Major evolutionary events in the origin and diversification of the fern genus Polystichum (Dryopteridaceae)

Recent advances in molecular systematics of the ferns make it possible to address long-standing questions about classification of the major fern genera, such as the worldwide genus Polystichum (Dryopteridaceae), comprising at least 200 species. In this study we examined rbcL sequences and morphological characters from 55 fern taxa: 34 were from Polystichum and 21 were from other genera in the Dryopteridaceae. We found that Phanerophlebia, possibly including Polystichopsis, is the sister group to Polystichum sensu lato (s.l.), including Cyrtomium. Polystichum as commonly recognized is paraphyletic. Our results lead us to suggest recognizing the clade of earliest diverging Polystichum species as a distinct genus (Cyrtomidictyum) and to continue to recognize Cyrtomium as a separate genus, leaving a monophyletic Polystichum sensu stricto (s.s.). We resolved a tropical American clade and an African clade within Polystichum s.s. However, the resemblance between the once-pinnate, bulb-bearing calciphilic species found in Asia and the West Indies appears to be the result of convergent evolution. Optimizing our morphological character transformations onto the combined phylogeny suggests that the common ancestor of Polystichum s.l. and Phanerophlebia had evolved the common features of the alliance, including ciliate petiole-base scales, once-pinnate fronds, ultimate segments with scarious tips, peltate indusia, and microscales.     

Gametophyte development and reproduction of the Asian fern Polystichum polyblepharum (Roem. ex Kunze) C. Presl (Dryopteridaceae,Polypodiopsida)

Abstract

The gametophytic generation of Polystichum polyblepharum (Dryopteridaceae), including spore germination, morphological development of the gametophytes, major vegetative features and reproduction strategies, was studied. Spore germination was of the Vittaria model and the developmental pattern was of the Aspidium model. Adult gametophytes were cordate and hairy, with unicellular hairs located at the margins and at the prothallus surface. The marginal ones were secretory. The gametophytes produced archegonia located in the central area between the notch and the rhizoids, but antheridia were never detected. Archegonia were of the normal type described for leptosporangiate ferns. Apogamous sporophytes appeared from a cellular outgrowth developed just under the apical notch. Initially, the outgrowth appeared completely surrounded by glandular hairs and scales, which persisted throughout the subsequent stages of leaf development.     

苦木化学成分研究

运用各种柱色谱和重结晶等方法对苦木Picrasma quassioides(D.Don)Benn.进行分离纯化,得到五个化合物。通过NMR等现代波谱学方法和技术鉴定化合物的结构分别为:高丽槐素-3-O-β-D-葡萄糖苷(trifolirhizin,1),高丽槐素(maackiain,2),3’,7-二羟基-4’-甲氧基异黄酮(3’,7-dihydroxy-4’-methoxyisoflavone,3),7-羟基香豆素(umbelliferone,4)和大黄素(emodin,5)。五个化合物均为首次从该属植物中分离得到。     

Dicentra scandens (D. Don) Walp. auch in der Flora Vietnams

The specimen 3064 of A. Petelot in 1927 from Chapa (Vietnam) is Dicentra scandens (D. Don) Walp. Anatomical characteristics of fruits and seeds are identically with such of the isotype, but morphological characteristics in the other parts are somewhat different.     

Antioxidant activity evaluation of essential oil and RAPD analysis of in vitro regenerated Blumea mollis (D. Don) Merr.

Essential oil obtained from the leaves of Blumea mollis (D. Don) Merr. was analyzed by gas chromatography and gas chromatography coupled with mass spectroscopy (GC and GC–MS). Bicyclic sesquiterpene, β-caryophyllene, was identified as a major compound which accounted for 24.54 %. Antioxidant activity of oil was significantly higher than that of methanol extract of callus. Murashige and Skoog (MS) medium supplemented with 4.4 μM BA showed multiple shoot induction after 8 weeks of culture. 4.6 μM Kin showed in vitro flowering and direct organogenesis was observed from the leaf explants on medium containing 4.4 μM BA and 5.4 μM NAA. Rooted plantlets developed on half strength MS medium fortified with 2.1 μM IBA were hardened and percentage survival was recorded up to 70. RAPD analysis revealed a little genetic variation in micropropagated plants.     

Inheritance of allozyme variants in bishop pine (Pinus muricuta D. Don)

Isozyme phenotypes are described for 45 structural loci and 1 modifier locus in bishop pine (Pinus muricata D. Don,) and segregation data are presented for a subset of 31 polymorphic loci from 19 enzyme systems. All polymorphic loci had alleles that segregated within single-locus Mendelian expectations, although one pair of alleles at each of three loci showed significant segregation distortion. The consistency of resolution and segregation at many loci in bishop pine makes electrophoretic analyses feasible for many purposes in this species.     

苦苣苔科吊石苣苔属一新异名

2017年,印度学者Joe等基于采自中国藏东南地区的植物标本,发表了合萼吊石苣苔的一新变种Lysionotus gamosepalus W. T. Wang var.biflorus A. Joe, Hareesh&M. Sabu,并且认为该新变种与原变种的主要区分特征包括叶缘稍具锯齿、每个腋生花序仅有2朵花、花冠被毛、具2枚卷曲的退化雄蕊。然而,近年来,笔者基于查阅大量标本和野外考察工作,认为所谓变种的形态特征是在合萼吊石苣苔(Lysionotus gamosepalus W. T. Wang)的变异范围之内,加之分布区完全重叠,生长环境类似,物候期一致,不宜作为变种等级处理。故在此将该变种处理为合萼吊石苣苔的异名。     

Pollination Ecology of Pedicularis megalantha D. Don (Scrophulariaceae) in the Himachal Himalaya

Abstract In the summer of 1990, the pollination ecology of Pedicularis megalantha was studied in the montane-subalpine spruce-fir forest zone (2750-3050 m) on the north slope of Mt. Huttoo at Narkanda, Himachal Pradesh, in the Indian Himalaya. Its yellow, long-tubed, nectarless flower with a curled rostrum overarched by a broad, inverted lower corolla lip was pollinated exclusively by Bombus albopleuralis and B. tunicatus workers hanging inverted from the corolla and vibrating pollen from introrse anthers concealed within the galea and releasing pollen through a small ventral opening in the galea base. The stigma, protruding from the tip of the rostrum, contacted pollen deposited on the ventral side of the insect's thorax. Corbicular pollen loads from P. megalantha pollinators indicated equal numbers of monolectic and oligolectic foragers. P. megalantha appeared to suffer from competition for pollinators by Cynoglossum wallichii at one site but to be favored in a mixed plant community with nectariferous species offering a forage resource complementary to Pedicularis pollen. As in P. punctata , the long, nectarless corolla tube of P. megalantha appears to function in extending the rostrate vibration pollination mechanism beyond the plant's foliage, which would interfere with its function. It is not an adaptation for nectar-foraging lepidopteran pollinators. P. megalantha was also found to be a root hemiparasite.     

A cytotaxonomic study of some species of Pleione D. Don (Orchidaceae)

For taxonomic purposes in the genus Pleione D. Don (Orchidaceae) breeding studies, chromosome numbers, karyotypes and analyses of pollen mother cells have been investigated. In addition to confirming many previous chromosome numbers, new tetraploid, hexaploid and triploid counts establish the existence of a tetraploid taxon (P. speciosa) , a hexaploid (P. bulbocodioides) and a triploid hybrid (P.humilis 'Frank Kingdon-Ward'). The karyotypes of the diploid species P. bulbocodioides, P.yunnanensis, P. humilis, P.forrestii and P. hookeriana are distinct, whereas those of P.formosana and P. limprichtii have similar morphology to that of P. bulbocodioides , which was also represented in the polyploid taxa. Karyotype morphology provides evidence to trace the putative parents of P. x confusa and P. humilis 'Frank Kingdon-Ward'. Results from pollen mother cells and karyotype analyses suggest that P.formosana and P. limprichtii are not cytologically differentiated from P. bulbocodiodes , and the taxa P. speciosa, P. limprichtii (tetraploid form) and P. bulbocodioides (6x) are of autopolyploid origin, being derived from the P. bulbocodioides genome. The species limits are discussed.     

黄花油点草胚胎发育研究

利用石蜡切片技术对百合科植物黄花油点草[Tricyrtis maculata(D.Don)Machride]双受精、胚及胚乳发育进行了研究,以明确其胚胎发育的特征,为百合科植物的系统研究提供生殖生物学资料。结果表明:(1)黄花油点草为珠孔受精;进入胚囊的2枚精子分别与卵细胞和中央细胞进行正常的双受精,其受精作用属有丝分裂前型。(2)受精后的初生胚乳核立即分裂,其发育方式为核型胚乳;早期的游离胚乳核沿胚囊的边缘分布,胚囊中央部位主要为胚乳细胞质,随着游离胚乳核数量的增加,胚乳核慢慢充满整个胚囊;当发育至球形胚早期阶段,在各胚乳核周围产生胚乳细胞壁,形成完整的胚乳细胞。(3)合子有较长的休眠时间,胚的发育方式为茄型;合子第一次有丝分裂为横裂,分裂后形成基细胞和顶细胞;基细胞经过3次横裂,形成一列胚柄细胞;顶细胞经过分裂形成胚体,依次形成球形胚、棒状胚和盾形胚。(4)种子成熟时胚无器官分化;成熟种子由种皮、胚和胚乳三部分组成。     

三叶香茶菜的组织培养及植株再生

1植物名称三叶香茶菜[Rabdosia ternifolia（D．Don）Hara]。 2材料类别带腋芽茎段。 3培养条件（1）诱导愈伤组织的培养基：MS＋6．BA2mg.L^-1（单位下同）＋NAA0．5;（2）芽分化及继代培养基：MS＋6．BA2＋IBA0．5：（3）诱导生根培养基：1／2MS＋IBA0．5＋NAA0．1。     

Effect of bracken (Pteridium a quilinum) and dryopteris (Dryopteris juxtaposita) fern toxicity in laboratory rabbits

Experimental studies with Bracken and Dryopteris ferns @ 25% concentrate ration mixture were conducted in rabbits. Fern fed rabbits showed progressive anaemia, leukopaenia, lymphopaenia and relative heterophilia. Significant elevations in serum enzymes like serum glutamate oxaloactate transminase (SGOT), serum glutamate pyruvate transminase (SGPT), alkaline phosphatase (ALP), urea and creatinine levels were seen. Histopathologically, rabbits showed mild to moderate vascular changes in most of visceral organs, vacuolar degenerative changes in hepatocytes, hypersecretory activity in intestine, presence of casts in renal tubules and degenerative changes in renal tubular lining epithelial cells. Dryopteris fed rabbits showed somewhat more severe degenerative and vascular changes in different intervals. A low level of toxic principle ptaquiloside was detected in Bracken and Dryopteris ferns by thin layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) methods.     

长距美冠兰及其近缘种的研究

讨论了长距美冠兰Eulophia dabia及其近缘种的分类与命名问题。Eulophia dabia的基名Bletia Dabia乃是D．Don(1825)合法发表的最早名称,尽管D．Don的“Dabia”很可能是在袭用Hamilton的“dubia”时拼写上的笔误。为了避免进一步的混乱,明智的做法是接受Don拼写的加词,而避开其语源上的麻烦。在分类方面,可以接受Hooker(1890)将Eulophia campestris Lindl．、E．rupestris Lindl、E．ramentacea Lindl．与Bletia Dabia D．Don：予以合并的观点,以及Deva&;Naithani(1986)将Eulophia hormusjii Duthie并入 E．dabia的做法。此外,本文还将Eulophia turkestanica (Litw．)Schltr．和E. faberi Rolfe也归并入 Eulophiadabia。因此,长距美冠兰是一个广布种,白土库曼东部经塔吉克、阿富汗东部、巴基斯坦、克什米尔地区,印度北部、尼泊尔、锡金、不丹、缅甸北部直到中国(云南西南部、四川中部到东部、贵州西南部和江苏),海拔在400~2300 m之间。     

Seasonal nitrogen partitioning in Japanese cedar (Cryptomeria japonica,D. Don) tissues

Plant and Soil - Plant species diversity impacts ecosystem processes, but its effects on runoff and soil erosion are not fully understood. Herbaceous vegetation control concentrated runoff and soil...     

Genetic Conservation of Insular Populations of Monterey Pine (Pinus Radiata D. Don)

Monterey pine (Pinus radiata D. Don) has only five extant native populations: three disjunct populations along the coast of California, USA and two on Mexican islands. All populations have been influenced by human activity, but the island populations in particular have been affected by introduced biota. On Guadalupe Island, the pine population has suffered drastically from overgrazing by introduced goats. We visited both island populations and described their status, took measurements, and made seed collections. We counted approximately 200 mature pine trees and virtually no seedlings on Guadalupe Island: a reduction of approximately half the population in the last 50 years. The trees are all large (mean diameter of 144 cm) –considerably larger than trees from the other four populations – and arguably near the end of their natural lifespan. The population on Cedros Island is much more robust, with thousands of trees. None sampled were as large as those on Guadalupe Island (mean diameter of 20 cm) and many groves were young and even-aged – presumably the consequence of natural regeneration after a recent fire. Tissue samples from trees on both islands did not show evidence of infection from the pitch canker pathogen, Fusarium circinatum, that has caused significant mortality in the three mainland populations. Caution is recommended in any restoration activity for the Guadalupe Island pines. Inbreeding levels could indicate the need for some planting or seeding intervention but there are also risks associated with this. Natural regeneration – after goat removal – is preferred.     

Pharmacological properties and preliminary phytochemical analysis of Pseudocaryopteris foetida (D.Don) P.D. Cantino leaves

Medicinal plants have significant contribution in pharmaceutical industries being producers of compounds utilized as precursors for drug development. A plant of Lamiaceae family; Pseudocaryopteris foetida had not been investigated for its biomedical potential. Current research was aimed to investigate phytochemical analysis, cytotoxic potential and antioxidant activity of crude methanolic extract and fractions of Pseudocaryopteris foetida (leaves). The preliminary phytochemical analysis of crude methanolic extracts and fractions of Pseudocaryopteris foetida revealed that plant is rich in phenolic and flavonoid classes of secondary metabolites while presence of tannin was observed only in crude methanolic extract. The cytotoxicity was determined using brine shrimp lethality test. Different concentrations (25, 50, 100, 150, 200 and 250 µg/mL) of crude methanolic extract and fractions exhibited dose dependent cytotoxicity. However, The LD₅₀ for all the extracts was more than 200 µg/mL indicating weak cytotoxic potential of Pseudocaryopteris foetida. The antioxidant capabilities of crude methanolic extract and fraction of Pseudocaryopteris foetida were analyzed by in vitro bio assays including DPPH, ABTS, Reducing power and phosphomolybdate antioxidant assays using ascorbic acid as standard. The crude methanolic extract showed IC₅₀ (256.38 ± 0.6 and 314.95 ± 1.1 µg/mL) for DPPH and ABTS respectively, while total antioxidant capacity was calculated as 55.79 ± 0.5 µg/mL for crude methanolic extract of Pseudocaryopteris foetida while ascorbic acid indicated total antioxidant capacity of 71.89 ± 2.3 µg/mL. Study concluded that leaves of Pseudocaryopteris foetida were the rich source of antioxidant phytochemicals. Based on preliminary investigations further research should be focused to isolate bioactive phytochemicals as leading source of clinical medicines in future.     

Dioecy in Fitzroya cupressoides (Molina) I.M. Johnst. and Pilgerodendron uviferum (D. Don.) Florin (Cupressaceae)

The aim of this study was to determine the dioecious or monoecious condition of Fitzroya cupressoides and Pilgerodendron uviferum. The study area lies west of the Nahuel Huapi National Park in northern Patagonia (Argentina), where these species form mixed stands. One hundred individuals of each species were studied over three successive years. The nature and position in the crown of their reproductive organs were recorded. Results showed that both species are dioecious. This feature has been confirmed on trees of these species growing in other sites within their natural distribution area in Argentina and Chile.