Heritability of first-order-lateral roots in five Quercus species: effect on 1-0 seedling quality evaluation
Heritability estimates (h2) were calculated for first-order lateral root (FOLR) numbers on a family plot mean basis for 5 Quercus species: Q. alba, Q. falcata, Q, michauxii, Q. pagoda, and Q. rubra. All species were grown with the same nursery soil fertility protocol and the same seedling bed density (54-67/m2). Regardless of Quercus species, seedlings with the fewest FOLR (0-3) were not generally competitive in the nursery bed environment and had the smallest root collar diameter and height. In any family, those individuals with the most robust root systems exhibited the fastest growth and occupied the dominant crown position. Based upon root morphology and stem characteristics, less than 50 percent of the seedlings from any species may be competitive and occupy a dominant crown position in the nursery.