Svevo x Zavitan RILs mapping population
The Mapping population consisting of 150 Recombinant Inbreed Lines (RILs) developed by Single Seed Decent (SSD) from a cross between elite durum wheat (cv. Svevo) and highly drought tolerant wild emmer (acc. Zavitan). This mapping population is based on high yielding durum cultivar Svevo, with good baking quality, well adapted to the Mediterranean environment. The wild emmer accession, Zavitan, was collected in Israel and tested for drought resistance in the field and laboratory, confirming high tolerance to drought; improved water-used efficiency and yield. The mapping population have been genotyped using the high throughput 90K-SNP array chip (Illumina) to produce a high density genetic map which serve as platform for mapping of QTLs associated with drought and heat resistance.
Spikelet and grains of the two parental lines of the RILs mapping populations: Triticum turgudum ssp. durum cultivar Svevo and Triticum turgidum ssp. dicoccoides accession Zavitan.
Genotyping
The wheat 90K iSelect SNP genotyping assay was used for genotyping of the RILs, detecting segregation for 16,387 polymorphic markers. The genetic map was constructed based on the genotypic data of 140 RILs and included a total of 14,088 markers grouped into 2,296 genetic loci (unresolvable by recombination) in 14 linkage groups, corresponding to the 14 chromosomes of tetraploid wheat. The map was 2,110 cM long with an average distance of 0.92 cM between adjacent markers. This ultra-dense SNP-based genetic map with a high level of synteny to barley provides a useful framework for genetic analyses of important traits, positional cloning and markerassisted selection, as well as for comparative genomics and genome organization studies in wheat and other cereals.
To read more see Avni et al. (2014) Mol Breeding, 34:1549-1562.
Comparison between the Svevo × Zavitan map genetic distance and the physical distance in syntenic barley genes.
Example for the potential of the mapping population to improve durum wheat. Field evaluation of the 150 RILs derived from cross between durum cultivar Svevo and wild emmer accession Zavitan. Marvin phenotype analysis of grain length (Y axis) and wide (X-axis) as well as thousand kernel weight (TKW, marked with circles). The two parental lines marked with Red (S=svevo and Z=zavitan)
SNP Ra_c46811 from the 90K illumina's assay was converted into a fluorogenic 5’ nuclease assay and used to genotype progeny of the Svevo × Zavitan cross. The assay was performed using ABI7500 real-Time PCR machine and analyzed using the SDS software (ABI). The red cluster represents homozygous plants for the Svevo allele, the blue cluster represents homozygous plants for the Zavitan allele and the green cluster represents heterozygous plants.
