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Since the mid-1980s, our understanding of avian reproductive strategies has shifted as new molecular technologies have revealed how common promiscuity is in many monogamous avian species. However, the prevalence and importance of extra-pair paternity in polygynous species is less well studied. We used microsatellite loci from related icterid species to identify the extra-pair paternity rate in a polygynous population of Bobolinks (Dolichonyx oryzivorus) that bred in the Champlain Valley of Vermont from 2002 to 2018. We assigned paternity for 120 nestlings and found that 42% of nestlings were sired by extra-pair males. These results highlight the importance of extra-pair paternity in the reproductive behavior of Bobolinks that breed in agricultural habitats. Received 29 March 2020. Accepted I October 2021. Key words: leteridae, loci, polygyny, Vermont. Desde mediados de la decada de 1980, nuestro entendimiento de las estrategias reproductivas de aves ha cambiado, mientras nuevas tecnologias moleculares nos revelan que tan comun es la promiscuidad en muchas especies de aves monogamas. Sin embargo, la prevaleneia e importancia de la paternidad extra-pareja especies poliginas esta menos bien estudiada. Usamos loci de microsatelites de ictcridos emparentados para identificar la tasa de paternidad extra-pareja en una pohlacion poligina del tordo arrocero Dolichonyx otyzlvorus que anida en el Champlain Valley de Vermont de 2002-2018. Asignamos la paternidad de 120 polluelos y encontramos que 42% de estos fueron procreados por machos extra-pareja. Estos resultados destacan la importancia de la paternidad extra-pareja en el comportamiento reproductive de los tordos arroceros que anidan en habitats agricolas. Palabras clave: leteridae, loci, poliginia. Vermont., Prior to the widespread use of genetic tools, most avian species were thought to be genetically monogamous (Lack 1968, Gavin and Bollinger 1985, Gowaty 1985). However, mounting evidence has suggested [...]

Premise: Studies of hybridizing species are facilitated by the availability of species-specific molecular markers for identifying early- and later-generation hybrids. Cattails are a dominant feature of wetland communities, and a better understanding of the prevalence of hybrids is needed to assess the ecological and evolutionary effects of hybridization. Hybridization between Typha angustifolia and T. latifolia produce long-lived clones, known as Typha xglauca, which are considered to be invasive. Although morphological variation in cattails makes it difficult to recognize early- and later-generation hybrids, several dominant, species-specific RAPD markers are available. Our goal was to find codominant, species-specific markers with greater polymorphism than RAPDs, to identify later-generation hybrids more efficiently. Methods: We screened nine SSR (simple sequence repeat) loci that were described from populations in Ukraine, and we surveyed 31 cattail populations from the upper Midwest and eastern USA. Key results: Seven SSR loci distinguished the parent taxa and were consistent with known species-specific RAPD markers, allowing easier detection of backcrossing. We used linear discriminant analysis to show that [F.sub.1] hybrid phenotypes were intermediate between the parent taxa, while those of backcrossed plants overlapped with the hybrids and their parents. Log(leaf length/leaf width), spike gap length, spike length, and stem diameter explained much of the variation among groups. Conclusions: We provide the first documentation of backcrossed plants in hybridizing cattail populations in Michigan. The diagnostic SSR loci we identified should be extremely useful for examining the evolutionary and ecology interactions of hybridizing cattails in North America. Key words: cattail; gene flow; hybrid; introgression; invasive species; molecular markers; morphological traits; species-specific markers; STRUCTURE; Typha; wetlands. doi: 10.3732/ajb.1000187

Genetic marker systems have improved dramatically in the past 10 yr. Each new system needs to be evaluated for its distribution of markers on genetic linkage maps to validate its use for genetic analysis. The resulting maps an also useful for establishing the genetic positions of genes affecting important phenotypes. We have constructed a high density map in soybean [Glycine max (L.) Merr.] using a 300 RIL (recombinant inbred line) population from BSR101 x PI437.654 by first constructing an RFLP (restriction fragment length polymorphism) 'scaffold' map based on the entire population. The RFLP anchored map was then further populated with AFLP (amplified fragment length polymorphism) markers based on only a 42 RIL subset. We report here an 840 marker map consisting of 165 RFLP, 25 RAPD (random amplified polymorphic DNA), and 650 AFLP markers spread over 29 linkage groups representing 3441 cM distance. Although clustering of AFLP markers occurred, markers were mapped to every linkage group and were well distributed relative to other marker systems. The AFLP marker system appears to be a useful approach for generating high density genetic maps in soybean., GENETIC MAPPING has been greatly enhanced in the last decade with the introduction of novel genetic marker systems. These systems have resulted in increased capabilities for detecting DNA polymorphism and [...]

Amplified fragment length polymorphism (AFLP) markers were utilized to determine the phylogenetic relationship between Bacillus anthracis and related Bacillus species. Polymerase chain reaction analysis of the Bacillus genome with AFLP markers indicated the presence of low levels of molecular variation in Bacillus anthracis due to low rates of evolution that restricted the generation of molecular diversity. Furthermore, genomic analysis indicated the close phylogenetic relationship between Bacillus anthracis and Bacillus cereus.

We explored the nature and impact of competitive interactions between the salt marsh foundational plant Spartina alterniflora and invasive Phragmites australis in New England under varying levels of anthropogenic influence from nutrient loading and temperature warming. Plants were grown with and without competition in mesocosms over a four-month growing season. Mesocosms were split evenly among three levels of nutrient additions and two temperatures varying by an average of ~3° C, manipulated using small greenhouses. We measured aboveground productivity as total biomass, numbers of new stems, and mean stem height. Nutrient enrichment increased all growth parameters, while competition generally reduced aboveground biomass and the production of new stems in both species. Most importantly, smooth cordgrass suffered no negative consequences of competition when no nutrients were added and temperature was elevated. The results of this study suggest that minimizing nutrient loading into coastal marshes could be an important factor in slowing the spread of common reed into the low marsh zone of New England salt marshes as global temperatures continue to warm. [ABSTRACT FROM AUTHOR]

Ecologists have a growing appreciation for the influence of intraspecific, or genotypic, diversity on ecosystem functioning in species depauperate systems such as salt marshes, with intraspecific interactions serving as one potential driver of such diversity. We examined the role of intraspecific interactions, both competitive and facilitative, in structuring populations of Spartina alterniflora , a foundational salt marsh plant known to influence community structure and function throughout its native distribution in eastern North America. We conducted a transplantation experiment at a created site in southwestern Louisiana, USA, by growing five S. alterniflora genotypes, or clones, for two years in all possible combinations, and monitored their interactions using morphological measurements and molecular marker genotyping. Using stem densities as a proxy for above-ground biomass, we found support for our hypothesis that interactions have a mutually limiting effect on growth, although we were unable to find statistical support for competitive asymmetries between specific clone pairs, which would have explained earlier observations of declining genotypic diversity in aging marshes. Using proportions of stems flowering as a proxy for reproductive effort, we also found support for our hypothesis that interactions can have a stimulatory effect on flowering, which could promote genotypic diversity through the recruitment of outcrossed seedlings in a species known for severe inbreeding depression. Reproductive interactions were at times mutually inhibitory or stimulatory, as evidenced by positive correlations of flowering responses between clones. To our knowledge, ours is one of the first studies to evaluate the outcome of one-on-one interactions among genotypes of a foundational clonal plant. [ABSTRACT FROM AUTHOR]