Genetic control of alpha-amylase activity in rye grain was investigated by QTL mapping based on DS2 ? RXL10 intercross consisting of 99 F5-6 families propagated at one location during four vegetation seasons. A wide range of variation in -amylase activity and transgression effects were found among families and parental lines. This variation was shown to be determined in 40.1% by 7 significant (LOD score not less than 2.5) and 2 putative QTLs (2 < LOD < 2.5) distributed on all rye chromosomes except 4R. Two significant QTLs located on 3RL and 5RL chromosome arms were expressed each year. The third significant QTL was detected in three years (1RL). The other four significant QTLs (2RL, 5RS, 6RL, 7RL) were found in one year of study. The number and composition of QTLs were specific for a given year varying from three to six. QTLs were not correlated with isoenzyme polymorphisms at the structural alpha-Amy1 loci. A QTL associated with a region containing the alpha-Amy3 locus was detected on chromosome 5RL. Both high- and low-activity QTL alleles were found in each parental line, which explains the appearance of transgressive recombinants in the segregating population.
This study presents an attempt to supply breeders of hybrid rye with more genetic information on inbred lines, using molecular markers. Eighteen polymorphic loci detected by means of the RAPD (Random Amplified Polymorphic DNA) technique and mapped on 2R-7R rye chromosomes, were applied to study genetic similarities among forty inbred lines of rye. The lines were grouped in four main clusters revealed on dendrogram, which was generally consistent with the pedigree data. Mapped RAPD markers were shown to be a useful tool for phenetic studies in rye. Additionally, a system of 20 polymorphic fragments, detected by three primers, was developed for fingerprinting of rye lines. The system of RAPD markers, which was developed in this study, should be helpful in characterisation of rye genetic stocks used for breeding.
A linkage map of rye, previously developed using DS2 ? RXL10 F2 mapping population, was enriched with 179 AFLP and 19 RAPD marker loci. The current map covers 1386 cM and contains 480 markers including 200 RFLPs, 179 AFLPs, 88 RAPDs, 12 protein loci and one dwarfing gene. AFLPs generated by EcoRI/MseI primer combinations were distributed over the entire genome as distinct loci or clusters of 2-14 tightly linked DNA fragments. New marker loci mapped distally to the existing framework, significantly increased coverage of chromosomes 1R, 2R and 5R. The average marker distance is now 2.9 cM, but in seven regions the closest markers are still more than 20 cM apart. A detailed description of the newly mapped AFLP and RAPD loci is presented. The relationship with other published rye maps is discussed.
Location of the loci that control preharvest sprouting and alpha-amylase activity in rye was studied based on intercross S120?S76, consisting of 110 genotypes of F2 and F3 progenies. The genetic map currently consists of 141 loci distributed in 11 linkage groups, covering a distance of 506.4 cM, and was enriched during this study with 24 sequence-specific markers (7 SCARs, 7 SSRs, and 10 STSs). The extended map was applied for composite interval mapping of the loci controlling preharvest sprouting and ?-amylase activity, revealing 3 significant QTLs for preharvest sprouting, located on chromosomes 3R, 5R and 6R (in 1999), and one QTL for ?-amylase activity found on chromosome 2R (in 2000).
The study aimed at testing the usefulness of recently developed SCAR markers on rye (Secale cereale L.) chromosome 4R in hybrid breeding based on the C source of male sterility-inducing cytoplasm. Of 10 markers studied, 4 revealed polymorphisms between 2 inbred lines (544cms-C and Ot0-20) crossed to develop F2 and BC1 mapping populations. Analyses performed on 94 F2 and 93 BC1 plants allowed to extend a formerly constructed genetic map of chromosome arm 4RL. Three SCAR markers (SCP14M55, SCP15M55 and SCP16M58) were mapped in the vicinity of gene Rfc1, which restores male fertility in the C cytoplasm. The 3 tested SCAR markers proved to be effective in marker-assisted selection (MAS) for male fertility/sterility.
Genetic analysis of two rye interline crosses and a set of wheat/rye chromosomal additoin lines was performed to reveal the mechanism underlying wide variation range of alpha-amylase activity in sound grain.THe long arm of chromosome 6R was found to be responsible for increased enzyme synthesiis during late stages of triticale grain maturation.Only nuclear genes seemed to control alpha-amylase activity, as reciprocal crosses between rye lines showed no maternal effects.Low enzyme activity showed complete dominance over high level of its synthesis.Segregation ratios, observed in F2 and BC1 crosses, indicated that recessive alleles at two independent duplicative loci underline intensive alpha-amylase production.
RAPD (random amplified polymorphic DNA) polymorphism was studied in 23 malting and non-malting spring barley cultivars included in the official list of Polish cultivated varieties. Twenty-four 10-mer primers were tested in each cultivar, giving altogether 149 amplification products, 45% of which were polymorphic. The number of polymorphic bands revealed by one primer ranged from 1 to 6, with an average of 2.8. Genetic distance for all pairs of compared varieties was estimated and a dendrogram was constructed using unweighted pair group method of arithmetic means. The genetic distance between cultivars ranged from 0.11 for cvs. Apex and Bryl to 0.62 for cvs. Orthega and Madonna. Of the seven malting cultivars only two (Brenda and Stratus) formed one group at D = 0.25. The genetic distance between cvs. Brenda and Scarlett, especially recommended for brewery, was equal to 0.34. The detected polymorphism appeared to be sufficient for assessing genetic distances between cultivars, but on the basis of this polymorphism groups of malting and non-malting cultivars were not clearly distinguished.
A new genetic map of rye, developed by using the 541 ? Ot1-3 F2 intercross, consists of 148 marker loci, including 99 RAPDs, 18 SSRs, 14 STSs, 9 SCARs and 7 ISSRs, and spans the distance of 1401.4 cM. To the 7 rye chromosomes, 8 linkage groups were assigned and compared with the reference map of the DS2 ? RXL10 F2 intercross by using 24 common markers. The 2 combined maps contain altogether 611 marker loci (70?109 per chromosome) and constitute a substantial source of information useful for further genomic studies in rye. From 21 to 37 RAPD marker loci are distributed randomly along each chromosome length and their total number for all 7 rye chromosomes is 177. This abundance of RAPD marker loci in the rye genetic map can be exploited for development of SCARs in regions containing important genes or QTL.
A new genetic map of rye, developed by using the 541 ? Ot1-3 F2 intercross, consists of 148 marker loci, including 99 RAPDs, 18 SSRs, 14 STSs, 9 SCARs and 7 ISSRs, and spans the distance of 1401.4 cM. To the 7 rye chromosomes, 8 linkage groups were assigned and compared with the reference map of the DS2 ? RXL10 F2 intercross by using 24 common markers. The 2 combined maps contain altogether 611 marker loci (70?109 per chromosome) and constitute a substantial source of information useful for further genomic studies in rye. From 21 to 37 RAPD marker loci are distributed randomly along each chromosome length and their total number for all 7 rye chromosomes is 177. This abundance of RAPD marker loci in the rye genetic map can be exploited for development of SCARs in regions containing important genes or QTL.
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