Recurrent selection for improved seed germination results in greater seedling growth potential

Abstract

Rapid seedling development increases the probability of stand establishment. This research investigated the seedling growth of three little bluestem [Schizachyrium scoparium (Michx.) Nash] populations (NU-1, UC-2, and UO-2), three selection generations (Recurrent Selection Cycles 0 [C0], 1 [C1], and 2 [C2]), and four seedling ages (3-, 4-, 5-, and 6-wk-old seedlings). Lines NU-1 C1 and NU-1 C2 were developed from NU-1 C0 using two cycles of recurrent selection for increased seed germination at a low water potential. Other lines were created similarly from UC-2 C0 and UO-2 C0. The greenhouse experiment was a three-by-three-by-four factorial of population, generation, and age in a randomized complete block design replicated nine times and repeated twice. Root length, shoot height, and root and shoot biomass varied with population and generation, and shoot/root ratio varied with population (P ≤.01). Root length averaged 17.6 cm among populations and ranged from 16.4 cm for generation C0 to 18.3 cm for C2. Shoot height averaged 7.0 cm among populations and ranged from 6.5 cm for generation C0 to 8.3 cm for C2. Root biomass averaged 13.5 mg among populations and ranged from 11.3 mg for generation C0 to 16.5 mg for C2. Shoot biomass averaged 13.0 mg among populations and ranged from 11.1 mg for generation C0 to 15.8 mg for C2. Shoot/root ratio varied from 0.87 for population UC-2 to 1.06 for NU-1. Plant materials with rapid seedling growth should lead to better establishment and persistence.