Infertile Lantana camara Cultivars UF-1011-2 and UF-1013A-2A

Lantana (Lantana L., Verbenaceae) is widely produced and used in the United States, especially in the south. A 2003 survey of the Florida nursery industry, which consisted of more than 5000 nurseries, indicated that 19.0% of the responding nurseries produced lantana, and the annual sales value of lantana in Florida was estimated to be more than $40 million (Wirth et al., 2004). Lantana plants produce showy flowers all year round in frost-free areas and dieback to the ground in the winter in zones 8b or lower. They attract butterflies, tolerate harsh environmental conditions, have low maintenance requirements, and are easy to propagate. These attributes make lantana highly desirable for use in containers, hanging baskets, and landscapes (Schoellhorn, 2004). A majority of lantana cultivars found in commercial production and landscape use belong to Lantana camara L. It is native to the West Indies (Sanders, 2001) and was introduced to most tropical regions by 1900 (Howard, 1969). It has escaped cultivation and has hybridized (as pollen donor) with Lantana depressa Small, a now endangered species native to South Florida (Hammer, 2004; Sanders, 1987). Lantana camara has been listed as a Category I invasive species in Florida by the Florida Exotic Pest Plant Council (FLEPPC) (2015). The invasiveness of L. camara was evaluated by the University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) Assessment of Non-Native Plants in Florida’s Natural Areas, and it concluded that L. camara should not be recommended for commercial production or landscape use in South, Central, and North Florida (UF/IFAS Assessment, 2016). The assessment was based on the evaluation of escaped and naturalized (resident-type) L. camara plants. A research program was initiated in 2004 at UF/IFAS’s Gulf Coast Research and Education Center (GCREC) to identify and develop infertile L. camara cultivars. Czarnecki (2011) and Czarnecki et al. (2014) evaluated 26 commercial L. camara cultivars in Florida and found out that a majority of them were fertile. There has been a strong need for the development of new infertile L. camara cultivars. In response to this need, hundreds of triploid lantana lines were generated and evaluated between 2004 and 2009, and two highly infertile lines were released as new cultivars (‘UF-T3’ and ‘UF-T4’) in 2011 (Czarnecki et al., 2012). Subsequently, additional triploid lantana breeding lines were created in 2010 and 2011. Some of these lines showed excellent potential in observational trials at GCREC in 2011–13. A number of the most promising lines were installed in two replicated ground trials in Florida in June 2015. Plants in these ground trials were evaluated for plant performance, flowering, and fruit production, and provided fresh flowers for pollen stainability tests; seeds collected from these plants were subjected to seed viability and germination tests between Fall 2015 and Summer 2016. A separate study was carried out in 2015 to determine the hybridization potential of several most promising lines (low or no seed set, excellent flowering, and performance)with L. depressa. From these trials and studies, two of the most promising lines were selected and released as new infertile L. camara cultivars, ‘UF-10112’ and ‘UF-1013A-2A’.