Molecular screening of domestic germplasm for allelic variants at the dwarfing gene Rht8 locus in wheat

摘要

In last 7 years, researches revealed the presence of 16 allelic variants at the Xgwm 261 locus with 165, 174, 180, 192, 194, 196, 197, 198, 200, 201 202, 204, 205, 207, 210 and 215 base pairs, while nearly 90% of the worldwide wheat germplasm carry one of the alleles with 165bp, 174bp or 192bp. The results of microsatellite screening of 269 wheat varieties and advanced lines from Serbia and Montenegro showed clear selection pressure for the three main fragments at Rht8 locus, but also trend to expand allelic variability in the locus (in the most recent varieties and advanced lines) avoiding "adaptive uniformity" of the elite germplasm. The presence of 192bp allele as diagnostic of Rht8 has been confirmed as quite common in wheat genotypes from Serbia and Montenegro, but not at the rate it has been determined in earlier researches. Out of 269 registered wheat varieties and advanced lines 73.6% carry 192bp allele, 14.9% are with 174bp allele, 7% carry 165 fragment and 4.56% novel fragments around 200bp in length. This research revealed that from the beginning of the 1990s wheat breeding objectives in Serbia and Montenegro were partially focused towards novel alleles (different from 192bp) at Xgwm261 locus. Recently registered varieties from Novi Sad have either the 192bp fragment (Cipovka, Simfonija, Balada, Arija, Rapsodija Helena, Diva, Vila, Astra), 174bp fragment (Sofija, Dragana, Italija Francuska, Oda) or fragments around 200bp (Sonata, Kantata, Jefimija). In addition, two very promising advanced lines (NS 260/02 and NS 2-4629/1) and some excellent advanced lines frequently used as parents in hybridization (NS 20/96, NS 23/94, NS 85/97 and L152/89) also carry allele around 200bp in size.