Inflorescence Rachis Research Articles

Vascular development of the grapevine (Vitis vinifera L.) inflorescence rachis in response to flower number, plant growth regulators and defoliation.

The grapevine inflorescence is a determinate panicle and as buds emerge, shoot, flower and rachis development occur simultaneously. The growth and architecture of the rachis is determined by genetic and environmental factors but here we examined the role of flower and leaf number as well as hormones on its elongation and vascular development. The consequences of rachis morphology and vascular area on berry size and composition were also assessed. One week prior to anthesis, Merlot and Cabernet Sauvignon field vines were exposed to manual flower removal, exogenous plant growth regulators or pre-bloom leaf removal. Manual removal of half the flowers along the vertical axis of the inflorescence resulted in a shorter rachis in both cultivars. Conversely, inflorescences treated with gibberellic acid (GA3) and the synthetic cytokinin, 6-benzylaminopurine (BAP) resulted in a longer rachis while pre-bloom removal of all leaves on the inflorescence-bearing shoot did not alter rachis length relative to untreated inflorescences. Across the treatments, the cross-sectional areas of the conducting xylem and phloem in the rachis were positively correlated to rachis girth, flower number at anthesis, bunch berry number, bunch berry fresh mass and bunch sugar content at harvest. Conversely, average berry size and sugar content were not linked to rachis vascular area. These data indicate that the morphological and vascular development of the rachis was more responsive to flower number and plant growth regulators than to leaf removal.

Flowers regulate the growth and vascular development of the inflorescence rachis in Vitis vinifera L.

The rachis, the structural framework of the grapevine (Vitis vinifera L.) inflorescence (and subsequent bunch), consists of a main axis and one or more orders of lateral branches with the flower-bearing pedicels at their fine tips. The rachis is crucial both for support, and transport from the shoot. Earlier suggestions that the flowers per se affect normal rachis development are investigated further in this study. Different percentages (0, 25, 50, 75 or 100) of flowers were removed manually one week before anthesis on field-grown vines. Treatment effects on subsequent rachis development (curvature, vitality, anatomy, starch deposit) were assessed. Sections, both fixed and embedded, and fresh hand-cut were observed by fluorescence and bright-field optics after appropriate staining. Emphasis was on measurement of changes in cross-sectional area of secondary xylem and phloem, and on maturation of fibres and periderm. Specific defects in rachis development were dependent on the percent and location of flower removal one week prior to anthesis. The rachises curved inwards where most of the flowers were removed. When fully de-flowered, they became progressively necrotic from the laterals back to the primary axes and from the distal to the proximal end of those axes, with a concurrent disorganisation of their anatomy. A few remaining groups of flowers prevented desiccation and abscission of the rachis axes proximal to the group, but not distally. Flower removal (50%) reduced rachis elongation, while 75% removal reduced xylem and phloem area and delayed phloem fibre and periderm development. 75% flower removal did not affect starch present in the rachis during berry development. Developing flowers affect the growth and vitality of the rachis and the development of its vascular and support structures. The extent of these effects depends on the cultivar and the number and position of flowers remaining after some are removed one week before anthesis.

Natural history of the mistletoe-feeding Thereus lomalarga (Lepidoptera, Lycaenidae, Eumaeini) in Colombia.

The natural history and morphology of the immature stages of the butterfly Thereus lomalarga Robbins, Heredia & Busby are described and illustrated. The food plant is Oryctanthus alveolatus (H.B.K.) Kuijt (Loranthaceae). Chaetotaxy of the first instar is described and compared with that of three locally studied Thereus species. Larvae have four instars, and the dorsal nectary organ becomes functional in the third instar. They are facultatively tended by ants belonging to seven genera that are attracted to O. alveolatus by floral disc nectaries, honeydew producing Hemiptera, and secretory wounds produced by Hemiptera on the fleshy inflorescence rachis. The average period from egg to eclosion under lab conditions was 35.68 days. Females emerged before males. Adults of both sexes feed on nectar from the flowers of the food plant and on hemipteran secretions; adults were not observed feeding on other flowers. Campopleginae and Chalcidinae were the most important parasitoids.

Understanding taxonomic position of local endemic Agropyron deweyi (Poaceae) using morphological characters and sequences of nuclear and chloroplast DNA regions

AbstractIn this study, both morphological characters and molecular techniques were used to determine the taxonomic position of the local endemic Agropyron deweyi within the genus. Plant length, inflorescence type, flower, leaf, spike, spikelet, indumentum and lemma structures were studied as morphological characters. DNA sequences of the nuclear ribosomal DNA internal transcribed spacer region (nrDNA ITS) and four chloroplast DNA regions [trnT-trnL intergenic spacer (IGS), trnL intron, trnL-trnF IGS and matK gene] were analyzed as part of molecular investigations. The results demonstrated that no remarkable morphological differences exist among studied specimens of A. deweyi and A. cristatum complex. Based on 12 sequences of 4 Agropyron taxa produced from the current study and different numbers of sequences obtained from GenBank, our results support the conclusion that the taxonomic status of Agropyron deweyi is synonymous to that of the species A. cristatum. Sequence divergences were estimated using Kimura two-parameter model, and the phylogenetic analyses were performed using the maximum parsimony (MP) and maximum likelihood (ML) methods. No genetic variation was observed among samples of native A. deweyi and A. cristatum complex regardless of the analyzed region. Agropyron deweyi was especially very similar to A. cristatum subsp. pectinatum var. pectinatum in terms of morphological characters such as inflorescence rachis tough at maturity, spikelets with distinct gaps, indumentum glabrous, and lemma glabrous. Therefore, when all morphological and molecular results are taken into account, A. deweyi and A. cristatum subsp. pectinatum var. pectinatum should be considered as synonym.

Two new species of Disteganthus (Bromeliaceae) from Suriname and French Guiana

Two new species of Disteganthus (Bromeliaceae: Bromelioideae) are described and illustrated. Disteganthus gracieae is described to place specimens previously misidentified as Disteganthus lateralis, but that differ substantially from this species by their gradually narrowed leaf blades, slender inflorescence rachis, long-pedicellate flowers, long-connate sepals, and glabrescent ovaries. Disteganthus morii is described from recent collections in central Suriname and can be distinguished from other species in the genus by its narrow leaves and densely floccose, long flowers. Because these new additions increase the number of species of Disteganthus from two to four, an updated description of the genus, including a taxonomic key and a general overview of the geographic distribution of the species, is presented.

A new species of Allagoptera (Arecaceae) from the Cerrado of central Brazil

A new species of Allagoptera from the Cerrado of central Brazil is described. The new species is distinguished by its solitary habit, open crown, and very long inflorescence rachis conspicuously curved at maturity. The new species, A. robusta, is compared morphologically and anatomically with A. campestris and A. leucocalyx.

Cloning and expression analysis of DtpsMADS1 gene from Doritaenopsis hybrid.

Plant MADS-box genes encode a family of highly conserved transcription factors which involved in many different developmental processes,including floral formation and flowering. To elucidate the molecular mechanisms of floral development in the monocotyledonous species Doritaenopsis hybrid,we isolated cDNA of a MADS-box gene from this plant by the method of 3' and 5' rapid amplification of cDNA ends using degenerate primers designed according to the MADS-box protein family conserved region from inflorescence rachis at flowering stage. The full length cDNA of this gene is 960 bp,with a 37 bp 5' UTR,an ORF of 753 bp and 185 bp 3' UTR encoding 245 putative amino acids. Sequence and phylogenetic analysis indicated a high degree of predicted protein sequence identity with those from other species. The gene belongs to the class of AP1 / FUL-like group of MADS-box genes and was termed as DtpsMADS1(accession No. JQ065097). Real-time quantitative PCR(qRT-PCR)results showed that DtpsMADS1 had obvious expression specificity in different organs;DtpsMADS1 had higher levels of expression in root and leaf at pre-flowering stage and post-flowering stage,meanwhile had lower levels of expression at seedling stage and full-blossom stage; The expression of DtpsMADS1 in inflorescence rachis showed the same tendency as root and leaf;However,only trace expression level was detected in flower organs. The results suggested that DtpsMADS1 could be involved in regulating the flowering process,not in floral morphogenesis.

Vegetative growth and cluster development in Shiraz grapevines subjected to partial root-zone cooling.

Heterogeneity in root-zone temperature both vertically and horizontally may contribute to the uneven vegetative and reproductive growth often observed across vineyards. An experiment was designed to assess whether the warmed half of a grapevine root zone could compensate for the cooled half in terms of vegetative growth and reproductive development. We divided the root system of potted Shiraz grapevines bilaterally and applied either a cool or a warm treatment to each half from budburst to fruit set. Shoot growth and inflorescence development were monitored over the season. Simultaneous cooling and warming of parts of the root system decreased shoot elongation, leaf emergence and leaf expansion below that of plants with a fully warmed root zone, but not to the same extent as those with a fully cooled root zone. Inflorescence rachis length, flower number and berry number after fertilization were smaller only in those vines exposed to fully cooled root zones. After terminating the treatments, berry enlargement and the onset of veraison were slowed in those vines that had been exposed to complete or partial root-zone cooling. Grapevines exposed to partial root-zone cooling were thus delayed in vegetative and reproductive development, but the inhibition was greater in those plants whose entire root system had been cooled.

Salvia tonaticensis (Lamiaceae), a rare new species from Mexico

Salvia tonaticensis is described and illustrated as a new species to science. It is known from the extreme southern portion of the Estado de Mexico and northern Guerrero, Mexico. It belongs to section Polystachyae; however, unlike the species of the section hitherto known, it possesses simple, bifurcate and trifurcate multicellular hairs on the stems, abaxial leaf surface, petioles, and inflorescence rachis. The flowers are also larger than those of other species of the section, and the calyces are densely tomentose with purple or white multicellular hairs that vary from simple to dendriform. Within the section this species shows some morphological similarities to S. connivens.

Antioxidant Activity of Moringa oleifera Tissue Extracts

Moringa oleifera is an important source of antioxidants, tools in nutritional biochemistry that could be beneficial for human health; the leaves and flowers are used by the population with great nutritional importance. This work investigates the antioxidant activity of M. oleifera ethanolic (E1) and saline (E2) extracts from flowers (a), inflorescence rachis (b), seeds (c), leaf tissue (d), leaf rachis (e) and fundamental tissues of stem (f). The radical scavenging capacity (RSC) of extracts was determined using dot-blots on thin layer chromatography stained with a 0.4 mM 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) solution; spectrophotometric assays were recorded (515 nm). Antioxidant components were detected in all E1 and E2 from a, b and d. The best RSC was obtained with E1d; the antioxidants present in E2 reacted very slowly with DPPH. The chromatogram revealed by diphenylborinate-2-ethylamine methanolic solution showed that the ethanolic extract from the flowers, inflorescence rachis, fundamental tissue of stem and leaf tissue contained at least three flavonoids; the saline extract from the flowers and leaf tissue revealed at least two flavonoids. In conclusion, M. oleifera ethanolic and saline extracts contain antioxidants that support the use of the plant tissues as food sources.

Lecythidaceae Poit. in the Tupé Sustainable Development Reserve, Manaus, Brazil

Lecythidaceae is the family of the Brazil nut, and comprises about 300 species belonging to 17 genera with pantropical distributions. One hundred and twenty-two species belonging to nine genera are distributed throughout Brazil, demonstrating its greatest diversity in the Amazon rainforest where Lecythidaceae is also one of the most abundant families. It is usually difficult to collect fertile material from these trees because of their canopy heights, and species determinations using sterile material can be complex because of their morphological similarities. There have been relatively few studies of this family even though it is one of the most important groups in the Amazon region, and a detailed taxonomic treatment of the species of Lecythidaceae in the Tupe Sustainable Development Reserve was therefore the goal of the present work. Ten species were found, Allantoma lineata (Mart. ex O.Berg) Miers, Bertholletia excelsa Bonpl., Couratari tenuicarpa A.C.Sm., Lecythis poiteaui O. Berg; and six species of Eschweilera, the richest genus. The descriptions and identification keys of the species used 56 characters. The main reproductive characters useful for distinguishing the species were the pubescence of the inflorescence rachis, pedicel length and trichomes presence, floral symmetry, hood type, filament shape, stigma shape, fruit shape and size, and aril type. The most diagnostic vegetative characters were the type and color of the outer bark, inner bark color, midrib prominence, and petiole shape and pubescence.

Uma nova espécie de <i>Butia</i> (Becc.) Becc. (Arecaceae) para o Rio Grande do Sul, Brasil

Uma nova espécie de Butia (Becc.) Becc. (Arecaceae): Butia witeckii K. Soares & S. Longhi, nativa da região central do Rio Grande do Sul - Brasil é descrita e ilustrada. Espécie próxima de Butia yatay (Mart.) Becc. e Butia paraguayensis (Barb. Rodr.) L. H. Bailey, difere destas pelo tamanho e peso do fruto (3,6- 5,6x3,0-4,1 cm com 23,61-43,05 gramas); tamanho, peso e forma do endocarpo/pirênio (2,8-3,5x1,6-2,3 cm com 3,43-10,11 gramas, providos de três quinas longitudinais e formato quase sempre piramidal no lado dos poros de germinação), e pelo número de pinas (folíolos) de cada lado da raque (43-61 pinas). Difere-se da última espécie também pelo comprimento da parte expandida da bráctea peduncular (50-85 cm), pelo comprimento da raque da inflorescência (49-63 cm) e pelo porte (3,0-6,1 metros de altura).

Molecular Detection of Phytoplasma Associated with Yellow Leaf Disease in Areca Palms (Areca catechu) in India.

The arecanut palm (Areca catechu L.), Arecaceae family, is one of the most important commercial crops in the world, which yields fruits called arecanut that are used as a medicine and chewing substance (1). Yellow leaf disease (YLD) is one of the most serious diseases in areca palms in India. It reduces the yield as much as 50% over a period of 3 years immediately following disease incidence. Foliar yellowing, the most conspicuous symptom, begins from the inner whorl and spreads to the outer parts of the crown. Chlorosis is observed on almost all leaves in the whorl from edges of the leaflet to the midrib region. Stems become spongy and friable and the conducting strands are destroyed. Microscopic detection is evidence of the association of phytoplasma in YLD-affected areca palms (3). There is no evidence for molecular level detection of phytoplasma in YLD-affected palms. To prove the phytoplasma association in YLD-affected palms in India, samples (inflorescence, spindle leaf, mature leaf, and root) were collected from 15 (5 severe, 5 middle, and 5 early stage of the disease) YLD-affected areca palms and two symptomless palms at Sullia District, Karnataka. DNA was extracted from rachis of inflorescence, midrib of spindle leaf, and meristem of root samples as previously described (2). With universal primers there was no consistency in amplification. Then we used two sets of seminested primers, 1F7/7R3-1F7/7R2 and 4Fwd/3Rev-4Fwd/5Rev, which were designed to amplify the coconut root (wilt) disease (RWD) phytoplasma (2). With the seminested primers, 1F7/7R3-1F7/7R2, a 493-bp amplicon was obtained from 15 of 15 palms. With the seminested primers, 4Fwd/3Rev-4Fwd/5Rev, a 1.3-kb amplicon was seen in 11 samples and the positive control sample (sugarcane grassy shoot DNA). The amplicons were cloned and sequenced and two representative sequences were deposited in GenBank (GU552782 and HM215624). A BLAST search showed that the sequence has 99% nt identity with sugarcane white leaf phytoplasma (FM208260, 16sr XI), coconut RWD phytoplasma (GQ850122, 16sr XI), 98% nt identity with bermuda grass white leaf phytoplasma (AJ550986, 16sr XIV), and only 91% nt identity with YLD-affected areca phytoplasma reported from China (FJ998269 and FJ694685). The phylogenetic analysis revealed the clustering of YLD phytoplasma with 16s rRNA XI and 16s rRNA XIV groups. However, the YLD phytoplasma is closely related to the 16s rRNA XI group. PhytoDB-group identifier tool (http://220.227.88.253/phytodb) showed YLD phytoplasma from India belongs to the 16sr XI group. Earlier we reported the association of 16sr XI group phytoplasma with coconut RWD in India (2) and the YLD phytoplasma reported here has 99% nt identity with RWD phytoplasma. In southern India, coconut and arecanut are grown together in adjacent fields and there is a possible occurrence of the same phytoplasma in two different hosts. The current study proved the association of phytoplasma through nested PCR in YLD-affected areca palms in India and it is clustered with 16sr RNA XI group. Purushothama et al. (4) couldn't detect the phytoplasma with YLD-affected areca palms. To our knowledge, this is first report of the association of 16SrXI group phytoplasma with the arecanut YLD in India.

PRODUCCIÓN MASIVA DE Trichoderma harzianum Rifai EN DIFERENTES SUSTRATOS ORGÁNICOS

One of the substrates used to reproduce Trichoderma spp., it is the rice grain of, which has relatively high cost. With the purpose of finding an organic, economic and available substrate in the region, in the one which this fungus has a good development and a high production of viable spores, this investigation has as objectives to evaluate 15 organic substrates in the massive reproduction and viability of spores from T. harzianum, and to associate it with the nutrimental composition of the evaluated substrate. Husk tomato (flower calyx); rice (flower glumes, lemma and palea); garlic (coriaceous cataphyllary); cocoa (seed coat); sesame (fruit pericarp); peanut (fruit pericarp); coffee (fruit pericarp); bean sheath (fruit pericarp); corn cob (feminine inflorescence rachis); grains of rice, sorghum, bird seed and corn; soybean and corn stubble were evaluated. A randomized complete block design with eight replications design was used. It was quantified the number and viability percentage of the spores and it was correlated with the proximal chemical analysis. The corn cob is the best substrate as much in the production as in the spores germination of T. harzianum with 4.43 x 108 ml-1 and 99.0 % of viability. In base with the proximal chemical analysis, the mycelium development, esporulated and spores viability, T. harzianum has a good production in those organic substrates that have high humidity percentage, low content of minerals, protein and fat, and an intermediate fiber percentage.

A New Species of Dimeria (Poaceae, Panicoideae, Andropogoneae) from Goa, India

Dimeria veldkampii Kiran Raj & Sivadasan, from north Goa of the northern Western Ghats, is illustrated and described as a new species of Poaceae belonging to the subtribe Dimeriinae of the tribe Andropogoneae. The species resembles D. woodrowii Stapf, but differs mainly by its inflorescence rachises being singly or doubly circinately recurved and by the immediate shedding of the spikelets as diaspores. Comparative morphological features of the new species and D. woodrowii are described, and a dichotomous key to the constituent species of Dimeria sect. Annulares Bor is provided.

Validation of the Name Pararuellia Alata (acanthaceae)

During preparation of a treatment of Acanthaceae for the Flora of China, it was determined that Pararuellia alata H. P. Tsui from Yunnan, China, was not validly published because the herbarium in which the type is conserved was not specified. The name is herein validated with the herbarium now specified. The species can be distinguished from other Chinese Pararuellia Bremekamp by its winged inflorescence rachis.

Antioxidant activity of Catalpa bignonioides

Antioxidant activity of methanolic extracts from inflorescence rachises, corollas, calyxes, leaves, valves of capsules and hypertrophied placenta of Catalpa bignonioides by 1,1-diphenyl-2-picrylhydrazyl reduction (DPPH) and tyrosine nitration inhibition induced by peroxynitrite was tested.

<I>Sleumeria</I> (Icacinaceae): A New Genus from Northern Borneo

A new genus of Icacinaceae, Sleumeria, is described from northern Borneo. The only known species, Sleumeria auriculata, is a large woody scrambler with spirally arranged leaves with entire margins and prominent reticulation, hairs that dry a distinctive yellow-brown, and racemose or compound racemose inflorescences. The habit, leaf arrangement, and inflorescence type place Sleumeria in a group of climbing Icacinaceae near to Sarcostigma, but it is distinguished from that and other closely related genera by the combination of distinctly pedicellate flowers arranged singly or in pairs along the inflorescence rachis, swollen sagittate anther connectives, and a spherical ovary with a distinct filiform style with an unlobed stigma. Investigation of the stem anatomy confirms the relationship with Sarcostigma, especially the presence of successive cambia, but the new genus differs, amongst other anatomical characters, in lacking islands of included phloem within the xylem.

Inflorescence and bunch architecture development in Vitis vinifera L.

Inflorescence development from budburst to harvest was analysed in four cultivars of grapevine. Two cultivars with tight or compact bunches (Riesling, Chardonnay) and two with loose or open bunches (Exotic and Sultana) were selected to define differences in bunch development for future genetic analysis. A range of phenotypic characters for both inflorescence and shoot architecture were measured. Differences in the rate of rachis elongation rates were observed between tight and loose bunch cultivars commencing at the earliest stages of inflorescence development after budburst. At anthesis, five phenotypic characters showed significant differences between tight and loose cultivars: (1) total inflorescence length, (2) node number per inflorescence rachis, (3) combined length of two consecutive internodes of the rachis and (4) shoot node position at which the inflorescence was present and (5) mature tendril length. A quantitative estimate of bunch compactness was calculated at bunch maturity. Exotic and Sultana had significantly more open space than did compact bunch cultivars Riesling and Chardonnay. Comparison of flower number at anthesis and berry number at maturity indicated that the proportion of berries set was similar in all cultivars studied and, therefore, did not contribute to variability in bunch openness between cultivars. Internode length of the inflorescence rachis was the major trait responsible for inflorescence openness. Cellular studies using SEM, fluorescence microscopy and DNA content demonstrated that differences in rachis internode lengths were mostly associated with cell expansion.

Lithocarpus glaucus, a new species of Fagaceae from China

Lithocarpus glaucus (Fagaceae) is described and illustrated. L. glaucus resembles L. hancei, but can easily be distinguished by its bigger leaves, glabrous inflorescence rachis and the cupule only covering the base of the nut.