Hybridization between Invasive Populations of Dalmatian Toadflax (Linaria dalmatica) and Yellow Toadflax (Linaria vulgaris)

2009 ◽  
Vol 2 (4) ◽  
pp. 369-378 ◽  
Author(s):  
Sarah M. Ward ◽  
Caren E. Fleischmann ◽  
Marie F. Turner ◽  
Sharlene E. Sing
Keyword(s):  
First Generation ◽  
Seed Morphology ◽  
Width Ratio ◽  
Putative Hybrid ◽  
Phenotypic Traits ◽  
Parent Species ◽  
Linaria Dalmatica ◽  
Yellow Toadflax ◽  
Hybrid Plants ◽  
Dalmatian Toadflax

AbstractAlthough there is evidence that interspecific hybridization can initiate invasion by nonnative plants, there are few documented examples of novel hybridization events between introduced plant species already exhibiting invasive behavior. We conducted morphometric and molecular analyses of toadflax plants with intermediate morphology found at two sites in Montana, which were co-invaded by yellow toadflax and Dalmatian toadflax. Field-collected putative hybrid plants had intermediate morphometric scores (mean 0.47, on a scale of 0.0 = indistinguishable from Dalmatian toadflax to 1.0 = indistinguishable from yellow toadflax) for a suite of phenotypic traits that differentiate the parent species (leaf length : width ratio, growth form, seed morphology, inflorescence type, and ventral petal shape). Inter-simple sequence repeat (ISSR) analysis of a subset of these putative hybrids revealed combinations of species-diagnostic bands, confirming the presence of DNA from both parent species. Controlled interspecific hand-pollinations generated viable first generation (F1) hybrid plants that also had intermediate morphometric scores (mean 0.46) and a mix of species-diagnostic ISSR bands from both parents. The hand-generated F1hybrids crossed readily with both parent species to produce viable first generation backcrossed (BC1) plants. Our results confirm that hybridization is occurring between invasive populations of yellow toadflax and Dalmatian toadflax, and that the hybrid progeny are viable and fertile. This example of hybridization between alien congeners is of concern as the parent taxa are already known to be highly invasive. Further research is needed to assess the invasive potential of hybrid toadflax populations, and the likelihood of introgressive trait transfer between the parent species.

Rapid differentiation of the sexes of adult Mecinus janthinus (Coleoptera: Curculionidae) based on external leg morphology

2004 ◽  
Vol 136 (6) ◽  
pp. 835-837 ◽  
Author(s):  
V.A. Carney ◽  
J. Rau ◽  
S.M. Little ◽  
R.A. De Clerck-Floate
Keyword(s):  
British Columbia ◽  
Control Agent ◽  
Linaria Dalmatica ◽  
Noxious Weeds ◽  
Yellow Toadflax ◽  
Mecinus Janthinus ◽  
Southern Alberta ◽  
Dalmatian Toadflax ◽  
Successful Control ◽  
Leg Morphology

The stem-boring weevil, Mecinus janthinus Germar (Coleoptera: Curculionidae), was introduced from Europe to Canada in 1991 to control the noxious weeds Dalmatian toadflax, Linaria dalmatica (L.) P. Mill., and yellow toadflax, Linaria vulgaris P. Mill. (Scrophulariaceae) (De Clerck-Floate and Harris 2002; McClay and De Clerck-Floate 2002). Since its release, M. janthinus has established well on Dalmatian toadflax in British Columbia (BC) and, to a lesser extent, southern Alberta (De Clerck-Floate and Miller 2002), and it is beginning to show promise as a successful control agent against this weed (De Clerck-Floate and Harris 2002). However, it appears that M. janthinus has not thrived on yellow toadflax in Alberta (McClay and De Clerck-Floate 2002).

Revision of the genus Calpurnia (Sophoreae: Leguminosae)

Bothalia ◽  
1999 ◽  
Vol 29 (1) ◽  
pp. 5-23 ◽  
Author(s):  
A. J. Beaumont ◽  
R. P. Beckett ◽  
T. J. Edwards ◽  
C. H. Stiron
Keyword(s):  
Southern Africa ◽  
Leaf Morphology ◽  
Seed Morphology ◽  
Putative Hybrid ◽  
Seedling Morphology

Taxa recognised in this revision are:  Calpurnia aurea (Aiton) Benth. subsp.  aurea; C.  aurea (Aiton) Benth. subsp.  indica Brummitt; C. floribunda Harv ; C. glabrata Brummitt; C. intrusa (R.Br in W.T.Aiton) E.Mey.; C. reflexus A.J.Beaumont sp nov.;  C. sericea Harv. and  C. woodii Schinz. A putative hybrid between  C. sericea and  C. woodii is recorded. With the exception of C aurea, all species are restricted to southern Africa.  C. reflexus is possibly extinct, and C.  woodii is considered rare. Characters examined in this revision are habitat, habit, vestiture, leaf morphology and anatomy; floral, pollen, fruit and seed morphology and anatomy; and seedling morphology. Illustrations and a key to taxa are provided.

Dalmatian Toadflax (Linaria dalmatica): New Host for Cucumber Mosaic Virus

2007 ◽  
Vol 21 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Courtney L. Pariera Dinkins ◽  
Sue K. Brumfield ◽  
Robert K. D. Peterson ◽  
William E. Grey ◽  
Sharlene E. Sing
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Aphid Transmission ◽  
Negative Control ◽  
Enzyme Linked Immunosorbent Assay ◽  
New Host ◽  
Tobacco Plants ◽  
Linaria Dalmatica ◽  
Mechanical Methods ◽  
Dalmatian Toadflax

To date, there have been no reports of Dalmatian toadflax serving as a host for cucumber mosaic virus (CMV). Infestations of Dalmatian toadflax may serve as a reservoir of CMV, thereby facilitating aphid transmission of CMV to both agricultural crops and native plants. The goal of this study was to determine whether Dalmatian toadflax is a host for CMV. Dalmatian toadflax seedlings were randomly assigned to two treatments (18 replicates/treatment): no inoculation (control) and inoculation with CMV (Fast New York strain). The Dalmatian toadflax seedlings were inoculated by standard mechanical methods and tested for the presence of CMV using enzyme-linked immunosorbent assay (ELISA). Ten of the 18 CMV-inoculated toadflax plants tested positive for the virus; 6 of the 18 displayed systemic mosaic chlorosis and leaf curling. All control plants tested negative. Transmission electron microscopy obtained from CMV-positive plants confirmed the presence of CMV based on physical properties. To verify CMV infestation, tobacco plants were assigned to the following treatments (six replicates/treatment): no inoculation (control), CMV-negative (control) inoculation, and a CMV-positive inoculation. Plants were inoculated by standard methods. Five of the 6 tobacco plants treated with the CMV-positive inoculum tested positive for CMV using ELISA. All control plants tested negative for the virus.

The biology of Canadian weeds. 106. Linaria dalmatica (L.) Mill.

1997 ◽  
Vol 77 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Ksenija Vujnovic ◽  
Ross W. Wein
Keyword(s):  
North America ◽  
Vegetative Reproduction ◽  
The United States ◽  
Weed Biology ◽  
Linaria Dalmatica ◽  
Plant Parts ◽  
Leaf Surfaces ◽  
Dalmatian Toadflax ◽  
Canadian Provinces ◽  
The 1960S

Dalmatian Toadflax, Linaria dalmatica (L.) Mill. (Scrophulariaceae), is an important weed of rangelands, agricultural crops and waste areas in North America. The literature is less extensive than for the closely related yellow toadflax (Linaria vulgaris Mill.). Introduced from Eurasia as an ornamental plant into North America by 1894, it became naturalized in seven Canadian provinces and all of the United States of America west of the 100th meridian except for New Mexico. In North America it ranges from ca. 35° to 56°N latitude and it grows from near sea level to altitudes up to ca. 2800 m. Production of up to one-half million seeds per plant and its long-lived perennial nature make the species highly competitive and able to invade cropland and even stands of native ungrazed vegetation. Linaria dalmatica is a hemicryptophyte with strong vegetative reproduction and dormant seeds. Growth of creeping roots after removal of aboveground plant parts limits the effectiveness of control treatments such as grazing, clipping, mowing or burning. Several herbicides control the species for the short term; the smooth and waxy leaf surfaces may hinder herbicide uptake. Experimental biological control with insects since the 1960s shows promise. Key words: Linaria dalmatica, Dalmatian toadflax, Scrophulariaceae, weed biology, control, review

Microscopic Airway Reopening Through Cascades of Plugs Ruptures

2009 ◽  
Author(s):  
M. Baudoin ◽  
Y. Song ◽  
C. N. Baroud ◽  
P. Manneville
Keyword(s):  
Flow Resistance ◽  
First Generation ◽  
Human Lung ◽  
Careful Analysis ◽  
Initial Distribution ◽  
Width Ratio ◽  
Airway Reopening ◽  
Successive Generations ◽  
Binary Network ◽  
Lung Airways

The inner surface of lung airways is covered by a thin layer of mucus whose thickness is usually about 2 or 3% of the total radius of the duct. However certain diseases like asthma, chronic bronchitis or allergies can induce a hypersecretion of mucus, leading to the formation of liquid plugs which occlude the airways. These plugs can considerably alter the distribution of air during the breathing cycle. It is therefore fundamental to understand the propagation of air in the presence of such plugs and in particular airway reopening. Some studies have been performed on real lungs but there was no visualization of the airways, and only information at the entrance was reported. The purpose of this experimental work is to create a synthetic network, reproducing only the main features of the lung airways, to visualize and understand the physics of airway reopening. The human lung is made of about 24 generations with diameters ranging from about 2 cm for the trachea to 100 μm for the smallest ones. As a consequence, the physics is very different for the first and the last generations. The present work focuses on the last micrometric generations for which inertia and gravity can be neglected (small Reynolds and Bond numbers). For this purpose a binary network made of PDMS was designed and fabricated. It is composed of 6 generations with a width of 700 μm for the first generation and a width ratio of 0.8 between the branches of successive generations. A random initial distribution of plugs is inserted inside this network by using syringe pumps and finally some air is introduced inside the airways. The reopening of the network takes place through a series of cascades of plugs ruptures. A single cascade can be explained by a simple model, based on the flow resistance of the plugs and the liquid deposited on the walls. The correlation between successive cascades is extracted from a careful analysis of the data. This study improves considerably our understanding of cascades of plug ruptures, which might be valuable to enhance the treatment of such diseases.

Eleocharis compressa × Eleocharis erythropoda, a new natural hybrid spike rush from Ontario

1994 ◽  
Vol 72 (6) ◽  
pp. 837-842 ◽  
Author(s):  
P. M. Catling
Keyword(s):  
Surface Roughness ◽  
Cross Section ◽  
Cross Sections ◽  
Roughness Length ◽  
Putative Hybrid ◽  
Natural Hybrid ◽  
Surface Roughness Length ◽  
Hybrid Plants ◽  
Section Shape ◽  
Spike Rush

Partially sterile plants from eastern Ontario are identified as Eleocharis compressa × Eleocharis erythropoda on the basis of intermediacy in perianth bristle length, tubercle shape, achene surface roughness, length of rhizome internodes, culm cross-section shape, and length of terminal lobes of scales. Both putative parents occurred with the hybrid plants. The hybrid plants had tardily deciduous scales and either bifid or trifid styles. They superficially resemble E. erythropoda most closely but differ markedly in their scaly rhizomes with shorter internodes 3.8 – 7 mm long. They are most readily distinguished from E. compressa by their elliptic or broadly rectangular culm cross sections and some perianth bristles exceeding 0.5 mm in length. This putative hybrid involves taxa in different subseries that would normally be regarded as too distantly related to permit hybridization. Key words: Eleocharis compressa, Eleocharis erythropoda, Cyperaceae, hybrid, taxonomy, classification.

Effect of Timing on Chemical Control of Dalmatian Toadflax (Linaria dalmatica) in California

2013 ◽  
Vol 6 (3) ◽  
pp. 362-370 ◽  
Author(s):  
Guy B. Kyser ◽  
Joseph M. DiTomaso
Keyword(s):  
Residual Activity ◽  
Early Spring ◽  
High Rate ◽  
Effective Control ◽  
Grass Species ◽  
Optimal Timing ◽  
Linaria Dalmatica ◽  
Time Of Application ◽  
Dalmatian Toadflax ◽  
Second Year

AbstractDalmatian toadflax is listed as a noxious weed in most of the western United States, but control of this species has not been extensively studied in California. Studies in other states show effective control of Dalmatian toadflax with picloram, but this herbicide is not registered for use in California. In addition, reports vary as to the optimal timing for herbicide applications. In this study we evaluated several herbicides with combined foliar and soil-residual activity at two times of application: postsenescence (fall) and rosette (winter to early spring). We applied two series of treatments (2008 and 2009 to 2010) on adjacent sites in high desert scrub of southern California. In the year of treatment and the following year, we evaluated Dalmatian toadflax cover and presence/absence of associated dominant species (≥ 5% cover). Although time of application, treatment, and timing by treatment interaction all produced significant differences in Dalmatian toadflax cover in the 2008 trial, only the high rate of aminocyclopyrachlor (280 g ae ha−1) applied to dormant plants in fall consistently reduced cover through the second year. No treatments at the rosette stage consistently produced 2 yr of control. In 2009 to 2010, treatments were more effective, probably owing to higher precipitation in spring. In both dormant and rosette applications made in 2009 to 2010, aminocyclopyrachlor (140 and 280 g ae ha−1) and aminocyclopyrachlor + chlorsulfuron (140 g ae ha−1+ 53 g ai ha−1) gave second year control; chlorsulfuron at the dormant stage (105 and 158 g ai ha−1) and aminopyralid at the rosette stage (245 g ae ha−1) also gave 2 yr of control. The treatments had only minor effects on grass species. The response of broadleaf species varied among treatments, with aminocyclopyrachlor at the high rate increasingEriogonumspp., but greatly reducing Asteraceae species. These results provide options for the management of Dalmatian toadflax in California and other western states.

Platanthera lacera × leucophaea, a new cryptic natural hybrid, and a key to northeastern North American fringed-orchids

1999 ◽  
Vol 77 (8) ◽  
pp. 1144-1149 ◽  
Author(s):  
Paul M Catling ◽  
Vivian R Brownell
Keyword(s):  
North American ◽  
Hybrid Origin ◽  
Putative Hybrid ◽  
Herbarium Specimens ◽  
Morphological Attributes ◽  
Quantitative Characters ◽  
Hybrid Plants ◽  
York County ◽  
Spur Length ◽  
Platanthera Leucophaea

To evaluate the putative hybrid origin of fringed-orchids from York County, Ontario, morphological attributes of hybrid flowers were evaluated with respect to both a random sample of herbarium specimens and populations from the hybrid location. The putative hybrids were intermediate in spur length, petal width, and vertical distance across opening to the spur as well as in eight other quantitative characters. The hybrid is named Platanthera ×hollandiae Catling & Brownell (= Platanthera lacera (Michx.) G. Don × Platanthera leucophaea (Nutt.) Lindl.). With pale greenish-white flowers, partly reflexed lateral sepals, and a horizontally linear spur opening, the putative hybrid plants resemble P. lacera but can be readily distinguished by their relatively long spurs, relatively broad lateral petals, and ovoid instead of strap-shaped viscidium. A key including characteristics of the column is included that allows the separation of all northeastern North American fringed-orchids and their known natural hybrids.Key words: orchid, hybrid, Platanthera lacera, Platanthera leucophaea, Canada, Ontario.

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