Metabolites correlated with cereal cyst nematode resistance in oats (Avena sativa) identified using single seed descent lines

S. Bahraminejad, R. E. Asenstorfer, K. J. Williams, Y. Hayasaka, P. K. Zwer, I. T. Riley, C. J. Schultz


Secondary metabolites in plants are widely believed to be important for plant resistance to a range of pests and pathogens, but identifying key metabolites remains a challenge. To test whether the phenotypic extremes of a single seed descent (SSD) mapping population can be used to identify important metabolites, we analysed extracts from selected individuals of an SSD mapping population. The Avena sativa population was segregating for cereal cyst nematode (CCN), Heterodera avenae, resistance and resistance to the stem and bulb nematode, Ditylenchus dipsaci. CCN data were collected over three years, 2000, 2001 and 2002. Reversed-phase high performance liquid chromatography provided a profile of compounds from root extracts, allowing us to compare SSD individuals with high CCN count to individuals with a low CCN count. Several avenacins were positively identified by mass spectrometry, but were not correlated with CCN count. There was no significant correlation between flavonoids in oat roots and shoots with either CCN count or stem and bulb nematode resistance. However, three fractions recovered from root tips had a significant correlation with CCN count. Two of the fractions contained putative avenacins that have not been previously reported, whilst the third fraction contained a compound that was too unstable to characterise. This study highlights the potential of SSD populations for identification of bioactive compounds.

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