Evaluation, genetic variation, and selection for improvement of a seeded, turf-type buffalograss population (Buchloe dactyloides [Nutt.]; Engelm).

摘要

Since the early 1980's, buffalograss (Buchloe dactyloides (Nutt.) Engelm) has received increasing attention for its potential as an alternative turfgrass because of its low input demand and large area of adaptation. Such widespread interest has generated competitive activity in the development of buffalograss as a turf to fit various market niches.; Buffalograss is a warm season, predominantly dioecious, perennial short grass known for its low maintenance potential as both a turf and forage crop for most of this century. Its area of adaptation reflects the heterogeneous nature of its ecotypes, ranging from the northern Great Plains states into Mexico. The extensive variation in buffalograss populations permits selection for improvement as long as characters identified for improvement are heritable and stable.; Economics and competitive demand for improved buffalograss varieties require that a plant breeder work on several traits simultaneously. Historically, after selection, populations reverted back to the original aesthetic quality which was deemed unacceptable by the turfgrass industry. A system addressing the multiple traits associated with aesthetically acceptable, environmentally sound turfgrass must be developed to permit realistic improvement.; Early breeding programs may have failed to use family structures and compatible crosses after recurrent selection for synthetic combinations. Environmental pressures, linkage relationships, non-additivity, random drift, and assortative mating greatly affect realized inheritance of a multiple trait system. Only through generations of selection and development of family structure for particular traits will we be able to fully understand buffalograss genetics.; Therefore, the following dissertation project was designed to (1) evaluate methods of measuring several buffalograss characters required for low input turfgrass; (2) estimate genetic variation, heritability of the particular traits, and genotypic stability across seasonal environments for the test population; and (3) develop a multiple trait selection index that simultaneously includes several traits in the selected population.; Results from the three-year study derived 12 half-sib buffalograss families selected on seven characteristics: Bur yield, evapotranspiration, early- and mid-season turfgrass quality under non-irrigated conditions, fall dormancy, and 3- and 15-day seedling emergence.