scholarly journals Increased genetic diversity as a defence against parasites is undermined by social parasites: Microdon mutabilis hoverflies infesting Formica lemani ant colonies

2006 ◽  
Vol 274 (1606) ◽  
pp. 103-110 ◽  
Author(s):  
M.G Gardner ◽  
K Schönrogge ◽  
G.W Elmes ◽  
J.A Thomas
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Social Insects ◽  
Empirical Test ◽  
Social Parasite ◽  
Social Parasites ◽  
Ant Colonies ◽  
Nestmate Recognition Cues ◽  
Immune Defences ◽  
Two Populations

Genetic diversity can benefit social insects by providing variability in immune defences against parasites and pathogens. However, social parasites of ants infest colonies and not individuals, and for them a different relationship between genetic diversity and resistance may exist. Here, we investigate the genetic variation, assessed using up to 12 microsatellite loci, of workers in 91 Formica lemani colonies in relation to their infestation by the specialist social parasite Microdon mutabilis . At the main study site, workers in infested colonies exhibited lower relatedness and higher estimated queen numbers, on average, than uninfested ones. Additionally, estimated queen numbers were negatively correlated with estimated average numbers of mates per queen within infested colonies. At another site, infested colonies also exhibited significantly lower worker relatedness, and estimated queen numbers were comparable in trend. In contrast, in two populations of F. lemani where M. mutabilis was absent, relatedness within colonies was high (40 and 90% with R >0.6). While high genetic variation can benefit social insects by increasing their resistance to pathogens, there may be a cost in the increased likelihood of infiltration by social parasites owing to greater variation in nestmate recognition cues. This study provides the first empirical test of this hypothesis.

Genetic variation between and within two populations of Rhabdocline pseudotsugae in Germany

2016 ◽  
Vol 46 (5) ◽  
pp. 716-724 ◽  
Author(s):  
Kristin Morgenstern ◽  
Jens-Ulrich Polster ◽  
Doris Krabel
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Spatial Distribution ◽  
Pseudotsuga Menziesii ◽  
Early Stage ◽  
Start Codon ◽  
Fruiting Bodies ◽  
Clear Differentiation ◽  
High Degree ◽  
Two Populations

Knowledge of the ecology and biology of Rhabdocline pseudotsugae Sydow is still at a very early stage. Recent results indicate the existence of an endophytic stage of the fungus in the form of symptomless infections in various Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) tissue types. This study represents the first description of genetic variation between and within two populations of R. pseudotsugae. Needles featuring fruiting bodies of R. pseudotsugae were collected from sample areas in Saxony and North Rhine-Westphalia (in Germany), with different fungal genotypes distinguished using the start codon targeted polymorphism (SCoT) and branch point signal sequences (BPS) techniques. Five of the 20 primers tested could be selected for further investigation. A total of 349 fragments were amplified at an average of 69.8 fragments per primer. Results showed the two sample areas to exhibit a high degree of both genetic variability and genetic diversity. A clear differentiation between the sample areas was not observed. There was nevertheless a clear connection between the genetic distance and spatial distribution of the fruiting bodies of R. pseudotsugae within the sample areas themselves.

Genetic diversity studies of alfalfa germplasm (Medicago sativa L. subsp. sativa) of United States origin using microsatellite analysis

2017 ◽  
Author(s):  
Shuying Yin ◽  
Yanrong Wang ◽  
Zhibiao Nan
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Polymorphic Information Content ◽  
The United States ◽  
Microsatellite Analysis ◽  
Information Index ◽  
Diversity Studies ◽  
Two Populations

This study aimed to understand the genetic diversity and population structure of alfalfa germplasm from the United States. In this study, the population structure and genetic diversity of six alfalfa cultivars of United States origin were investigated by microsatellite analysis with 40 individuals per cultivar. A total of 312 discernible alleles were amplified from the whole genome with an average of 31.2 alleles per locus. The average values of polymorphic information content and Shannon’s information index were 0.928 and 0.133, respectively, showing high levels of genetic diversity. Two populations were identified by STRUCTURE software with principal coordinate analysis and neighbour-joining clustering. Analysis of molecular variance analysis (AMOVA) revealed that the majority of genetic variation was within cultivars (96.42%) rather than between cultivars (3.58%). In conclusion, analyses of genetic diversity and population structure may be useful for the genetic analysis and utilization of genetic variation in alfalfa breeding.

scholarly journals ECOLOGY AND THE RAPD TECHNIQUES USED TO ASSESS THE GENETIC DIVERSITY IN PTEROLOBIUM HEXAPETALUM, A SCRAMBLING MEDICINAL SHRUB IN MARUTHAMALAI AND CHENNIMALAI HILLS, THE WESTERN GHATS

2019 ◽  
pp. 72-77 ◽  
Author(s):  
SHARMILA S. ◽  
AKILANDESWARI D. ◽  
RAMYA E. K. ◽  
MOWNIKA S.
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Tamil Nadu ◽  
Climatic Factors ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Climatic Conditions ◽  
Individual Bands ◽  
Reproductive Characters ◽  
Two Populations

Objective: To investigate the ecological and genetic diversity, climatic factors, edaphic factors morphological and reproductive characters and RAPD analysis of medicinal plant species Pterolobium hexapetalum in two hills viz., Maruthamalai (arid) and Chennimalai (very arid), which is located in Coimbatore and Erode districts, Tamil Nadu. Methods: The present research was carried out by using a random amplified polymorphic DNA (RAPD) analysis was made to determine the genetic variation between the two populations of the medicinal shrub, Pterolobium hexapetalum in an environmental gradient. Among the five primers tested, the OPN7 (80 %) and OPN17 (71.4 %) produced higher polymorphism was used in RAPD analysis. Results: The results of RAPD analysis showed the presence of 51 individual bands were formed, out of which, 29 were polymorphic bands which showed the existence of genetic variation between populations. A dendrogram was constructed based on Jaccard’s coefficient to determine the degree of genetic relationship among the two populations and analysed. The primers OPN7 and OPN17 were clustered together at a genetic distance level 10. Considering the elevation and proximity, the temperature ranges from 18 °C to 37.6 °C in Maruthamalai hill and 20 °C to 39.4 °C in Chennimalai hill. Conclusion: From the morphoecological studies the results indicated that both arid and very arid climatic conditions showed slight differences in their vegetative and reproductive characters.

The genetic diversity of Myrciaria floribunda (Myrtaceae) in Atlantic Forest fragments of different sizes

2007 ◽  
Vol 23 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Edivani Villaron Franceschinelli ◽  
Giuliana Mara Patrício Vasconcelos ◽  
Elena Charlotte Landau ◽  
Kátia Yukari Ono ◽  
Flávio Antonio Maes Santos
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Atlantic Forest ◽  
Diversity Indices ◽  
Forest Tree ◽  
Forest Fragments ◽  
Allozyme Electrophoresis ◽  
Large Fragment ◽  
Effective Number ◽  
Two Populations

The genetic diversity of Myrciaria floribunda, a common Atlantic Forest tree, was investigated in six populations located in two small fragments (10 and 18 ha), two medium-sized fragments (36 and 44 ha) and one large fragment (3003 ha). Two populations occur in the large fragment. It is expected that smaller fragments should have lower genetic diversity and higher inbreeding. Distances between fragments varied from 0.66 to 10 km. On average 32 young trees smaller than 20 cm basal girth were sampled in each population. Allozyme electrophoresis was carried out, and six loci were scored. The effective number of alleles was lower for populations of the two small fragments (1.46 and 1.51) and higher for populations of the large (1.62 and 1.71) and medium ones (1.69 and 1.84). Small fragments showed lower values of expected and observed heterozygosities than large and medium fragments. Most of the genetic variability occurs within populations, and there was a moderate genetic variation among them ($\hat{\theta}_p$ = 0.097). Our findings show a tendency of lower genetic diversity within small and isolated fragments and higher genetic differentiation among them. But, few correlations between genetic diversity indices and fragment features (size and isolation) were significant.

Comparing Genetic Variation within Red Winter Wheat Populations with and without Image-Based Optical Sorter Selection

2019 ◽  
Vol 9 (2) ◽  
pp. 266-277
Author(s):  
Hussein M. Khaeim ◽  
Anthony Clark ◽  
Tom Pearson ◽  
Dr. David Van Sanford
Keyword(s):  
Genetic Variation ◽  
Fusarium Head Blight ◽  
Heading Date ◽  
Fusarium Head Blight Resistance ◽  
Gibberella Zeae ◽  
Mass Selection ◽  
Head Blight ◽  
Red Winter Wheat ◽  
Two Populations ◽  
Head Scab

Head scab is historically a devastating disease affecting not just all classes of wheat but also barley and other small grains around the world. Fusarium head blight (FHB), or head scab, is caused most often by Fusarium graminearum (Schwabe), (sexual stage – Gibberella zeae) although several Fusarium spp. can cause the disease. This study was conducted to determine the effect of mass selection for FHB resistance using an image-based optical sorter. lines were derived from the C0 and C2 of two populations to compare genetic variation within populations with and without sorter selection. Our overall hypothesis is that sorting grain results in improved Fusarium head blight resistance. Both of the used wheat derived line populations have genetic variation, and population 1 has more than population 17. They are significantly different from each other for fusarium damged kernel (FDK), deoxynivalenol (DON), and other FHB traits. Although both populations are suitable to be grown for bulks, population 1 seems better since it has more genetic variation as well as lower FDK and DON, and earlier heading date. Lines within each population were significantly different and some lines in each population had significantly lower FDK and DON after selection using an optical sorter. Some lines had significant reduction in both FDK and DON, and some others had either FDK or DON reduction. Lines of population 1 that had significant reduction, were more numerous than in population 17, and FDK and DON reduction were greater.

Allozyme Variation and Population Substructuring in the Caucasian Ground Lizards Lacerta derjugini and Lacerta praticola

2011 ◽  
Vol 4 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Ross D. MacCulloch ◽  
Ilya S. Darevsky ◽  
Robert W. Murphy ◽  
Jinzhong Fu
Keyword(s):  
Genetic Diversity ◽  
Allozyme Variation ◽  
Close Proximity ◽  
Geographic Separation ◽  
Population Substructuring ◽  
Allozyme Loci ◽  
Two Populations

Genetic diversity at 35 allozyme loci was surveyed in Lacerta derjugini (3 populations) and L. praticola (2 populations). Indices of variability were consistent with those found in other Caucasian Lacerta. There was little genetic substructuring between two populations of L. praticola despite considerable geographic separation. Conversely, populations of L. derjugini in close proximity to one another exhibited considerable substructuring.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

scholarly journals Genetic Diversity of Landraces and Improved Varieties of Rice (Oryza sativa L.) in Taiwan

Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ai-ling Hour ◽  
Wei-hsun Hsieh ◽  
Su-huang Chang ◽  
Yong-pei Wu ◽  
Han-shiuan Chin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Indigenous Peoples ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Genetic Erosion ◽  
Germplasm Conservation ◽  
Gene Pools ◽  
Improved Varieties ◽  
Breeding Goals

Abstract Background Rice, the most important crop in Asia, has been cultivated in Taiwan for more than 5000 years. The landraces preserved by indigenous peoples and brought by immigrants from China hundreds of years ago exhibit large variation in morphology, implying that they comprise rich genetic resources. Breeding goals according to the preferences of farmers, consumers and government policies also alter gene pools and genetic diversity of improved varieties. To unveil how genetic diversity is affected by natural, farmers’, and breeders’ selections is crucial for germplasm conservation and crop improvement. Results A diversity panel of 148 rice accessions, including 47 cultivars and 59 landraces from Taiwan and 42 accessions from other countries, were genotyped by using 75 molecular markers that revealed an average of 12.7 alleles per locus with mean polymorphism information content of 0.72. These accessions could be grouped into five subpopulations corresponding to wild rice, japonica landraces, indica landraces, indica cultivars, and japonica cultivars. The genetic diversity within subpopulations was: wild rices > landraces > cultivars; and indica rice > japonica rice. Despite having less variation among cultivars, japonica landraces had greater genetic variation than indica landraces because the majority of Taiwanese japonica landraces preserved by indigenous peoples were classified as tropical japonica. Two major clusters of indica landraces were formed by phylogenetic analysis, in accordance with immigration from two origins. Genetic erosion had occurred in later japonica varieties due to a narrow selection of germplasm being incorporated into breeding programs for premium grain quality. Genetic differentiation between early and late cultivars was significant in japonica (FST = 0.3751) but not in indica (FST = 0.0045), indicating effects of different breeding goals on modern germplasm. Indigenous landraces with unique intermediate and admixed genetic backgrounds were untapped, representing valuable resources for rice breeding. Conclusions The genetic diversity of improved rice varieties has been substantially shaped by breeding goals, leading to differentiation between indica and japonica cultivars. Taiwanese landraces with different origins possess various and unique genetic backgrounds. Taiwanese rice germplasm provides diverse genetic variation for association mapping to unveil useful genes and is a precious genetic reservoir for rice improvement.

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