scholarly journals A Microsatellite Analysis Used to Identify Global Pathways of Movement of Phytophthora cinnamomi and the Likely Sources of Wildland Infestations in California and Mexico

2019 ◽  
Vol 109 (9) ◽  
pp. 1577-1593 ◽  
Author(s):  
María Socorro Serrano ◽  
Todd Osmundson ◽  
Alejandra Almaraz-Sánchez ◽  
Peter J. P. Croucher ◽  
Tedmund Swiecki ◽  
...  
Keyword(s):  
Phytophthora Cinnamomi ◽  
Genotypic Diversity ◽  
Microsatellite Analysis ◽  
Long Distance ◽  
High Frequencies ◽  
Minimum Spanning Network ◽  
Natural Settings ◽  
Long Distance Movement ◽  
Genic Diversity ◽  
Group 1

The genetic structure of a sample of isolates of the oomycete plant pathogen Phytophthora cinnamomi from natural and agricultural outbreaks and the long-distance movement of individual genotypes were studied using four microsatellite markers to genotype 159 isolates of Californian, Mexican, and worldwide origins. Allelic profiles identified 75 multilocus genotypes. A STRUCTURE analysis placed them in three groups characterized by different geographic and host ranges, different genic and genotypic diversity, and different reproductive modes. When relationships among genotypes were visualized on a minimum spanning network (MSN), genotypes belonging to the same STRUCTURE group were contiguous, with rare exceptions. A putatively ancestral group 1 had high genic diversity, included all A1 mating type isolates and all Papuan isolates in the sample, was rarely isolated from natural settings in California and Mexico, and was positioned at the center of the MSN. Putatively younger groups 2 and 3 had lower genic diversity, were both neighbors to group 1 but formed two distinct peripherical sectors of the MSN, and were equally present in agricultural commodities and natural settings in Mexico and California. A few genotypes, especially in groups 2 and 3, were isolated multiple times in different locations and settings. The presence of identical genotypes from the same hosts in different continents indicated that long-distance human-mediated movement of P. cinnamomi had occurred. The presence of identical genotypes at high frequencies in neighboring wildlands and agricultural settings suggest that specific commodities may have been the source of recent wild infestations caused by novel invasive genotypes.

From sand to sea: tracing the production and trade in glass beads from the 10th-century Cirebon shipwreck in the Java Sea

2020 ◽  
Author(s):  
Carolyn Swan
Keyword(s):  
Glass Production ◽  
Glass Beads ◽  
Rock Crystal ◽  
Long Distance ◽  
Merchant Ship ◽  
The Indian Ocean ◽  
Java Sea ◽  
Indian Ocean World ◽  
Long Distance Movement ◽  
Lapis Lazuli

Around the year 970 CE, a merchant ship carrying an assortment of goods from East Africa, Persia, India, Sri Lanka, Southeast Asia, and China foundered and sank to the bottom of the Java Sea. Thousands of beads made from many different materials—ceramic, jet, coral, banded stone, lapis lazuli, rock crystal, sapphire, ruby, garnet, pearl, gold, and glass—attest to the long-distance movement and trade of these small and often precious objects throughout the Indian Ocean world. The beads made of glass are of particular interest, as closely-dated examples are very rare and there is some debate as to where glass beads were being made and traded during this period of time. This paper examines 18 glass beads from the Cirebon shipwreck that are now in the collection of Qatar Museums, using a comparative typological and chemical perspective within the context of the 10th-century glass production. Although it remains uncertain where some of the beads were made, the composition of the glass beads points to two major production origins for the glass itself: West Asia and South Asia.

scholarly journals Maize resistance to Sugarcane mosaic virus

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 542-544
Author(s):  
R. Pokorný ◽  
M. Porubová
Keyword(s):  
Mosaic Virus ◽  
Systemic Infection ◽  
Sugarcane Mosaic Virus ◽  
Resistant Line ◽  
Mechanisms Of Resistance ◽  
Long Distance ◽  
Maize Hybrids ◽  
Resistant Lines ◽  
Maize Resistance ◽  
Long Distance Movement

Under greenhouse conditions 12 maize hybrids derived from crosses of four resistant lines with several lines of different level of susceptibility were evaluated for resistance to Czech isolate of Sugarcane mosaic virus (SCMV). These hybrids were not fully resistant to isolate of SCMV, but the symptoms on their newly growing leaves usually developed 1 to 3 weeks later in comparison with particular susceptible line, the course of infection was significantly slower and rate of infection lower. As for mechanisms of resistance, the presence of SCMV was detected by ELISA in inoculated leaves both of resistant and susceptible lines, but virus was detected 7 days later in resistant line. Systemic infection developed only in susceptible lines. These results indicate restriction of viral long distance movement in the resistant line.

scholarly journals Inferring Modes of Colonization for Pest Species Using Heterozygosity Comparisons and a Shared-Allele Test

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 823-831
Author(s):  
J A Sved ◽  
H Yu ◽  
B Dominiak ◽  
A S Gilchrist
Keyword(s):  
Distance Measure ◽  
Fruit Fly ◽  
Small Samples ◽  
Pest Species ◽  
Long Distance ◽  
Resampling Methods ◽  
Shared Allele ◽  
The Core ◽  
Direct Sampling ◽  
Long Distance Movement

Abstract Long-range dispersal of a species may involve either a single long-distance movement from a core population or spreading via unobserved intermediate populations. Where the new populations originate as small propagules, genetic drift may be extreme and gene frequency or assignment methods may not prove useful in determining the relation between the core population and outbreak samples. We describe computationally simple resampling methods for use in this situation to distinguish between the different modes of dispersal. First, estimates of heterozygosity can be used to test for direct sampling from the core population and to estimate the effective size of intermediate populations. Second, a test of sharing of alleles, particularly rare alleles, can show whether outbreaks are related to each other rather than arriving as independent samples from the core population. The shared-allele statistic also serves as a genetic distance measure that is appropriate for small samples. These methods were applied to data on a fruit fly pest species, Bactrocera tryoni, which is quarantined from some horticultural areas in Australia. We concluded that the outbreaks in the quarantine zone came from a heterogeneous set of genetically differentiated populations, possibly ones that overwinter in the vicinity of the quarantine zone.

scholarly journals Differential Tropism in Roots and Shoots of Resistant and Susceptible Cassava (Manihot esculenta Crantz) Infected by Cassava Brown Streak Viruses

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1221
Author(s):  
Samar Sheat ◽  
Paolo Margaria ◽  
Stephan Winter
Keyword(s):  
Virus Replication ◽  
Central Africa ◽  
Streak Virus ◽  
Virus Infections ◽  
Long Distance ◽  
Manihot Esculenta Crantz ◽  
Cassava Brown Streak Virus ◽  
Cassava Brown Streak Disease ◽  
Long Distance Movement ◽  
Brown Streak

Cassava brown streak disease (CBSD) is a destructive disease of cassava in Eastern and Central Africa. Because there was no source of resistance in African varieties to provide complete protection against the viruses causing the disease, we searched in South American germplasm and identified cassava lines that did not become infected with the cassava brown streak viruses. These findings motivated further investigations into the mechanism of virus resistance. We used RNAscope® in situ hybridization to localize cassava brown streak virus in cassava germplasm lines that were highly resistant (DSC 167, immune) or that restricted virus infections to stems and roots only (DSC 260). We show that the resistance in those lines is not a restriction of long-distance movement but due to preventing virus unloading from the phloem into parenchyma cells for replication, thus restricting the virus to the phloem cells only. When DSC 167 and DSC 260 were compared for virus invasion, only a low CBSV signal was found in phloem tissue of DSC 167, indicating that there is no replication in this host, while the presence of intense hybridization signals in the phloem of DSC 260 provided evidence for virus replication in companion cells. In neither of the two lines studied was there evidence of virus replication outside the phloem tissues. Thus, we conclude that in resistant cassava lines, CBSV is confined to the phloem tissues only, in which virus replication can still take place or is arrested.

Pollen as an Indicator of Long-distance Movement of Heliothis zea (Lepidoptera: Noctuidae)

1987 ◽  
Vol 16 (5) ◽  
pp. 1148-1151 ◽  
Author(s):  
W. H. Hendrix ◽  
T. F. Mueller ◽  
J. R. Phillips ◽  
O. K. Davis
Keyword(s):  
Heliothis Zea ◽  
Long Distance ◽  
Long Distance Movement ◽  
Lepidoptera Noctuidae

scholarly journals The Determinant of Potyvirus Ability to Overcome the RTM Resistance of Arabidopsis thaliana Maps to the N-Terminal Region of the Coat Protein

2009 ◽  
Vol 22 (10) ◽  
pp. 1302-1311 ◽  
Author(s):  
V. Decroocq ◽  
B. Salvador ◽  
O. Sicard ◽  
M. Glasa ◽  
P. Cosson ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Coat Protein ◽  
Biological Properties ◽  
Terminal Region ◽  
Plum Pox Virus ◽  
Lettuce Mosaic Virus ◽  
Long Distance ◽  
Resistance Breaking ◽  
Viral Determinant ◽  
Long Distance Movement

In Arabidopsis thaliana Columbia (Col-0) plants, the restriction of Tobacco etch virus (TEV) long-distance movement involves at least three dominant RTM (restricted TEV movement) genes named RTM1, RTM2, and RTM3. Previous work has established that, while the RTM-mediated resistance is also effective against other potyviruses, such as Plum pox virus (PPV) and Lettuce mosaic virus (LMV), some isolates of these viruses are able to overcome the RTM mechanism. In order to identify the viral determinant of this RTM-resistance breaking, the biological properties of recombinants between PPV-R, which systemically infects Col-0, and PPV-PSes, restricted by the RTM resistance, were evaluated. Recombinants that contain the PPV-R coat protein (CP) sequence in an RTM-restricted background are able to systemically infect Col-0. The use of recombinants carrying chimeric CP genes indicated that one or more PPV resistance-breaking determinants map to the 5′ half of the CP gene. In the case of LMV, sequencing of independent RTM-breaking variants recovered after serial passages of the LMV AF199 isolate on Col-0 plants revealed, in each case, amino acid changes in the CP N-terminal region, close to the DAG motif. Taken together, these findings demonstrate that the potyvirus CP N-terminal region determines the outcome of the interaction with the RTM-mediated resistance.

scholarly journals On the nature of cross-linguistic transfer: A case study of Andean Spanish

2012 ◽  
Vol 16 (1) ◽  
pp. 111-131 ◽  
Author(s):  
ANTJE G. MUNTENDAM
Keyword(s):  
Language Contact ◽  
Long Distance ◽  
Andean Spanish ◽  
Pragmatic Transfer ◽  
Elicitation Study ◽  
Linguistic Transfer ◽  
Syntactic Properties ◽  
Elicitation Studies ◽  
Long Distance Movement

This paper presents the results of a study on cross-linguistic transfer in Andean Spanish word order. In Andean Spanish the object appears in preverbal position more frequently than in non-Andean Spanish, which has been attributed to an influence from Quechua (a Subject–Object–Verb language). The high frequency of preverbal objects could be explained by focus fronting. The main syntactic properties of focus fronting in Spanish are weak crossover and long distance movement. Two elicitation studies designed to test for these properties in non-Andean Spanish, Andean Spanish and Quechua show no evidence of syntactic transfer from Quechua into Andean Spanish. Rather, the analysis of naturalistic data and an elicitation study on question–answer pairs show that there is pragmatic transfer from Quechua into Andean Spanish. The study has implications for theories of syntax and language contact, and especially for the debate on the nature of cross-linguistic transfer.

scholarly journals An Investigation into Marmot Migration in Grand Teton National Park

1996 ◽  
Vol 20 ◽  
pp. 78-82
Author(s):  
George Montopoli ◽  
Nick Visser ◽  
Hank Harlow
Keyword(s):  
National Park ◽  
Movement Patterns ◽  
Snow Melt ◽  
Marmota Flaviventris ◽  
Long Distance ◽  
The North ◽  
North Fork ◽  
Males And Females ◽  
Study Sites ◽  
Long Distance Movement

In 1994 and 1995, a high abundant winter snowfall at higher elevations appeared to result in long distance movement patterns by yellow-bellied marmot (Marmota flaviventris) over snow to lower, snowfree elevations where food was more available. As the snow melted and food became abundant, the marmots return to higher altitudes. In 1996, we continued to investigate the potential for migrational movements, by studying two study sites at different elevations in the North Fork of Cascade Canyon. Four marmots at each site were implanted with intraperitoneal tracking transmitters. Of eight marmots that were equipped with intraperitoneal transmitters, six demonstrated significant movements of greater than 0.5 km, one did not, and one most likely died as a result of predation before any movement could be observed. Of the six that demonstrated significant movements within the canyon, only one moved distances greater than 1 km. Marmots, after emerging from hibernation, migrated down canyon to snowfree areas as they become available. With progressive snow melt, most marmots move upward to higher elevations, but not to the extent originally expected. Instead, they moved to the first available habitat where food was obtainable, and other (dominant) marmots accepted their presence. This movement is exhibited in both males and females, yearlings and adults, and melanistic and normal colored marmots.

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