Epigenetics’ Role in the Common Bean (Phaseolus vulgaris L.) and Soybean (Glycine max (L.) Merr.) Nodulation: a Review

Plant Molecular Biology Reporter - Nitrogen-fixing bacteria establish symbiosis with legumes for the biological nitrogen fixation process in specific root structures called nodules. Among these...     

ПРИСПОСОБЛЕНИЯ К ПЛАНИРОВАНИЮ ПЕРЕДНИХ КОНЕЧНОСТЕЙ У ЛЕТЯГИ(Pteromys volans L.)

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苹果蠹蛾Cydia pomonella(L.)

<正>苹果蠹蛾Cydia pomonella(L.)是世界重要的苹果害虫,原产于欧洲中南部,现在已经入侵世界5大洲71个国家。该入侵昆虫1953年首次报道在中国新疆发现,目前已入侵新疆、甘肃、宁夏、内蒙古、黑龙     

Does body size difference in the leeches Glossiphonia complanata (L.) and Helobdella stagnalis (L.) contribute to co-existence?

The effect of predator and prey body size on the feeding success of the British lake-dwelling leeches Glossiphonia complanata and Helobdella stagnalis was examined in the laboratory, and any involvement of size difference between the leeches in allowing coexistence in the field assessed. G. complanata breeds in advance of H. stagnalis and maintains a body size advantage throughout their annual life-cycle. In experiments, conducted at 14 °C and a photoperiod of 16 hrs L: 8 hrs D, three size classes of leeches of each species were each exposed to each of three size classes of each of five prey species, viz. Tubifex sp., Chironomus sp., Asellus aquaticus, Lymnaea peregra and Potamopyrgus jenkinsi. For each prey species, three different types of experiments were performed: one leech exposed to four prey individuals; four leeches of the same species with sixteen prey; and two leeches of each species with sixteen prey. In the first experiment, all sizes of G. complanata were capable of feeding on all sizes of the prey types offered; the same was true for H. stagnalis with exceptions of feeding on large A. aquaticus and large L. peregra. For both species, but especially for G. complanata, there was a trend within each size class of leech for decreasing proportions of fed leeches with increasing prey size, and within each size class of prey for an increasing proportion of fed leeches with increasing leech size; however there were several exceptions to these trends. Both leeches fed extensively on Tubifex sp. but there were significant differences in the proportions feeding on other prey types; G. complanata fed more on A. aquaticus and the two snail species, and less on Chironomus, than H. stagnalis. The effect of increasing the number of leech individuals from one to four individuals, of the same or mixed species, had little effect on the proportion of leeches which had fed. It is concluded that large G. complanata will have access to large individuals of certain prey taxa denied H. stagnalis, which may lessen the intensity of interspecific competition.     

Bastardierung von Flußbarsch (Perca fluviatilis L.) und Kaulbarsch (Acerina cernua L.)

Ohne Zusammenfassung     

Spermatogenesis and sperm—spermatheca relations in Spirorbis spirorbis (L.)

The differentiation from early spermatid to spermatozoon is described with special emphasis on the formation of the helix of chromatin and mitochondrial junctions. The role of microtubules in morphogenesis is discussed.

New observations on the role of the recently described spermatheca are presented; phagocytosis and digestion of spermatozoa are proven, and the various origins of the sperm found in the spermatheca are specified.     

Nanoparticle (CdS) interaction with host (Sesamum indicum L.) – its localization,transportation, stress induction and genotoxicity

The present study highlights the nanoimpact of cadmium sulfide quantum dots on a plant system (Sesamum indicum L.) encompassing uptake of nanoparticles (NPs), subsequent translocation following root to leaf transportation pathway using both water- and food-conducting elements and deposition in nucleus and cytoplasm with no preferential subcellular localization. Nanocrystal agglomeration, mucilaginous sheathing and vesicularization studied are the host toxicity minimization attempt. Cellular stress due to NPs is recorded in the form of elevated production of hydrogen peroxide and malondialdehyde. However, non-synchronous activation of ascorbate peroxidase-monodehydroascorbate reductase-glutathione reductase-glutathione S-transferase enzyme system contributes to failure of anti-oxidative response and persistence of stress environment. Flow cytometric assessment reveals changes in cellular metabolic event along with blockage of cell division at G₁ phase and enhances apoptotic cell death. Nuclear internalization along with oxidative burst results in generation of DNA double-strand break which can be the focal point of genome alteration and subsequent gene mutation.     

Chiasma frequency variation inCepaea hortensis (Müll.) and a comparison withC. nemoralis (L.)

Chiasma frequency variation has been studied in 12 populations ofCepaea hortensis and the results compared with those previously obtained forC. nemoralis from the same populations. Variation in chiasma frequency is effectively restricted to a single large bivalent. In both species there are significant differences between populations in chiasma frequency. Although mean population mean chiasma frequencies are similar inC. hortensis andC. nemoralis, C. hortensis is less variable thanC. nemoralis. This can be seen, to a greater or lesser extent, at several levels-(i) within cells, (ii) between cells, (iii) between snails, and (iv) between populations-and is most noticeable when interstitial chiasmata are considered separately from terminal chiasmata. Data from 6 populations suggest that chiasma frequency remains stable between successive years. It is suggested that, since sympatric populations were studied, the most likely explanation for differences in chiasma frequency statistics between the two species is thatC. hortensis andC. nemoralis are responding differently to similar selective pressures.     

The chromosome morphology ofArabidopsis thaliana (L.)Heynh. and some remarks on the problem ofHylandra suecica (Fr.) Löve

The chromosome number ofA. thaliana from three localities in Central Bohemia was found to be 2n=10. All the chromosomes (length 1,5–2,6μm) belong to the atelocentric type, four pairs (m) having the centromere in the median and one pair (sm) in the submedian region. In connection with the discussion on the origin ofH. suecica the author presents the following preliminary results: a) the failure to cross the tetraploidCardaminopsis arenosa (L.)Hayek withA. thaliana; b) the successful crossing of the diploidC. petraea (L.)Hiit. withA. thaliana; c) the discovery of a diploid population ofC. arenosa (2n=16) in the Tatra Mts. (Czechoslovakia).     

Rapid in vitro propagation of Matteuccia struthiopteris (L.) Todaro – an edible fern

A rapid and efficient in vitro plant regeneration method was developed for Matteuccia struthiopteris (L.) Todaro (Ostrich fern). Side shoots, originating in meristems of sectioned rhizomes, were used as explant material. A very high rate of meristem multiplication was achieved by culturing the explants in half-strength MS liquid medium supplemented with 2.0 mg/l N-(4-Pyridyl)-N′-phenylurea (4-PU) and 0.5 mg/l thidiazuron (TDZ). Multiplication of the shoot primordia was faster in suspension culture than on solid medium. Rhizogenesis and growth of regenerants were best achieved on hormone-free one-quarter-strength MS solid medium amended with 0.4% agar and 1.0% activated charcoal. Regenerated plantlets continued to grow after transfer to soil in a phytotron. Received: 19 March 1998 / Revision received: 17 July 1998 / Accepted: 3 August 1998     

Does fin damage allow discrimination among wild,escaped and farmed Sparus aurata (L.) and Dicentrarchus labrax (L.)?

The present study compares fin damages in gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax) according to their wild, escaped or farmed origins. In addition, the potential applicability of fin condition indices (Fin Erosion Index ‘FEI’ and Fin Splitting Index ‘FSI’) as identification tools is discussed. Farmed seabream fins evidenced more erosion and splitting (FEI ± SD: 2.1 ± 0.3; FSI ± SD: 1.9 ± 0.6) than wild seabream fins (FEI: 0.8 ± 0.6; FSI: 1.2 ± 0.9), a result of farming conditions in open‐sea cages. Escaped seabream fin erosion was between that of farmed and wild seabream (FEI: 1.6 ± 0.4), which could indicate that fins in farmed fish recover over time from farming abrasions once they are in the wild. However, the fins of escaped seabream seem to be weaker than those of the wild fish, and therefore might be more susceptible to suffer other types of erosion such as splitting or nipping (FSI: 2.3 ± 0.7). No significant differences were found in seabass FEI according to their origins, although wild seabass presented significantly more split caudal fins (FSI: 3.3 ± 2.8) than the farmed seabass (FSI: 1.2 ± 1.1) and escapees (FSI: 2.5 ± 1.6). Therefore, FEI for seabream could be used as tools not only to distinguish between wild and farmed fish, but also to identify recent escapees, improving further assessments on the contribution of seabream escapees in fishery landings. However, the healing potential of damaged fins must be considered for the proper identification of escapees. Use of fin condition indices from both species could be helpful for aquaculture management, to assess fish welfare in fish farms stocks, and improve the knowledge of handling, stock densities and open‐sea cage environment conditions.     

Pollen–pistil interaction in protogyny and self-incompatibility system of Indian mustard (Brassica juncea (L.) Coss.)

The pollen morphology of two species of Drosera has been investigated by means of both light and electron microscopy. The apertures are situated proximally, a state rarely found in the pollen of Angiospermous plants. The pollen morphology of Aldrovanda, Dionea and Drosophyllum is compared.     

Linking phytochemistry to traditional uses and pharmacology of an underexplored genus – Psydrax: a review

Phytochemistry Reviews - The genus Psydrax is one of the ethno-medicinally important genera of the Rubiaceae family which has only received a limited scientific attention, despite coming from a...     

海巴戟(Morinda citrifolia L.)组织培养研究

以海巴戟（Morinda citrifolia L．）种子为试材,在不剥除种皮的情况下,在MS无激素培养基上播种1年内未见发芽,在剥除种皮的情况下,在MS无激素培养基上发芽率最高,50d内可达75％。海巴戟子叶和下胚轴均能单独由细胞分裂素BA0．7～2．0mg／L诱导不定芽发生,不定芽可直接从外植体发生,也可从愈伤组织发生,添加生长素NAA0．05～0．1mg／L则完全抑制不定芽发生,同时强烈促进愈伤组织生长和不定根发生。带芽茎段在BA1．5mg／L配合低浓度生长素时均能通过腋芽萌发和不定芽发生而增殖。芽梢在NAA0．1mg／L、IBA0．1mg／L或IAA0．1mg／L均有根群发生,但NAA0．1mg／L诱导生根时切口愈伤组织较多,部分不定根由愈伤组织发生。而IAA0．1mg／L诱导生根时根群欠发达,以IBA0．1mg／L最佳。     

A Bayesian analysis of gene flow from crops to their wild relatives: cultivated (Lactuca sativa L.) and prickly lettuce (L. serriola L.) and the recent expansion of L. serriola in Europe

Interspecific gene flow can lead to the formation of hybrid populations that have a competitive advantage over the parental populations, even for hybrids from a cross between crops and wild relatives. Wild prickly lettuce (Lactuca serriola) has recently expanded in Europe and hybridization with the related crop species (cultivated lettuce, L. sativa) has been hypothesized as one of the mechanisms behind this expansion. In a basically selfing species, such as lettuce, assessing hybridization in natural populations may not be straightforward. Therefore, we analysed a uniquely large data set of plants genotyped with SSR (simple sequence repeat) markers with two programs for Bayesian population genetic analysis, STRUCTURE and NewHybrids. The data set comprised 7738 plants, including a complete genebank collection, which provided a wide coverage of cultivated germplasm and a fair coverage of wild accessions, and a set of wild populations recently sampled across Europe. STRUCTURE analysis inferred the occurrence of hybrids at a level of 7% across Europe. NewHybrids indicated these hybrids to be advanced selfed generations of a hybridization event or of one backcross after such an event, which is according to expectations for a basically selfing species. These advanced selfed generations could not be detected effectively with crop‐specific alleles. In the northern part of Europe, where the expansion of L. serriola took place, the fewest putative hybrids were found. Therefore, we conclude that other mechanisms than crop/wild gene flow, such as an increase in disturbed habitats and/or climate warming, are more likely explanations for this expansion.     

Emission of hydrogen sulfide by twigs of coniferes — acomparison of Norway spruce (Picea abies (L.) Karst.), Scotch pine (Pinus sylvestris L.) and Blue spruce (Picea pungens Engelm.)

The emission of reduced volatile sulfur compounds from twigs of Norway spruce (Picea abies (L.) Karst.) was measured in the field by cryosampling and gaschromatographic analysis. Trees were growing in the Erzgebirge (E-Germany) at Oberbärenburg and at the Kahleberg and at a third stand in NW-Bavaria (S-Germany). Emission rates were also measured for Scotch pine (Pinus sylvestris L.) and Blue spruce (Picea pungens Engelm.) at the Kahleberg. Twigs still attached to the trees were enclosed in a flow-through gas exchange cuvette. H₂S was detected as the predominant reduced sulfur compound emitted from the twigs. The mean H₂S emission rate from twigs of Norway spruce varied between 0.04 pmol kg^-1 dw s^-1 at Würzburg and 6.21 pmol kg^-1 dw s^-1 at the Kahleberg. Comparing different species at the Kahleberg, the mean H₂S emission rate was almost the same from twigs of Norway spruce (6.2 pmol kg^-1 dw s^-1) and Blue Spruce trees (5.9 pmol kg^-1 dw s^-1) but it was approximately 18 times higher for Scotch pine (110 pmol kg^-1 dw s^-1). The percentage of SO₂-exclusion via H₂S-emission of the tree species investigated at the Kahleberg is calculated on the basis of data on SO₂ fluxes. It is very small for Norway spruce and Blue spruce. However, for Scotch pine, H₂S emission contributes about 10% to the detoxification of SO₂.     

红花烟草(Nicotiana tabacum L.)与黄花烟草(N.rustica L.)的种间试管受精

用试管受精方法来克服远缘杂交不亲和性,以获得用常规杂交技术所不能得到的远缘杂种,仅有石竹科和茄科的例子,而且其中也尚缺乏细胞学和生化方面的资料。在栽培红花烟草×栽培黄花烟草中的种间试管受精工作迄今尚未见报道。我们用试管受精方法在上述种间杂交组合中克服了烟草远缘杂交不亲和性并获得了种间杂种,同时对其进行了形态学和细胞学观察以及过氧化物酶同功酶分析。供试材料为栽培红花烟草(Nicotianatabacum L.cv.千斤黄,2n=48)和栽培黄花烟草(M.rustica L.cv.蛤蟆烟、羊耳烟,2n=48)。其杂交组合为:千斤黄×蛤蟆烟和千斤黄×羊耳烟。