Fingerprinting varieties of barley to study yield stability

Yield stability is a very important trait for breeders, but almost impossible to select for. Our research aims at expanding the knowledge on the genetics of stability. In a germplasm of 148 barley cultivars we assessed associations of 75 AFLP markers with yield and two stability statistics, b(i) and s(di)(2). The number of markers significantly correlated with yield, b(i), or s(di)(2) was 11, 3, and 10, respectively. Multiple linear regression analysis showed that a subset of markers explained 40% of the variance for yield, 16% for b(i), and 59% for s(di)(2). Many correlated markers could be located on existing linkage maps of four mapping populations. One yield correlated marker coincided with a yield QTL found in an Apex x Prisma population. Stability statistics bi was not correlated with s2di, and none of the markers were associated with both statistics, suggesting that these statistics are under different genetic control. In conclusion, fingerprinting a set of cultivars is a promising way to screen the barley genome for loci controlling yield and yield stability.