scholarly journals Invasive Russian Knapweed (Acroptilon repens) Creates Large Patches Almost Entirely by Rhizomic Growth

2017 ◽  
Vol 10 (2) ◽  
pp. 119-124
Author(s):  
John F. Gaskin ◽  
Jeffrey L. Littlefield
Keyword(s):  
Local Scale ◽  
Distance Scale ◽  
Maximum Diameter ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Invasive Weed ◽  
Russian Knapweed ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Herbicide Use

Russian knapweed is an outcrossing perennial invasive weed in North America that can spread by both seed and horizontal rhizomic growth leading to new shoots. The predominant mode of spread at the local scale and dispersal at the long-distance scale informs control but has not been quantitatively researched. We used amplified fragment-length polymorphisms (AFLPs) of DNA collected from 174 shoots in two discrete patches of Russian knapweed at each of three locations in Montana. Out of the 174 shoots collected, we found nine AFLP genotypes. Three out of the six patches were monotypic; the other three patches each had one rare genotype. No genotypes were shared between patches. The maximum diameter of a genet (a genetic individual) was 56.5 m. These results indicate that patch expansion at the local scale is almost entirely by rhizomes that spread and develop new shoots. At the long-distance scale, dispersal is by seed. Controlling seed development through biological control and herbicide use may be effective at stopping long-distance dispersal but may not affect expansion of existing patches.

scholarly journals The role of mucilage envelope in the endozoochory of selected plant taxa

2020 ◽  
Vol 108 (1) ◽  
Author(s):  
A. Kreitschitz ◽  
E. Haase ◽  
S. N. Gorb
Keyword(s):  
Digestive System ◽  
Columba Livia ◽  
Local Scale ◽  
Ocimum Basilicum ◽  
Long Distance Dispersal ◽  
Morphological Adaptation ◽  
Long Distance ◽  
Germination Ability ◽  
First Time

AbstractMyxodiaspory (formation of mucilage envelope around seeds and fruits) is a common adaptation to dry habitats known in many families of Angiosperms. The mucilage envelope of some seeds seems to be also a unique morphological adaptation which protects myxospermatic diaspores while passing through the bird’s digestive system. To evaluate the protective potential of mucilage, we fed the diaspores of seven plant species (representing three different mucilage types and three species of non-mucilaginous plants) to pigeons, Columba livia domestica. Twenty-four hours later, we collected the droppings of pigeons and examined a total of 18,900 non-destroyed diaspores to check for mucilage presence and germination ability. Out of all the examined diaspores, 4.5% were mucilaginous seeds. Among them, the highest number (12.2–13.5%) of viable diaspores belonged to the hemicellulosic type of mucilage (from Plantago species). Only 3.7% of germinating diaspores with pectic mucilage (Linum usitatissimum) were collected, and no seeds representing cellulosic mucilage (e.g., Ocimum basilicum). For non-mucilaginous plants, we collected only a few individual seeds (0.1% out of 8100 seeds used). We noted that the mucilaginous seeds found in the droppings were able to germinate; however, the germination ability was generally smaller in comparison to the control (i.e., not digested) seeds. Our results revealed that the presence of mucilage envelope has an impact on diaspore dispersal and survivability. With our experiments, we demonstrated for the first time that the mucilage envelope, especially of the non-cellulosic type, supports endozoochory. We also showed that non-mucilaginous seeds can be occasionally dispersed via endozoochory and are able to germinate. The results of our studies can explain the ways of plants distribution at a small, local scale as well as in long-distance dispersal, e.g., between islands or even continents.

scholarly journals Limited long-distance dispersal success in a Western European fairy shrimp evidenced by nuclear and mitochondrial lineage structuring

2019 ◽  
Vol 66 (3) ◽  
pp. 227-237
Author(s):  
Paula C Rodríguez-Flores ◽  
Ernesto Recuero ◽  
Yolanda Jiménez-Ruiz ◽  
Mario García-París
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Iberian Peninsula ◽  
Isolation By Distance ◽  
Local Scale ◽  
Long Distance Dispersal ◽  
Evolutionary Potential ◽  
Long Distance ◽  
Widespread Species ◽  
Spatio Temporal

Abstract Anostraca are known by their ability for long-distance dispersal, but the existence in several species of deep, geographically structured mtDNA lineages suggests their populations are subjected to allopatric differentiation, isolation, and prevalence of local scale dispersion. Tanymastix stagnalis is one of the most widespread species of Anostraca and previous studies revealed an unclear geographical pattern of mtDNA genetic diversity. Here, we analyze populations from the Iberian and Italian Peninsulas, Central Europe, and Scandinavia, with the aim to characterize the patterns of genetic diversity in a spatio-temporal framework using mtDNA and nuclear markers to test gene flow among close populations. For these aims we built a time-calibrated phylogeny and carried out Bayesian phylogeographic analyses using a continuous diffusion model. Our results indicated that T. stagnalis presents a deeply structured genetic diversity, including 7 ancient lineages, some of them even predating the Pleistocene. The Iberian Peninsula harbors high diversity of lineages, with strong isolation and recent absence of gene flow between populations. Dispersal at local scale seems to be the prevailing dispersal mode of T. stagnalis, which exhibits a pattern of isolation-by-distance in the Iberian Peninsula. We remark the vulnerability of most of these lineages, given the limited known geographic distribution of some of them, and the high risk of losing important evolutionary potential for the species.

Rediscovery of pycnidia in Thamnolia vermicularis: implications for chemotype occurrence and distribution

2013 ◽  
Vol 45 (3) ◽  
pp. 397-411 ◽  
Author(s):  
Janice M. LORD ◽  
Allison KNIGHT ◽  
Jennifer M. BANNISTER ◽  
Lars R. LUDWIG ◽  
William M. MALCOLM ◽  
...  
Keyword(s):  
Genetic Variation ◽  
English Language ◽  
Its Region ◽  
Local Scale ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Apparent Absence ◽  
Reproductive Structures ◽  
Low Levels ◽  
The 19Th Century

AbstractThamnolia vermicularis is a globally widespread arctic-alpine lichen with two distinct chemotypes. The intermixing of these chemotypes at the local scale and lack of genetic variation between them is puzzling given the apparent absence of specialized reproductive structures. Apothecia and conidiomata were originally reported for Thamnolia in the second half of the 19th century, but putative apothecia proved to be parasitic in origin. This study presents conclusive microscopic evidence for the existence of pycnidial conidiomata containing conidia on thalli of Thamnolia vermicularis from geographically widespread locations. Sequences of the internal transcribed spacer (ITS) region of ribosomal DNA from excised pycnidial conidiomata matched that of thallus tips from individual Thamnolia thalli. Our examination of the historic literature found that the occurrence of pycnidial conidiomata was never disproved, but this information was lost from the post-1920s English-language literature. Our rediscovery of pycnidial conidiomata indicates that Thamnolia vermicularis possesses a reproductive strategy with the potential for long-distance dispersal of multitudes of mitotically produced conidia, providing a plausible explanation for the cosmopolitan distribution of the species and the low levels of genetic variation among populations. Reversible processes, for example alternative splicing, warrant consideration as explanations for chemotype intermixing.

A Demonstration of a 1:1 Correspondence Between Chiasma Frequency and Recombination Using a Lolium perenne/Festuca pratensis Substitution

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 307-314 ◽  
Author(s):  
J King ◽  
L A Roberts ◽  
M J Kearsey ◽  
H M Thomas ◽  
R N Jones ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Chiasma Frequency ◽  
Chiasma Formation ◽  
Grass Species ◽  
Festuca Pratensis ◽  
Single Chromosome ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Frequency Counts

Abstract A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line (2n = 2x = 14). The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study chiasma formation in a single marked bivalent. Recombination occurs freely in the F. pratensis/L. perenne bivalent, and chiasma frequency counts give a predicted map length for this bivalent of 76 cM. The substituted F. pratensis chromosome was also mapped with 104 EcoRI/Tru91 and HindIII/Tru91 amplified fragment length polymorphisms (AFLPs), generating a marker map of 81 cM. This map length is almost identical to the map length of 76 cM predicted from the chiasma frequency data. The work demonstrates a 1:1 correspondence between chiasma frequency and recombination and, in addition, the absence of chromatid interference across the Festuca and Lolium centromeres.

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