Abstract
Background Leaf rust (LR), caused by Puccinia triticina and is an important disease of wheat (Triticum aestivum L.). The most sustainable method for controlling rust diseases is deployment of cultivars incorporating adult plant resistance (APR). However, phenotyping breeding populations or germplasm collections for resistance in the field is dependent on weather conditions and limited to once a year. In this study, we explored the ability to phenotype APR to LR under accelerated growth conditions (AGC; i.e. constant light and controlled temperature) using a method that integrates assessment at both seedling and adult growth stages. A panel of 21 spring wheat genotypes, including disease standards carrying known APR genes (i.e. Lr34 and Lr46) were characterised under AGC and in the field.ResultsDisease response displayed by adult wheat plants grown under AGC (i.e. flag-2 leaf) was highly correlated with field-based measures (R2 = 0.77). The integrated method is more efficient—requiring less time, space, and labour compared to traditional approaches that perform seedling and adult plant assays separately. Further, this method enables up to seven consecutive adult plant LR assays compared to one in the field.ConclusionThe integrated seedling and adult plant phenotyping method reported in this study provides a great tool for identifying APR to LR. Assessing plants at early growth stages can enable selection for desirable gene combinations and crossing of the selected plants in the same plant generation. The method has the potential to be scaled-up for screening large numbers of fixed lines and segregating populations. This strategy would reduce the time required for moving APR genes into adapted germplasm or combining traits in top crosses in breeding programs. This method could accelerate selection for resistance factors effective across diverse climates by conducting successive cycles of screening performed at different temperature regimes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13007-016-0117-7) contains supplementary material, which is available to authorized users.
Highlights
Leaf rust (LR), caused by Puccinia triticina and is an important disease of wheat (Triticum aestivum L.)
Drysdale carries Lr1 (Table 1), which is ineffective against the pathotype used in this study [27] and displayed a susceptible response (8.0; Fig. 1)
Avocet carries race specific adult plant resistance (APR) gene Lr13, which is effective against the pathotype used in this study
Summary
Leaf rust (LR), caused by Puccinia triticina and is an important disease of wheat (Triticum aestivum L.). The most sustainable method for controlling rust diseases is deployment of cultivars incorporating adult plant resistance (APR). Tritici, which causes leaf rust (LR), is regarded one of the most geographically widespread disease of wheat and can incur yield losses ranging 10–70 % [2, 3]. It results in reduction of kernels per head, lower kernel weight, degradation in grain quality and increased costs. ‘all stage resistance’ (ASR), is typically expressed at all growth stages, Riaz et al Plant Methods (2016) 12:17 conferred by a single ‘major effect’ gene often associated with a hypersensitive response and is often race specific. Additional sources of resistance are needed for stacking or pyramiding in new cultivars, which will serve to protect these highly valuable genes against the rapidly evolving nature of P. triticina
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
