Piper is the largest genus and important Pantropical components of the Piperaceae family with approximately 1000-2000 species in the world. China is in the northern verge of its natural distribution. In this study, floristic geography of the Piper genus in China was analyzed to reveal its botanical characteristic, origins of speciation and its dispersal channels. The study results showed Yunnan province is one of the very important distribution regions for Piper species, served as the center of the Piper species dispersal toward to the eastern and northern regions of China with gradually reduced species numbers. The similarity level appeared to be low for its species among different provinces, and the Piper distribution regions could be approximately clustered into three clades: tropical clade, subtropical clade and Taiwan clade. Cladistically, Piper species found in China have the highest proportions which were endemic to China, and then followed by Piper species distributed in Tropical Asia, only few species belonged to Pantropical and East Asia arealtypes. The floristic geography of Piper genus in China is related to that of IndoChinese Peninsula, Java Islands and Indian Peninsula in some degrees, but not closely related. This study revealed Yunnan province is one of the central of origins for the Piper species, and or one of the central of regions for its species diversification, and the Piper species of Taiwan mainly came from Philippine islands and further diversified into Taiwan clade. Our study results presented a useful method for the systematic studying of Piper genus taxonomy and the evolution of Piper speciation.
In this paper, twentyeight species of the genus Salix, with similar phenotypic characters, were selected to study the leaf epidermal microfeatures under Scanning Electronic Microscope (SEM). Seven types of wax layer are totally detected in those species, including smooth layer, crust, fissured layer, nonentire platelets, membraneous platelets, conicoids and scalelike conicoids. Among those types, conicoids and scalelike conicoids are exclusively found in Salix, while nonentire platelets and membraneous platelets in Salix are depicted for the first time. The microfeatures of leaf hairs of Salix plants under SEM are less diversified than their macrofeatures, with detectable microfeature variations on hair length, density and degree of curve (straight, slightly curved and deeply curved). In conclusion, our results showed leaf epidermal microfeatures of wax layer types and stomatal apparatus are relatively unchangeable, which are valuable in the discrimination of similar Salix species. The Salix species from colder region and/or higher elevation usually bear diverse microfeatures, which might be adaptive evolution to colder environments.
Pollen grains of four species representing four genera of Annonaceae were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The pollen grains are tetrads in Annona muricata and Pseuduvaria trimera under SEM. The type of tetrad is various, being tetragonal, rhomboidal, Tshaped, decussate and tetrahedral. The sculpture of pollen in A.muricata is psilate and foveolate, but rugulate in P.trimera. The pollen grains are monad in Oncodostigma hainanense and Uvaria macclurei. In the former species, the ornamentation is rugulate, and in the latter it is coarsely folded. Under TEM, the tectum is thick and continuous in O.hainanense and U.macclurei. The materials from infratectal layer are less accumulated. There is an intermediate infratectal layer in O.hainanense, for some irregular columellae and sparse granules are both observed, but there is a granular infratectal layer in U.macclurei. Basal layer consists of an outer layer and a foliated inner layer. The outer layer is thick, and flat or fluctuant. The inner layer is composed of two to four foliations. The morphological differences are great among different genera or different species in the same genus, indicating a high diversity of pollen morphology in Annonaceae. There are both primitive and derived characters in O.hainanense or P.trimera. Such as in P.trimera, small size pollen grain and imperforate tectum are primitive characters, but tetrad and columellar infratecal layer are derived.
We studied the light effects on style curvature and anther dehiscence of Alpinia mutica. The results showed that light did not change the style movement directions of catamorph, neither the anther opening time. The first style curvature of anamorph moved downwards in darkness, and moved upwards in light.Meanwhile, the anther did not dehisce in darkness, but dehisced in light. The second style curvature of anamorph depended on the light condition of first curvature. If kept in darkness all the time after first downward curvature, the styles did not move upwards and the anther did not dehisce. If first curvature occurred in light, the styles curved downwards both in darkness and light conditions. This research indicated that under different light conditions the combinations of style and anther states in two morphs made the stigma untouch the pollen from the same flower and therefore guaranteed the herkogamy and dichogamy. Although the behavior of style and anther in two morphs were similar, the mechanisms that regulated these behavior were different.
Four wild species of tobacco (Nicotiana alata, N.rustica, N.repanda and N.stocktonnii) and four fluecured tobacco (K326, Hongda, Yun87, Yun97), were used as experimental materials in this research. The interspecific reciprocal crosses were carried out in order to study the compatibility. The seed setting percentage of cross was counted in field, and then test seed germination. Pollen tube behaviors were observed via fluorescence microscope after pollination. The results indicated that N.rustica, N.repanda and N.stocktonnii were incompatibility with the fluecured tobacco. The pollen of N.rustica passed through the pistil of K326, but the pollens of N.repanda and N.stocktonnii were rarely growth on the pistil of K326. In spite of the pollen of N.alata passed through the pistil of K326, the hybrid tobacco seed had no vigor by the seed germination test. The female of N.alata was incompatibility with the fluecured tobacco.
Mammal frugivory and apparent seed dispersal of Balanophora harlandii (Balanophoraceae) in Xishuangbanna, Yunnan Province, China is reported for the first time. The possibility of the conspicuous, fleshy, spadiciform infructescences mimicking mushrooms for dispersal by mycophagous rodents is discussed.
The effect of flowering time on nectar secretion, effective pollinators activities and fruit set in Epimedium wushanense were revealed by Oneway ANOVA. Among the three stage of flowering, the differences in nectar standing crop and sugar content of E.wushanense were very remarkable. In this three populations, the nectar standing crop in the initial stage was higher than that in other stages, but the sugar content of nectar was higher in the last stage. The results indicated that the activities of effective pollinators were influenced by the flowering time significantly. During a day, the activities of effective pollinators were mainly concentrated in the noon. At the same time the visiting frequency of effective pollinators in last stage was higher than that in the initial and middle stage. It was also indicated that the fruit set, the seed number and percentage of seed abortion per fruit of E.wushanense were influenced by the flowering time significantly. During the initial and the middle stage of flowering, the fruit set and the seed number per fruit were bigger than that in the last stage of flowering. But the percentage of seed abortion per fruit was higher in the last stage. So, in order to make work more effective, we should choose the fruits of E.wushanense in the initial of flowering stage for experiments and breeding, and pay attention to the flowering regulation in artificial cultivation.
Ophiocordyceps sinensis is an entomophagous fungus endemic to alpine regions of the Tibetan Plateau. It has been long known by its synonym Cordyceps sinensis both in scientific and nonscientific communities. O.sinensis, a unique entomophagous fungus parasitizing the larvae of the genus Thitarodes, mainly distributed in the alpine meadows of the QinghaiTibet Plateau, is known as a valuable invigorant of traditional Chinese medicine for centuries in China. In order to research characteristics of O.sinensis, taking sample from Dalag County to laboratory for measuring content of amino acids and elements, and comparing the results with other examples selected from Sichuan, Yunnan and Tibet. The results show that content of amino acids is ample in O.sinensis, and the level of contents is clearly visible from basal caterpillar to stroma. Comparison with examples of Yunnan, Sichuan and Tibet, the amino acids is in average level. In addition, there were abundant mineral elements in O.sinensis.
The chemical composition of the elaiosome of Sloanea hemsleyana (Elaeocarpaceae) was analyzed by gas chromatographymass spectrometry. The relative content of each compound was determined by area normalization. Eleven compounds were identified, accounting for 97.6% of the total oil composition. The major compounds were Palmitic acid (36.0%) and Oleic acid (35.0%), which were favour food for ant. And it was demonstrated that the seed of S.hemsleyana can be dispersed by ant Pheidole sp. in the habitat of Kunming Botanical Garden. As for the defensive function of elaiosome of S.hemsleyana need to be identified in field.
In this study, we carried out a systematic comparison of the de novo transcriptome assembly performance of eight assemblers (ABySS, Velvet, SOAPdenovo, Oases, Trinity, Multiplek, TIDBA and TransABySS), processing Illumina RNASeq reads from F1 hybrids (Drosophila MS) of Drosophila melanogaster and Drosophila sechellia and cultivated rice. Our study showed that Trinity and TransABySS were the most effective for producing transcriptomes from our trial datasets using single kmer and multiple kmer methods, respectively, although the performance levels of the other tested assemblers were comparable. We found that using single kmer assemblers generally produced fewer total numbers of bases than multiple kmer assemblers, although even the best assembler’s results showed lower quality than some researchers may desire. Therefore, we developed and tested a novel de novo transcriptome assembly method, ETM, which employs a combination of multiple kmer tools with Trinity assembler. The ETM method yielded superior results from our trial datasets. Our results will assist the growing number of transcriptome projects using Illumina RNASeq reads and provide guidelines for choosing appropriate software.
In Arabidopsis, the tapetum plays important roles in anther and pollen development by providing enzymes for callose dissolution, materials for pollenwall formation, and nutrients for microspore development. This paper describes the functional analyses of the ST273 gene in anther and pollen development by using Arabidopsis male sterile mutant st273. Mutant st273 was identified from a TDNA insertion mutant population, and genetic analysis showed that st273 mutant was controlled by a single recessive nuclear gene. A mapbased cloning approach was used, and ST273 gene was mapped to be linked to a molecular marker CIW11 on chromosome 3. Bioinformatics analysis revealed that there is a TDF1 gene near the marker CIW11. Sequencing analysis indicated that st273 mutant had a G459 to A459 basepair change in the third exon of TDF1 gene, which resulted in premature termination mutation in this region. Allelism test indicated that ST273 and TDF1 belong to the same locus. The mutant plant grows normally during the vegetative growth stage, but show developmental defects at the reproductive growth stage. Alexander staining showed that there was no pollen in the mature anther locule. Cytology observation indicated that the mutant tapetum was enlarged and vacuolated, the tetrads could not release the microspores timely, and finally no pollen was formed in the anther. These results demonstrated that ST273 protein plays an important role in tapetum and microspore development.
Several VQ proteins are recently identified as WRKY factorsinteracting partners in Arabidopsis and involved in regulating physiological processes. Searching of genomic databases found that VQ gene family is specific to land plants and these VQ genes encode proteins characteristic of a conserved VQmotif. It consists of 34 representatives in Arabidopsis and can be divided into two groups based on the similarity of the amino acid sequences. To understand the functions of Arabidopsis VQ proteins, we examined the expression profiles of AtVQ genes in various defenserelated hormones treatments. qRTPCR analysis revealed that a majority of them were differently regulated in response to salicylic acid (SA), methyl jasmonate (MeJA), or 1aminocyclopropane1carboxylate (ACC). And some members are induced by two of these three hormones. Moreover, four members (AtVQ3, AtVQ18, AtVQ23 and AtVQ24) are induced by SA, MeJA and ACC simultaneity. However, there is only one AtVQ gene (AtVQ27) is upregulated after spraying of abscisic acid (ABA). These results suggest that Arabidopsis VQ genes may be involved in plant defense responses.
A 4231bp DNA fragment of B mating type pheromone receptor from strain YAASM0711 of Agrocybe salicacola was obtained by using degenerate PCR and DNA walking techniques. The result of alignment and structure prediction of DNA sequences showed that one 1194bp nucleotides gene ASRcb1 encoding B mating pheromone receptor was found, including four introns(72bp, 49bp, 48bp and 41bp) and five extrons (217bp, 113bp, 67bp, 138bp and 449bp). The spliced open reading frame (ORF) contains 984bp nucleotides encoding 327 amino acid residues, and includes seven transmembrane protein regions as in its similar sequences of Coprinus cinerea and Laccaria bicolor pheromone receptors. The genetic evolution of pheromone receptor showed ASRcb1 was clustered with more receptors, which suggested multiple ways of evolution occurred in fungi.
