Article

Distribution of common genotypes of Myzus persicae (Hemiptera : Aphididae) in Greece, in relation to life cycle and host plant

Department of Entomology, The Natural History Museum, London, SW7 5BD, UK.
Bulletin of Entomological Research (Impact Factor: 1.91). 07/2007; 97(3):253-63. DOI: 10.1017/S0007485307004907
Source: PubMed

ABSTRACT

Microsatellite genotyping was used to identify common clones in populations of the Myzus persicae group from various hosts and regions in mainland Greece and southern Italy and to compare their distribution and occurrence on tobacco and other crops. Common clones were defined as genotypes collected at more than one time or in more than one population; and, therefore, unlikely to be participating in the annual sexual phase on peach. Sixteen common genotypes were found, accounting for 49.0% of the 482 clonal lineages examined. Eight of these genotypes were subjected, in the laboratory, to short days and found to continue parthenogenetic reproduction, i.e. they were anholocyclic. Four of the six commonest genotypes were red, and one of these accounted for 29.6% of the samples from tobacco and 29.4% of those from overwintering populations on weeds. All six commonest genotypes were found on weeds and five of them both on tobacco and on other field crops. In mainland Greece, the distribution of common clones corresponded closely with that of anholocyclic lineages reported in a previous study of life cycle variation. Common genotypes were in the minority in the commercial peach-growing areas in the north, except on weeds in winter and in tobacco seedbeds in early spring, but predominated further south, away from peach trees. This contrasts with the situation in southern Italy, reported in a previous paper, where peaches were available for the sexual phase, yet all samples from tobacco were of common genotypes.

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Available from: JOHN A. TSITSIPIS, Jun 17, 2014
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    • "Microsatellite analysis has also been widely used to investigate the genetic structure of the M. persicae population. Bayesian clustering and admixture analyses helped classify green peach aphid genotypes into three groups, corresponding to the common persicae, the bisexual nicotianae, and unisexual nicotianae (Blackman et al., 2007). Angela (2006) classified 18 geographic populations of green peach aphids in Italy into two categories, and the genetic distance between these populations was positively correlated to the geographic distance. "
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    ABSTRACT: The tobacco aphid, Myzus persicae nicotianae (Hemiptera: Aphididae), is an important agricultural pest that feeds on host plants and transmits plant viruses in China. To effectively control this pest, we investigated the genetic variation and genetic structure of 54 populations of tobacco aphids collected in China, using five microsatellite loci. An average of 7 alleles with effective number ranging from 1.5 to 6.6 was detected using these five loci, and the average polymorphic information content (PIC) was 0.652, suggesting that the five selected microsatellite loci were polymorphic and suitable for the study of population genetics. The expected heterozygosities in the populations studied ranged from 0.128 and 0.653, with an average value of 0.464. However, the observed heterozygosities ranged from 0.250 and 0.942 (average = 0.735), revealing a high genetic variability and heterozygosity excess in the Chinese tobacco aphid populations. The global fixation index (FST) and mean gene flow (Nm) were 0.34 (P < 0.0001) and 0.50, respectively, suggesting the high genetic differentiation among Chinese populations. The 54 populations of tobacco aphids were classified into two groups. The populations did not cluster geographically, as populations from the same provinces were usually present in different clusters. This was also confirmed by the Mantel test, which showed no significant correlation between the genetic distance and geographical distance or altitude. Long distance migration might be responsible for the lack of distance-related isolation.
    Preview · Article · Dec 2015 · Genetics and molecular research: GMR
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    • "Molecular and morphological studies have revealed that populations of M. persicae on Nicotiana tabacum L. (Solanaceae) are genetically and morphologically different from those on other host plants, and support the existence of a host race associated with tobacco (Blackman, 1987; Blackman & Spence, 1992; Margaritopoulos et al., 1998, 2000, 2003, 2007a, 2007b; Zitoudi et al., 2001; Blackman et al., 2007). Microsatellite or DNA short tandem repeats (STR) are codominant markers that have been successfully used to provide information about the population structure in aphids in relation to their life cycle, host, geographical distribution and dynamics (Sunnucks et al., 1997; Simon et al., 1999; Delmotte et al., 2002; Guillemaud et al., 2003; Vorburger et al., 2003a; Vorburger, 2006; Blackman et al., 2007; Margaritopoulos et al., 2007a). "
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    ABSTRACT: Diverse agroecosystems offer phytophagous insects a wide choice of host plants. Myzus persicae is a polyphagous aphid common in moderate climates. During its life cycle it alternates between primary and secondary hosts. A spatial genetic population structure may arise due to environmental factors and reproduction modes. The aim of this work was to determine the spatial and temporal genetic population structure of M. persicae in relation to host plants and climatic conditions. For this, 923 individuals of M. persicae collected from six plant families between 2005 and 2008 in south-eastern Spain were genotyped for eight microsatellite loci. The population structure was inferred by neighbour-joining, analysis of molecular variance (AMOVA) and Bayesian analyses. Moderate polymorphism was observed for the eight loci in almost all the samples. No differences in the number of alleles were observed between primary and secondary hosts or between geographical areas. The proportion of unique genotypes found in the primary host was similar in the north (0.961 ± 0.036) and the south (0.987 ± 0.013), while in the secondary host it was higher in the north (0.801 ± 0.159) than in the south (0.318 ± 0.063). Heterozygosity excess and linkage disequilibrium suggest a high representation of obligate parthenogens in areas with warmer climate and in the secondary hosts. The F ST-values pointed to no genetic differentiation of M. persicae on the different plant families. F ST-values, AMOVA and Bayesian model-based cluster analyses pointed to a significant population structure that was related to primary and secondary hosts. Differences between primary and secondary hosts could be due to the overrepresentation of parthenogens on herbaceous plants.
    Preview · Article · Mar 2013 · Bulletin of entomological research
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    • "Similarly, common (asexual) and sexual genotypes from a non-tobacco growing areas of Greece and from southern Italy do not have the ability to use tobacco as a suitable host-plant (Nikolakakis et al., 2003; Margaritopoulos et al., 2003; 2005; Blackman et al., 2007). On the other hand, the genotype of M. persicae nicotianae used in our study exhibited a higher performance on pepper than on tobacco, which reinforces the notion that M. persicae nicotianae can use other plant species as suitable hosts like tobacco (Semtner et al., 1998; Nikolakakis et al., 2003; Blackman et al., 2007). "

    Full-text · Article · Dec 2010
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