Growth Habit Characteristics Research Articles

Species, clover‐inclusion, and nitrogen fertilizer effects on sod tensile strength of fine fescue taxa

AbstractIncreasing fertilization rates from 0 to 49 kg N ha−1 during establishment of fine fescue (Festuca spp.) taxa can promote faster grow‐in; however, the influence on sod production (tensile strength and handling) is unknown. More information is needed on both fine fescue taxa and the effects N fertilizer or inclusion of clover (Trifolium spp.) during establishment on sod strength. Field experiments were repeated in 2019–2020 and 2020–2021 in Indiana to quantify differences among four fine fescue taxa and N fertilizer or clover‐inclusion effects on sod production. Six N fertilizer levels ranged from 0 to 122.5 kg N ha−1 during the first 8 weeks after planting (WAP), and two treatments consisted of inclusion of either annual or perennial clover + 0 kg N ha−1 at seeding. Sod harvest variables were measured at harvests from 9 to 12 months after planting (MAP). Results indicate fine fescue growth habit characteristics play a large role in sod strength differences. The highest to lowest sod strength and handling was ranked as follows: strong creeping red fescue (F. rubra L. ssp. rubra Gaudin) > slender creeping red fescue [F. rubra ssp. littoralis (G. Mey.) Auquier] ≥ Chewings fescue (F. rubra ssp. commutata Gaudin) ≥ hard fescue (F. brevipila Tracey). A minimal effect on sod strength and handling at multiple sod harvests (9–12 MAP) was observed from increasing N fertilizer levels during first 8 wk of establishment or from clover inclusion.

The last phylum: Occupation of Bryozoa morpho-ecospace (colony growth habits) during the early phase of the Great Ordovician Biodiversification Event

Most major phyla, and all skeletonized phyla have their first appearance in the Cambrian. The exception is the Phylum Bryozoa, which first appear in the Early Ordovician (Tremadocian 1b). Bryozoans have an excellent fossil record, due in part to their benthic marine habitat with skeletal colonies composed largely of stable, low-Magnesium calcite. These factors provide an unrivaled opportunity to observe patterns and rates of radiation of a new phylum into disparate morpho- ecospace through the Great Ordovician Biodiversification Event (GOBE).In this study, the colonial growth habits of all known skeletonized Bryozoa (181 species) from the Early and Middle Ordovician are characterized in a new classification scheme based on processes of growth, rather than their end geometry as most traditional classifications of bryozoan growth habits. These fundamental categories are: orientation, dimensions of primary growth, width of colony unit, layers of zooecia, substrate relationships, space utilization, skeleton mineralization, plus sub-categories of orientation based on their geometry.In the Early and Middle Ordovician there are 85 unique growth habits defined by these eight growth habit characters. By the end of Middle Ordovician, about 4.8% of the morpho-ecospace defined by two subsets of the characters had been occupied by five bryozoan orders (represented by 34 families, 77 genera). When plotted by Ordovician stage time-slices (ca. 2.2 my each), a sharp increase in taxonomic and growth habit occurrence is observed at the Early-Middle Ordovician transition, earlier than in other groups. Individual growth habit character states also show significant changes at this transition. In the Early Ordovician, low bryozoan taxonomic and growth habit richness is due in part to sampling bias and modified search methods are need, however, the overall patterns (Early-Mid. Ordovician transition) observed in this study are robust and not expected to change fundamentally with additional data.

Natural variation in GmGBP1 promoter affects photoperiod control of flowering time and maturity in soybean.

The present study screened for polymorphisms in coding and non-coding regions of the GmGBP1 gene in 278 soybean accessions with variable maturity and growth habit characteristics under natural field conditions in three different latitudes in China. The results showed that the promoter region was highly diversified compared with the coding sequence of GmGBP1. Five polymorphisms and four haplotypes were closely related to soybean flowering time and maturity through association and linkage disequilibrium analyses. Varieties with the polymorphisms SNP_-796G, SNP_-770G, SNP_-307T, InDel_-242normal, SNP_353A, or haplotypes Hap-3 and Hap-4 showed earlier flowering time and maturity in different environments. The shorter growth period might be largely due to higher GmGBP1 expression levels in soybean that were caused by the TCT-motif with SNP_-796G in the promoter. In contrast, the lower expression level of GmGBP1 in soybean caused by RNAi interference of GmGBP1 resulted in a longer growth period under different day lengths. Furthermore, the gene interference of GmGBP1 also caused a reduction in photoperiod response sensitivity (PRS) before flowering in soybean. RNA-seq analysis on GmGBP1 underexpression in soybean showed that 94 and 30 predicted genes were significantly upregulated and downregulated, respectively. Of these, the diurnal photoperiod-specific expression pattern of three significant flowering time genes GmFT2a, GmFT5a, and GmFULc also showed constantly lower mRNA levels in GmGBP1-i soybean than in wild type, especially under short day conditions. Together, the results showed that GmGBP1 functioned as a positive regulator upstream of GmFT2a and GmFT5a to activate the expression of GmFULc to promote flowering on short days.

Caracterización morfo-agronómica de poblaciones de zapallo criollo (cucurbita maxima Duch.) colectadas en los valles andinos de la Argentina

En los valles andinos de la Argentina las familias producen hortalizas en forma tradicional principalmente para el autoconsumo. El zapallo (Cucurbita maxima) es un cultivo americano de gran importancia en las economías regionales andinas. Estas poblaciones criollas de zapallos se están perdiendo por el éxodo rural, la sustitución de semilla criolla por semilla comercial y las sequías frecuentes. Constituyen reservorios de genes de interés para el mejoramiento y para garantizar la seguridad alimentaria local, por lo que su conservación y caracterización son fundamentales para evitar la erosión genética. Durante 2005 se realizaron colectas en Valle Fértil, provincia de San Juan y en el noroeste argentino; se colectaron 61 poblaciones, de las cuales 27 se seleccionaron y evaluaron durante dos años en la EEA La Consulta INTA, Mendoza. Se midieron 49 caracteres de planta, flor, fruto y semilla, bajo un diseño experimental completamente aleatorizado y tres repeticiones por población. Los cultivares comerciales Marino FCA y Veronés INTA se emplearon como testigos. Las poblaciones se agruparon por caracteres de fruto, hábito de crecimiento y semilla, observándose gran diversidad morfológica entre y dentro de cada población. El trabajo permitió seleccionar materiales con caracteres de interés para el mejoramiento de la especie.

Dwarf olive trees for ornamental use: a morphological evaluation

SummaryOlive (Olea europaea L.) has played a important role in human civilisation and has been central to the development of culture and food. The use of olive trees as ornamental plants has been recorded since ancient times. However, among perennial species olive is rarely recommended for decorative purposes due to its dimensions and large canopy size, which limit its use alongside roadways, for example. A dwarf olive derived by tissue culture methods was characterised morphometrically for its potential use as an ornamental tree. The morphological characters measured in dwarf and micropropagated control plants of the olive cultivar ‘Frangivento’, were subjected to univariate (i.e., analysis of variance) and multivariate (i.e., principal components analysis) analyses. Compared to control plants, the dwarf plants showed reduced tree height, reduced dimensions of leaves and inflorescences, and the presence of many prompt shoots (i.e., those that originated from buds that differentiated in the same year that they were formed). All these morphological characters contributed to the architecture of the dwarf plant, and were related to the regular “rounding-off” of the canopy. The aesthetic, ecological, and growth-habit characteristics of those biotechnologicallyproduced dwarf olive trees support their use as an ornamental plant.

'Florida Whitewater'—A White Lance-leaved Caladium for Small Pots, Hanging Baskets, or Sunny Landscapes

Received for publication 14 May 2001. Accepted for publication 21 Sept. 2001. This research was supported by the Florida Agricultural Experiment Station and grants from the Gloeckner Foundation and the Florida Caladium Growers Association, and approved for publication as Journal Series R-08379. Caladiums [Caladium bicolor (Ait.) Vent., syn. Caladium ×hortulanum Birdsey] grown for their colorful foliage are members of the aroid family (Araceae Juss.) native to tropical America (Croat, 1979). Although their native habitat largely consists of dense, moist forests with heavy shade, many of the ≈90 cultivars grown today retain their bright color in full sun (Bell and Wilfret, 1998). Demand for caladiums is increasing because of their great diversity in leaf color and shape, adaptability to various light conditions, and relatively low maintenance requirements (Harbaugh and Tjia, 1985). As much as 90% of the caladium tubers produced are used by the container plant industry primarily in 10and 15-cm containers (D. Bates, personal communication). Many popular cultivars require excision of dominant buds (de-eyeing) on the tuber in order to produce an attractive container-grown plant. Bud excision eliminates apical dominance resulting in greater leaf production and reduced plant height (Evans et al., 1992), but is a costly, labor-intensive procedure. ‘Florida Whitewater’ (Fig. 1) is a highly compact plant producing numerous, uniquely narrow, lanceolate leaves without requiring bud excision. Excellent sun tolerance enhances its potential usage in the landscape as a border or in combination with caladium cultivars with differing foliar and growth habit characteristics.

Sophora (Fabaceae) in New Zealand: Taxonomy, distribution, and biogeography

A taxonomic treatment is provided for the Sophora microphylla complex in New Zealand. Sophora microphyllu sens. str. is endemic to New Zealand, and includes those plants with a distinct divaricating and/or strongly flexuose juvenile Phase, orange‐brown to Yellow‐brown Juvenile stems, and distant leaflets. S. chathamica is reinstated at species rank, S.fulvida is a new combination provided for the taxon previously known as S. microphylla Var. fulvida, and S. godleyi and S. molloyi are described as new species. S. chathamica, S. fulvida, S. godleyi and S. molloyi lack a divaricating and/or strongly flexuose juvenile phase and are each distinguished by a number of leaf characters. S. fulvida and S. godleyi have distinctive leaf hairs. S. chathamica is a predominantly coastal species in Northland, Auckland, Waikato, Wellington, and the Chatham Islands, S.fulvida occurs in Northland and North Auckland on volcanic rock outcrops S. godleyi Occurs on calcareous mudstone and sandstone in eastem Taranaki King country, Wanganui and Manawatu, and S. molloyi is restricted to extremely dry and exposed bluffs and rock outcrops of southern North Island headlands, Kapiti Island, and several islands in Cook Strait. Cluster analyses of 11 leaf and 4 growth habit characters provide additional support for the revised classification, and variation in 7 leaf characters is evaluated with box plots. A key is provided to Sophora in New Zealand, hybridism is discussed, an assessment of each species’ conservation status is made, and biogeography is reconsidered in view of the new taxonomic treatment.

Morphological evaluation of olive germplasm present in Tuscany region

This work was done to quantify, evaluate and preserve the genetic variation of the olive (Olea europaea L.) from Tuscany and to look for ready-to-use valuable characters. Principal component analysis (PCA) was used to compare fruit, pit, leaf and growth habit characteristics among 83 accessions. Clustering of cultivars would suggest the existence of a strictly related genetic base with little morphological differences. Numerical analysis of phenotypical characters enabled to discriminate among accessions and to reduce the number of cultivars for further studies. It can be used as a rapid method to classify and compare phenotypes within large olive collections. The collected germplasm can be a useful sources of variability for those attributes not traditionally accounted for in olive plant selection. Several late-ripening cultivars, interesting for oil-quality; two cultivars with suited for low-pruning cultivation growth habit as well as four accessions with peculiar leaves, employable as ornamental, were identified. Furthermore, some cultivar with different initial growth potential, susceptible to be used for wood production or high density plantation, were catalogued. Data and photographs of most of the accessions here described were transferred to Internet where are available for consultation at the address http: //www.area.fi.cnr.it/olivo/olivit.htm

Bryozoan growth habits: Classification and analysis

Bryozoans are an important part of the benthic marine fauna in a wide variety of modern environments and are found in rock forming abundance in a number of settings throughout much of the Phanerozoic. Bryozoologists and nonspecialists have grouped taxa into colonial growth forms (e.g., erect fenestrates or encrusting sheets), both to simplify analyses and because correlations exist between some colony growth forms and the environmental conditions in which the organism lived. These correlations allow for the possibility of paleoenvironmental analyses based on skeletons alone. Existing bryozoan colonial growth form classifications do not, however, fully exploit the ecological information present in colony form.A new scheme is proposed here (Analytical Bryozoan Growth Habit Classification), which provides a list of colony-level morphological characteristics for bryozoan growth habits. This differs from previous approaches to bryozoan growth form analysis in that it is a classification of growth habit characteristics rather than a classification of morphological groups as such. The classification is based on eleven character classes, which describe the orientation of the colony and its occupation of, and placement in space. The overall colony shape is described based on the arrangement of modules in colonial growth. This classification provides a common ground for systematic comparison of character states among varied bryozoan growth habits. This approach allows for the evaluation of correlations among observed morphological character states and specific environmental conditions in which they develop. In addition, these growth habit characters can be used to recognize, characterize, evaluate, and apply more traditional growth form groups in broader studies.

Morphological variation within collections of Moroccan almond clones and Mediterranean and North American cultivars

Cultivated almonds (Prunus dulcis (Miller) D.A. Webb) in Morocco are still propagated from seeds by farmers to overcome transplant failure of grafted trees. Almond collections in southern Morocco conducted since 1975 have resulted in the selection of clones planted at 3 experimental stations. Principal component analysis (PCA) was used to compare kernel, nut, leaf, and growth habit characteristics among 67 selected Moroccan clones and 14 introduced cultivars. Clustering of clones from similar countries and collection areas would suggest the existence of different almond populations. The Moroccan clones did not cluster separately from the foreign cultivars. Three Moroccan clones had exceptionally large nuts and kernels while 7 selections had high yield potential due to high spur density. Moroccan selections tended to be characterized by small leaves in comparison to foreign cultivars. No evidence was found to suggest the existence of separate populations within the Moroccan almond germplasm.

Somaclonal variation in soybean plants regenerated from tissue culture

Callus cultures of soybean (Glycine max (L.) Merr.) genotypes PI 88788, PI 438489B, and cultivar Bedford were initiated in vitro from seedling explants consisting of the cotyledonary node plus epicotyl from germinated mature seed. Plants were regenerated from these callus cultures and subsequently evaluated for qualitative variation in three to four subsequent generations. Variant phenotypes observed that have not been previously reported from tissue culture include lanceolate leaves, leaf variegation (chimeral variegated plants), pod variegation on otherwise normal plants, and change in growth habit from indeterminate to determinate. The lanceolate leaf, chimeral variegated plant, and change from indeterminate to determinate growth habit characters were inherited through at least three generations (R0-R2), and segregation occurred in each generation. Pod variegation was inherited through the two generations tested thus far and segregation occurred in each generation. No variation was observed in control plants derived from normal seed. Variants appeared more frequently in regenerants from PI 88788 and PI 438489B than from Bedford. These results confirm and extend the finding that certain tissue culture techniques may be used to induce novel plant formation from somatic tissue of soybean.

Experiments on direct isolation of Pythium spp. from Finnish sugar beet soils

Pythium spp. were successfully isolated directly from sugar beet soils by the method of Ricci et al. (1976). The isolates obtained were divided in to four groups on the basis of morphological and growth habit characters. The groups showed large differences in in vitro pathogenicity. The importance of some factors affecting the estimation of Pythium propagule density is studied and discussed.

‘Tuscarora’ Lagerstroemia1

Abstract ‘Tuscarora’, with dark coral flowers (Fig.1), is the first significant flower color break recovered among L. indica L. × L. fauriei Koehne progeny. Lagerstroemia, commonly known as crapemyrtle, for the most part has been commercially distributed only in red, pink, lavender, and white flower forms. Although The Lagerstroemia Handbook/Checklist (1) enumerates numerous cultivars, few have proved superior to unnamed color forms, or have been of commercial significance, because of mildew incited by Erysiphe lagerstroemiae E. West. From earlier hybridization at the U.S. National Arboretum, 6 mildew-resistant L. indica cultivars (‘Catawba’, ‘Cherokee’, ‘Conestoga’, ‘Potomac’, ‘Powhatan’, and ‘Seminole’) have been introduced (2, 3). More recently, the profuse flowering of L. indica was recombined with the bark coloration, mildew resistance, and growth habit characteristics of L. fauriei to produce ‘Muskogee’ and ‘Natchez’ (4). ‘Tuscarora’ is another noteworthy advance in the breeding of mildew-free Lagerstroemia cultivars.

‘Chesapeake’ Viburnum1

Abstract Viburnum ‘Chesapeake’, which is the thirteenth Viburnum cultivar introduction from the U.S. National Arboretum shrub breeding program, has outstanding foliage and growth habit characteristics (1, 2, 3, 4). This cultivar belongs to the Section Lantana of the genus that includes such other significant landscape viburnums as V. X burkwoodii Burk. & Skip.; V. X burkwoodii ‘Mohawk’ (Egolf); V. carlesii Hemsl.; V. X carlcephalum Burk.; and V. X carlcephalum ‘Cayuga’ (Egolf). These viburnums are cultivated extensively in north temperate regions for their medium stature; subcoriaceous, deciduous to semi-evergreen leaves; and abundant, fragrant, white to pink flowers. Although ‘Chesapeake’ recombines some of the characteristics of these cultivars and species, it is distinct with coriaceous, dark green leaves; dense branching; and a compact growth habit.