Cryptic sympatric species arise when reproductive isolation is established in sympatry, leading to genetically divergent lineages that are highly similar morphologically or virtually indistinguishable. Although cryptic sympatric species have been reported in various animals, fungi, and protists, there are few compelling examples for plants. This investigation presents a case for cryptic sympatr...

Tetraploid inheritance has two extremes: disomic in allotetraploids and tetrasomic in autotetraploids. The possibility of mixed, or intermediate, inheritance models has generally been neglected. These could well apply to newly formed hybrids or to diploidizing (auto)tetraploids. We present a simple likelihood-based approach that is able to incorporate disomic, tetrasomic, and intermediate inher...

BACKGROUND AND AIMS Intraspecific genome size variability of Festuca pallens occurring on relict rocky steppes in Central Europe was studied on two ploidy levels and three geographical scales: (1) local scale of 24 populations, (2) landscape scale of three transects in river canyons or hill systems, and (3) global scale of 160 samples covering the whole distribution area. METHODS DAPI flow cy...

Tetraploidization is believed to promote genome instability and tumorigenesis. Whether tetraploids per se are intrinsically unstable and transforming remain incompletely understood. In this report, tetraploidization was induced with cell fusion using mouse fibroblasts. Due to the unequal segregation of chromosomes during multipolar mitosis, the majority of cells were eliminated by p53-dependent...

The extent and spatial patterns of genetic variation at allozyme markers were investigated within and between diploid and autotetraploid knapweeds (Centaurea jacea L. sensu lato, Asteraceae) at contrasted geographic scales: (1) among populations sampled from a diploid-tetraploid contact zone in the northeastern part of the Belgian Ardennes, and (2) within mixed populations from that zone where ...

Unilateral introgression from diploids to tetraploids has been hypothesized to be an important evolutionary mechanism in plants. However, few examples have been definitively identified, perhaps because data of sufficient depth and breadth were difficult to obtain before the advent of affordable high-density genotyping. Throughout Japan, tetraploid Miscanthus sacchariflorus and diploid Miscanthu...

Platycladus orientalis (L.) Franco (syn. Thuja orientalis L.), Thuja occidentalis L., and T. plicata D. Don. are conifers often used in the landscape. Most of the available cultivars of these species share the character of having foliage that turns an off-color during winter as a result of photoinhibition. Tetraploids of the related japanese-cedar [Cryptomeria japonica (L. f.) D. Don.] have exh...

We used flow cytometry and extensive geographic surveys of herbivore attack to test whether repeated evolution of autotetraploidy in the perennial herb Heuchera grossulariifolia Rydb. (Saxifragaceae) has created evolutionary barriers to attack by the specialist moth herbivore Greya politella (Prodoxidae). We found that the moth has colonized tetraploid as well as diploid populations, has coloni...

Chromosome numbers are reported here for the first time from 117 individuals of Solidago rugosa and S. fistulosa. Including 178 previously published reports two species plus latissimifolia, chromosome have been determined 295 269 locations. Only diploids (2n = 18) were found throughout range fistulosa on coastal plain in eastern U.S.A. (44 counts). Diploids northern portion tetraploids 36) hexa...

Polyploidization is one of the few mechanisms that can produce instantaneous speciation. Among animals, gray tree frogs (Hyla versicolor complex) have been the source of considerable debate regarding speciation by polyploidization. Molecular evidence and advertisement calls indicate that tetraploid gray tree frogs originated multiple times from extant diploid gray tree frogs and two lineages of...