Population genetic structure and demography of Magnolia kobus: variety borealis is not supported genetically

Species delimitations by morphological and by genetic markers are not always congruent. Magnolia kobus consists of two morphologically different varieties, kobus and borealis. The latter variety is characterized by larger leaves than the former. For the conservation of M. kobus genetic resources in natural forests, the relationships between morphological and genetic variation should be clarified. We investigated variations in nuclear microsatellites, chloroplast DNA (cpDNA) sequences and leaf morphological traits in 23 populations of M. kobus over the range of species. Two genetically divergent lineages, northern and southern were detected and their geographical boundary was estimated to be at 39°N. The northern lineage consisted of two genetic clusters and a single cpDNA haplotype, while the southern one had multiple genetic clusters and cpDNA haplotypes. The northern lineage showed significantly lower genetic diversity than the southern. Approximate Bayesian computation indicated that the northern and southern lineages had experienced, respectively, population expansion and long-term stable population size. The divergence time between the two lineages was estimated to be 565,000 years ago and no signature of migration between the two lineages after divergence was detected. Ecological niche modeling showed that the potential distribution area in northern Japan at the last glacial maximum was very small. It is thus considered that the two lineages have experienced different population histories over several glacial-inter-glacial cycles. Individuals of populations in the central to northern part of Honshu on the Sea of Japan side and in Hokkaido had large leaf width and area. These leaf characteristics corresponded with those of variety borealis. However, the delimitation of the northern and southern lineages detected by genetic markers (39°N) was not congruent with that detected by leaf morphologies (36°N). It is therefore suggested that variety borealis is not supported genetically and the northern and southern lineages should be considered separately when identifying conservation units based not on morphology but on genetic markers.

The role of ABC genes in shaping perianth phenotype in the basal angiosperm Magnolia

It is generally accepted that the genus Magnolia is characterised by an undifferentiated perianth, typically organised into three whorls of nearly identical tepals. In some species, however, we encountered interesting and significant perianth modifications. In Magnolia acuminata, M. liliiflora and M. stellata the perianth elements of the first whorl are visually different from the others. In M. stellata the additional, spirally arranged perianth elements are present above the first three whorls, which suggests that they have been formed within the domain of stamen primordia. In these three species, we analysed expression patterns of the key flower genes (AP1, AGL6, AP3, PI, AG) responsible for the identity of flower elements and correlated them with results of morphological and anatomical investigations. In all studied species the elements of the first whorl lacked the identity of petals (lack of AP3 and PI expression) but also that of leaves (presence of AGL6 expression), and this seems to prove their sepal character. The analysis of additional perianth elements of M. stellata, spirally arranged on the elongated floral axis, revealed overlapping and reduced activity of genes involved in specification of the identity of the perianth (AGL6) but also of generative parts (AG), even though no clear gradient of morphological changes could be observed. In conclusion, Magnolia genus is capable of forming, in some species, a perianth differentiated into a calyx (sepals) and corolla (petals). Spirally arranged, additional perianth elements of M. stellata, despite activity of AG falling basipetally, resemble petals.

[Research on standard of Magnoliae Officinalis Cortex commercial specification and grade]

The market and literature were studied to understand the existing situation of Magnoliae Officinalis Cortex goods, and the collected samples were analyzed, combined with the actual production, a new standard of Magnoliae Officinalis Cortex commercial specification and grade was drafted. Magnoliae Officinalis Cortex goods was divided into two categories according to the source in the old standard. Then each category was divided into four kinds of specifications according to the site. Each kind of specification was divided into several grades according to the length and weight. To judge the quality of Magnoliae Officinalis Cortex goods was mainly based on the appearance quality. In the new standard, the classification of commercial specification and grade is based on the thickness, magnolol and honokiol content. The goods of Magnoliae Officinalis Cortex can be divided into three specifications: Tongpu, Genpu and Doupu. Tongpu is divided into three grades, the remaining two are not graded.

Biotemplating plasmonic nanoparticles using intact microfluidic vasculature of leaves

Leaves are an abundant natural resource, and consist of a sophisticated microfluidic network of veins that transport nutrients and water, thereby enabling photosynthesis. Here, we simultaneously exploit the microfluidics as well as chemistry of processed leaf vasculature (venation) in order to template the in situ generation of plasmonic metal (gold and silver) nanoparticles under ambient conditions. This biotemplating approach involves capillary flow of metal salts through skeleton leaf vasculature, and does not require additional reducing agents for plasmonic nanoparticle formation. Gold nanoparticles, 30-40 nm in diameter, and silver nanoparticles, approximately 9 nm in diameter, were formed within the intact leaf vasculature using this method. Absorption spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction analyses were employed to ascertain the formation of nanoparticles in the leaf veins. Fourier transform infrared (FT-IR) spectroscopy was employed in order to obtain insights into functional groups responsible for formation of the plasmonic nanoparticles within the leaves. Gold nanoparticles, templated within leaves, demonstrated excellent catalytic properties, thereby imparting catalytic and plasmonic properties to the leaf itself. Furthermore, nanoparticles can be recovered from the leaves as soluble dispersions by simply combusting the organic leaf matter. Taken together, this is a simple yet powerful biotemplating approach for the generation of plasmonic nanoparticles and formation of biotic-abiotic structures for diverse, low-cost applications in sensing, catalysis, and medicine.

Arabinogalactan proteins mark stigmatic receptivity in the protogynous flowers of Magnolia virginiana (Magnoliaceae)

PREMISE OF THE STUDY

Factors affecting floral receptivity in angiosperms remain opaque, but recent studies suggest that the acquisition of stigmatic receptivity associated with cell-wall-related arabinogalactan proteins (AGPs) may be a widespread feature of flowering plants. Here, the time during which a stigma is receptive is evaluated and related to the secretion of AGPs in Magnolia virginiana, a protogynous member of an early-divergent angiosperm clade (magnoliids) with a clearly discernible female receptive phase.

METHODS

Magnolia virginiana flower phenology was documented, and histochemical changes in the stigma before and after pollination were examined. Stigmatic receptivity was evaluated in relation to the secretion of AGPs detected in whole mounts and immunolocalized in sectioned stigmas.

KEY RESULTS

Protogynous Magnolia flowers had a precise window of stigmatic receptivity, which is concomitant with the secretion of two AGPs labeled for different epitopes. After pollen germination and tube growth, these two AGPs could no longer be detected in the stigmas, suggesting that these AGPs interact with the growing male gametophytes and could be markers of stigmatic receptivity.

CONCLUSIONS

These results show that the period of stigmatic receptivity is finely coordinated with the secretion of two arabinogalactan proteins on stigmas of flowers of M. virginiana. This first report of AGP presence in stigmatic tissues in a member of the magnoliids, together with recently described similar patterns in eudicots, monocots, and members of early-divergent lineages of flowering plants, suggests an ancient and widespread role for AGPs on stigmatic receptivity in angiosperms.

[The relationship between the quality and the leaf shape of Magnolia officinalis produced in Hubei enshi]

OBJECTIVE

To reveal the relationship between the quality and the leaf shape of Magnolia officinalis produced in Hubei Enshi.

METHODS

Determined the content of magnolol and honokiol by HPLC with methanol-water (78:22) and the detective wavelength was 294 nm.

RESULTS

The content of magnolol and honokiol in the leaf of Magnolia officinalis was usually higher if the leaf apex was convex and the leaves were short. In certain years, the content of magnolol and honokiol in Cortex Magnoliae officinalis was positively correlated with the bark thickness.

CONCLUSION

The leaf shape of Magnolia officinalis produced in Hubei Enshi is directly related to the phenolic content of leaf itself. But it has nothing to do with the content of magnolol and honokiol in Cortex Magnoliae officinalis.

[Identification of the different cultivated Magnolia biondii]

OBJECTIVE

To distinguish Magnolia biondii of ten different cultivated.

METHODS

The original species can be identified by the morphological characteristics and microscopic characteristics. The volatile oil is determinated by the method of Chinese pharmacopoeia.

RESULTS

The ten cultivated Mangolia biondii have obviously differents in morphological characteristics, microscopic characteristics and volatile oil.

CONCLUSION

It is important for development application of Magnolia biondii and variety improvement.

Giant flowers of Southern magnolia are hydrated by the xylem

Flowering depends upon long-distance transport to supply water for reproductive mechanisms to function. Previous physiological studies suggested that flowers operated uncoupled from stem xylem transport and received water primarily from the phloem. We demonstrate that the water balance of Southern magnolia (Magnolia grandiflora) flowers is regulated in a manner opposite from that of previously examined flowers. We show that flowers of Southern magnolia rely upon relatively efficient xylem hydraulic transport to support high water demand during anthesis. We measured rapid rates of perianth transpiration ranging from twice to 100 times greater than previous studies. We found that relatively efficient xylem pathways existed between the xylem and flower. Perianth hydraulic conductance and the amount of xylem to transpirational surface area ratios of flowers were both approximately one-third those measured for leafy shoots. Furthermore, we observed that perianth tissues underwent significant diurnal depressions in water status during transpiring conditions. Decreases in water potential observed between flowers and vegetative tissues were consistent with water moving from the stem xylem into the flower during anthesis. Xylem hydraulic coupling of flowers to the stem was supported by experiments showing that transpiring flowers were unaffected by bark girdling. With Southern magnolia being a member of a nearly basal evolutionary lineage, our results suggest that flower water balance represents an important functional dimension that influenced early flower evolution.

Automatic discrimination of fine roots in minirhizotron images

Minirhizotrons provide detailed information on the production, life history and mortality of fine roots. However, manual processing of minirhizotron images is time-consuming, limiting the number and size of experiments that can reasonably be analysed. Previously, an algorithm was developed to automatically detect and measure individual roots in minirhizotron images. Here, species-specific root classifiers were developed to discriminate detected roots from bright background artifacts. Classifiers were developed from training images of peach (Prunus persica), freeman maple (Acer x freemanii) and sweetbay magnolia (Magnolia virginiana) using the Adaboost algorithm. True- and false-positive rates for classifiers were estimated using receiver operating characteristic curves. Classifiers gave true positive rates of 89-94% and false positive rates of 3-7% when applied to nontraining images of the species for which they were developed. The application of a classifier trained on one species to images from another species resulted in little or no reduction in accuracy. These results suggest that a single root classifier can be used to distinguish roots from background objects across multiple minirhizotron experiments. By incorporating root detection and discrimination algorithms into an open-source minirhizotron image analysis application, many analysis tasks that are currently performed by hand can be automated.

[Studies on the microstructure of cortex herbs]

OBJECTIVE

Provide a basis for the micro-identification of cortex herbs.

METHOD

The microstructure characteristics of different types and positions of cortex herbs have been compared, studied, systematized and arranged.

RESULT

The characteristic and the rule of the common micro-identification of cortex herbs inquiring table have been compiled.

CONCLUSION

The microstructure characteristics of cortex herbs as an important basis for the micro-identification of cortex herbs study value.

The outer integument and funicular outgrowth complex in the ovule of Magnolia grandiflora (Magnoliaceae)

The development of the outer integument and funicular outgrowth in the ovule of Magnolia grandiflora was examined by microtomy and scanning electron microscopy to reveal the morphology and evolution of the outer integument, a novel angiosperm structure. Early in development the outer integument is semiannular, decurrent to the lateral sides of the funiculus, and extends downwards beyond the funicular outgrowth that forms in the gap of the outer integument, and is transverse to the funiculus. The outer integument then overgrows the funicular outgrowth perpendicularly to the funiculus to form a micropyle together. The hood-shaped outer integument and the funicular outgrowth compose an envelope complex, and the interpretation of a single cupular outer integument is not supported. This envelope complex may differ from the cupular outer integument of other angiosperms, e.g., Nymphaeaceae, suggesting independent origin of apparently cupular outer integuments and hood-shaped outer integuments. Anatropous curving is due mainly to differential growth of the chalaza. The bistomic micropyle of Magnoliaceae seems to represent a derived character state, compared to an endostomic micropyle.

[A study on bark quality of Magnolia officinalis Rehd. et Wils]

OBJECTIVE

To understand the main factors influencing the bark quality of Magnolia officinalis so as to theoretically establish a basis for quality assessment, genetic improvement and layout of bark producing areas.

METHOD

Eighty-two samples from the main bark producing areas(11 counties of 7 provinces such as Zhejiang, Fujian, Sichuan, Hunan, Guangxi, Jiangxi and Hubei) were collected. Totally there were 121 samples, including 39 from the trial stand located in Jingning of Zhejiang the obtained out of the seeds from the bark producing areas mentioned above. HPLC was used in the analysis of phenols contained in the bark of Magnolia officinalis.

RESULT

The main factors influencing the bark quality have been made clear.

CONCLUSION

The quality is affected by provenance, leaf shape, DBH, tree height, crown size, age, bark thickness color of bark powder, oiliness, grounding nature, bark type, position of sampling, etc., of which provenance, leaf shape, powder color, bark thickness and DBH are the most influential factors. These factors should be fully considered when making quality assessment and genetic improvement of the bark of Magnolia officinalis.

[Study on genuineness of traditional Chinese medicine cortex Magnoliae officinalis]

It's found that a significant correlation between the samples of Magnoliae officinalis from the provenance in phenols content and varieties or forms. The total content of magnolol and honokiol in its bark is usually used as an index to measure the quality. Therefore, Cortex Magnoliae officinalis produced in Sichuan and Hubei being considered genuinenss and good in quality, should be actually referred to local varieties. This conclusion can also reveals the nature and scientific connotation of genuineness on Cortex Magnoliae Officinalis.

[A study on the relationship between tree age and bark quality in Magnolia officinalis]

Contents of magnolol and honokiol in 76 samples of Magnolia officinalis collected from 11 counties in Zhejiang, Fujian, Sichuan, Guangxi, Hunan, Jiangxi and Hubei are analyzed by means of HPLC. A study on the effect of tree age on effective ingredients in Magnolia offcinalis shows that the influence of tree age on the content of magnolol and honokiol is correlated with the varieties under cultivation, but a small effect on the content of the phenols with an indent at the tip of leaves. The content of magnolol in other types of leaves increases rapidly with increase in age, diameter of the trunk and thickness of the bark, with not many changes found at the age of 12 or up. Increase in age may be favorable to the full expression of oily characteristic. These results provide a scientific base for the determination of optimal time for harvesting bark from artificially established Magnolia officinalis stands.

[Study on the relationship between provenance, leaf type and quality in Magnolia officinalis]

An analysis of effective ingredients in 20 to 29 year old Magnolia officinalis of three different leaf types coming from various sources shows that the content of phenols differ extremely significantly in various leaf types which are a key to determination of quality of Magnolia officinalis also varies significantly among different sources which only have a significant effect on the content of magnolol. Varieties and types cultivated in different places are responsible for the variation in content of magnolol. The conclusions obtained from this study coincide with the traditional insight into quality of Magnolia officinalis.