Genetic variation in the early vigour of spring bread wheat under phosphate stress as characterised through digital charting

Early vigour is important for improving wheat water use efficiency, competitiveness with weeds, and ultimately productivity, but it is significantly affected by soil fertility. In the past rapid and reliable capture of early vigour in field-grown crops has proven problematic; could recent technological developments provide a satisfactory solution? This study uses modern quantitative image analyses to reveal the effects of genotype and phosphate fertilisation on the expression of early vigour. A large genetic variation in early vigour was identified among twenty wheat genotypes from ICARDA, Australia and CIMMYT. Early vigour was significantly increased through phosphate fertiliser application. Berkut, Correll, Axe and Hamam-4 showed almost no reduction in vegetative cover under low soil P. Whereas the early vigour of Yitpi, Excalibur, Seri and Babaga-3 was significantly increased with P fertiliser application. Also Berkut and Excalibur were phosphate-efficient and high vigour. The significant genetic variation for P responsive early vigour identified here using digital charting enhances the prospects of improving early vigour (and P efficiency) in wheat; additionally, it facilitates further quantitative trait loci studies on early vigour (and P responsiveness) in wheat, and their accelerated implementation in wheat breeding programs.

► Higher soil phosphate increases the early vigour of bread wheat.
► Digital image capture of early vigour is useful in wheat breeding programs.
► Large genetic variation found for phosphate efficient early vigour.
► Digital image capture correlates with important manual measurements.