Morphological variation within and among five annual Phalaris species

2002 ◽  
Vol 82 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Maria Matus-Cádiz ◽  
Pierre Hucl

Accessions of annual canarygrass (Phalaris canariensis L.; 2n = 2x = 12) held within germplasm collections generally lack adequate genetic characterization for utilization in crop improvement. The objective of this study was to assess the level of morphological variation of accessions of five annual Phalaris species, including 49 annual canarygrass, 48 P. minor Retz. (2n = 4x = 28), 24 P. brachystachys (2n = 2x = 12), 19 P. paradoxa L. (2n = 2x = 14), and three P. angusta Nees ex Tris. (2n = 2x = 14). In 1993 and 1994, accessions were grown under growth chamber and greenhouse conditions, respectively. Eighteen morphological traits were measured on five plants per accession. Phalaris canariensis had intermediate culm height, wider penultimate leaves, shorter and wider panicles, and larger caryopses relative to the other four species. The six qualitative traits were monomorphic in all five species, except for glume pubescence in P. brachystachysand inflorescence type in P. paradoxa. The limited variation within and among P. canariensis accessions supports the idea that germplasm collecting activities are needed to broaden the genetic diversity held in North American Phalaris collections. Key words: Phalaris, germplasm, morphological traits


2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.



Author(s):  
Purabi Kaushik ◽  
Jnyanashree Saikia ◽  
Kabitabala Kalita ◽  
Rajjyoti Deka ◽  
J. Saharia

Background: Duck farming plays a significant role, next to chicken in the socio-economic uplift men of the rural farmers of North-East India. Pati duck is the most common duck breed in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli, however it originatein Kerala. Genetic characterization plays a significant role for formulation of breeding strategies for improvement of any breed. Microsatellites are codominant in nature and are highly polymorphic. High level of allelic variation, co-dominant mode of inheritance and potential for automated analysis make them an excellent tool for genotyping, mapping and genetic characterization. Pati duck is the most common duck breed in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli however its origin in Kerela. Therefore, the present investigation was carried out to characterize these two duck breeds using microsatellite markers to evaluate the genetic diversity in these two duck population. Methods: For the present study, Blood sample were collected from 50 Patiducks and 50 Chara-Chambeli ducks from different parts of North-East India. Assessment of genetic characterization of duck breeds of north-east region were carried out using 16 microsatellite markers and population genetics analysis were done by POPGENE software. Result: In the present study, all the studied loci were highly polymorphic. Analysis generated a total of 41 microsatellite alleles. The number of observed alleles (Na) with an overall mean of 1.93±0.258. However, the effective number of alleles (Ne) with a mean of 1.6933±0.2712. The Shannon’s information index was found to a mean value of 0.5685±0.1693. The overall means for observed (HO) and expected (He) heterozygosities were 0.2889±0.2477 and 0.5289±0.0853, respectively. The chi-square (χ2) test for Hardy-Weinberg equilibrium revealed that all the loci are in within Hardy-Weinberg equilibrium.



2015 ◽  
Vol 8 (1) ◽  
pp. 1-28 ◽  
Author(s):  
Lior Laks

This paper examines morphological variation and change in the formation of instrument nouns in Hebrew. The change is always from one of the non-participle templates into a participle template and never the other way around. Nonetheless, not all instrument nouns (INs) change their template. I contend that the transition to the participle templates can be predicted based on systematic criteria. Such a change targets both morphological and thematic transparency between the IN and the related verb. Thematically, the participle IN corresponds to a thematic role that the verb assigns. The IN has to be agentive in order to be thematically transparent and undergo morphological change. The more transparent the thematic relation between the verb and the IN is, the greater the chance for morphological change. Morphologically, the formation of the participle form is also more transparent as it requires fewer changes between the verb and the IN. The only changes that occur are affixation and changing the vowels of the base verb, and the formation in the participle templates preserves the prosodic structure of the base verb. The analysis also provides further support to the stem modification theory and shows that the formation of the instrument noun is based on internal changes on the verbal base form without separate reference to the consonantal root.



Author(s):  
Patricia M. Lambert

In 1989, a pioneer cemetery associated with the 19th-century Latter-Day Saints colony in San Bernardino, California, was discovered during the construction of a baseball field. Among the remains of 12 individuals recovered from the cemetery were those of a young man of about 22 years, whose burial treatment differed notably from the other intact interments at the site. Unlike these coffin burials, Burial 5 was found in a sprawling position, apparently tossed unceremoniously into the grave pit. Dental morphological traits identified the genetic affinities of this man as Native American, perhaps a member of the local Cahuilla or Serrano tribes, whereas the other individuals appeared to be of European ancestry, an interpretation consistent with records kept by community members. A possible identity for this individual came from a journal account describing the shooting of an “Indian” by the local sheriff, who was then brought to the fort, died, and was buried before his fellow tribesmen arrived to determine what had transpired and perhaps to claim his remains. This chapter explores the identity and life history of this young man in the context of the history of the valley and the pioneer community in which he met his death.



2004 ◽  
Vol 218 ◽  
pp. 181-184 ◽  
Author(s):  
Koji Mori ◽  
David N. Burrows ◽  
George G. Pavlov ◽  
J. Jeff Hester ◽  
Shinpei Shibata ◽  
...  

We present year-scale morphological variations of the Crab Nebula revealed by the Chandra X-ray Observatory. Observations have been performed about every 1.7 years over the three years from launch. The variations are clearly recognized at two sites: the torus and the southern jet. The torus, which had been steadily expanding until 1.7 years ago, now appears to have shrunk in the latest observation. Additionally, the circular structures seen to the northeast of the torus have decayed into several arcs. On the other hand, the southern jet shows the growth of its overall kinked-structure. We discuss the nature of these variations in terms of the pulsar wind nebula mechanism.



Zootaxa ◽  
2020 ◽  
Vol 4861 (3) ◽  
pp. 429-443
Author(s):  
CAROLINA PIRES ◽  
MARCELO WEKSLER ◽  
CIBELE R. BONVICINO

The region of Lagoa Santa, Minas Gerais, Brazil, is one of the most important karstic areas of the Brazilian Quaternary due to the faunistic diversity of living and extinct forms. Among them, some taxa remain poorly studied, as is the case of Calomys anoblepas Winge 1887. Despite the recent allocation of the taxon within Juliomys, its description and morphological analysis are condensed, based on comparative few specimens and on few informative characters. In this study, we investigate characters proposed to distinguish species of Juliomys, and reevaluate the taxonomic status of the fossil Juliomys anoblepas. We analyzed 80 cranio-dental morphological characters in 233 specimens represented by the four species currently recognized: J. pictipes (Osgood 1933), J. rimofrons Oliveira & Bonvicino 2002, J. ossitenuis Costa, Pavan, Leite & Fagundes 2007, and J. ximenezi Christoff, Vieira, Oliveira, Gonçalves, Valiati & Tomasi 2016. We also performed principal component analysis on eight craniodental measurements available for the J. anoblepas hypodigm. The review of morphological systems and the evaluation of the characters used in the literature revealed that there are no diagnostic characters in the anterior portion of the skull and in the molar series of Juliomys, being difficult to differentiate the fossil from the other living species. Only six qualitative characters were variable and applicable to the hypodigm of J. anoblepas. Characters are polymorphic, invariable, or the fossil is not sufficiently complete to determinate its states. The taxon could not be morphometrically differentiated from J. pictipes and J. ossitenuis. Based on the results presented herein, we consider J. anoblepas as a nomen dubium and restrict its name to the taxon’s hypodigm. 



2014 ◽  
Vol 6 (2) ◽  
pp. 178-184 ◽  
Author(s):  
KiByung LIM ◽  
Adnan YOUNIS ◽  
Jong TAEK PARK ◽  
Yoon JUNG HWANG

In this study naturally growing morphological variation of Lilium tsingtauense (Korean wheel lily), from southern Chung San Island to northern Mount Seorak, was investigated in 16 habitats around the country. Morphological analysis revealed that this species had its own unique characteristics in different habitats. Flowers with luster are in actinomorphic form, with shades of orange, each plant having an average of 2.4 flowers that blossom upward. The shape of flower petals was from oval to oblong. The width of the petals, which determines the shape of the flower, significantly varied among regions. Flower petals showed purple spots and its occurrence greatly varied among plants from almost none to 300 spots per flower. In addition, when the number of spots increased, the flower color was more vivid. Leaves were typically one-tiered verticillate and most of the leaves were long, oval and some were lanceolate. Young leaves showed definitive patterns that faded during growth. Starting from the verticillate leaves, stems below the leaves were smooth, although 81% of all stems, above the verticillate leaves, showed rough micro-protrusions. Bulb shapes were long and vertically elliptical. The ramentum was light yellow in color and the base was darker, with the color fading toward the upper region of the plant. The shape of the ramentum was long, with a pointy end, and its adhesiveness was weak. This study offers basic fundamental information for the effective exploitation and recognition of L. tsingtauense resources as a potential cut flower and potting plant in floral trade worldwide.



Paleobiology ◽  
2018 ◽  
Vol 44 (1) ◽  
pp. 101-117
Author(s):  
Pablo S. Milla Carmona ◽  
Darío G. Lazo ◽  
Ignacio M. Soto

AbstractThe complex morphological evolution of the bivalvePtychomyathroughout the well-studied Agrio Formation in the Neuquén Basin (west-central Argentina, lower/upper Valanginian–lowest Barremian) constitutes an ideal opportunity to study evolutionary patterns and processes occurring at geological timescales. Ptychomyais represented in this unit by four species, the morphological variation of which needs to be temporally assessed to obtain a thorough picture of the evolution of the group. Here we use geometric morphometrics to measure variation in shell outline, ribbing pattern, and shell size in these species. We bracket the ages of our samples using a combination of ammonoid biostratigraphy and absolute ages and study the anagenetic pattern of evolution of each trait by means of paleontological time-series analysis and change tracking. We find that evolution inPtychomyais mostly speciational, as the majority of traits show stasis, with the exceptions of shell size inP. coihuicoensisand shell outline inP. windhauseni, which seem to evolve directionally toward larger and higher shells, respectively.Ptychomyadisplays changes in its average morphology and disparity, which are the result of a mixture of taxonomic turnover and mosaic evolution of traits. Pulses of speciation would have been triggered by ecological opportunity, as they occur during the recovery of shallow-burrowing bivalve faunas after dysoxic events affecting the basin. On the other hand, the presence of directional patterns of evolution inP. coihuicoensisandP. windhauseniseems to be the result of a general shallowing-upward trend observed in the basin during the upper Hauterivian–lowest Barremian, as opposed to the cyclical paleoenvironmental stability inferred for the early/late Valanginian–early Hauterivian, which would have prompted stasis inP. koeneniandP. esbelta.



Author(s):  
P. Vermeiren ◽  
C. Lennard ◽  
C. Trave

Abstract Intertidal crabs display distinct morphological traits that allow differential interactions with biotic and abiotic features of the intertidal landscape, but are also influenced by allometry and sexual selection. This study aimed to explore the influence of sexual, allometric and habitat factors on morphological variation in the intertidal mangrove crab assemblage. A standardized photographic protocol was developed using readily available, low-cost technology to capture the morphology of carapaces and claws as sets of Cartesian landmarks. Digitization errors were 1 to 2 orders of magnitude smaller than the variation among individuals. In Tubuca seismella and Tubuca signata (superfamily Ocypodoidea), species that have traditionally been studied for sexual dimorphism, standardized major claw sizes were 2.8 and 3.7, respectively, times larger for males than females. Sexual dimorphism in claw size was also observed for Metopograpsus frontalis and Parasesarma longicristatum (superfamily Grapsoidea), with the largest claw in males being 15% and 33%, respectively, larger than in females. In contrast to size, claw shape did not relate to sex, except for T. seismella. Carapace shape, although variable among individuals and displaying asymmetry, was unrelated to sex. Claw and carapace shapes displayed high correlations, with values around 0.78. Carapace shapes grouped into taxonomic families and linked to habitat preferences, while claw shapes varied along a taxonomic gradient. These results complement studies on crab morphology that focus on specific factors or species, and stress the importance of multiple, interacting factors including sexual, allometric and habitat influences as drivers of morphological trait variability.



1975 ◽  
Vol 53 (10) ◽  
pp. 978-987 ◽  
Author(s):  
Ernest Small

A number of authors have suggested that fruit characters are important in the taxonomic delimitation of Cannabis, particularly in contrasting wild and domesticated plants on the one hand and plants of limited and pronounced intoxicant potential on the other. Variation in achenes was assessed in plants cultivated for fiber and for drug purposes, and in plants growing outside of cultivation in various areas of the world. It was found that domesticated plants have large achenes which usually lack an adhering, patterned perianth and also lack an elongated base. In contrast, achenes of uncultivated plants are much more variable, ranging from those which closely resemble the fruits of domesticated plants to ones which are small and possess an adhering perianth and an elongated base. It appears that the latter morphological syndrome is adaptive in wild plants, and it is hypothesized that the degree of development of these characters in uncultivated plants is indicative of the extent of departure or independence from the effects of domestication.



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