White Perianth Research Articles

Molecular mechanism of different flower color formation of Cymbidium ensifolium.

Cymbidium ensifolium is one of the national orchids in China, which has high ornamental value with changeable flower colors. To understand the formation mechanism of different flower colors of C. ensifolium, this research conducted transcriptome and metabolome analyses on four different colored sepals of C. ensifolium. Metabolome analysis detected 204 flavonoid metabolites, including 17 polyphenols, 27 anthocyanins, 75 flavones, 34 flavonols, 25 flavonoids, 18 flavanones, and 8 isoflavones. Among them, purple-red and red sepals contain a lot of anthocyanins, including cyanidin, pelargonin, and paeoniflorin, while yellow-green and white sepals have less anthocyanins detected, and their metabolites are mainly flavonols, flavanones and flavonoids. Transcriptome sequencing analysis showed that the expression levels of the anthocyanin biosynthetic enzyme genes in red and purple-red sepals were significantly higher than those in white and yellow-green sepals of C. ensifolium. The experimental results showed that CeF3'H2, CeDFR, CeANS, CeF3H and CeUFGT1 may be the key genes involved in anthocyanin production in C. ensifolium sepals, and CeMYB104 has been proved to play an important role in the flower color formation of C. ensifolium. The results of transformation showed that the CeMYB104 is involved in the synthesis of anthocyanins and can form a purple-red color in the white perianth of Phalaenopsis. These findings provide a theoretical reference to understand the formation mechanism of flower color in C. ensifolium.

Two new species of Moraea Mill. (Iridaceae: Iridoideae) from the southern African winter rainfall area

Moraea atromontana Goldblatt & J.C.Manning and M. cistiflora Goldblatt & J.C.Manning (Iridaceae: Iridoideae: Irideae) are two recently discovered species of this African and Eurasian genus of some 233 species. Both are members of subg. Vieusseuxia, and narrow endemics of the southern African winter rainfall zone in the Western Cape, South Africa. Moraea atromontana from the Swartberg near Calitzdorp, with a solitary leaf and derived, 3-lobed inner tepals, is morphologically similar to M. algoensis Goldblatt and M. unguicularis Ker Gawl. but differs in its larger, white flowers with a distinctive dark blue streak on the tepal claws, inner tepal limbs with a laxly spreading central cusp and short, downcurved lateral lobes, and much longer filament column; and M. cistiflora from the middle slopes of the Waaihoek Mtns near Wolseley, stands out in the section in its bowl-shaped flowers with subequal inner and outer tepals, white perianth with dark central eye, relatively long filament column with broad, spreading style branches and crests, and long capsules.

<p><strong><em>Tupistra nganii </em></strong><strong>(</strong><strong>Asparagaceae</strong><strong>)</strong><strong>, a new species with greenish yellow flowers from northern Vietnam</strong><strong> and southwestern China</strong><strong></strong></p>

Tupistra nganii is described and illustrated as a new species from Ha Giang Province in northern Vietnam and Yunnan Province in southwestern China. The new species is most similar to T. muricata from Thailand and Laos, from which it differs by the greenish white or yellow perianth and longer exserted stamens. Additionally, Tupistra longispica is reinstated on the basis of new morphological evidences.

Identification of Genes Involved in Flavonoid Biosynthesis of Chinese Narcissus (Narcissus tazetta L. var. chinensis)

Chinese narcissus (Narcissus tazetta L. var. chinensis Roem.) is a popular flower in Asia. However, flower colors are limited with all cultivars having a white perianth and yellow corona. Previous studies have shown no anthocyanin accumulation in this species. The reason for an absence of anthocyanins remains unknown, with the flavonoid biosynthetic pathway in this flower recently being investigated. In this study, a transcriptomic approach combined with gene expression and biochemical analysis was used to predict and annotate genes in the flavonoid biosynthetic pathway. Results showed that the major flavonoid metabolites are flavonols and proanthocyanidins. Proanthocyanidin biosynthesis is exclusively catechin-based, with the gene encoding leucoanthocyanidin reductase (LAR) being well expressed. We identified 16 unigenes encoding key enzymes involved in flavonoid biosynthesis. Flavonol synthase (FLS) and dihydroflavonol reductase (DFR) appear to play important roles in regulating proanthocyanidin and flavonol levels, while anthocyanidin synthase (ANS) expression is not detected. Our results suggest that the absence of anthocyanins in Chinese narcissus is due to high expression of LAR and FLS, and a lack of ANS expression.

Zephyranthes pseudoconcolor(Amaryllidaceae: Amaryllidoideae), a New Species from Mexico, and Clarification ofZ. concolor

The new species Zephyranthes pseudoconcolor Flagg, G. Lom. Sm. & Garcia-Mend. is described from Guanajuato, San Luis Potosi, and Tamaulipas, and figures are included. This species has affinities with Z. concolor (Lindl.) S. Wats. (authorial attribution of that combination, formerly incorrectly attributed to Benth. & Hook. f., is corrected in this paper) but is distinguished by having a smaller, pale lemon-yellow flower (inside and outside) basally increasingly lime with a lime-green perianth tube, shorter stigmatic lobes, and pedicel length greater than perianth length. For most of its taxonomic history, Z. pseudoconcolor has been identified as Habranthus concolor Lindl. or Z. concolor, resulting in H. concolor being redescribed as H. immaculatus Traub & Clint (with white perianth limbs inside and out). The new species and Z. concolor have been treated as distinct species for 60 years but with misapplied specific nomenclature.

Persicaria changhuaensis sp. nov. (Polygonaceae) from northwestern Zhejiang, China

Persicaria changhuaensis sp. nov., belonging to P. sect. Echinocaulon (Polygonaceae), from Zhejiang, eastern China, is described and illustrated. The new species is morphologically similar to P. senticosa (Meisn.) H. Gross ex Nakai and P. sagittata (L.) H. Gross ex Nakai var. sieboldii (Meisn.) Nakai, but differs from the former in having an ocrea without a reniform‐orbicular wing at apex, pubescent peduncle, triangular bracteoles, white perianth, and stamens exserted from the perianth. Compared to P. sagittata var. sieboldii, it differs in having the leaf blade triangular‐hastate, sparsely retrorsely‐prickled on abaxial veins, sparsely ciliate at the margin, pubescent peduncle, triangular bracteoles, and stamens exserted from the perianth.

Review of species limits in Geissorhiza leipoldtii (Iridaceae: Crocoideae) and G. heterostyla with the recognition of new taxa plus important new records in the genus

Field research and herbarium study in the genus Geissorhiza (Iridaceae) has led us to revise the taxonomy of some species. Geissorhiza leipoldtii was previously more widely circumscribed to include G. ixioides as synonym as well as collections that we recognize here as the new species G. nutans. Typical G. leipoldtii has upright to half nodding flowers with a pure white perianth and ascending stamens with longer anthers and usually equal filaments. Geissorhiza ixioides, last collected in 1897 and not again until now, differs in its mauve or pink flowers with a dark centre, short stamens, and short style dividing opposite the middle of the anthers. Geissorhiza nutans stands out in its smaller, nodding flowers with translucent white to pale mauve or pale pink perianth and unilateral, horizontal to drooping stamens with markedly unequal filaments, the upper one half as long as the lower two. We recognize two subspecies in G. heterostyla: subsp. heterostyla with a pubescent stem and nodding, usually blue to violet flowers; and subsp. rosea with a smooth stem and upright to half nodding, white, pale blue or pale mauve flowers. Geissorhiza now includes 102 species, all from the winter rainfall zone of southern Africa. In addition, we document significant range extensions in G. aspera and G. karooica, and report important new records for the critically endangered G. Geissorhiza malmesburiensis. These findings broaden our understanding of the diversity of Geissorhiza and assist in conservation assessments of the species.

Pendulorchis gaoligongensevar.lushuiensis(Orchidaceae, Vandeae), a New Variety from Yunnan, China

Pendulorchis gaoligongense G. Q. Zhang, K. Wei Liu & Z. J. Liu var. lushuiensis L. J. Chen, X. C. Shi & W. H. Rao (Orchidaceae, Vandeae) is described and illustrated as a new variety from Yunnan, China. It differs from the typical variety, P. gaoligongense, by having shorter leaves that are 30–40 cm, smaller flowers that are 4–5 mm diameter, and a reddish white perianth (vs. leaves 40–60 cm, flowers 8–9 mm diameter, and a purple-red perianth).

Aspidistra xuansonensis (Asparagaceae), a new species from northern Vietnam

The genus Aspidistra is the most diverse in southern China and northern Vietnam. We describe a new species Aspidistra xuansonensis from northern Vietnam including two varieties: A. xuansonensis var. xuansonensis with greenish white perianth and A. xuansonensis var. violiflora with purple perianth. We present DNA barcoding data of plastid psbA-trnH and nuclear 5SNTS regions for these two varieties in comparison with three other species of Aspidistra. Morphology of monopodial shoots of A. xuansonensis is described in detail. A. xuansonensis resembles recently described A. lingyunensis but differs in longer leaf petioles, longer lamina, perianth tube shape (tubular, widened at the base vs. funnel-shaped), higher anther position, and pistil shape (suddenly obconic to nearly umbrella-shaped vs. obconic gradually widened to stigma).

Aspidistra lingyunensis sp. nov. (Asparagaceae) from limestone areas in Guangxi, China

Aspidistra lingyunensis C. R. Lin & L. F. Guo (Asparagaceae) is described and illustrated as a new species from limestone areas in northwestern Guangxi, China. It resembles A. obconica C. R. Lin & Yan Liu in leaf size and its obconical and purplish red pistil, but differs by having a yellowish white perianth, with lobes oblong, explanate, 6–7 mm long, subequal to tube and a white stigma surface, ca 3 mm in diameter. The new species is rare, currently known only from northwestern Guangxi.

New taxa of <i>Hesperantha</i> (Iridaceae: Crocoideae) from the southern African winter rainfall region and a review of the <i>H. pilosa</i> complex

The southern and tropical Africa genus Hesperantha Ker Gawl., now with 85 species, is distinguished in subfam. Crocoideae by the style dividing into relatively long, usually laxly spreading style branches at or shortly below the mouth of the perianth tube (rarely well within the tube or above the mouth of the tube) and, with a few exceptions, by hard, woody corm tunics. We describe three new species here. H. dolomitica Goldblatt J.C.Manning, a narrow endemic of limestone outcrops on slopes north of the Vars River in the Knersvlakte, Western Cape, has the bell-shaped corms characteristic of the small sect. Hesperantha but is distinctive in the section in its pure white perianth with relatively long tube and soft-textured, falcate to distally trailing leaves. H. laxifolia Goldblatt J.C.Manning from the Pakhuis Mtns, Western Cape, stands out in sect. Hesperantha in its prostate, somewhat succulent foliage leaves, and spikes of 2–5 white flowers with unusually short filaments less than 1 mm long and particularly short anthers, ± 4 mm long. The short style branches, ± 4 mm long, remain suberect rather than laxly spreading. H. secunda Goldblatt J.C.Manning from the Roggeveld Escarpment, Northern Cape, has until now been included in H. pilosa but differs in its secund spike of nodding flowers with short style branches, and leaves with broadly winged margins. We also recognize a new subsp. bracteolata (R.C.Foster) Goldblatt J.C.Manning of H. pilosa (L.f.) Ker Gawl. for populations of plants with diurnal flowers with usually blue or purple (occasionally white) tepals lacking dark pigmentation on the reverse. With additional material to hand, we reduce blue-flowered H. ciliolata Goldblatt to synonymy in subsp. bracteolata and report range extensions for H. pilosa subsp. pilosa, now recorded as far east as the Langeberg near Cloete’s Pass.

Flavonoids in white and yellow perianths and yellow anthers of tulips (Tulipa gesneriana L.)

The content of flavonoids in white and yellow perianths and yellow anthers of a few tulip cultivars were determined at the stage of full flowering. To analyses of flavonols a HPLC method was used. In anthers (yellow) of all analyzed cultivars (Oscar, Pax, Profesor Wóycicki, Biała Dama, White Virgin, Calypso, Diana) high content of quercetin (2,35 - 6,01 mg·g<sup>-1</sup> F.W.), kaempferol (1,09 - 9,47 mg·g<sup>-1</sup> F.W.) and apigenin (1,34 - 8,24 mg·g<sup>-1</sup> F.W.) was found. In analyzed white perianth of cvs. Oscar and White Virgin also high content of quercetin (1,3 - 1,80 mg·g<sup>-1</sup> F.W.) and kaempferol (1,90 mg·g<sup>-1</sup> F.W.) was documented and only traces of apigenin was found. In the yellow perianth of cv. Profesor Wóycicki the level of quercetin and kaempferol was much lower than in perianth of cvs. Oscar and White Virgin, and apigenin was absent. Thus, yellow anthers and white and yellow perianth of tulip cultivars are a rich source of flavonols.

<p><strong>The "lady in white", a showy new species of <em>Cryptocentrum</em> (Orchidaceae, Maxillariinae) from Colombia</strong></p>

Cryptocentrum misasii P.Ortiz & Carnevali is described and illustrated. This distinctive, showy new species has been collected only once in western Colombia at Cerro Mecana, Serrania del Baudo (Choco), at 800–1000 m elevation. Cryptocentrum misasii is easily distinguished from all other species of Cryptocentrum by its large white flowers. On morphological grounds, it is referable to subgenus Cryptocentrum due to its monopodial habit, distichous leaves, and ovary plus spur totally enclosed by the floral bract. Within subgenus Cryptocentrum , C. misasii is most similar to C. dodsonii , from which it is amply distinct by its large flowers with sepals of up to 24.5 mm (vs. 9.5–16.0 mm in C. dodsonii ) and white perianth segments (vs. bright yellow to yellow or yellow-green in C. dodsonii ). Identifications are provided for the Cryptocentrum species featured in Dr. Misas-Urreta's book on the orchids of the Serrania del Baudo. The conservation status of the species was assessed as Critically Endangered (D) by the IUCN criteria.

Crocus jablanicensis(Iridaceae), a New Species from the Republic of Macedonia, Balkan Peninsula

Crocus jablanicensis N. Randj. & V. Randj. sp. nova (Iridaceaeis described from the Balkan Peninsula. It is found on Mt. Jablanica in the western part of Macedonia, where it grows in alpine grasslands around snowmelts. It is compared with the morphologically similar C. cvijicii and C. veluchensis. In contrast to these species, C. jablanicensis has white styles and stigmas and a glabrous, white perianth throat.

Endogenous Auxin Profile in the Christmas Rose (Helleborus niger L.) Flower and Fruit: Free and Amide Conjugated IAA

The reproductive development of the Christmas rose (Helleborus niger L.) is characterized by an uncommon feature in the world of flowering plants: after fertilization the white perianth becomes green and photosynthetically active and persists during fruit development. In the flowers in which fertilization was prevented by emasculation (unfertilized) or entire reproductive organs were removed (depistillated), the elongation of the peduncle was reduced by 20–30%, and vascular development, particularly lignin deposition in sclerenchyma, was arrested. Chlorophyll accumulation in sepals and their photosynthetic efficacy were up to 80% lower in comparison to fertilized flowers. Endogenous auxins were investigated in floral and fruit tissues and their potential roles in these processes are discussed. Analytical data of free indole-3-acetic acid, indole-3-ethanol (IEt), and seven amino acid conjugates were afforded by LC-MS/MS in floral tissues of fertilized as well as unfertilized and depistillated flowers. Among amino acid conjugates, novel ones with Val, Gly, and Phe were identified and quantified in the anthers, and in the fruit during development. Reproductive organs before fertilization followed by developing fruit at post-anthesis were the main source of auxin. Tissues of unfertilized and depistillated flowers accumulated significantly lower levels of auxin. Upon depistillation, auxin content in the peduncle and sepal was decreased to 4 and 45%, respectively, in comparison to fruit-bearing flowers. This study suggests that auxin arising in developing fruit may participate, in part, in the coordination of the Christmas rose peduncle elongation and its vascular development.

Downregulation of putative UDP-glucose: flavonoid 3-O-glucosyltransferase gene alters flower coloring in Phalaenopsis

Anthocyanin is the primary pigment contributing to red, violet, and blue flower color formation. The solubility of anthocyanins is enhanced by UDP glucose: flavonoid 3-O-glucosyltransferase (UFGT) through transfer of the glucosyl moiety from UDP-glucose to 3-hydroxyl group to produce the first stable pigments. To assess the possibility that UFGT is involved in the flower color formation in Phalaenopsis, the transcriptional activities of PeUFGT3, and other flower color-related genes in developing red or white flower buds were examined using RT-PCR analysis. In contrast with chalcone synthase, chalcone isomerase, and anthocyanidin synthase genes, PeUFGT3 transcriptional activity was higher expressed in the red color of Phalaenopsis cultivars. In the red labellum of Phalaenopsis 'Luchia Lady', PeUFGT3 also showed higher expression levels than that in the white perianth. PeUFGT3 was predominantly expressed in the red region of flower among various Phalaenopsis cultivars. To investigate the role of PeUFGT3 in red flower color formation, PeUFGT3 was specifically knocked down using RNA interference technology via virus inducing gene silencing in Phalaenopsis. The PeUFGT3-suppressed Phalaenopsis exhibited various levels of flower color fading that was well correlated with the extent of reduced level of PeUFGT3 transcriptional activity. Furthermore, there was a significant decrease in anthocyanin content in the PeUFGT3-suppressed Phalaenopsis flowers. The decrease of anthocyanin content due to PeUFGT3 gene silencing possibly caused the faded flower color in PeUFGT3-suppressed Phalaenopsis. Consequently, these results suggested that the glycosylation-related gene PeUFGT3 plays a critical role in red color formation in Phalaenopsis.

Why sexually deceptive orchids have colored flowers

Sexually deceptive orchids provide no reward to their pollinators. Instead, they mimic the sex pheromone of receptive insect females to attract males which pollinate the flowers in mating attempts. Nearly all species of the Mediterranean orchid genus Ophrys are sexually deceptive and pollinated by solitary bees and wasps. Due to the use of a highly specific olfactory communication channel most Ophrys species have, in contrast to food deceptive or rewarding orchids, an inconspicuous greenish perianth and a dark brownish labellum. However, some species possess a bright pink or white perianth, and the functional significant of such colour signals in the orchid-pollinator communication system is unknown. We recently showed that the pink perianth of Ophrys heldreichii increases the performance of its bee pollinator, males of the long-horned bee Eucera (Tetralonia) berlandi, to detect the flower at short-range. At great distances (>30cm) from the flower, male search behavior was found to be olfactory guided and unaffected by the spectral property of the perianth, i.e. chromatic and green receptor-specific contrast. However, in the near vicinity of the flower (<30cm), where spatial vision is sufficient to detect the flower, search time only correlated with the green receptor-specific contrast between the perianth and the background.

New Taxa and Revisions to the Taxonomy of Southern African Lapeirousia Subgenus Lapeirousia (Iridaceae Subfamily Ixioideae)

Studies of the pollination biology of the southern African species of Lapeirousia subg. Lapeirousia have indicated the need for several taxonomic changes in the alliance. Lapeirousia simulans is a new species, until now confused with L. arenicola, a fairly widespread species of the Cape west coast: L. simulans occurs sympatrically with L. arenicola, but subtle differences in flower patterning, capsule and seed morphology, and bract size separate the two. New evidence indicates that varieties spinosa and tenuis of L. divaricata should both be treated as separate species, and they are recognized here as L. spinosa and L. tenuis. The former is an allopatric vicariant of L. divaricata, differing in its compact growth form and larger flowers. Lapeirousia tenuis, however, appears to be more closely related to L. dolomitica, from which it differs in flower size, tepal color, and length of the perianth tube. Examination of living plants matching the type of L. macrospatha indicates that the species was incorrectly treated as conspecific with L. barklyi. The two differ consistently in flower color and markings, the length of the perianth tube, and the shape of the floral bracts, and are most likely not immediately related. Lastly, populations of the widespread L. pyramidalis with a dark blue, purple, or red perianth, a longer perianth tube, and odorless flowers are segregated here as subspecies regalis. Subspecies regalis is most likely adapted to a different pollinator than subspecies pyramidalis, which has a pale blue, pink, or white perianth, a shorter perianth tube, and a strong floral odor. The tropical and southern African genus Lapeirousia Pourret comprises some 40 species currently segregated in two subgenera (Goldblatt & Manning, 1990, 1992). Subgenus Lapeirousia, with 21 species, is centered in the coastal and near interior parts of southwestern Africa but includes two tropical African species (Goldblatt, 1990). Subgenus Paniculata Goldblatt & Manning, with 19 species, comprises the largely tropical African section Paniculata (14 species), with one species in the southwestern part of southern Africa, and section Fastigiata Goldblatt (5 species), restricted to the southwestern Cape region of South Africa (Goldblatt & Manning, 1992). Field studies of the pollination biology of subgenus Lapeirousia, conducted over the past two years, have yielded new information about the genus and indicated the need for substantial taxonomic revision. Sixteen southern African species were included in subgenus Lapeirousia by Goldblatt (1972), who then treated it as section Lapeirousia. One cryptic species, included in L. arenicola Schlechter, is now understood to be a distinct species, here described as L. simulans. Lapeirousia divaricata N. E. Brown, treated by Goldblatt (1972) as comprising three varieties, is now reconstituted. Variety spinosa Goldblatt, raised to species rank as L. spinosa, differs consistently from L. divaricata in its ecology and morphology and merits separate species status. Variety tenuis Goldblatt, now L. tenuis, appears to be more closely related to L. dolomitica Dinter than to L. divaricata. It has broadly conic corms with spiny margins identical to those of L. dolomitica a d can be distinguished from this species largely by its short-tubed flower with narrow tepals and noninflated floral bracts. In the widespread Lapeirousia pyramidalis (Lamarck) Goldblatt, patterns of floral variation suggest the need for the recognition of two subspecies. Typical subspecies pyramidalis has strongly scented white, pale blue, or pale pink flowers with a perianth tube of intermediate length. What we recognize here as subspecies regalis is restricted to the northwestern Cape and has darkly pigmented, red, purple, or v olet flowers with a long perianth tube and no scent. Lastly, it is now apparent that L. barklyi Baker and L. macrospatha Baker were incorrectly united by NOVON 4: 339-346. 1994. This content downloaded from 207.46.13.131 on Sat, 15 Oct 2016 04:26:09 UTC All use subject to http://about.jstor.org/terms

Geographic variability of flower colour inCrocus scepusiensis (Iridaceae)

The distribution of four variants for flower colour ofCrocus scepusiensis in the northern part of the Western Carpathians is described. The frequency of white stigmata morphs declines from east to west. In the center of the area stigmata colour morphs show strikingly patchy distribution. White perianth morphs usually occur at low frequencies and their distribution with minor exceptions is restricted to the central part of the area, where patchy distribution of the morphs is a rule. These distribution patterns suggest that the founder effect has played a major role in determining the genetic composition of individual populations. The cline for stigmata colour may also be explained by the dynamics of population expansion. No influence of selection can be demonstrated, but the association between perianth and stigmata colour, and the excessively low frequency of white perianth morphs may imply that the polymorphisms are not selectively neutral.