鞑靼荞麦离体再生体系的建立

研究了苗龄、外植体、激素配比对鞑靼荞麦(Fagopyrum tataricum Gaertn.)离体培养的影响,初步建立了鞑靼荞麦离体再生体系.结果表明,鞑靼荞麦离体再生的最佳取材时间为苗龄6～8 d;诱导愈伤组织的最适培养基为Ms+2.0 mg/L 2,4.D+1.5 mg/L 6-BA,子叶诱愈率达75%左右,下胚轴诱愈率可高达86.62%;愈伤组织分化的最适培养基为MS+0.1 mg/L IAA+2.0 mg/L 6-BA+1.0 mg/L K1.+0.5 mg/L TDZ,来自下胚轴愈伤组织的分化率可达9.52%.下胚轴的诱愈率与分化率均高于子叶,更适于离体再生培养.培养基巾加入AgNO_3后,能有效降低褐化率.生根最适培养基为含有0.5 mg/L NAA的1/2MS培养基,生根率在50%左右.TDZ在诱导鞑靼荞麦的愈伤组织分化出芽的过程中起到明显的促进作用,可提高分化率约20%.表3图2参23     

In vitro mass multiplication of screw pines (<Emphasis Type="Italic">Pandanus</Emphasis> spp.) - an important costal bio- resource

An efficient in vitro mass multiplication protocol was developed for selected species of screw pine (Pandanus fascicularis Lam., P. furcatus Roxb.). The protocol could be successfully used for large scale production of planting materials leading to cultivation and making bio-fences or green belts in coastal areas, wetlands for protection and preventing soil erosion. This will facilitate the replenishment of the bio resource and also provide good breeding space for various fauna associated with it. For developing the tissue culture protocol, shoot tips and tillers from the mature plants were used as the explants. Surface sterilization with 0.1 % mercuric chloride for 1 min. Yielded good fraction (65 %) of contamination free explants. Explants inoculated in MS solid medium supplemented with 6-benzylaminopurine (BAP, 2.5 mg/l) and indole-3-acetic acid (IAA, 0.5 mg/l), induced 2–3 shoot buds in 5 weeks. These buds either individually or along with the explant portion, sub-cultured to fresh media containing the same hormonal combinations, resulted induction of 5–6 shoot buds in 4 weeks. Repeated subcultures of shoot buds in the same medium produced 8–10 shoot buds in every 4 weeks. Shoot elongation was achieved (~ 3 cm) by transferring the shoot clusters or individual shoots to basal medium, and the elongated shoots were rooted in vitro or ex vitro. Root induction in shoots (87.4 %) was achieved in MS medium supplemented with 0.1 mg/l indole-3-butyric acid (IBA). Rooted shoots were established in paper/polythene cups filled with fine sand, which subsequently recorded 85 % establishment under the shade-net house with proper irrigation. Plants grown in poly-bags were later successfully established in different field conditions and recorded 100 % survival.     

铬胁迫下不同品种小麦萌发和内源激素的变化

采用K2(CrO4)3溶液,设5个浓度,对3种不同抗性的小麦品种(新麦19、矮抗58和豫麦18)进行萌发期胁迫处理,研究了幼苗的发芽势、发芽率、根长、芽长及内源激素含量的变化.结果表明:(1)随着铬浓度的增加,发芽势、发芽率和芽长均基本呈"先升后降"趋势;(2)同一浓度铬处理下,发芽率、发芽势和芽长从大到小的顺序依次为:新麦19、矮抗58、豫麦18,根长从大到小的顺序为:豫麦18、新麦19、矮抗58;(3)150 mg L-1的铬胁迫下,IAA与ABA在小麦幼苗、幼根中含量降低,在籽粒中含量升高,其中新麦19籽粒和根芽中ABA含量均高于其他品种的;(4)不同浓度铬胁迫下,IAA/ABA值在新麦19中最低,变化幅度最小,新麦19表现出较强的抵抗铬胁迫能力.图3表1参20     

TDZ和CPPU在虎杖组织培养中的应用

将高活性细胞分裂素类物质TDZ和CPPU应用于虎杖的组织培养研究.经实验筛选发现,虎杖茎段比叶柄、叶片更容易诱导愈伤组织的形成,其诱导愈伤组织较适的培养基组成为MS 0.5mg/LCPPU 0.2mg/LNAA,适宜的愈伤组织增殖培养基为SH 0.05mg/LTDZ 1.0mg/LNAA;诱导芽分化的适宜培养基为MS 0.05mg/LTDZ 0.5mg/LNAA;促进幼苗生长的培养基为MS 0.1mg/LCPPU 1.0mg/LNAA 0.5%活性炭;快速生根及壮苗的培养基为1/2MS 1.0mg/LNAA 0.5%活性炭.TDZ和CPPU在愈伤组织的诱导、不定芽的分化及组培苗的生长等方面表现出不同的效果.以此方式进行虎杖人工快速繁殖,繁殖系数可达到5～7,繁殖时间缩短为2～3wk.图4表2参12     

水浮莲(Pisia stratiotes Linn.)的体外再生与繁殖

建立了水生单子叶植物水浮连(Pistia stratiotes Linn.)通过器官发生途径的体久高效再生与繁殖方法.采用叶、茎节和匍匐茎为外植体诱导愈伤组织,只有茎节能够在添加2,4-D和6-BA的MS基本培养基上形成合愈伤组织,而叶和茎在含有不同组合植物激素的培养基上都不能够诱导愈伤产生.将愈伤组织转到添加6-BA和NAA的MS固体分化培养基可以在2wk内形成小苗,将小苗移至含NAA的MS固体生根培养基形成完整的植株.将生根苗转入无植物激素的不同基本液体培养基里比较其生长效果,其中含有2倍大量元素的SH培养基最适合其生长繁殖,在2wk内可由1个小苗每秒殖出10个新的植株.本研究是关于该植物体外再生的首次报道.水浮莲体外再生及繁殖系统的建立不公可以用于在无菌条件下进行基础生理生化研究,还可以用于该植物遗传达室转化系统的建立.由于该植物生长迅速且为无性繁殖,生产成本低,通过基因工程方法表达外源基因将可以用于重组药用蛋白的生产及污染水体的转基因植物修复.     

Geochemical caper fingerprints as a tool for geographical origin identification

The identification of geographical origin of food products is important for both consumers and producers to ensure quality and avoid label falsifications. The caper plant (Capparis spinosa L., Brassicales Capparidaceae), a xerophytic shrub common in the Mediterranean area, produces buds and fruits that are commercialized in brine at high price. Those grown in Italy in the Aeolian Islands are renowned for their high quality. This study is aimed to establish a correlation between the geological and geochemical features of soil and the chemical composition of caper buds grown in two Aeolian Islands, Lipari and Salina. Major and trace elements were investigated by X-ray fluorescence and inductively coupled plasma-mass spectrometry in soil and caper samples from three localities in Lipari and Salina, and data from the three sites were compared by a nonparametric test, a correlation test and multivariate statistics (principal component analysis). The results allowed to discriminate soils according to geolithological characteristics of each area and detect a statistically significant correspondence between soil and caper samples for the elements Co, Fe, Mg and Rb, identifying thus possible geochemical caper fingerprints of origin. These results may also be useful to protect the high quality of Aeolian caper products by a suitable “Made in Italy” trademark and avoid falsifications and frauds.     

Production dynamics of the eelgrass, <Emphasis Type="Italic">Zostera marina</Emphasis> in two bay systems on the south coast of the Korean peninsula

Production dynamics of eelgrass, Zostera marina was examined in two bay systems (Koje Bay and Kosung Bay) on the south coast of the Korean peninsula, where few seagrass studies have been conducted. Dramatically reduced eelgrass biomass and growth have been observed during summer period on the coast of Korea, and we hypothesized that the summer growth reduction is due to increased water temperature and/or reduced light and nutrient availabilities. Shoot density, biomass, morphological characteristics, leaf productivities, and tissue nutrient content of eelgrass were measured monthly from June 2001 to April 2003. Water column and sediment nutrient concentrations were also measured monthly, and water temperature and underwater irradiance were monitored continuously at seagrass canopy level. Eelgrass shoot density, biomass, and leaf productivities exhibited clear seasonal variations, which were strongly correlated with water temperature. Optimal water temperature for eelgrass growth in the present study sites was about 15–20°C during spring period, and eelgrass growths were inhibited at the water temperature above 20°C during summer. Daily maximum underwater photon flux density in the study sites was usually much higher than the light saturation point of Z. marina previously reported. Densities of each terminal, lateral, and reproductive shoot showed their unique seasonal peak. Seasonal trends of shoot densities suggest that new eelgrass shoots were created through formation of lateral shoots during spring and a part of the vegetative shoots was transformed into flowering shoots from March. Senescent reproductive shoots were detached around June, and contributed to reductions of shoot density and biomass during summer period. Ambient nutrient level appeared to provide an adequate reserve of nutrient for eelgrass growth throughout the experimental period. The relationships between eelgrass growth and water temperature suggested that rapid reductions of eelgrass biomass and growth during summer period on the south coast of the Korean peninsula were caused by high temperature inhibition effects on eelgrass growth during this season.     

籼稻单倍体绿芽无性系二倍化的研究

以籼稻单倍体绿芽无性系为材料,研究秋水仙碱等处理对水稻植株染色体二倍化的影响．结果显示：（1）以500mg／L秋水仙碱溶液振荡处理籼稻单倍体绿芽48h,其二倍化率达60％～75％,处理时间过长或处理浓度过高．虽植株染色体二倍率有所提高,但二倍体植株的得率下降;（2）秋水仙碱在愈伤组织阶段处理,其染色体二倍率远高于非愈伤组织化的绿芽二倍率,高达96％～100％,其实未经处理的绿芽愈伤组织再生植株也能获得较高的加倍率;（3）在培养基中添加多效唑（2．5mg／L）也能增加籼稻植株染色体二倍率,由原来的3．3％提高到6．6％．     

麻疯树胚乳愈伤组织诱导及其污染消除

经过比较分析各种消毒方法,获得了较为理想的麻疯树(Jatrophacurcas)胚乳愈伤组织,并动态观察其类型、形态特征、增殖速率和形态发生能力,为麻疯树胚乳植株再生及愈伤组织和细胞培养生产药用成分奠定了基础.以麻疯树成熟胚乳为外植体进行愈伤组织的诱导,测试0.4mg/L的分裂素(BA、KT与TDZ)与2.0mg/L的生长素(IAA、IBA、NAA与2,4D)搭配组合的诱导效果.结果表明,对胚乳愈伤诱导效果而言,2.0mg/L的2,4D效果最好,NAA的效果次之,IBA又次之,IAA的效果最差.BA和KT诱导效果差异不显著,TDZ的添加可促进胚乳愈伤组织的诱导.选择适宜的消毒剂(种类、浓度)和消毒(处理)时间对胚乳外植体的接种成功具有至关重要的作用.在本试验所采取的灭菌方式中,用70%酒精处理30s,然后用10%NaClO处理25min,灭菌效果最佳,同时对胚乳外植体的生长影响最小.图3表1参23     

百喜草茎叶发酵前后甲醇溶提物对离体条件下AM真菌的生长效应

发酵前后百喜草（Paspalum notatum Fl     

Artificial wounding decreases plant biomass and shoot strength of the brown seaweed Ascophyllum nodosum (Fucales, Phaeophyceae)

Brown seaweeds can serve as habitat and food for a number of mesoherbivore species, but the effect of mesoherbivore grazing on the fitness of individual seaweed plants is not well documented. Here we investigate how mechanical wounding, which mimics the grazing damage made by the herbivorous gastropod Littorina obtusata, affects the biomass change, apical growth, and individual shoot strength of the fucoid seaweed species Ascophyllum nodosum both in natural field populations and in the laboratory. We did not detect a significant effect of wounding on apical shoot growth in the laboratory, but wounding decreased the plant biomass in half of the studied A. nodosum populations in the field. Furthermore, we found that the strength of individual A. nodosum shoots was significantly lower when compared with unwounded control shoots initially after wounding. However, after 11 days incubation in the laboratory, the strength of the wounded shoots had increased almost to the level of the control shoots, although there was still a significant difference in the force required to break the shoots. These results indicate that wounding can increase the tissue loss (and thereby decrease the fitness) of A. nodosum plants in natural populations, probably through weakening of individual shoots. However, A. nodosum appears to have a mechanism to strengthen the shoots after mechanical wounding, and therefore, the timing of damage (e.g. prior to a storm) probably determines the amount of plant tissue lost through wave-induced forces.     

Fragmentation of Phragmites Habitats, Minimum Viable Population Size, Habitat Suitability, and Local Extinction of Moths, Midges, Flies, Aphids, and Birds

Results from populations of insects and birds inhabiting Phragmites habitats were used to analyze effects of fragmentation. Flush-crash cycles of the stem-boring moth Archanara geminipuncta (Lepidoptera, Noctuidae) showed regionally concurrent, local extinctions despite an originally enormous population size (more than 180,000 adults), emphasizing the importance of metapopulation dynamics. Further, A. geminipuncta could be considered a keystone species, since shoot damage facilitated more than twenty species of herbivores, saprovores (of the caterpillars' feces), and their parasitoids. The gall midge Lasioptera arundinis could survive only in side shoots induced by shoot damage of A. geminipuncta .
Small Phragmites stands had thinner shoots (due to a water or nutrient deficiency) and shoots with more leaves (due to a better light supply) than large stands, thereby influencing species-specific demands for habitat suitability and nutritiousness of reed tissue. In other words significance of habitat fragmentation could not be assessed by area alone. For example, two chloropid flies depending on thin, yellowish shoots survived only in small habitats or in the unmown edges of large habitats.
Local persistence of Phragmites herbivores depended on much larger population sizes than could be expected from a population size sufficient to maintain genetic variation. At least 11,000 adults of the gall midge Giraudiella inclusa (or more than 84,000 galls) were necessary to avoid local extinction.
With regard to conservation management of reed habitats, nature reserves should consist of old and unmown reeds, have fewer disturbed (particularly, fewer mown) habitat edges, measure more than two hectares (priority should go to the largest remaining fragments), and be surrounded by nearby reed habitats providing reservoir populations and diverse shoot types.     

根表铁锰膜对不同生育期水稻吸收和转运As的影响

采用土壤盆栽试验法,研究不同生育期水稻根表铁锰膜形成及其对As吸收和转运的影响。结果表明,两个水稻品种YD6和NK57均在分蘖期形成的铁锰膜量最多,成熟期形成的铁锰膜量最少。水稻根系和茎叶吸收积累As随着水稻不同品种和不同生育期变化较大,As的吸收和积累与铁锰膜形成存在相关性。与分蘖期相比,YD6和NK57成熟期根系As含量分别减少81.6%和62.1%。孕穗期YD6和NK57茎叶As含量分别比分蘖期减少86.4%和65.5%,比成熟期减少87.8%和67.1%。分蘖期水稻根系和茎叶As含量与DCB-Fe或DCB-Mn浓度均呈显著的负相关关系,而孕穗期水稻根系和茎叶As含量与DCB-Fe浓度呈显著的正相关关系,说明不同生育期铁锰膜对水稻植株吸收和转运As的影响不同。两个水稻品种不同生育期,As均主要富集和分配在根表铁锰膜中,铁锰膜中As的分配比率达62.9%～84.9%。NK57从根表铁锰膜、根系和茎叶向籽粒转运As的能力比YD6强,籽粒中As含量是YD6的2.1倍。结果表明可以通过选育As低积累和低转运的水稻品种,来降低污染地区As对人体健康的威胁。     

Drastic decline of an extensive eelgrass bed in Nova Scotia due to the activity of the invasive green crab (Carcinus maenas)

In 2001–2002, there were severe declines of eelgrass (Zostera marina) in estuaries along the Nova Scotia coast of the southern Gulf of St. Lawrence. We examined the relationship between the recent invasion of European green crabs (Carcinus maenas) and the eelgrass decline in Benoit Cove in Tracadie Harbour. The abnormally abundant eelgrass wrack consisted mainly of entire shoots, not the usual blades. Three separate methods yielded similar estimates of the rate of shoot removal from the eelgrass beds (direct quadrat counts, “mark–recapture” of tagged shoots in the eelgrass bed, and rate of shoot appearance in the shore wrack). From 14 July to 8 September 2002, the shoot density in the bed fell by about 75 %. Similar rates of decline occurred in crab enclosures (4.4 crabs m^?2) placed in the eelgrass bed. Green crab foraging, involving the tearing of shoots and the digging of large pits, was the reason for the drastic decline of the eelgrass bed in Benoit Cove. It is clear that an invasion of green crabs to a region where they had not previously existed can both destroy eelgrass beds and restrict their recovery.     

Effects of nutrient concentration and litter cover on quantitative shoot parameters and belowground biomass of Zizania latifolia (L)

This study investigated the effect of nutrient concentration and litter cover on the development of quantitative shoot parameters and belowground biomass (BGB) production of Zizania latifolia. Zizania latifolia is a common emergent aquatic species in East Asia. Four treatments were done at the study site, and were observed between May 2003 and December 2005. The treatments are namely, high nutrient (HN) with litter cover (HNWL), high nutrient without litter cover (HNNL), low nutrient (LN) with litter cover (LNWL), and low nutrient without litter cover (LNNL). The quantitative shoot parameters and BGB had higher values for treatments with high nutrient (HN) compared to the low nutrient treatments (LN), independent of the presence of litter cover. Furthermore, the life span of the secondary shoots was also higher in HN treatments compared to LN treatments. The BGB productivity was higher in the HNNL treatment compared to the other treatments. The LNWL treatment showed the least developed quantitative shoot parameters, e.g. plant height, and the lowest BGB for Z. latifolia. It was generally observed that the combined effects of low nutrients and litter cover negatively affected shoot development and BGB production.     

Rooting response in stem cuttings from five species of mangrove trees: effect of auxins and enzyme activities

An experiment was conducted to optimise rooting in stem cuttings of the mangrove tree species Bruguiera parviflora, Cynometra iripa, Excoecaria agallocha, Heritiera fomes and Thespesia populnea. Cuttings were girdled or non-girdled and treated with the auxins indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and naphthalene-acetic acid (NAA) and amylase, IAA-oxidase, peroxidase and polyphenol oxidase activities were measured. The best rooting performance (in terms of root number) was in stem cuttings of E. agallocha followed by C. iripa and H. fomes when treated with IBA + NAA. IAA and IBA combinations were more effective in T. populnea and B. parvifolia. Variations in rooting response were markedly reflected in amylase, IAA-oxidase, peroxidase and polyphenol oxidase activities. Sharp increases in amylase and polyphenol-oxidase activities were associated with enhanced rooting in E. agallocha, C. iripa and H. fomes. On the contrary, lowered IAA-oxidase and peroxidase activities favoured rooting in T. populnea and B. parviflora. A higher number of roots occurred in pre-girdled cuttings in comparison to non-girdled cuttings. Received: 30 March 1999 / Accepted: 6 October 1999     

Effect of polystimulin growth regulators and scion clones on graft success and subsequent growth in Atlantic cedar (Cedrus atlantica Manetti)

Atlantic cedar (Cedrus atlantica Manetti) was grown, grafting onto the rootstocks of 2 years old Lebanon cedar (Cedrus libani L.). The mixture of polystimulin (PS) growth regulators was used to determine the effects on graft success and subsequent growth during three growing seasons. Scion clones had no effect on grafts success. PS increased the graft success by 20% in comparison to controls. PS-treated grafts burst their buds 18-20 days earlier than control grafts and increased shoot elongation. The PS-treated grafts had 4-5 cm longer shoots than controls at the end of three growing seasons. Thus, this research indicates the significance of PS-application on graft success and subsequent shoot growth on Atlantic cedar. It suggested that use of PS-treated grafts was more profitable than controls. Polystimulins which were used in small doses contributed significantly to the metabolism of Atlantic cedar seedlings after grafting.     

Salt stress induced alteration in growth characteristics of a grass Pennisetum alopecuroides

Salinity is one of the major abiotic stresses that adversely affect crop productivity and quality. The present investigation was carried out to study the alterations in the growth characteristics of a grass species, Pennisetum alopecuroides under the influence of sodium chloride (NaCl) salinity. From the results it is clear that shoot length of Pennisetum alopecuroides was increased by 13.17% at 100 mM NaCl concentration while the root length was observed to be increased at 50 mM NaCI concentration by 26.93%.Maximum height of the plant was observed by 18.23% at 50 mM while shoot to root ratio was higher at 300 mM concentrations by 29.17% increase over the control. Moreover, the maximum percent increase in leaf area was recorded as 11.17% (100 mM). Fresh weight was increased by 50.92% at 100 mM while dry weight of the experimental grass was increased by 33.64% at the same concentration of salt to the rooting medium while moisture percentage was increased to a maximum by 24.61% at 50 mM. It appears that the grass species studied exhibit a moderate salinity tolerance as far as linear growth of plant is concerned.     

Selenium improves physiological responses and nutrient absorption in wheat (Triticum aestivum L.) grown under salinity

Abstract

Salinity is a serious limiting factor for crop growth and production. The present study was conducted to investigate the response of wheat grown at salinities of 0.12, 0.30 and 0.60?S?m^?1 on soil supplemented with 0, 0.5, 1 and 4?mg?kg^?1 Se as selenite. Chlorophyll a and b, carotenoid contents, Fe, Zn and Se in shoots as well as shoot dry weight were negatively affected by increased salinity. Se had a dual effect: at 0.5?mg?kg^?1, chlorophyll b, proline, and shoot Fe content were increased, catalase activity was stimulated; there was no effect on Zn content and shoot dry weight. At the two higher concentrations, Se led to decreases in chlorophyll content, nutrient concentration, and shoot dry weight. Thus, moderate addition of Se to soil could be a strategy to improve physiological responses and micronutrient status in wheat under salinity stress.     

Enhanced Ni phytoextraction by effectiveness of chemical and biological amendments in sunflower plant grown in Ni-polluted soils

A greenhouse study was conducted as a completely randomised design in a factorial arrangement to assess how inoculation of AMF (arbuscular mycorrhizal fungus) and application of EDTA (ethylenediaminetetracetic acid) as biological and chemical amendments can affect the Ni (nickel) phytoremediation in Ni-polluted soils using sunflower plant. The results showed that the inoculation of AMF increased root colonisation while applying EDTA and high level of Ni decreased it. Microbial incubation has a positive effect on both shoot and root dry yields; however, co-application of Ni and EDTA demoted the growth rate. Shoot nutrients uptake of plants decreased as Ni levels increased. In inoculated plants, shoot uptake of Zn, Fe and Mn was higher in all Ni levels than non-inoculated plants. Ni uptake in plant shoots and roots increased with applying both AMF and EDTA. However, the mean Ni concentration and uptake in inoculated plants along with applying EDTA are higher in sunflower shoots than in roots. As Ni levels increased, Ni extraction and uptake efficiencies increased; it can be concluded co-application of EDTA and AMF was effective in increasing phytoextraction potential of sunflower plants in Ni-contaminated sites. This study highlights that AMF could be suitable for cleaning Ni-polluted areas and it could significantly contribute to phytoremediation technology.