Submitted to: Euphytica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2006
Publication Date: 7/25/2006
Citation: Seiler, G.J., Campbell, L.G. 2006. Genetic variability for mineral concentration in the forage of Jerusalem artichoke cultivars. Euphytica. 150:281-288. Interpretive Summary: Jerusalem artichoke, a wild perennial sunflower native to North America, is often present in pastures, crops, and rangelands, but its overall forage quality is not well understood. Jerusalem artichoke has been used as a forage crop in Europe for years. Knowing the elemental composition and variability of the concentrations in forage of the various cultivars offer breeders the opportunity to use these cultivars for improving the forage quality of Jerusalem artichoke. The objectives of this study were to determine the genotypic variability of nitrogen, phosphorus, potassium, calcium, magnesium and the calcium to phosphorus ratio in forage of ten Jerusalem artichoke cultivars at flowering over a 2-year period, determine if selection among and within populations is feasible, and to examine relationships among the elements. The adequacy of Jerusalem artichoke forage at flowering for maintenance of a ruminant animal was classified as follows: N, Ca, Mg, K as adequate, P inadequate, and Ca/P ratio as excessive. Cultivars of Jerusalem artichoke contained sufficient genetic variability for the major nutritional elements. The high variability within populations will allow selection for specific elements, except phosphors. The genetic variability observed in the cultivars will provide breeders the opportunity to develop strategies for improving the feed-quality of Jerusalem artichoke cultivars.
Technical Abstract: One of the potential uses of Jerusalem artichoke (Helianthus tuberosus L.) is as a forage crop. Information on inherent differences in forage nutritional quality is essential if the quality of the forage is to be improved through breeding. The objectives of this study were to determine the genotypic variability of N, P, Ca, Mg, K and the Ca/P ratio in the forage of ten Jerusalem artichoke cultivars at flowering over a 2-year period, determine if selection among and within cultivars is feasible, and examine relationships among the mineral elements. The adequacy of Jerusalem artichoke forage at flowering for maintenance of a ruminant animal was classified as follows: N, Ca, Mg, K as adequate, P inadequate, and the Ca/P ratio as high. There were genotypic differences among the ten cultivars for N, K, P, Ca, Mg, and the Ca/P ratio for both years and averaged across years. The magnitude of the genotypic variance components indicated that a substantial proportion of the total variation for these elements was due to cultivar, indicating the possibility of improvement through hybridization and selection. Within-cultivar variation for N, Ca, and K was high, but variable, indicating potential for improvement with further selection within cultivars. Cultivar variance for P and Mg were very low, suggesting it will be difficult to improve these elements through selection. Unfortunately, P is inadequate in the forage to begin with, and our data indicated that selecting within cultivars for high P might not be very successful.