Nineteen fig varieties and lines fromEurope and Asia have been fingerprinted by ISSR, RAPD, and SSR markers, respectively, using 13, 19, and 13 primer combinations. All primers produced 258 loci, with the highest number of loci (119) generated by RAPD (R p : 48.42). Clustering analysis was applied to the three marker datasets to elucidate the genetic structure and relationships among these varieties. Mean genetic similarities were 0.787, 0.717, and 0.749, respectively, as determined using ISSR, RAPD, and SSR. Each marker system produced incompletely separated clusters, although a weak binding group based on race type appeared in the combined dataset. Comparisons of coefficients revealed no correlation between different similarity matrices; congruence was observed between similarity matrices and co-phenetic matrices in all markers. Analysis of molecular variance (AMOVA) showed that most of the total polymorphism was attributable to within-group variance (ISSRs + RAPDs, 97.41%; SSRs, 90.18%). These results suggest that the genetic diversity of this fig population is low and that multiple marker utilization is critical to estimate the relatedness of figs at the variety level. Additionally, it was presumed that 'Houraihi', the oldest variety in Japan, was disseminated independently of other foreign varieties in the 17th century or before then.

Reduced levels of trienoic fatty acids (TAs) in chloroplast membranes induce thermotolerance in several plant species, but the underlying mechanisms remain unclear. TA peroxidation in plant cell membranes generates cytotoxic, TA-derived compounds containing α,β-unsaturated carbonyl groups. The relationship between low TA levels and the amounts of cytotoxic TA-derived compounds was examined using thermotolerant transgenic cyclamen (Cyclamen persicum Mill.) with low TA contents. Changes in the levels of the cytotoxic TA-derived acrolein (ACR), methyl vinyl ketone (MVK), (E)-2-hexenal, 4-hydroxy-2-nonenal, and malondialdehyde were analysed in the leaf tissues of wild-type (WT) and thermotolerant transgenic cyclamen under heat stress. Levels of ACR and MVK in the WT increased in parallel with the occurrence of heat-induced tissue damage, whereas no such changes were observed in the thermotolerant transgenic lines. Furthermore, exogenous ACR and MVK infiltrated into leaves to concentrations similar to those observed in heat-stressed WT leaves caused similar disease symptoms. These results suggest that thermotolerance in transgenic cyclamen depends on reduced production rates of ACR and MVK under heat stress, due to the low level of TAs in these plants.

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Interspecific hybridization is an effective method to generate a new crop that gains available functions in a short time. Interspecific hybrids (2n = 16) between Allium fistulosum L. (2n = 16) and Allium schoenoprasum L. (2n = 16) were produced by reciprocal crossings through ovary culture, but the hybrids were much fewer in the combination using A. schoenoprasum as a seed plant. All the hybrids have eight long chromosomes originated from A. fistulosum and eight short chromosomes originated from A. schoenoprasum. In addition, the hybridity was confirmed by randomly amplified polymorphic DNA (RAPD) analysis and cleaved amplified polymorphic sequence (CAPS) analysis of the rDNA internal transcribed spacer (ITS) region. The interspecific hybrids showed a vigorous growth habit; their foliage was slightly bloomy and deep green. The hybrids did not form bulbs, but rather propagated vegetatively by tillering. Carotene contents of the hybrids and both parents were quantified using high-performance liquid chromatography (HPLC). The contents of all edible parts of the hybrids were approximately seven times higher than those of either parent. These results indicate that the hybrid is a new and carotene-rich vegetable of Allium species.Abbreviations: BDS medium, B5 medium modified by Dunstan and Short (1977); CAPS, cleaved amplified polymorphic sequences; HPLC, high-performance liquid chromatography; ITS, internal transcribed spacer; PCR, polymerase chain reaction; RAPD, randomly amplified polymorphic DNA

Abstract:Retrotransposons have been used frequently for the development of 23 molecular markers by using their insertion polymorphisms among cultivars, because 24 multiple copies of these elements are dispersed throughout the genome and inserted 25 copies are inherited genetically. Although a large number of long terminal repeat 26 (LTR) retrotransposon families exist in the higher eukaryotic genomes, the 27 identification of families that show high insertion polymorphism has been challenging. 28Here, we performed an efficient screening of these retrotransposon families using an 29Illumina HiSeq2000 sequencing platform with comprehensive LTR library 30 construction based on the primer binding site (PBS), which is located adjacent to the 5 31 LTR and has a motif that is universal and conserved among LTR retrotransposon 32 families. The paired-end sequencing library of the fragments containing a large number 33 of LTR sequences and their insertion sites was sequenced for seven strawberry 34 cultivars (Fragaria x ananassa Duchesne) and one diploid wild species (F. vesca). 35Among them, we screened 24 families with a "unique" insertion site that appeared only 36 in one variety and not in any others, assuming that this type of insertion should have 37 occurred quite recently. Finally, we confirmed experimentally the selected LTR 38 families showed high insertion polymorphisms among closely related cultivars. 39 40