The different physicochemical and colorimetric parameters which de®ne fruit quality were evaluated in 12 varieties of tomato (Lycopersicon esculentum Mill) from several localities in SE Spain, using three widely grown commercial (F 1 ) hybrids as controls. Several local varieties were identi®ed with better scores for speci®c quality parameters (fruit ®rmness, soluble solids content, pH, citric and malic acids and lycopene) than the commercially grown hybrids. These may ®nd a place in the market as distinctive quality fruits or as source material for optimal quality characteristics in breeding programmes. The correlations obtained in the overall study of the results point to the advantages and disadvantages of choosing certain quality parameters. The colorimetric study showed that the ratio between the chromatic co-ordinates of the CIELAB system (a*/b*) separated the fruits of the different varieties as a function of their external colour better than the tomato colour index (TCI).

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We have analysed the chromosome organisation and the location and temporal appearance of different proteins in X and B chromosomes in the grasshopper Eyprepocnemis plorans throughout the first meiotic prophase. We have used adult males that carry a B chromosome collected in natural Spanish populations. The scaffold organisation has been analysed by means of silver stained chromatid cores. In addition, we have detected by immunolabelling the presence of phosphoepitopes, the ensemble of cohesin axes, the location of histone γ-H2AX, and recombinase Rad51. Our observations demonstrate that X and B chromosomes share similarities in chromatin organisation and in the expression of the tested proteins, which strongly differ from those of the autosomes. These results could be interpreted either as a support to the hypothesis that the Bs analysed here originated from the X chromosome, and/or that their chromatin composition and precocious condensation could determine their meiotic behaviour.

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Satellite DNA (satDNA) constitutes an important fraction of repetitive DNA in eukaryotic genomes, but it is barely known in most species. The high-throughput analysis of satDNA in the grasshopper Pyrgomorpha conica revealed 87 satDNA variants grouped into 76 different families, representing 9.4% of the genome. Fluorescent in situ hybridization (FISH) analysis of the 38 most abundant satDNA families revealed four different patterns of chromosome distribution. Homology search between the 76 satDNA families showed the existence of 15 superfamilies, each including two or more families, with the most abundant superfamily representing more than 80% of all satDNA found in this species. This also revealed the presence of two types of higher-order repeats (HORs), one showing internal homologous subrepeats, as conventional HORs, and an additional type showing non-homologous internal subrepeats, the latter arising by the combination of a given satDNA family with a non-annotated sequence, or with telomeric DNA. Interestingly, the heterologous subrepeats included in these HORs showed higher divergence within the HOR than outside it, suggesting that heterologous HORs show poor homogenization, in high contrast with conventional (homologous) HORs. Finally, heterologous HORs can show high differences in divergence between their constituent subrepeats, suggesting the possibility of regional homogenization.