The view of B-chromosome polymorphisms that is coming into favor resembles the so-called "parasitic" model, which was first advanced 45 yr ago. Since time, repeated and ongoing efforts have been made to ascribe an adaptive role B's (e.g., in terms phenotypic advantage, effects variability, etc.), but success this direction has singularly lacking. Consistently repeatedly, data indicate harmful effects, or at best neutral undetectable are associated with provide evidence potency accumulation...

Supernumerary B chromosomes (Bs) are a major source of intraspecific variation in nuclear DNA amounts numerous species plants. They favour large genomes, and create polymorphisms for natural populations. By studying Bs we can gain useful knowledge about the organization, function evolution genomes. There also significant biological questions concerning origin structural organization Bs, way which these selfish elements establish themselves by exploiting replicative machinery their host...

Abstract Retrotransposon or retrotransposon-like sequences have been reported to be conserved components of cereal centromeres. Here we show that the published are derived from a single conventional Ty3-gypsy family nonautonomous derivative. Both autonomous and elements likely colonized Poaceae centromeres at time common ancestor but maintained since by active retrotransposition. The retrotransposon is also present lower copy number in Arabidopsis genome, where it shows less pronounced...

Abstract Drosophila suzukii is a pest of soft and stone fruits that attracted to yeast volatile metabolites. has distinct summer winter morphs which are found in different habitats. Complex communities yeasts likely differ between habitats thus we hypothesized their attraction volatiles from species combinations species. We presented D. with isolation combinations, as either post-culture mixes or co-cultured, measured activity the flies laboratory choice tests Locomotor Activity Monitor...

Abstract A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line (2n = 2x 14). In this recombination occurs throughout length F. pratensis/L. bivalent. The and recombinants between it its L. homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent physical locations sites recombination, enabling range recombinant chromosomes used for mapping chromosome. map,...

A second family of highly repeated sequences has been identified on the B chromosome rye (Secale cereale). The E3900 was detected as a variant band in EcoRI digests +B DNA. clone basic repeat obtained, and organization investigated by genomic hybridization. no apparent homology to or other members Gramineae. localized situ hybridization end long arm chromosome. previously characterized E1100 sequence shows same location family. These results are discussed light current theories origin chromosomes.

An Italian ryegrass and hybrid sward was harvested on 11 May 1994. The mean dry‐matter (DM) content of the herbage 197 g kg –1 fresh matter (FM), nitrogen water‐soluble carbohydrate contents were 20 272 DM respectively. Approximately 72% total (TN) in form protein‐nitrogen. treated with either no additive, formic acid (3·3 l t ) (Add‐F, BP) or inoculant (2·3 (Live‐system, Genus) ensiled 100 silos. Changes effluent composition time showed that silage fermentation protein breakdown delayed by...

Two experiments describe the ensiling potential of whole‐crop forage peas ( Pisum sativum ) and field beans Vicia faba ). In Experiment 1, (cv. Magnus) Mayo) were harvested at 10, 12 14 weeks after sowing, ensiled in 10 kg mini‐silos either untreated or treated with an inoculant Lactobacillus plantarum terms yield potential, optimum growth stage for harvesting occurred growth. contrast, delaying harvest until gave highest yields dry matter (DM) crude protein (CP). Changes crop maturity had...

Abstract Drosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various species are attracted volatile metabolites produced by individual associated yeast isolates, but fruits naturally harbour a rich diversity of species. Here, we report the relative attractiveness D. yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four 12 single isolates were attractive , which...

Drosophila suzukii (spotted wing drosophila—SWD) is an economically important pest of soft and stone fruit worldwide. Control relies on broad-spectrum insecticides, which are neither fully effective nor environmentally sustainable. The sterile insect technique (SIT) a proven, friendly pest-management tool. Here, we investigated, for the first time, potential using SIT to control D. in field conditions without physical barriers that limit invasion. A proprietary method rearing irradiation...

Abstract A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line (2n = 2x 14). The chromatin F. and L. can be distinguished by genomic in situ hybridization (GISH), it is therefore possible visualize substituted background study chiasma formation marked bivalent. Recombination occurs freely pratensis/L. bivalent, frequency counts give predicted map length for this bivalent 76 cM. was also mapped...

SUMMARY Direct-cut silage was made in mid-October 1985 from established swards of predominantly hybrid ryegrass ( Lolium perenne x multiflorum ). The crop contained 161 g dry matter/kg and 94 soluble carbohydrate/kg ensiled bunker silos with (i) no additive (control), (ii), formic acid (5 litres/t) or (iii) addition 45 kg rolled barley per tonne grass silo. inclusion reduced effluent production to 27 litres/t compared 51 litres for the control 60 treatment. Losses DM were small but total...

Abstract Fungal metabolic volatiles attract Drosophila suzukii which oviposits in ripening fruits, but there are few data describing the fungal microbiomes of commercial fruits susceptible to this insect pest. We tested hypothesis that fruit type and stage have a significant effect on surface communities using DNA metabarcoding approaches found strong support for differences all three community biodiversity metrics analysed (numbers, types, abundances taxa). There was an average fivefold...