Genetic variation and inheritance of randomly amplified polymorphic DNA (RAPD) markers in female grass carp (Ctenopharyngodon idella) and male bighead carp (Hypophthalmichthys nobilis) and their F1 offspring hybrid have been studied. For this purpose, genomic DNA was extracted from muscle tissue according to phenol-chloroform method, and six decamer primers were used for amplifying polymorphic ...

Hybridization between divergent lineages often results in reduced hybrid viability. Here we report findings from a series of independent molecular analyses over several seasons on four life stages of F1 hybrids between the newts Triturus cristatus and T. marmoratus. These two species form a bimodal hybrid zone of broad overlap in France, with F1 hybrids making up about 4% of the adult populatio...

"Ecological" speciation occurs when reproductive isolation evolves as a consequence of divergent selection between populations exploiting different resources or environments. We tested this hypothesis of speciation in a young stickleback species pair by measuring the direct contribution of ecological selection pressures to hybrid fitness. The two species (limnetic and benthic) are strongly diff...

The river floodplain species Rorippa amphibia, Rorippa sylvestris, and their hybrid Rorippa x anceps were studied here, with the aim of identifying potential species differences with respect to flooding tolerance, and of assessing their expression in F1 hybrids. Parents and their F1 hybrids were subjected to three flooding treatments mimicking natural conditions, and growth-related and leaf mor...

Two F1 hybrids one between wild C. annuum var glabrisculum and C. frutescens (H1) and another between wild C. annuum var antigua and C. frutescens (H2) were obtained. Cytogenetic analysis of F1 hybrids showed that the parental genomes differ from each other by 2 or 1 translocations, 1 inversion and some minor structural alterations leading to reduced homologies between the respective parental g...

The eggplant (Solanum melongena) semi-long black varietal type is the most important in most European markets. Although open pollinated, pure lines and F1 hybrid cultivars exist within this varietal group, the latter predominate in the commercial production of eggplants, especially under greenhouse conditions. However, molecular markers studies have found that modern F1 hybrids present a reduce...

Whether to develop inbred cultivars or F1 hybrids is a dilemma faced by many rice (Oryza sativa L.) breeders. This could be partially answered if one could select superior recombinant inbred lines with an equal yielding ability and good quality traits from commercial F1 hybrids. Thus, it was attempted in this study to select superior inbred lines from 2 commercial F1 hybrids after application o...

Previous work has demonstrated that genomic incompatibilities work together with ecologically divergent selection to promote and maintain reproductive isolation between incipient species (dwarf and normal) of lake whitefish (Coregonus clupeaformis (Mitchill, 1818)). Whitefish spawn in groups with external fertilization, which creates conditions for strong sperm competition. In this study, we as...

BACKGROUND Hybrid weakness, a phenomenon opposite to heterosis, refers to inferior growth and development in a hybrid relative to its pure-line parents. Little attention has been paid to the phenomenological or mechanistic aspect of hybrid weakness, probably due to its rare occurrence. METHODOLOGY/PRINCIPAL FINDINGS Here, using a set of interspecific triploid F1 hybrids between Oryza sativa, ...

Heterosis has been widely exploited as an approach to enhance crop traits during breeding. However, its underlying molecular genetic mechanisms remain unclear. Recent advances in RNA sequencing technology (RNA-seq) have provided an opportunity to conduct transcriptome profiling for heterosis studies. We used RNA-seq to analyze the flower transcriptomes of two F1 hybrid soybeans (HYBSOY-1 and HY...