Rapid generation cycling of an F2 population derived from a cross between Lens culinaris Medik. and Lens ervoides (Brign.) Grande after aphanomyces root rot selection |
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| Authors: | Monika M Lulsdorf Sabine Banniza |
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| Institution: | Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada |
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| Abstract: | Cultivated lentil (Lens culinaris Medik.) is susceptible to aphanomyces root rot (ARR), whereas partial resistance is present in wild lentil including Lens ervoides (Brign.) Grande. Approximately six generations of selfing are required to fix a desired trait in a population, which usually requires 2 years in a breeding programme, so the primary objective was to develop a rapid generation cycling (RGC) technique that achieves this goal in 1 year. Rapid generation cycling was then tested on an F2 population (LR‐59) derived from a L. culinaris × L. ervoides cross in combination with a reliable ARR screening technique, which generates a wide range of disease severities conducive to selection. Phenotyping of an F2 population of more than 1,200 plants resulted in scores ranging from 2.4 to 4.0 on a scale from zero to five. Plants with scores lower than 4.0 were selected for advancement for five generations using a modified single‐seed descent method, optimum growing conditions, 20‐hr photoperiod and harvest of immature seeds. Seeds were germinated in a 100 μM gibberellin solution. Average generation length after phenotyping was 56 days resulting in five generations within approximately 300 days. Using a modified inoculation protocol, ARR phenotyping of the F7 population resulted in scores ranging from 1.4 to 4.0. This inexpensive, nonsterile speed breeding protocol saves 1 year in the development of lentil varieties with improved ARR resistance. |
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| Keywords: |
Aphanomyces euteiches
ex vitro single‐seed descent |
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