the european corn borer, ostrinia nubilalis (hübner), is an important insect pest of corn, zea mays l., crop in moghan region. in field experiments, the density of eggs and larvae of o.nubilalis and percentage of eggs and larvae parasitisms were studied on four corn hybrids ns704 (commercial cultivar), ns770, ns640 and mv524 (cultivars with high yield). furthermore, in this study, the predators...

As an alternative to sexual crossing, protoplasts from two strains of moss (Physcomitrella patens) can be hybridized using polyethylene glycol (PEG). Although the efficiency is low, it requires no sophisticated apparatus. Hybrids are readily obtained using complementary auxotrophic mutants or strains with transgenic antibiotic resistance markers. It is now routine to obtain hybrids using transg...

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, ...

in order to evaluate the utilization ability of drought resistance indices such as: yield index (yi), yield stability index (ysi), stress susceptibility index (ssi), tolerance (tol), mean productivity (mp), geometric mean productivity (gmp) and stress tolerance index (sti) in sunflower hybrids, three separate experiments were conducted as randomized complete block design at the research field o...

The development of chromophore-carbon nanotube hybrids requires efficient and accurate methods to investigate their photophysical properties. Using the ability of the fluorescence labeling of surface species (FLOSS) technique to determine the density of covalently attached dyes to the surface of single-walled carbon nanotubes (SWCNTs), the luminescence of dye-SWCNT hybrids was quantitatively st...

RNA-DNA hybrids are naturally occurring obstacles that must be overcome by the DNA replication machinery. In the absence of RNase H enzymes, RNA-DNA hybrids accumulate, resulting in replication stress, DNA damage and compromised genomic integrity. We demonstrate that Mph1, the yeast homolog of Fanconi anemia protein M (FANCM), is required for cell viability in the absence of RNase H enzymes. Th...

Tree invasions have substantial impacts on biodiversity and ecosystem functioning, and trees that are dispersed by animals are more likely to become invasive. In addition, hybridisation between plants is well documented as a source of new weeds, as hybrids gain new characteristics that allow them to become invasive. Corymbia torelliana is an invasive tree with an unusual animal dispersal mechan...

Natural hybridization can produce individuals that vary widely in fitness, depending upon the performance of particular genotypes in a given environment. In a hybrid zone with habitat heterogeneity, differences in physiological responses to abiotic conditions could influence the fitness and spatial distribution of hybrids and parental species. This study compared gas exchange physiology of Ipom...

"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...