Myrcia longipetiolata (Myrtaceae), a New Species from the Atlantic Forest of Bahia, Brazil

Abstract— Myrcia longipetiolata, a new species of Myrcia, is here described and illustrated. With a phylogenetic hypothesis, we show that this species belongs to Myrcia clade 10, a morphologically recognized and narrowly distributed group of species, which was recently discovered. Myrcia longipetiolata resembles M. unana due to its long leaves, acute or acuminate leaf apex, cuneate leaf base, long petioles, and they share the same area of occurrence. Myrcia longipetiolata differs from M. unana by its larger leaves, larger number of leaf secondary veins, marginal vein more distant from the leaf margin, lanceolate bracteoles, smaller and truncate, rounded, or apiculate calyx lobes with whitish to yellowish trichomes, and smaller floral disc. Besides the phylogenetic placement of M. longipetiolata within the genus, morphological comparisons with related species and comments on its distribution, habitat, and conservation status are also provided.

Regeneration from leaf explants of steppe cherry (Prunus fruticosa Pall)

The article represents data on morphogenesis from leaf explants of three steppe cherry genotypes, as well as the degree of somaclonal variability at in vitro and ex vitro stages, and in the field. It was revealed that a content of 6-benzylaminopurine, 4.43 μM, in combination with auxin, 0.5–0.6 μM, stimulates in the light the direct organogenesis in the tissues of the leaf base. This reaction was observed from 16.7 to 75.0% of explants, depending on the genotype. An equal 6-benzylaminopurine - auxin ratio (1: 1) led to the callus along with microshoots. Depending on the genotype, up to 30.0% of explants had such a mixed type of organogenesis. The mitotic index value in the apical leaflets differed depending on the day time. At the stage of micropropagation itself, an increase of the mitotic index was observed from 10 to 16 hours; at the stage ex vitro, no significant differences in the mitosis frequency were revealed within this time interval. No significant differences were found between the level of the mitotic index for plants obtained directly from leaves and those from buds. The mitosis passed without disturbances. No phenotypic changes in plant habit, shape and color of leaves were found.

Quercus ngochoaensis (Fagaceae), a new species from Ba Vi National Park, northern, Vietnam

A new species of Quercus (Fagaceae), Q. ngochoaensis, from Ba Vi National Park, Ha Noi, northern Vietnam is described and illustrated. This species is morphologically similar to Q. glauca in having glabrous twigs, cuneate leaf base, two or three fruits per infructescence, almost entire margin of lamellate rings on cupule except the lowest three rings, slightly convex scar at the base of a nut. However, it differs from Q. glauca in having smaller leaves, cup-shaped cupule enclosing 1/2–2/3 of the nut, 7–8 lamellate rings on cupule, and subglobose nut. In addition to the description, DNA barcodes of the two partial plastid regions of matK, rbcL and the nuclear region of ITS of the new species are provided.

Piper Ribesioides Wall., a Newly Recorded Species for the Flora of Vietnam

We here reported a newly recorded Piper species for the flora of Vietnam, namely Piper ribesioides Wall. (Piperaceae). This species is most morphologically similar to P. politifolium C.DC. by sharing glabrous plants and fruits with a stipe, but it differs from the latter having a monoecious habit (vs. dioecious), stamens 4 (vs. 2), and a cordate leaf base with equal or subequal lobes (vs. oblique with unequal lobes). Descriptions, illustrations, information on ecology, and taxonomic notes of the species is provided.

Revision of Begonia (Begoniaceae) in Bidoup-Nui Ba National Park, Southern Vietnam, including two new species

The Begonia species occurring in Bidoup-Nui Ba National Park (Lam Dong Province, southern Vietnam) are reviewed based on recent floristic field surveys. Five species were recognized from the montane forests, and two of which are new to science. The new species belong to Begonia sect. Platycentrum and are named as B. hongiaoensis C.W.Lin, T.C.Hsu & Luu and B. lamdongiana C.W.Lin, T.C.Hsu & Luu, repectively. Begonia hongiaoensis most closely resembles B. siamensis Gagnep from northern Thailand. Both species have a rhizomatous habit and bear ovate leaves. However, the new species differs by its stoloniferous habit, shallowly cordate leaf base and 5-tepaled pistillate flowers. Begonia lamdongiana is similar to B. coelocentroides Y.M.Shui & Z.D.Wei, a hairy leaf species of the same section in Yunnan of China, but is markedly distinct in its glabrous petioles, inflorescences, pedicels and ovaries, and larger bracts.

Rumex acetosella (sheep's sorrel).

R. acetosella is perennial, reproducing by both creeping roots and seed. It has relatively shallow, extensive slender roots. Early growth is as basal rosettes of leaves. Leaves are 1-8 cm long, smooth, variable in shape but primarily consisting of three lobes, primary lobe is linear to egg-shaped terminating in a point; two secondary lobes appear at the base of the primary lobe and point outwards giving an arrowhead-shape appearance to the leaves which are sour in taste. It has long basal leaf stalks and short-stalked to sessile leaves on the upper stem; a membranous sheath (modified stipules) surrounds the stem above the leaf base. Multiple stems can appear from a single crown growing upright, 15-40 cm in height, slender, branching near the top to form a loose leafless panicle. Flowers are unisexual with male and female appearing on separate plants (dioecious). Males have six stamens on short filaments, females have three styles with branched stellate stigma. Flowers consist of three inner and three outer tepals, appearing red to yellowish, borne on raceme near the top of the stem. Flower stalks are jointed close to the flower. Seeds are three sided (achenes), ca. 1.5 mm in length, shiny reddish brown in colour. A reddish brown hull often adheres to the seed and is rough in texture (Buchholtz et al., 1954; Hitchcock and Cronquist, 1981; Gleason and Cronquist, 1991; Pojar and MacKinnon, 1994; Douglas et al., 1999).

Light Intensity Influence on Growth and Photosynthetic Characteristics of Horsfieldia hainanensis

Due to both anthropogenic and natural causes, the number of Horsfieldia hainanensis has been decreasing each year in the Tongza Branch nursery (109.534 525°E, 18.763 516°N) of the Hainan Academy of Forestry, China. Consequently, the protection of H. hainanensis is urgent, as is that of most rare tree species. To develop a more comprehensive understanding of the H. hainanensis growth environment, we took 3-year-old H. hainanensis saplings as the research object. We controlled the light intensity by setting different shade amounts to explore the growth and photosynthetic characteristics of H. hainanensis under different light intensities. We found that shade can promote growth and increase the contents of certain substances. Light transmittance of 44.41% can increase plant height (by 29.545%) and biomass (by 66.676%). Light transmittance of 16.19% can increase the pigment content; Chl increased by 40.864%, Chl a increased by 38.031%, and Chl b increased by 48.412%. Light transmittance of 7.30% can increase the soil plant analysis development (SPAD) value of each part of the leaf; the leaf base increased by 41.000%, the leaf margin increased by 32.574%, the blade tip increased by 49.003%, and the leaf average increased by 40.466%. The specific leaf area can reduce the specific leaf weight. We also found that compared to full light, reducing the light transmittance can increase the total chlorophyll (Chl), chlorophyll A (Chl a), and chlorophyll B (Chl b) contents, and the Chl-SPAD-leaf base, leaf edge, leaf tip, average content, and light-saturated net photosynthetic rate. This can in turn reduce the apparent quantum efficiency (AQY), light compensation point (LCP), and dark respiration rate (Rd). In addition, we found a strong correlation between seven of the photosynthetic pigment indicators (Chl, Chla, Chl b, Chl-SPAD-leaf base, leaf margin, leaf tip, and mean) and the three photosynthesis physiological parameters (AQY, LCP, and Rd). The light transmittance of 44.41% (one layer of shading net) treatment group was conducive to the growth of H. hainanensis and photosynthetic characteristic improvement. Therefore, our light transmittance selection of approximately 44.4% is significant for the natural return of H. hainanensis.

Highly Efficient Leaf Base Protoplast Isolation and Transient Expression Systems for Orchids and Other Important Monocot Crops

Versatile protoplast platforms greatly facilitate the development of modern botany. However, efficient protoplast-based systems are still challenging for numerous horticultural plants and crops. Orchids are globally cultivated ornamental and medicinal monocot plants, but few efficient protoplast isolation and transient expression systems have been developed. In this study, we established a highly efficient orchid protoplast isolation protocol by selecting suitable source materials and optimizing the enzymatic conditions, which required optimal D-mannitol concentrations (0.4–0.6 M) combined with optimal 1.2% cellulose and 0.6% macerozyme, 5 μM of 2-mercaptoethanol and 6 h digestion. Tissue- and organ-specific protoplasts were successfully isolated from young leaves [∼3.22 × 106/g fresh weight (FW)], flower pedicels (∼5.26 × 106/g FW), and young root tips (∼7.66 × 105/g FW) of Cymbidium orchids. This protocol recommends the leaf base tissues (the tender part of young leaves attached to the stem) as better source materials. High yielding viable protoplasts were isolated from the leaf base of Cymbidium (∼2.50 × 107/g FW), Phalaenopsis (1.83 × 107/g FW), Paphiopedilum (1.10 × 107/g FW), Dendrobium (8.21 × 106/g FW), Arundina (3.78 × 106/g FW) orchids, and other economically important monocot crops including maize (Zea mays) (3.25 × 107/g FW) and rice (Oryza sativa) (4.31 × 107/g FW), which showed marked advantages over previous mesophyll protoplast isolation protocols. Leaf base protoplasts of Cymbidium orchids were used for polyethylene glycol (PEG)-mediated transfection, and a transfection efficiency of more than 80% was achieved. This leaf base protoplast system was applied successfully to analyze the CsDELLA-mediated gibberellin signaling in Cymbidium orchids. We investigated the subcellular localization of the CsDELLA-green fluorescent protein fusion and analyzed the role of CsDELLA in the regulation of gibberellin to flowering-related genes via efficient transient overexpression and gene silencing of CsDELLA in Cymbidium protoplasts. This protoplast isolation and transient expression system is the most efficient based on the documented results to date. It can be widely used for cellular and molecular studies in orchids and other economically important monocot crops, especially for those lacking an efficient genetic transformation system in vivo.

Begonia scorpiuroloba, a new species in Begonia sect. Platycentrum (Begoniaceae) from southern Guangxi of China

Begonia scorpiuroloba sp. nov., a new species in Begonia sect. Platycentrum (Begoniaceae) from southern Guangxi of China, is described and illustrated. Morphologically, it is mostly similar to B. pedatifida, but differs clearly by its narrower lobes, denser hairs on leaf surface, obtuse angle of leaf base, subequal tepals of female flowers and late flowering. This new species is endemic to Guangxi and is assigned to Endangered (EN) according to the IUCN Red List Categories and Criteria.