Isolation of a chromosomally engineered durum wheat line carrying the common wheat Glu-D1d allele.

摘要

A 1DL chromosomal segment, containing the Glu-D1d allele encoding the 5+10 HMW glutenin subunits, was transferred into the 1AL arm of a tetraploid derivative by means of ph1c induced homoeologous recombination in backcross progeny derived from an initial common wheat (Triticum aestivum) X durum wheat (T. durum) cross. The involvement of 1AL in the exchange, which could not be directly proved by the protein assay because of the null condition at the Glu-A1 locus in all durum wheat parents used, wasunequivocally demonstrated using the D genome specific, highly repeated DNA sequence pAs1 as probe in fluorescence in situ hybridization (FISH) experiments. The Glu-D1d tetraploid carrier in fact exhibits a normal 1AS and a recombined 1AL, with a distalsegment of clear 1DL origin. The difference between the FISH patterns of recombined and normal 1AL was used to discriminate homozygous from heterozygous Glu-D1d carriers already in F2 populations, in which the recombined chromosome appeared to be transmitted normally through both germlines. Preliminary tests also show no reduction in fertility due to either one or two doses of the engineered chromosome, whose impact on various pasta and bread making quality parameters will be assessed.