Publication Date
1997
Description
The genetic composition of mixed populations of white clover growing in low fertility, grass-dominant hill pastures was estimated four and eight years after populations were established. Populations were based on an adapted ('Grasslands Tahora') or poorly adapted ('Grasslands Huia') cultivar, and received either no fertiliser, or 35kg P /ha /year. The P response curve of surviving plants was also determined, and compared with plants grown from 'standard' seedlines of the respective cultivars. Between years 4 and 8, the proportion of the populations constituted by plants true-to-type for the sown cultivar remained steady at 56 - 58% for Tahora, but fell from 43% to 14% for Huia, indicating that selection forces were operating on the introduced populations. Tahora and Huia survivors from fertilised and unfertilised pastures did not differ from each other, or from plants grown from 'standard' seedlines, in their response to added P in the glasshouse. Selection forces do not appear to favour clover plants with superior ability to acquire or utilise available P in this environment; rather, it is suggested that defoliation stress is the dominant selection force.
Citation
Chapman, D F., "Phosphorus Availability, Defoliation Tolerance, and Genetic Differentiation in White Clover" (2024). IGC Proceedings (1997-2023). 28.
https://uknowledge.uky.edu/igc/1997/session10/28
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Phosphorus Availability, Defoliation Tolerance, and Genetic Differentiation in White Clover
The genetic composition of mixed populations of white clover growing in low fertility, grass-dominant hill pastures was estimated four and eight years after populations were established. Populations were based on an adapted ('Grasslands Tahora') or poorly adapted ('Grasslands Huia') cultivar, and received either no fertiliser, or 35kg P /ha /year. The P response curve of surviving plants was also determined, and compared with plants grown from 'standard' seedlines of the respective cultivars. Between years 4 and 8, the proportion of the populations constituted by plants true-to-type for the sown cultivar remained steady at 56 - 58% for Tahora, but fell from 43% to 14% for Huia, indicating that selection forces were operating on the introduced populations. Tahora and Huia survivors from fertilised and unfertilised pastures did not differ from each other, or from plants grown from 'standard' seedlines, in their response to added P in the glasshouse. Selection forces do not appear to favour clover plants with superior ability to acquire or utilise available P in this environment; rather, it is suggested that defoliation stress is the dominant selection force.
