UF Savanna Cultivar Group—Eight Colors of Heat-tolerant Lisianthus for Potted Plants

Abstract

A lisianthus [Eustoma grandifl orum (Raf.) Shinners; Gentianaceae Juss.] breeding program was initiated in 1985 at the University of Florida’s Gulf Coast Research and Education Center, Bradenton. The emphasis was on development of pot or bedding plant types with heat-tolerance and and basal branching pot and bedding plant types. Cultivars differ signifi cantly in their sensitivity to high temperatures (Fukuda et al., 1994; Harbaugh et al., 1992; Li et al., 2002). Seedlings of most commercial lisianthus cultivars form rosettes (formation of a basal cluster of leaves with no fl owering stems) when grown at or above 25 to 28 C (Harbaugh et al., 1992; Harbaugh, 1995; Ohkawa et al., 1991; Ohkawa et al., 1994; Pergola, 1992). ‘Maurine Blue’ (Harbaugh and Scott, 1996) and ‘Florida Blue’ (Harbaugh et al., 1996) were the fi rst heat-tolerant lisianthus whose seedlings could be grown at 28 t 31 °C without rosetting. Maurine Blue’ was intended to be used as a fl owering potted plant when grown with the use of growth retardants or as a bouquet cutfl ower without growth retardants. Additional colors have been added over the years that also were heat-tolerant with vegetative and fl ower characteristics similar to ‘Maurine Blue’. The Maurine cultivar group now includes pink, pink-lilac, white, light blue, lilac (Harbaugh and Scott, 1998), blue/white (Harbaugh and Scott, 2003), and pink/white (Harbaugh and Scott, 2005 a) bicolored fl ower colors. When grown without growth retardants, these cultivars have a height suitable for the bouquet cut-fl ower market. ‘Florida Blue’ was semi-dwarf and intended to be used as a bedding plant. Additional colors added to form the Florida cultivar group included light blue, pink (Harbaugh and Scott, 1999), silver (Harbaugh and Scott, 2001), blue/white and pink/white (Harbaugh and Scott, 2005 b) bicolored fl ower colors. The UF Savanna cultivar group is heattolerant and intermediate in height between the Florida cultivar group and the Maurine cultivar group. The UF Savanna cultivar group edge, ‘Savanna Blue Frost’ and ‘Savanna Pink Frost’ fl ower colors are not available in other commercial pot type lisianthus.