The wild ancestor of cultivated barley, Hordeum vulgare subsp. spontaneum (K. Koch) A. & Gr. (H. spontaneum), is a source of wide genetic diversity, including traits that are important for malting quality. A high ␤-amylase trait was previously identified in H. spontaneum strains from Israel, and transferred into the backcross progeny of a cross with the domesticated barley cv Adorra. We have used Southern-blot analysis and ␤-amy1 gene characterization to demonstrate that the high ␤-amylase trait in the backcross line is co-inherited with the ␤-amy1 gene from the H. spontaneum parent. We have analyzed the ␤-amy1 gene organization in various domesticated and wild-type barley strains and identified three distinct ␤-amy1 alleles. Two of these ␤-amy1 alleles were present in modern barley, one of which was specifically found in good malting barley cultivars. The third allele, linked with high grain ␤-amylase activity, was found only in a H. spontaneum strain from the Judean foothills in Israel. The sequences of three isolated ␤-amy1 alleles are compared. The involvement of specific intron III sequences, in particular a 126-bp palindromic insertion, in the allele-dependent expression of ␤-amylase activity in barley grain is proposed.

Genetic diversity was studied in a collection of 61 accessions of Brassica rapa, which were mostly oil-type turnip rapes but also included two oil-type subsp. dichotoma and five subsp. trilocularis accessions, as well as three leaf-type subspecies (subsp. japonica, pekinensis, and chinensis) and five turnip cultivars (subsp. rapa). Two-hundred and nine SNP markers, which had been discovered by amplicon resequencing, were used to genotype 893 plants from the B. rapa collection using Illumina BeadXpress. There was great variation in the diversity indices between accessions. With STRUCTURE analysis, the plant collection could be divided into three groups that seemed to correspond to morphotype and flowering habit but not to geography. According to AMOVA analysis, 65% of the variation was due to variation within accessions, 25% among accessions, and 10% among groups. A smaller subset of the plant collection, 12 accessions, was also studied with 5727 GBS-SNPs. Diversity indices obtained with GBS-SNPs correlated well with those obtained with Illumina BeadXpress SNPs. The developed SNP markers have already been used and will be used in future plant breeding programs as well as in mapping and diversity studies.

No abstract

No abstract

Two hundred and nineteen lines derived from the backcross progenies of eight different Hordeum spontaneum strains were evaluated for β-amylase and β-glucanase activity five days after germination under aseptic conditions. The activities were determined on the basis of soluble protein or grain mass. The recurrent parent cultivar, Adorra, served as the standard. Putative recombinants with high B-amylase activity were relatively easily achieved from high-activity strains of H. spontaneum. Recombinants with high β-glucanase were rare. They appear to be eliminated, possibly due to the strong selection for the domesticated phenotype during the derivation process.