ISRN Botany The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. The Effect of Phosphorus Reduction and Competition on Invasive Lemnids: Life Traits and Nutrient Uptake Mon, 10 Feb 2014 14:20:26 +0000 Introduction of invasive macrophytes often leads to competition with native species or with already established invasive species. Competition between invasive species in multiple-invaded systems is expected to be particularly high, especially when they share growth form and position in the water column. We performed indoor experiments between invasive free-floating Lemna minuta and Landoltia punctata in monocultures and mixtures under a phosphorus gradient concurring with hypereutrophic, eutrophic, mesotrophic, and oligotrophic conditions. Our results showed that a phosphorus reduction from hypereutrophic to eutrophic had important negative impacts on the relative growth rate (RGR) of both species. A further reduction to mesotrophic condition did not alter either species RGR. However, species strategies and nutrient uptake differed. Both intra- and interspecific interference occurred; however, the intensity differed between phosphorus concentrations. Difference in RGR (RGRD) showed L. minuta to gain at high phosphorus levels, while a reduction favoured L. punctata. In oligotrophic condition, either species hardly produced new daughter fronds. Our results are useful to (1) understand the effects of phosphorus and setting target values in the process of eutrophication reduction and (2) diminish the impacts of invasive lemnids since a water column phosphorus reduction would prevent large impacts. Joëlle Gérard and Ludwig Triest Copyright © 2014 Joëlle Gérard and Ludwig Triest. All rights reserved. Overexpression of a Novel Component Induces HAK5 and Enhances Growth in Arabidopsis Tue, 21 Jan 2014 09:33:06 +0000 Plants have developed mechanisms to adapt to the potassium deficient conditions over the years. In Arabidopsis thaliana, expression of a potassium transporter HAK5 is induced in low potassium conditions as an adaptive response to nutrient deficiency. In order to understand the mechanism in which HAK5 is regulated, the full-length cDNA overexpressor gene hunting system was employed as a screening method. Of 40 genes recovered, At4g18280 was found to be dramatically induced in response to potassium-deficiency and salt stress. Plants overexpressing this gene showed higher HAK5 expression and enhanced growth. These plants were also less sensitive to potassium-deficiency in terms of primary root growth. Taken together, these data suggest that this novel component, At4g18280, contributes to regulation of HAK5 and, consequently, tolerance to potassium-deficiency in plants. Eri Adams, Celine Diaz, Minami Matsui, and Ryoung Shin Copyright © 2014 Eri Adams et al. All rights reserved. Factors Affecting Seedling Emergence and Dry Matter Characteristics in Musa balbisiana Colla Tue, 13 Aug 2013 10:15:23 +0000 The effects of storage duration (0, 2, 4, 6, 8, and 10 days), sterilization with sodium hypochlorite (0, 5, 10, 15, and 20%), and weaning media on seedling characteristics and dry matter content in Musa balbisiana seedlings were studied. The experiment was factorial in a completely randomized design with five replicates. The result indicates that increase in NaOCl concentration and number of days in storage significantly increased the period of seedling emergence. Also, soaking in NaOCl for 20 min had significant effect on average seedling emergence at 15 and 20% concentrations, compared to 10 min soaking at the same concentrations. The combined effects of storage duration and sterilization resulted in a decrease in the duration of seedling emergence. Seeds previously sterilized with either water or NaOCl had no significant effect on seedling growth, leaf and corm dry weight, but affected almost all the dry matter traits. A mixture of poultry manure, top soil, and river sand as weaning media gave better seedling growth and increased dry matter characteristics. We conclude that M. balbisiana seeds require after-ripening treatment to enhance germination, sterilizing seeds with 5% NaOCl for 10 min and air-drying under ambient condition for 2–6 days were found most appropriate, and a mixture of poultry manure, top soil, and river sand is recommended as weaning medium for growth and dry matter composition in M. balbisiana seeds. A. B. Nwauzoma and K. Moses Copyright © 2013 A. B. Nwauzoma and K. Moses. All rights reserved. Ecological Implications of Acorn Size at the Individual Tree Level in Quercus suber L. Mon, 05 Aug 2013 12:02:08 +0000 Few studies have determined the influence of acorn size on germination and predation percentage at tree level. To evaluate the seed size influence at individual tree level, trees producing two different sizes of acorn were chosen. Our results show that smaller acorns were significantly more infested (49.6–75.3%) than larger ones (11.0–27.33%). About germination, big acorns achieved the best germination percentage compared to the smaller ones (18% in infested and 76% in sound acorns for the small acorn group versus 69.3% in infested and 93.3% in sound acorns belonging to the big acorn group). We also found that there was a difference in behaviour between big and small seeds at tree level. The same size belonging to different functional groups presented a difference at the behavioural level per tree. Infested small acorns from trees 8 and 10 had only 33 and 13% germination, while big acorns from trees 2, 3, and 6 (there was no difference between both sizes) presented 67, 97, and 83%, respectively. These results indicate that the production of acorns with two different sizes could be a strategy for species regeneration, producing each size for a different purpose. Soledad Ramos, Francisco M. Vázquez, and Trinidad Ruiz Copyright © 2013 Soledad Ramos et al. All rights reserved. Effect of Seed Size and Pretreatment Methods on Germination of Albizia lebbeck Mon, 29 Jul 2013 13:40:45 +0000 Albizia lebbeck is a multipurpose tree species prioritised for conservation in Malawi. The different plant parts are used in traditional medicine to treat different diseases. However, the seeds are dormant, and the tree species remain undomesticated. A study was conducted to evaluate the effect of seed size and presowing on the germination of Albizia lebbeck in a nursery. Seeds were grouped into four categories in regard to their length, small (≤0.5 cm), medium ( cm), large (≥0.8 cm), and mixture of small, medium, and large seeds. The seeds were subjected to five main seed pretreatment methods, namely, soaking in sulphuric acid for 2 minutes, nicking, soaking in hot water for 5 minutes, soaking in cold water for 24 hours, and control where seeds were sown without any treatment. The results indicate that combination of nicking and large seeds produced the highest (100%) germination. Hot water treatment was effective in large seeds producing 67.5% germination. The increased germination for mechanically scarified seeds through nicking suggests that seed dormancy in Albizia lebbeck is mainly due to its hard seed coat. Therefore, it is recommended to farmers to adopt use of nicking and large seeds, since it is safe and effective. Edward Missanjo, Chikumbutso Maya, Dackious Kapira, Hannah Banda, and Gift Kamanga-Thole Copyright © 2013 Edward Missanjo et al. All rights reserved. Relationship between Carbon Stock and Plant Biodiversity in Collaborative Forests in Terai, Nepal Tue, 02 Jul 2013 10:31:41 +0000 Reducing emission from deforestation and forest degradation (REDD+) programme has prime concern to carbon stock enhancement rather than biodiversity conservation. Participatory managed forest has been preparing to get benefit under this programme, and collaborative forest is one of them in Nepal. Hence, this research is intended to assess the relationship between carbon stock and biodiversity. Three collaborative forests (CFMs) were selected as study sites in Mahottari district, Nepal. Altogether 96 sample plots were established applying stratified random sampling. The plot size for tree was 20 m × 25 m. Similarly, other concentric plots were established. Diameter at breast height (DBH) and height were measured, species were counted, and soil samples were collected from 0–0.1, 0.1–0.3, and 0.3–0.6 m depths. The biomass was calculated using equation of Chave et al. and converted into carbon, soil carbon was analyzed in laboratory, and plant biodiversity was calculated. Then, relation between carbon stock and biodiversity was developed. Estimated carbon stocks were 197.10, 222.58, and 274.66 ton ha−1 in Banke-Maraha, Tuteshwarnath, and Gadhanta-Bardibas CFMs, respectively. The values of Shannon-Wiener Biodiversity Index ranged 2.21–2.33. Any significant relationship between carbon stock and biodiversity, and was not found hence REDD+ programme should emphasize on biodiversity conservation. Ram Asheshwar Mandal, Ishwar Chandra Dutta, Pramod Kumar Jha, and Siddhibir Karmacharya Copyright © 2013 Ram Asheshwar Mandal et al. All rights reserved. Ethnobotanical Studies of Port Harcourt Metropolis, Nigeria Tue, 18 Jun 2013 14:55:14 +0000 The objective of this study was to show the different ways medicinal herbs are used by the indigenous people in Port Harcourt metropolis (07 °3′ E, 04° 51′ N) in the Niger Delta region, Nigeria. One hundred and fifty structured questionnaires were administered, including oral interviews to herbal practitioners and users located at different parts of the city. Also, three popularly known herbal companies—Emiola naturalist care, Yem-Kem international herbal center, and Abiola medical herbal center—were included as they are healthcare providers, especially the medium income group. The results showed that a total of 83 plant species were recorded and classified according to their family, botanical, common, and local names. Also, the plant part used, mode of preparation, and type of ailment cured were included. The most frequently used plant parts were leaves followed by barks, roots, and fruits and with malaria fever as the most treated ailment. Deforestation, agricultural expansion, and fire were noted as the most important factors threatening the availability of these plants. The authors are of the opinion that paying special attention to the medicinal plants found in the area through conservation may help to amplify their role in the healthcare system, poverty alleviation, and environmental protection. A. B. Nwauzoma and Magdalene S. Dappa Copyright © 2013 A. B. Nwauzoma and Magdalene S. Dappa. All rights reserved. An Effective Procedure for In Vitro Culture of Eleusine coracana (L.) and Its Application Sun, 02 Jun 2013 16:36:28 +0000 Efficient protocols for callus production, plantlet regeneration, protoplast isolation, and micronucleation of finger millet (Eleusine coracana (L.) Gaertn.) were developed. White nodulated calli were formed on medium with N6 macrosalts, MS microsalts, 2.4-dichlorophenoxyacetic acid (2 mg L−1), kinetin (0.4 mg L−1), 1-naphthalene acetic acid (2 mg L−1), and certain additives. It was found that appropriate supplementation leads to formation of numerous shoots. Healthy rooted plantlets formed on hormone-free media. Although different tested additives had no significant effect on percentage of callus formation, it affected callus quality that further dictated plant-forming capacities. Seedlings were better source tissues for protoplasts isolation compared to callus cultures. About protoplasts were isolated from one gram of seedling coleoptyles. Microcolonies were visible after 20–25 days' incubation on KM8p medium supplemented with glutamine (100 mg L−1) and proline (500 mg L−1). Here we also present a procedure of an efficient induction of micronuclei after chlorpropham (10 μM) and cytochalasin-B (20 μM) seedlings treatment with subsequent microprotoplasts isolation. This technique is discussed for the transfer of alien chromosomes and genes from finger millet by microprotoplast-mediated chromosome transfer. Alla I. Yemets, Galina Ya. Bayer, and Yaroslav B. Blume Copyright © 2013 Alla I. Yemets et al. All rights reserved. Modulating Plant Calcium for Better Nutrition and Stress Tolerance Mon, 18 Mar 2013 11:02:18 +0000 External Ca2+ supplementation helps plants to recover from stress. This paper considers genetic methods for increasing Ca2+ to augment stress tolerance in plants and to increase their nutritional value. The transport of Ca2+ must be carefully controlled to minimize fluctuations in the cytosol while providing both structural support to new cell walls and membranes, and intracellular stores of Ca2+ for signaling. It is not clear how this is accomplished in meristems, which are remote from active transpiration—the driving force for Ca2+ movement into shoots. Meristems have high levels of calreticulin (CRT), which bind a 50-fold excess of Ca2+ and may facilitate Ca2+ transport between cells across plasmodesmatal ER. Transgenes based on the high-capacity Ca2+-binding C-domain of CRT1 have increased the total plant Ca2+ by 15%–25% and also increased the abiotic stress tolerance. These results are compared to the overexpression of sCAX1, which not only increased total Ca2+ up to 3-fold but also caused Ca2+ deficiency symptoms. Coexpression of sCAX1 and CRT1 resolved the symptoms and led to high levels of Ca2+ without Ca2+ supplementation. These results imply an important role for ER Ca2+ in stress tolerance and signaling and demonstrate the feasibility of using Ca2+-modulating proteins to enhance both agronomic and nutritional properties. Dominique (Niki) Robertson Copyright © 2013 Dominique (Niki) Robertson. All rights reserved. No Reproductive Interference from an Alien to a Native Species in Cerastium (Caryophyllaceae) at the Stage of Seed Production Mon, 31 Dec 2012 17:58:04 +0000 Reproductive interference, adverse interspecific interaction during the mating process, has been regarded as a powerful driver of species displacement between species. Recent empirical reports have described its importance in biological invasions. This study was undertaken to test whether a rare herbaceous plant species indigenous to Japan suffered reproductive interference from an alien species of the genus Cerastium. Field observations and a transplanting experiment were conducted to ascertain the effects of coexistence with an alien species on the seed production of the native species. Results show that coexistence with the alien species did not significantly decrease seed numbers, but it significantly affected the seed weight only in field observations. In this study, the reproductive process of the native species was examined only at or before the seed production stage. Because the interspecific pollen transfer might produce hybrids with low viability or fertility, reproductive interference cannot be denied in this study. To test reproductive interference at such latter stages, additional studies should be conducted. Consequently, detection of reproductive interference demands high costs in some species. Based on these results and suggestions, the necessity of narrowing down the target species for testing of reproductive interference is discussed to elucidate the universality of reproductive interference. Koh-Ichi Takakura Copyright © 2012 Koh-Ichi Takakura. All rights reserved. Disturbance of Opportunistic Small-Celled Phytoplankton in Lake Kinneret Wed, 26 Dec 2012 11:18:55 +0000 In spite of the chaotic dynamics of specific populations, similarity of annual species-abundance distributions was proven for phytoplankton assemblage during a “stable” period (1985–1994) of Lake Kinneret (Israel). This similarity declined during the “extreme” years (1995–1999) that followed, characterized by explicit changes in the phytoplankton annual-succession pattern. The rank-abundance distributions of species exhibit a pronounced difference between the taxonomically rich central region, producing the reliable assemblage backbone and highly variable tails of a few species. Therefore, the distribution pattern comparison enhances the importance of ubiquitous small disturbances valuable for diagnostics. Some phyla (in this case, Cyanophyta) were especially vulnerable to structural changes. A simple disturbance index was constructed, based on opportunistic small-celled species. The fine-structure disturbances, which can provide early-warning information, are discussed. Yury Kamenir and Zvy Dubinsky Copyright © 2012 Yury Kamenir and Zvy Dubinsky. All rights reserved. Phytoliths as a Tool for the Identification of Some Chloridoideae Grasses in Kerala Sun, 23 Dec 2012 09:03:01 +0000 The phytoliths of eight genera including fifteen species of grasses under the subfamily Chloridoideae in Kerala were studied. Phytoliths were studied after chemical isolation. Every species was found to produce a diverse array of phytoliths. However the frequency assemblages of phytoliths, their size, and orientation in the epidermal layer appear to vary among the different species and hence can be used for the delimitation of the taxa. Consequently, an identification key following the International Code for Phytolith Nomenclature was developed for all the species studied. P. I. Jattisha and M. Sabu Copyright © 2012 P. I. Jattisha and M. Sabu. All rights reserved. Highlights in Seagrasses’ Phylogeny, Physiology, and Metabolism: What Makes Them Special? Mon, 10 Dec 2012 11:09:39 +0000 The marine seagrasses form an ecological and therefore paraphyletic group of marine hydrophilus angiosperms which evolved three to four times from land plants towards an aquatic and marine existence. Their taxonomy is not yet solved on the species level and below due to their reduced morphology. So far also molecular data did not completely solve the phylogenetic relationships. Thus, this group challenges a new definition for what a species is. Also their physiology is not well understood due to difficult experimental in situ and in vitro conditions. There remain several open questions concerning how seagrasses adapted secondarily to the marine environment. Here probably exciting adaptation solutions will be detected. Physiological adaptations seem to be more important than morphological ones. Seagrasses contain several compounds in their secondary metabolism in which they differ from terrestrial plants and also not known from other taxonomic groups. Some of these compounds might be of interest for commercial purposes. Therefore their metabolite contents constitute another treasure of the ocean. This paper gives an introduction into some of the most interesting aspects from phylogenetical, physiological, and metabolic points of view. Jutta Papenbrock Copyright © 2012 Jutta Papenbrock. All rights reserved. Germination of Primed Seed under NaCl Stress in Wheat Mon, 03 Dec 2012 15:35:30 +0000 Soil salinity affects a large and increasing amount of arable land worldwide, and genetic and agronomic solutions to increasing salt tolerance are urgently needed. Experiments were conducted to improve wheat seed performance under salinity stress conditions after priming. An experiment was conducted using a completely randomized design of four replications for germination indices in wheat (Triticum aestivum L. cv. Caxton). Normal and primed seed with PEG6000 at  MPa and five concentrations of NaCl (0, 50, 100, 150, and 200 mM) were tested. Results indicate that priming seed significantly () increased germination percentage at first count and final count, coefficient of velocity of germination, germination rate index, and mean germination time, while increasing of NaCl concentration significantly reduced it. Priming seed improved germination attributes at all NaCl concentration levels. The priming appeared to be able to overcome the effect of salt stress at 50 to 100 mM and reduce the effect of NaCl at higher concentrations up to 200 mM. The primed seed gave both faster germination and led to higher germination when under salt stress. We conclude that using priming techniques can effectively enhance the germination seed under saline condition. Michael P. Fuller, Jalal H. Hamza, Hail Z. Rihan, and Mohammad Al-Issawi Copyright © 2012 Michael P. Fuller et al. All rights reserved. Starch Granule and Protein Accumulation during Seed Development of Ginkgo biloba L. Sun, 25 Nov 2012 16:20:09 +0000 We investigated starch and protein formation and accumulation in the seed of Ginkgo biloba L. In the testa, starch granules and protein bodies (PBs) started to form and accumulate 30 days after pollination; they decreased in size and completely disappeared before maturity. In the endosperm, starch granules began to accumulate 45 days after pollination, and the number and size of starch granules increased gradually within 65 days after pollination. Starch granules, which were mainly produced in plastids, proliferated mainly by constricting in the center and dividing to form smaller granules. Before harvest, there were ellipsoidal or irregularly shaped types, including A-type starch granules and some B- and C-type starch granules. In addition, PBI and PBII formed mainly in the outermost cells of the endosperm. However, the starch granules and protein bodies in endosperm cells around the embryo disappeared completely. The embryo cells contained many organelles, C-type starch granules, and PBI-type protein bodies. These results suggested that the starch granules were A-, B-, and C-types, and the protein bodies were PBI- and PBII-types in G. biloba. In addition, there were many significant differences in the formation, accumulation, and types of starch granules and protein bodies among the testa, endosperm, and embryo. Biao Jin, Yan Xie, Yan Lu, Di Wang, Min Zhang, and Li Wang Copyright © 2012 Biao Jin et al. All rights reserved. A Comparative Study of Two Endemic Isoëtes Species from South Italy Wed, 14 Nov 2012 19:17:54 +0000 Two Isoëtes taxa (Isoëtaceae, Pteridophyta) have recently been described in Puglia and Sicily (south Italy). Though morphologically similar (Ernandes, 2011), they differ in diagnostic characters and habitat preferences. In this paper, we highlight the differences and similarities between Isoëtes iapygia Ernandes, Beccarisi et Zuccarello (Ernandes et al., 2010) and Isoëtes todaroana Troia et Raimondo (Troia and Raimondo, 2009). Individuals are described in terms of selected diagnostic characters. Morphometric differences and other distinguishing characteristics suggest that I. iapygia and I. todaroana should be considered as separate species. Paola Ernandes and Silvano Marchiori Copyright © 2012 Paola Ernandes and Silvano Marchiori. All rights reserved. Integral Proteins in Plant Oil Bodies Wed, 14 Nov 2012 13:59:02 +0000 Hydrophobic storage neutral lipids are stably preserved in specialized organelles termed oil bodies in the aqueous cytosolic compartment of plant cells via encapsulation with surfactant molecules including phospholipids and integral proteins. To date, three classes of integral proteins, termed oleosin, caleosin, and steroleosin, have been identified in oil bodies of angiosperm seeds. Proposed structures, targeting traffic routes, and biological functions of these three integral oil-body proteins were summarized and discussed. In the viewpoint of evolution, isoforms of oleosin and caleosin are found in oil bodies of pollens as well as those of more primitive species; moreover, caleosin- and steroleosin-like proteins are also present in other subcellular locations besides oil bodies. Technically, artificial oil bodies of structural stability similar to native ones were successfully constituted and seemed to serve as a useful tool for both basic research studies and biotechnological applications. Jason T. C. Tzen Copyright © 2012 Jason T. C. Tzen. All rights reserved. Ethnobotanical Knowledge of Sterculia setigera Del. in the Sudanian Zone of Togo (West Africa) Wed, 14 Nov 2012 11:30:40 +0000 Ethnobotanical knowledge is useful in development of management and conservation of plant genetic resources. In this study, ethnobotanical investigations were conducted in Sudanian zone of Togo to identify use values knowledge of Sterculia setigera tree. Information was obtained with the aid of semistructured interviews. Three (3) ethnic groups: Bassar, Moba, and Konkomba belonging to ten (10) localities were investigated. Use knowledge of Sterculia setigera through these ethnic groups was assessed using four use indices: reported use (RU), plant part value (PPV), specific reported use (SU), and intraspecific use value (IUV). Sixty (60) informants of 43 years old were interviewed. The plant parts values and specific uses are raised more in the Moba's ethnic group. The main quoted uses are medicinal, religious, food, and cosmetic. Thus, fourteen (14) treatments of ailments are assigned to it. Considering the various uses, it is crucial to validate scientifically the therapeutic uses and safety of these plants through phytochemical screening, different biological activity tests, and toxicological studies. Wouyo Atakpama, Komlan Batawila, Marra Dourma, Hodabalo Pereki, Kpérkouma Wala, Kangbéni Dimobe, Koffi Akpagana, and Messanvi Gbeassor Copyright © 2012 Wouyo Atakpama et al. All rights reserved. Photosynthesis and Nitrogen Metabolism of Nepenthes alata in Response to Inorganic and Organic Prey N in the Greenhouse Wed, 14 Nov 2012 10:47:49 +0000 This study investigates the relative importance of leaf carnivory on Nepenthes alata by studying the effect of different nitrogen (N) sources on its photosynthesis and N metabolism in the greenhouse. Plants were given either inorganic , organic N derived from meal worms, Tenebrio molitor, or both and organic N for a period of four weeks. Leaf lamina (defined as leaves) had significant higher photosynthetic pigments and light saturation for photosynthesis compared to that of modified leaves (defined as pitchers). Maximal light saturated photosynthetic rates () were higher in leaves than in pitchers. Leaves also had a higher light utilization than that of pitchers. Both leaves and pitchers of plants that were supplied with both inorganic and organic prey N had a similar photosynthetic capacity and N metabolism compared to plants that were given only inorganic . However, adding organic prey N to the pitchers enhanced both photosynthetic capacity and N metabolism when plants were grown under deprivation condition. These findings suggest that organic prey N is essential for N. alata to achieve higher photosynthetic capacity and N metabolism only when plants are subjected to an environment where inorganic N is scarce. Jie He and Ameerah Zain Copyright © 2012 Jie He and Ameerah Zain. All rights reserved. To What Extent Do Protected Areas Determine the Conservation of Native Flora? A Case Study in the Sudanian Zone of Burkina Faso Wed, 14 Nov 2012 09:27:47 +0000 Natural vegetation contributes significantly to the daily needs of local people especially in the developing countries. This exerts a high pressure on freely accessible natural savannas and jeopardizes the conservation of protected areas. In Burkina Faso, conservation measures, such as the creation of protected forests, have been taken to safeguard the remaining indigenous vegetation. However, little is known about the effectiveness of these protected areas in conserving biodiversity. This study compared the diversity and structural characteristics of the vegetation communities in protected and unprotected areas in the Sudanian zone of Burkina Faso. A total of 208 species representing 41 families and 145 genera were found. Significant differences were found between the species richness in the north Sudanian sector for tree savannas and in the south Sudanian sector for the shrub savannas, tree savannas, savanna woodlands, and the woodlands of land use types. All tree size-class distributions in each vegetation type formed a reverse J-shaped curve, indicating vegetation dominated by juvenile individuals. Similarity in tree species composition between management regimes was found to be low, which reflects differences in habitat conditions, disturbance, and topography. Urgent measures are needed to ensure effective and efficient management and conservation of biodiversity in the protected areas of Burkina Faso. Lassina Traoré, Amadé Ouédraogo, and Adjima Thiombiano Copyright © 2012 Lassina Traoré et al. All rights reserved. Heterosis: Many Genes, Many Mechanisms—End the Search for an Undiscovered Unifying Theory Tue, 30 Oct 2012 14:56:18 +0000 Heterosis is the increase in vigor that is observed in progenies of matings of diverse individuals from different species, isolated populations, or selected strains within species or populations. Heterosis has been of immense economic value in agriculture and has important implications regarding the fitness and fecundity of individuals in natural populations. Genetic models based on complementation of deleterious alleles, especially in the context of linkage and epistasis, are consistent with many observed manifestations of heterosis. The search for the genes and alleles that underlie heterosis, as well as for broader allele-independent, genomewide mechanisms, has encompassed many species and systems. Common themes across these studies indicate that sequence diversity is necessary but not sufficient to produce heterotic phenotypes, and that the molecular pathways that produce heterosis involve chromatin modification, transcriptional control, translation and protein processing, and interactions between and within developmental and biochemical pathways. Taken together, there are many and diverse molecular mechanisms that translate DNA into phenotype, and it is the combination of all these mechanisms across many genes that produce heterosis in complex traits. Shawn Kaeppler Copyright © 2012 Shawn Kaeppler. All rights reserved. Female Short Shoot and Ovule Development in Ginkgo biloba L. with Emphasis on Structures Associated with Wind Pollination Tue, 28 Aug 2012 10:19:55 +0000 The orientation and morphology of the female cone are important for wind pollination in gymnosperms. To examine the role of female reproductive structures associated with wind pollination in Ginkgo biloba, we used scanning electron microscopy and semithin section techniques to observe the development of female short shoots and ovules in G. biloba before and during the pollination period. The ovule differentiation process was divided into six stages: undifferentiated, general stalk differentiation, integument differentiation, nucellus differentiation, collar differentiation, and mature stage. Before the pollination period, the integument tip generated the micropylar canal and the micropyle, while the nucellus tip cells degenerated to form the pollen chamber. During pollination, the micropylar canal surface became smooth, the micropyle split into several pieces and bore a pollination drop, and the pollen chamber directly faced the straight micropylar canal. The leaves and ovules were spirally arranged on the female short shoot, with the ovules erect and the fan-shaped leaves bent outwards and downwards. The ovules of G. biloba have differentiated some special architectural features adapted for pollen capture and transport. Together, these structures constitute a reproductive structural unit that may improve wind pollination efficiency at the female level. Biao Jin, Di Wang, Yan Lu, Xiao Xue Jiang, Min Zhang, Lei Zhang, and Li Wang Copyright © 2012 Biao Jin et al. All rights reserved. Moss and Soil Substrates Interact with Moisture Level to Influence Germination by Three Wetland Tree Species Mon, 16 Jul 2012 09:38:50 +0000 To assess germination success in different microsites of a forested wetland environment, seeds of three common western New York wetland tree species, Acer x freemanii, Fraxinus pennsylvanica, and Ulmus americana, were sown into flats in the greenhouse with three substrates (mosses Hypnum imponens or Thuidium delicatulum or bare soil) and three hydrological conditions (wet, moist, or dry) in a factorial design. For the three species both treatment regimes and the interaction were highly significant, except for Acer, in which the substrate regime was not significant. Fraxinus germination had the highest tolerance for wet conditions and lowest for dry conditions followed by Acer and then Ulmus. Significant interactions showed that the effect of hydrological regime on germination is influenced by substrate type. Moss decreased germination under drier conditions and increased germination under wet conditions by lifting the seeds away from the soil and creating drier conditions than on bare soil. It is also possible that interspecific competition for moisture played a role in decreasing germination under dry conditions. By influencing the regeneration niche for three major tree species of swamps in the northeastern United States, the bryophyte layer plays an important role in determining community composition. Alexander Staunch, Marie Redlecki, Jessica Wooten, Jonathan Sleeper, and Jonathan Titus Copyright © 2012 Alexander Staunch et al. All rights reserved. The Influence of Host Plants on Herbivore Community Composition on Brassica Crops in Western Siberia Sun, 17 Jun 2012 10:17:08 +0000 Experiments on three varieties of Brassica oleracea (white cabbage, red cabbage, and cauliflower) were conducted during the years 2008–2011 in Western Siberia (Russia) to study the influence of host plant on herbivore infestation. The results revealed the evidence of different infestation of white cabbage, red cabbage, and cauliflower by the common herbivores in Western Siberia. Flea beetles as the earliest herbivores preferred to infest white cabbage. Contrary to those herbivores, M. brassicae and P. xylostella larvae infested red cabbage most of all. The latest herbivore of all plants studied, P. brassicae, preferred cauliflower but not red cabbage. The possible contribution of some factors in summary effects observed in the study was discussed. Further studies are being planned in which tritrophic interaction including B. oleracea plant, herbivore, and microbial insecticides should be investigated. These studies will help to develop biological insect control on Brassica oleracea crops in order to supply ecologically safe plant protection. M. V. Shternshis, I. V. Andreeva, and E. I. Shatalova Copyright © 2012 M. V. Shternshis et al. All rights reserved. Sequences Analysis of ITS Region and 18S rDNA of Ulva Mon, 02 Apr 2012 14:08:43 +0000 Ulva, as the main genera involved in green tides in the Yellow Sea, has attracted serious concern in China. Especially, Ulva prolifera is one of the causative species of the occurring. This paper focused on the complete sequences analyses of ITS, 18S, and the combined data to determine phylogenetic relationships among taxa currently attributed to Ulva, Monostroma, and some other green algal. The samples are all concluded in the area of Yellow Sea, China. The results showed the content of G+C in 18S was approximately concentrated upon 49% in average of 19 subjects while the ITS region content of base G and C is obviously higher than A and T. Comparing the ITS and 18S rDNA sequences obtained in this paper to other species retrieved from GenBank, the genetic distance and the ratio of sequence divergence reflect that U. pertusa and U. prolifera had closer genetic relationship with an 18S rDNA, which had genetic distance of 0.007 while ITS had further genetic distance. According to further comparison, Ulva prolifera has closest genetic distance with Chloropelta caespitosa (0.057) and Ulva californica (0.057), which is a reverification coincided Chloropelta, Enteromorpha, and Ulva are not distinct genera. Zijie Lin, Zhongheng Lin, Huihui Li, and Songdong Shen Copyright © 2012 Zijie Lin et al. All rights reserved.