Aluminum Tolerance

Markers Xpsr914 and Xgdm125 for the Alt_BH gene.

Although the RFLP marker Xbcd1230 is located close to the Alt_BH locus, it is not useful for marker assisted selection in wheat because it is a multicopy locus. Two other markers are available, the RFLP marker Xpsr914 and the microsatellite Xgdm125 (see map). Chinese Spring has similar alleles to BH1146 for these two loci but has minor Al tolerance (approximately 4 ppm) compared to BH1146 (approximately 32 ppm). Therefore, a preliminary polymorphism screening is necessary before initiating a MAS introgression of BH1146 AltBH into different wheat lines.

PCR markers for rye

Miftahudin et al. (5) developed two PCR markers designated B1 and B4 for the rye Al tolerance locus Alt3 using genomic information from rice and EST sequences from wheat. These markers were tested for polymorphisms in the rye lines used in the mapping population (5) but could potentially be useful to introgress these segments in wheat. It is currently not known if the Alt3 allele from rye would provide a better level of tolerance than the AltBH allele when transferred to hexaploid wheat. P. Gustafson is currently transferring the rye Alt3 to wheat BH1146 to compare the effect of these two alleles (P. Gustafson unpublished).

Profiles of two PCR codominant markers for locus Alt3 in tolerant, sensitive, and heterozygous rye genotypes.  Marker B1 is a simple codominant marker, and marker B4 is a cleaved amplified polymorphism sequence (CAPS) marker. PT: Al-tolerant parent; PS: Al-sensitive parent; F1: F1 plant derived from a cross between PT and PS

Conditions presented here should be consider only as a starting point of method optimization