Setaria italica (L.) P. Beauv. is a model plant that attracts international attention, which is the second most widely cultivated species of millet, especially in East Asia. It has the longest history of cultivation among the millets, having been grown in China since sometime in the sixth millennium BC. It also has been a main crop of the indigenous people of Taiwan for a long time. However, insufficient researches had been conducted about the foxtail millet germplasm in Taiwan. To assess the genetic diversity of millet population, a total of 324 landraces of foxtail millet were collected from around Taiwan, and four years of field researches were conducted for agronomic traits observation. The genetic diversity of the millet population was measured using 33 agronomic traits and 40 microsatellite markers. Average number of alleles (2.4), highly polymorphic information content (PIC) (0.381), observed heterozygosity (0.190) and expected heterozygosity (0.354) were shown. Thirty-five SSR markers showed significant deviation from Hardy-Weinberg equilibrium in 324 landraces and all these markers had low null allele frequencies. Analysis with the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) method and Principal Component Analysis (PCA) revealed that the 324 landraces could be divided into three groups that coincided with the geographical areas, including northern Taiwan, central Taiwan, and sourthern Taiwan, which account for close relationship between crop distribution and human activities. Agronomical analyses with a plant height of 80.6 to 155.2 cm, spike length of 7.5 to 28.9 cm and growth periods of between 141 and 178 days had showed that there was enough variation to create promising lines for breeding programs. This study not only provides a complete foxtail millet germplasm from Taiwan but also demonstrates that the Taiwanese foxtail millets are very diverse and can be useful for selective breeding of specific traits and in enhancing the genetic base of breeding programs in the future.

Microstegium glabratum (Brongn.) A. Camus (Poaceae, Andropogoneae) is a new record for Taiwan, Japan (SW Ryukyus), and China (Hainan). Many specimens have been collected since its first discovery in 1915, but these were misidentified as M. ciliatum (Trin.) A. Camus or M. glaberrimum (Honda) Koidz. Its existence in Taiwan is confirmed by the phylogeny of ITS/5.8S sequences and its identity is figured out after examining the related specimens.

Foxtail millet is one of the world’s oldest cultivated crops. It has been adopted as a model organism for providing a deeper understanding of plant biology. In this study, 45 simple sequence repeats (SSR) markers of Setaria italica were developed. These markers showing polymorphism were screened in 223 samples from 12 foxtail millet populations around Taiwan. The most common dinucleotide and trinucleotide repeat motifs are AC/TG (84.21%) and CAT (46.15%). The average number of alleles (Na), the average heterozygosities observed (Ho) and expected (He) are 3.73, 0.714, 0.587, respectively. In addition, 24 SSR markers had shown transferability to six related Poaceae species. These new markers provide tools for examining genetic relatedness among foxtail millet populations and other related species. It is suitable for germplasm management and protection in Poaceae.

Cynodon nlemfuensis Vanderyst has recently become naturalized in low elevations of Taiwan, and Tripsacum dactyloides (L.) L. established its population in low elevations, central Taiwan. The occurrence of Eragrostis cumingii Steud. in lowlands and low elevations in Taiwan was confirmed. We describe these three grasses new to the flora of Taiwan. Besides, we provide a key to species of Cynodon in Taiwan, and the treatment of C. arcuatus J. Presl ex C. Presl, as the synonym of C. radiatus Roth ex Roemer & Schultes.

Orchids are known for their unique reproductive biology and ecological strategies. One of the remarkable reproductive characters of most orchid species is that ovule development is precisely initiated following pollination. Thus, orchids are attractive systems for investigating both the initiation and subsequent development of the ovule. Ethylene plays a critical role in ovary maturation and ovule differentiation in orchids. Genes corresponding to ethylene biosynthesis in orchid reproductive organs have been identified and characterized. The phosphorylation states of proteins involved in ethylene biosynthesis or ethylene signaling may be correlated with ovule development. Recently, an orchid GLOBOSA-like MADS-box gene was isolated from Phalaenopsis and shown to have a role in ovule development via auxin/ethylene signaling. Adopting functional genomics strategies will help us to get insights into the regulation network between ethylene signaling pathway and ovule developmental program in orchids.

Eragrostis atrovirens (Desf.) Trin. ex Steud. and E. tenuifolia (A. Rich.) Hochst. ex Steud. are new records for Taiwan. Eragrostis curvula (Schrad.) Nees has now become naturalized in low to high elevations. Descriptions, distribution maps, and ine-drawings are presented.

SUMMARY:Geranyl diphosphate (GDP) is the precursor of monoterpenes, which are the major floral scent compounds in Phalaenopsis bellina. The cDNA of P. bellina GDP synthase (PbGDPS) was cloned, and its sequence corresponds to the second Asp-rich motif (SARM), but not to any aspartate-rich (Asp-rich) motif. The recombinant PbGDPS enzyme exhibits dual prenyltransferase activity, producing both GDP and farnesyl diphosphate (FDP), and a yeast two-hybrid assay and gel filtration revealed that PbGDPS was able to form a homodimer. Spatial and temporal expression analyses showed that the expression of PbGDPS was flower specific, and that maximal PbGDPS expression was concomitant with maximal emission of monoterpenes on day 5 post-anthesis. Homology modelling of PbGDPS indicated that the Glu-rich motif might provide a binding site for Mg(2+) and catalyze the formation of prenyl products in a similar way to SARM. Replacement of the key Glu residues with alanine totally abolished enzyme activity, whereas their mutation to Asp resulted in a mutant with two-thirds of the activity of the wild-type protein. Phylogenetic analysis indicated that plant GDPS proteins formed four clades: members of both GDPS-a and GDPS-b clades contain Asp-rich motifs, and function as homodimers. In contrast, proteins in the GDPS-c and GDPS-d clades do not contain Asp-rich motifs, but although members of the GDPS-c clade function as heterodimers, PbGDPS, which is more closely related to the GDPS-c clade proteins than to GDPS-a and GDPS-b proteins, and is currently the sole member of the GDPS-d clade, functions as a homodimer.

Chikusichloa mutica Keng, a native species of the Poaceae within Malesia and mainland China, was recently found at low elevations of northern Taiwan, providing a new record for this species and the genus for the flora of Taiwan. Chikusichloa Koidz. can be easily distinguished from the other five genera of the subfamily Oryzoideae by its bisexual spikelets, stipitate florets, and only one stamen per floret. Herein, the authors provide a line drawing, photographs, distribution map, and description of Chikusichloa mutica.

Floral scent is a key modulating factor in plant-insect interactions and thus plays a central role in successful pollination. Closely related plant species that rely on different insects for pollination produce different odors. The floral scent is of paramount importance to plant reproduction and evolution. Orchidaceae is one of the largest monocotyledon families, containing more than 25,000 species. In orchids, large quantities of pollen are formed in masses spread by animals (bees, moths, flies and birds) and the floral scents serve as attractants for species-specific pollinators. These pollinators have played a major role in orchid evolution. The range of odors produced by orchids is enormous, providing an inexhaustible basis for specificity. Such diversity is advantageous in the evolution of an obviously successful family.

Poa compressa L., P. pratensis L., and P. trivialis L. were recently naturalized in the central part of Taiwan. The existence of P. acroleuca Steud. In Taiwan was confirmed by examining the specimens deposited in HAST, NCKU, TNM, TNU, and TAI. We treated these four bluegrasses with corresponding descriptions, illustrations, and distribution maps.

Bromus carinatus Hook. & Arn., Bromus hordeaceus L., Bromus pubescens Muhl. ex Willd. and Bromus secalinus L. were recently found at middle elevations of southern and central Taiwan, respectively. We present taxonomic treatments, distribution map, and line-drawings of these introduced alien brome grasses.

Arthraxon lancifolius (Trin.) Hochst., Lamium hybridum Vill., Matricaria matricarioides (Less.) Porter, and Thlaspi arvense L. were found recently in the mountains of central and southern Taiwan. Thlaspi is a new alien genus in the Taiwan flora. Descriptions, illustrations, and photos of these four alien plants are provided for identification.

BACKGROUND:Floral scent is one of the important strategies for ensuring fertilization and for determining seed or fruit set. Research on plant scents has hampered mainly by the invisibility of this character, its dynamic nature, and complex mixtures of components that are present in very small quantities. Most progress in scent research, as in other areas of plant biology, has come from the use of molecular and biochemical techniques. Although volatile components have been identified in several orchid species, the biosynthetic pathways of orchid flower fragrance are far from understood. We investigated how flower fragrance was generated in certain Phalaenopsis orchids by determining the chemical components of the floral scent, identifying floral expressed-sequence-tags (ESTs), and deducing the pathways of floral scent biosynthesis in Phalaneopsis bellina by bioinformatics analysis.RESULTS:The main chemical components in the P. bellina flower were shown by gas chromatography-mass spectrometry to be monoterpenoids, benzenoids and phenylpropanoids. The set of floral scent producing enzymes in the biosynthetic pathway from glyceraldehyde-3-phosphate (G3P) to geraniol and linalool were recognized through data mining of the P. bellina floral EST database (dbEST). Transcripts preferentially expressed in P. bellina were distinguished by comparing the scent floral dbEST to that of a scentless species, P. equestris, and included those encoding lipoxygenase, epimerase, diacylglycerol kinase and geranyl diphosphate synthase. In addition, EST filtering results showed that transcripts encoding signal transduction and Myb transcription factors and methyltransferase, in addition to those for scent biosynthesis, were detected by in silico hybridization of the P. bellina unigene database against those of the scentless species, rice and Arabidopsis. Altogether, we pinpointed 66% of the biosynthetic steps from G3P to geraniol, linalool and their derivatives.CONCLUSION:This systems biology program combined chemical analysis, genomics and bioinformatics to elucidate the scent biosynthesis pathway and identify the relevant genes. It integrates the forward and reverse genetic approaches to knowledge discovery by which researchers can study non-model plants.

Agrostis avenacea J. F. Gmel., Agrostis stolonifera L., Alopecurus pratensis L., and Deschampsia atropurpurea (Wahl.) Scheele were recently found at middle elevations of southern and central Taiwan, respectively. We present their descriptions, distribution map, and line-drawings.

Senecio inaequidens DC. and Sporobolus tenuissimus (Mart. ex Schrank) Kuntze were recently found in southern part of Taiwan. Senecio inaequidens occurred at middle-altitude mountain area, and Sporobolus tenuissimus was found at plain and low-altitude mountain area. The present study offered the taxonomic description, photographs and illustrations of these two species.

A newly recorded family, Phrymaceae, and species, Phryma leptostachya L., from Taiwan are described and illustrated. Phryma leptostachya was found near Chienshih Hsiang, in Hsinchu Hsien. The flowers of Phryma have unusually long hooked tips on the calyx and single-seeded fruit enclosed by the persistent calyx, which accounts for its isolated taxonomic position and recognition as an independent family, Phrymaceae. It is easily distinguished from the other related families, Scrophulariaceae, Lamiaceae, and Verbenaceae, respectively, in Taiwan.

Traditional breeding processes to genetically modify the long reproductive cycle and slow seed maturation of orchids have limits. We developed a more efficient protocol using particle bombardment to produce transgenic plants of Oncidium Sharry Baby ‘OM8’ (Orchidaceae). Pretreating protocorm-like bodies (PLBs) with 0.5 M sucrose for 2 h increased single-cell embryogenesis 3- to 4-fold; however, shoot formation was suppressed. In addition, new PLBs were regenerated from the entire sucrose-pretreated PLBs, whereas in untreated PLBs, this occurred only from the bases. Pretreated PLBs were bombarded with pSPFLP containing genes encoding a sweet pepper ferredoxin-like protein (pflp), hygromycin phosphotransferase (hpt) and β-glucuronidase (GUS) driven by the cauliflower mosaic virus 35S promoter. Pretreated PLBs showed a 14.8-fold increase in GUS expression over the untreated PLBs 40 days after bombardment. The presence of pflp and hpt transgenes in the 40 putatively stably transformed lines that produced 113 clones was confirmed by PCR analysis. Six lines (eight clones) were positive for both pflp and hpt transgenes. In addition, clones derived from these lines were either all positive or all negative for the two transgenes, which suggests homogeneity in pretreated PLBs with more single-cell embryogenesis. Thus, sucrose pretreatment enhanced the regeneration of PLBs, single-cell embryogenesis and efficiency of transformation.

In this study, we isolated and characterized the function of a GLOBOSA/PISTILLATA-like gene, PeMADS6, from a native Phalaenopsis species, P. equestris. Southern blot analysis showed PeMADS6 as a single copy in the Phalaenopsis genome. Results of the determination of temporal and spatial expression showed that PeMADS6 was expressed and thus participated in the development of the sepals, petals, labellum and column in Phalaenopsis. Further confirmation of the expression pattern of PeMADS6 was carried out with in situ hybridization. Repressed expression of PeMADS6 in the orchid ovary was found to be pollination regulated, which suggests that the gene may have an inhibitory effect on the development of the ovary or ovule. In addition, auxin acted as the candidate signal to regulate the repression of PeMADS6 expression in the ovary. Furthermore, the flowers of transgenic Arabidopsis plants ectopically overexpressing PeMADS6 showed the morphology of petaloid sepals, with a 3- to 4-fold increase in flower longevity. Concomitantly, delayed fruit maturation was also observed in the transgenic Arabidopsis, which is consistent with the inhibitory effect of PeMADS6 on the development of the ovary. Thus, as a B-function gene, PeMADS6, not only specifies floral organ identity but has functions in flower longevity and ovary development in orchids.

The variations in floral structure of Cuscuta in Taiwan were studied with special reference to C. campestris. The variations of the floral structure were described and illustrated by using light and scanning electron microscopy. The variations including the following: (1) the absence of floral organs; (2) the abnormal fusion of floral organs; (3) petaloid stamens; (4) the lack of distinctive anther lobes; (5) the unusual protrusions on ovaries; and (6) the extrusion of ovule on ovary surfaces. The variations occur in early developmental stages when the primordia of floral organ were initiated. The findings that the abnormal position of the ovule and the lateral fusion of the scale with the filament or the petal in the species of Cuscuta are first time reported here.

ActKey is an online interactive key program and database for identification of organisms. It differs from traditional dichotomous keys in providing multi-access entry points. Rather than answering questions to key couplets while following a pre-defined path, ActKey provides a wider strategy for identifying an unknown plant. The program is web-based and supports most popular internet browsers. Visitors can use interactive keys at the the www.efloras.org website as tools for identifications, and an earlier version of ActKey with over 70 interactive keys can be found at http://flora.huh.harvard.edu:8080/actkey/. Moreover, ActKey enables the taxonomist to create and edit a key online and publish it online instantly. The www.efloras.org website designed by Hong Song is used to host taxon- and specimen-based information, and ActKey is one of its many features. In this paper, we will demonstrate how to construct an ActKey for identifying Taiwan grasses using a character set of leaf anatomy. Fifteen characters were used. Pop-up windows display images illustrating the character states. Data from microscopic examination of sections of leaf blades of 176 species in five subfamilies of grasses in Taiwan are included. The constructed ActKey will be useful to identify Taiwan grasses especially when flowering material is unavailable.