypes of the two species are generally similar, but a distinguishable feature exists in one pair of chromosomes. The centromere of chromosome pair 10 is subterminally located in E. purpurea, but terminally located in E. angustifolia var. angustifolia, which can be readily recognized in mitotic metaphase cell plates. This finding may provide useful information for Echinacea evolutionary, genetic, and breeding studies.     

柿树化感作用的初步研究

采用培养皿滤纸法研究5种浓度的柿树叶和根水提液对受体植物萝卜、小麦、绿豆、白菜、番茄和黄瓜发芽及幼苗生长的影响,结果表明,柿树叶片提取液在5个浓度(10%、5%、2%、1%、0.5%)对萝卜、小麦和绿豆的种子发芽率、幼苗生长和叶绿素含量均有显著的抑制影响,只在高浓度下(10%和5%)对白菜、番茄和黄瓜的种子发芽率、幼苗生长和叶绿素含量有显著的抑制影响;而柿树根提取液在5个浓度对6种受试植物的测定参数均无显著的影响。试验初步证实了柿树叶片有化感潜力,可能对果树生产上的轮作、间作、套作及杂草的生物防治有一定的指导意义。     

Ethephon Promotes Germination of Echinacea angustifolia and E. pallida in Darkness

Seeds from five lots each of Echinacea angustifolia DC, and E. pallida (Nutt.) Nutt. were germinated in a growth chamber in light (40 μmol·m(-2)· s(-1)) or darkness at 25 °C for 16 to 20 d after soaking in 1 mM ethephon or water for 10 min, or moist stratification at 4 - 6 °C for two weeks. Either light or ethephon promoted seed germination of E. angustifolia and E. pallida, in comparison with darkness in nine of ten lots. Ethephon in the dark had similar or greater germination percentages than water with light. Ethephon with light improved germination in three of ten lots compared with ethephon in the dark. The effect of cold, moist stratification in comparison with darkness varied by seed lot. Five lots of E. purpurea (L.) Moench were tested; however, no treatment differences were measured. The finding that ethethon promoted E. angustifolia and E. pallida seed germination in darkness could be useful in the cultivation of these two species. Chemical name used: 2-chloroethylphosphonic acid (ethephon).     

芫荽对辣椒化感效应的研究

以芫荽地上部和根部为试材,研究其不同浓度的水提液对辣椒种子发芽和幼苗生理特性的影响.结果表明,芫荽水提液对辣椒种子发芽表现出一定的抑制作用,且这种作用随水提液浓度的增加而加大;芫荽水提液可使辣椒幼苗的丙二醛含量增加,随着水提液浓度的增加,根系活力先增加后降低,地上部和根部水提液的化感效应相似.     

Root shoot interactions in passionfruit (Passiflora sp.) under the influence of changing root volumes and soil temperatures

Summary

Passionfruit are grown in the tropics and subtropics where mean monthly soil temperatures at 15 cm range from about 10° to 30°C. The choice of rootstock can also influence production with most industries exploiting either the purple (Passiflora edulis f. edulis) or golden passionfruit (P. edulis tflavicarpa). We examined the relationship between shoot and root growth in purple x golden hybrid E-23 grafted onto golden passionfruit seedlings. Growth was manipulated by varying the volume of the soil available to the roots or temperature of the root zone. Shoot and root growth increased as root zone volume increased from 0.3, 1.4, 4, 12 to 24 1. Shoot weight (W_s) was correlated with root weight (W_R):W_S = 12.697 + 5.272 W_R + 0.195 W_R² (r² = 91%, P<0.001), with the plants allocating a smaller proportion of dry matter to the roots as root weight increased. Differences in shoot growth with pot volume were not due to changes in water or nutrient status. In the temperature experiment, the two critical root zone temperatures at 90% of maximum growth were about 20° and 35° C for vine extension, leaf area, node and leaf production, and 20° and 30°C for flower production. Leaf and stem dry weight were optimal between about 18° and 34°C, while maximum root growth occurred at 38°C. There was a weak relationship between shoot (W_s) and root dry weight (W_R): W_s = ?19.346 + 24.500 W_R ?1.046 W_R² (r² = 53%, .P<0.001). Apparently, variations in shoot growth at different soil temperatures cannot be explained solely by differences in root growth. Reduced growth at 10°C was associated with lower chlorophyll concentration, stomatal conductance and net CO₂ assimilation, but not lower leaf water potential. The concentration of most nutrients were lower at 10°C than at higher temperatures, but none was outside the range which would be expected to restrict growth. There appears to be a co-ordination of shoot and root growth as the soil volume available for root growth increases, whereas root temperature affects the roots and tops differently. The results of the pot volume experiment demonstrate the importance of rootstock vigour in passionfruit breeding. Productivity would be affected in cool subtropical areas with soil <20°C and in tropical areas with soil >30°C.     

NaCl胁迫对酸枣幼苗离子吸收与分配的影响

以酸枣水培幼苗为试验材料,研究了不同浓度NaCl胁迫对其活性氧、细胞膜透性、根系活力、不同器官Na+、K+、Ca2+和Mg2+离子含量的影响。结果表明：NaCl处理6 d,50、100 mmol ? L-1处理酸枣叶片无萎蔫症状,150、200 mmol ? L-1处理叶片萎蔫。在150、200 mmol ? L-1 NaCl处理下叶片H2O2积累增加,50、100、150、200 mmol ? L-1 NaCl处理下均有积累。随着NaCl处理浓度的升高,根、茎、叶中Na+含量均显著增加,叶片中K+、Ca2+和Mg2+含量显著下降,根和茎的K+和Mg2+含量变化不显著,Ca2+在200 mmol ? L-1NaCl处理下显著下降。根、茎、叶中K+/Na+、Ca2+/Na+、Mg2+/Na+均显著下降,但是根的K+/Na+值始终大于1。总之,NaCl胁迫下,维持根和茎中相对稳定的K+、Mg2+水平、保持根部K+/Na+比值 > 1,是酸枣幼苗对盐胁迫的一种适应。     

羊蹄甲属3种园艺树种分子鉴定及亲缘关系的ISSR分析

 利用ISSR-PCR方法对香港羊蹄甲属(Bauhinia) 中最常见3种园艺树种: 红花羊蹄甲(B. purpurea) 、宫粉羊蹄甲(B. variegate) 和洋紫荆(B. blakeana) 的遗传变异进行了研究, 从74个ISSR引物中筛选出9个多态性引物用于正式扩增, 共扩增出80条DNA带, 平均每个引物扩增的DNA带的数目为8.88条, 多态性条带数目为55条, 占总条带数的68.8%。其中, 有8个引物扩增出差异条带和特异条带,并分别能准确地鉴定羊蹄甲属3个园艺树种。本研究的结果表明, ISSR - PCR的DNA电泳谱带在检测香港羊蹄甲(B. blakeana) 品种的真实性方面非常有用。同时, 通过对3个种扩增条带的叠加性进行分析, 证实了洋紫荆杂交起源的父母本为红花羊蹄甲和宫粉羊蹄甲。     

钾对厚皮甜瓜成熟果实中芳香物构成及含量的影响

以4种不同钾肥量追施处理厚皮甜瓜中蜜5号后,采用气相色谱-质谱联用仪(GC-MS)测定了成熟果实中的芳香物成分，分别在低量钾肥、中量钾肥(CK)、中高量钾肥和高量钾肥处理中检测出32、35、34、39种芳香成分，各占其总峰面积的96.78 %、98.39 %、95.27 %、90.95 %。随钾肥施用量增加，果实中挥发性酯类物质与醇类物质的相对含量变化趋势相反。不同钾肥量处理成熟甜瓜果实特征芳香成分中，(E,Z)3,6-壬二烯-1-醇、(Z)-6-壬烯-1-醇乙酸酯、2，3-丁二醇二乙酸酯、2-甲基丁酸乙酯、（6Z）壬烯-1-醇、（Z）3-壬烯-1-醇等相对含量存在显著性差异，特征香气含量随钾肥施用量的增加而呈现先增加后降低的趋势，以适量钾肥处理（9.6 g·株^-1）为最佳，果实品质最好。     

Induction of hairy roots by Agrobacterium rhizogenes in relation to L-theanine production in Camellia sinensis

Summary

Theanine is a functional compound synthesised in roots of Camellia spp., especially tea (C. sinensis). Hairy roots were induced by two strains of Agrobacterium rhizogenes (15834 and LBA9402). The amino acid, catechin and caffeine compositions of hairy roots were determined by HPLC and compared with roots grown from tea seed. The results showed that the most suitable conditions to induce hairy roots were to use stem segments cut from 70 d-old plantlets, co-cultivated on YMB (yeast, mannitol broth) medium for 2 d, then induced on MS (Murashige and Skoog) medium for 4 weeks. Induced roots grown on LG₀ medium had 23.12 mg theanine g^–1 fresh weight, which was 23% higher than in roots grown from tea seed. Low concentrations of catechin, caffeine and epicatechin were detected in both root samples. Polymerase chain reaction (PCR) confirmed that the genes rol A, rol B and rol C of A. rhizogenes had been transferred into the DNA of the hairy root cells. The integrated genes for plant hormone synthesis from A. rhizogenes could increase hormone levels in the induced hairy roots, which in turn stimulated root growth and theanine synthesis. Hairy roots with higher concentrations of theanine, and lower levels of catechins and caffeine, are considered to be a good source for extracting L-theanine which is used as an active ingredient in food and medicine.     

Effect of leaf retention and flavonoids on rooting of Ilex paraguariensis cuttings

The effect of the mature leaf retention and the exogenous application of flavonoids (naringenin, quercetin and rutin at 30 μM for 12 h) was studied for adventitious rooting of Ilex paraguariensis cuttings. Softwood cuttings harvested from young 3-year-old plants and adult 10- and 20-year-old plants were rooted under intermittent fog. A strong correlation (r² = 0.72) between leaf retention and rooting was noted. The highest percentage of adventitious root formation (40%) was obtained when the leaf was artificially removed after 42 days of incubation. This data was supported by the histological analysis which provided anatomical evidence that cuttings have initiated root primordia by 21 days and the regenerated roots emerge through the epidermis after 35 days of incubation. A strong correlation between the position of the leaf and the site of roots regeneration was observed. A 100% of the rooted cutting with a single leaf only formed roots along the leaf axis at the base of the cutting. Quercetin increased the rooting percentage more than three times compared to the control and all flavonoids tested improved the distribution of roots around the stem without impacting the number of regenerated roots per rooted cutting from 20-year-old plants.     

青花菜不同器官生物活性物质和营养成分的研究

分析了青花菜花球、茎、叶和根中生物活性物质和营养成分组分与含量的差异。结果发现,花球中的总脂肪类、总吲哚类、总芥子油苷以及抗癌活性最强的4-甲基硫氧丁基芥子油苷的含量均显著高于其它器官,根系中苯乙基芥子油苷、4-甲基硫丁基芥子油苷和4-甲氧基-吲哚-3-甲基芥子油苷含量显著高于其它器官;花球中的可溶性蛋白、还原糖和可溶性固形物含量显著高于其它器官;叶片中的多酚、维生素C、叶绿素和类胡萝卜素含量以及抗氧化能力显著高于其它器官。叶片和根系生物活性物质含量丰富,可加以综合利用。     

猕猴桃GalUR表达与抗坏血酸积累的关系

 通过RT-PCR从美味猕猴桃（Actinidia deliciosa）果实中克隆了D–半乳糖醛酸还原酶（GalUR）全长 cDNA序列,并分析其序列特征,进行原核表达,制备特异抗体,分析其mRNA及蛋白表达水平与果实发育过程及不同组织中抗坏血酸（AsA）合成和积累的关系。结果表明：克隆的GalUR cDNA（GenBank登录号为GU339035）包含的最大开放阅读框（open reading frame,ORF）为990 bp,编码329个氨基酸残基,预测分子量为37 kD,与报道的草莓等其他植物GalUR具有较高的相似性。构建的pET-32a（＋）-GalUR载体在大肠杆菌BL21（E. coli BL21）中异源表达后,获得了主要以包涵体存在约58 kD的融合蛋白GalUR-His（His约21 kD）。以该蛋白制备抗体,与重组蛋白的Western杂交表明该抗体能与GalUR蛋白发生特异反应。对猕猴桃可溶性蛋白杂交显示,猕猴桃体内GalUR蛋白的分子量约37 kD。在猕猴桃不同组织和发育过程中,GalUR表达水平与AsA含量表现为高度一致,但前体饲喂发现,与L–半乳糖相比,D–半乳糖醛酸并不能有效促进猕猴桃AsA的合成。这些结果表明以单体形式存在的GalUR与猕猴桃AsA合成有着密切关系,但它可能并不是猕猴桃AsA积累的主要调控环节。     

镉胁迫下硫元素与肥料交互作用对镉在茭白各器官中积累的影响

以茭白（Zizania latifolia Turcz.）的单季茭品种蒋墅茭和双季茭品种葑红早为材料,以土壤为栽培介质,研究了100 mg/L Cd2＋胁迫下,不同浓度硫处理和不同种类肥料交互作用对茭白各器官中Cd2＋积累的影响。研究结果表明,Cd2＋在茭白不同器官的积累表现为根〉短缩茎〉叶〉肉质茎;不同肥料间,有机肥处理下茭白各器官中Cd2＋的积累量同比均显著低于无机肥处理;品种间存在明显差异,葑红早各器官中Cd2＋的积累量高于蒋墅茭;硫元素能促进茭白根系中的Cd2＋向地上部转移。     

Callus induction and plant regeneration in Cardiospermum halicacabum Linn. an important medicinal plant

Cardiospermum halicacabum Linn. is an important medicinal twining herb belonging to the family sapindaceae. A method for rapid micropropagation of C. helicacabum through plant regeneration from leaf and nodal explant derived calli has been developed. The nodal and leaf segments were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D; 0.5–9 μM) for callus induction. Callus production was highest at 5 μM 2,4-D where 96 and 90% of cultured leaf and nodal cuttings produced callus, respectively. The viable calli were maintained at reduced concentration of 2,4-D (2 μM). These calli were transferred to MS medium supplemented with various concentrations of 6-benzyladenine (BA; 2–10 μM) or kinetin (2–10 μM) alone or in combination with indole 3-acetic acid (IAA; 0.2–1.0 μM) for shoot regeneration. The addition of low concentrations of IAA into BA or kinetin containing medium significantly increased the frequency of shoot regeneration in both nodal cuttings and leaf-derived calli. The highest number of adventitious shoots (28 per callus) formed at 8 μM Kin and 0.5 μM IAA. For rooting of the shoots, half-strength MS medium supplemented with different concentrations of indole 3-acetic acid, indole 3-butyric acid (IBA) and (alpha)-naphthalene acetic acid (NAA) 1–5 μM was tried. The optimal result was observed on half-strength MS medium supplemented with 2.5 μM IBA, on which 91% of the regenerated shoots developed roots with an average of 4.2 roots per shoot within 45 days. The in vitro raised plantlets were acclimatized and transferred to soil with 90% success. This in vitro propagation protocol should be useful for conservation as well as mass propagation of this medicinal plant.     

氮素形态对平邑甜茶细胞分裂素水平和叶片生长的影响

以平邑甜茶(Malus hupenensis Rehd. ) 实生苗为试材, 在水培条件下研究NO₃^- 和NH₄⁺对植株不同器官细胞分裂素水平及对叶片生长的影响。结果表明: NO₃^- 处理0.5 h后, 根和叶片玉米素及其核苷(Z+ZR) 含量迅速升高, 并且始终高于NH₄⁺处理和对照。茎部玉米素及其核苷含量在NO₃^- 处理1 h后迅速升高, 但之后与NH₄⁺处理及对照差异不显著。就异戊烯腺嘌呤及其核苷(iP+iPA) 而言, 总体上看根中以NO₃^- 处理较高, 茎中各处理差异不大, 叶片中则以NH4+处理较高。NO₃^- 处理与NH₄⁺处理相比, 更能促进叶片生长, 这可能与叶片中较高的玉米素及其核苷含量和较低的ABA含量有关。     

Cultural Variation and Mycorrhizal Status of Blueberry Plants in NW Oregon Commercial Production Fields

ABSTRACT

Ericoid mycorrhizal fungi (EMF) form symbiotic relationships with roots of blueberry plants providing increased access to nutrients from fertilizers and soil. In August of 2001, we sampled 55 fields in Oregon to assess the mycorrhizal status of blueberry plants under production conditions and to determine whether any relationships exist between field characteristics, root distribution, soil characteristics and level of colonization by mycorrhizal fungi. Variation in measured soil characteristics, root type, root distribution and mycorrhizal colonization occurred with cultivar, field age, bed type, rate of nitrogen fertilization, irrigation type, and mulch. Root biomass was lower in the upper 15 cm of soil compared to 15-30 cm depth. Distribution of roots between the two sampled depths varied significantly with field age, nitrogen fertilization rate, and the time of 50% harvest for the different cultivars sampled. Root length was generally greatest in the upper 15 cm of the soil than at the 15-30 cm depth. Root colonization by ericoid mycorrhizal fungi (EMF) ranged from 0.5 to 44% of total root length with higher colonization generally occurring in the upper 15 cm of the soil where the majority of smaller, finer roots were found. Colonization generally increased with increasing plant age. In young plants the highest levels of colonization were found in roots from the upper 15 cm of soil while in older plants the highest levels of colonization were found in roots at the 15-30 cm depth. Colonization of roots by EMF in the upper 15 cm of the soil tended to decrease with increasing N fertilization rate, while root colonization at the 15-30 cm depth was unaffected by rate of N fertilization. Roots on cultivars that fruited early in the season tended to have higher levels of colonization than cultivars that fruited later in the growing season. Root biomass and root length were negatively correlated with soil pH and available Ca in soil, while root colonization by EMF was negatively correlated with ammonium levels in the soil. Differences in soil characteristics, root type and distribution, and mycorrhizal colonization found in this study need to be investigated in terms of production efficiency of blueberry in Oregon.     

增效剂和腐植酸肥料对番茄产量和品质的效应

通过在番茄苗期施用不同的增效剂和生长期施用腐植酸肥料,试验结果表明:增效剂和腐植酸可以起到显著的壮苗作用;株高、茎粗、叶片数、植株鲜重都有明显增加;还可以增强根系的活力、叶片的叶绿素含量和净光合速率,从而促进幼苗的生长发育,并可提高产量达30.8%,此外,显著提高番茄果实的品质;Vc的含量明显增加,可溶性糖的含量略有上升,有机酸的含量显著下降,硝酸盐的含量明显降低.