Selection for reduced seed dormancy in seven native grass species.

摘要

Lowland switchgrass (Panicum virgatum), big bluestem (Andropogon gerardii), indiangrass (Sorghastrum nutans ), upland switchgrass (Panicum virgatum), little bluestem (Schizachyrium scoparium), beaked panicum ( Panicum capillare), and purpletop (Tridens flavus) all show strong signs of seed dormancy which contributes to extremely poor field establishment. The objective of this work was to reduce seed dormancy by selecting individuals that exhibited reduced pre-stratification dormancy in laboratory tests. The classical breeding method of phenotypic recurrent selection was used to enhance germination. Of the three tall-stature species, lowland switchgrass made the greatest improvement in pre-stratification germination, followed by indiangrass and big bluestem. The four short stature species have shown various results after one cycle of selection at Starkville. A field emergence trial was also conducted to evaluate three cycles of breeding seed with five commercially available cultivars in which Cycle 3 seed produced more plants per hectare than any of the other cultivars or germplasm.;Key words: beaked panicum, big bluestem, biofuels, bluestem, indiangrass, little bluestem, lowland switchgrass, native grasses, purpletop, restoration, upland switchgrass.