ABSTRACT
In this chapter, the authors focus on physiological characters that are under genetic control, some of their research toward better understanding of physiological processes associated with tall fescue productivity and potential use of haploids and doubled haploids to accelerate incorporation of improved physiological characteristics into new or improved cultivars. The use of haploids and doubled haploids has great potential in understanding the physiological and biochemical processes that regulate growth of tall fescue. Tall fescue, by seasonal nature of growth patterns and its utilization by ruminants, provides a unique research opportunity for crop physiologists. Haploid plants derived from immature gametes of heterozygous tall fescue plants should include a wide range of genotypes for various physiological characters. K. M. Zarrough actively pursued the relationships between yield and tiller density of tall fescue genotypes. Genotypes selected for low yield per tiller tended to have higher tillering rates than those selected for high yield per tiller when vegetative plants were transplanted to the field.
