Adaptive winter wheat populations: development, genetic characterisation and application

Abstract

An increasingly fluctuating global climate is creating mounting problems for production in agricultural systems. One possible way to buffer these changes is with the use of genetically diverse composite cross populations. Here we demonstrate in replicated field trials that composite cross populations of winter wheat when grown in organic conditions had a similar yield to currently used pure lines, but had higher yield stability than the pure lines. When grown under high input conditions the populations maintained their stability, but yielded significantly lower than the pure line varieties, indicating that the populations are potentially more suitable to low-input and organic than to conventional systems. However, in separate pseudoreplicated on-farm trials conducted across the UK the improved stability shown in the replicated field trials was not repeatable.

The replicated field trials demonstrated that both populations and (complex) variety mixtures are more or less equivalent with regard to their agronomic performance. Preference for either populations or mixtures is therefore likely to follow other criteria than those based purely on agronomic performance.

The populations were tested to investigate the level of adaptation that may occur when grown continuously at the same specific sites for a number of years. The populations did not adapt to the cropping conditions under which they were grown; this was evident both from molecular data and from comprehensive field trials. Yearly fluctuations in weather conditions are likely to have counteracted any adaptation to the site-specific factors associated with cropping management and soil conditions.

The suitability of the populations for four different end uses were tested, these included bread making, malting, distilling and animal feed. For each end use the one or two most appropriate of the following populations were tested: a high yield population (YCCP), a high baking quality population (QCCP) and an all-rounder population (YQCCP). None of the populations were any more beneficial than current varieties for distilling or malting, however both the YCCP and YQCCP were found to be suitable for use as animal feed. In micronutrient tests the values observed for the population grain tested were generally comparable to values previously reported for winter wheat. On the basis of various agronomic and quality performance indicators, as well as marketability to end-users, the QCCP is seen as the most promising population among the three tested populations, and was singled out as being particular favourable for bread making.