Mapping wheat genes for root hair length in aneuploid lines of bread wheat

Long root hairs enable the efficient uptake of poorly mobile nutrients such as phosphorus. Mapping the chromosomal locations of genes that control root hair length can help exploit the natural variation within crops to develop improved cultivars. Liu et al. used genetic stocks of the wheat (Triticum aestivum) cultivar ‘Chinese Spring’ to map genes controlling root hair length.

Rhizosheath size of ‘Chinese Spring’ compared with a range of unrelated cultivars. Seedlings were grown for 3 d in a soil with no added mineral nutrients other than the CaCO3 used to adjust the pH to 6·5. Columns show mean values of six replicates, with the bars indicating standard errors. Asterisks denote ‘Chinese Spring’ and ‘Maringa’ as being significantly different (P < 0·05) from all the other lines as determined with a one-way ANOVA.

First, rhizosheath size was assayed as a rapid method to screen the lines. The trait was then verified in selected lines by directly measuring root hair length. Using this method, chromosomal deletion lines were screened to map chromosomal regions controlling root hair length. DNA analysis of wheat lines with a 90K Single Nucleotide Polymorphism (SNP) chip identified candidate genes that control root hair length.