Field establishment of little bluestem populations selected for improved laboratory seed germination in simulated dry conditions

Abstract

AbstractSuccessful field establishment begins with superior plant genetics, quality seeds, land preparation, sowing depth, weed control, and moisture. Our research examined the field‐establishment plant density of six populations of little bluestem [Schizachyrium scoparium (Michx.) Nash] and three selection generations at three locations over a 3‐yr period. Recurrent selection was used to develop C1 and C2 populations from six improved C0 populations (NU1, NU2, UC1, UC2, UO1, and UO2). In Cycle 1, open‐pollinated seeds from each C0 population were geminated in water of −0.8 MPa potential for 7 d. For each C0 population, seeds that germinated in 7 d were selected to create six C1 populations. Cycle 2 selection was identical to Cycle 1, except that C1 populations were used to create the six C2 populations. Plant density (number of plants m‒2) was determined using a frequency grid method at 30, 60, and 90 d after planting (DAP). The plant density of little bluestem varied with location (L), population (P), selection generation (G), DAP, L × P, L × G, P × G, and L × DAP interactions (P < .01). Averaged over generations and DAP, plant density averaged 7.6, 6.6, 6.5, 7.1, 6.6, and 7.1 plants m‒2 among populations NU1, NU2, UC1, UC2, UO1, and UO2, respectively. Averaged over populations and DAP, plant density averaged 5.9, 6.6, and 8.2 plants m‒2 for generations C0, C1, and C2, respectively. Thus, recurrent selection for increased laboratory seed germination in simulated dry conditions results in greater establishment plant densities of little bluestem.