Landscape and female fertility evaluation of seven heavenly bamboo cultivars as potential non-invasive alternatives to the wildtype

In recent years, breeding initiatives have been made to reduce the fecundity of invasive plants leading to sterile cultivars. The wildtype form of heavenly bamboo (Nandina domestica Thunb. (Berberidaceae) and seven cultivars were evaluated for landscape performance, fruit production and seed viability at three sites in Florida located in southwest, northcentral, and north Florida. For heavenly bamboo cultivars in north Florida, 'Emerald Sea', 'Greray' (Sunray®), 'Lemon-Lime', 'Murasaki' (Flirt™), 'SEIKA' (Obsession™), and 'Twilight' performed well throughout much of the study with average visual quality ratings between 3.54 and 4.60 (scale of 1 to 5). In northcentral Florida heavenly bamboo cultivars are 'Emerald Sea', 'Greray', 'Lemon-Lime', 'Murasaki', 'SEIKA', and 'Twilight' performed well throughout much of the study with average quality ratings between 4.49 and 4.94. In southwest Florida, 'Emerald Sea', 'Greray', 'Lemon-Lime', 'Murasaki', and 'SEIKA' performed well with average quality ratings between 3.40 and 4.83. At all three sites, 'Emerald Sea' and the wildtype were similar in size, having the greatest growth indices compared to medium-sized cultivars ('Greray', 'Lemon-Lime', 'Twilight' and 'SEIKA') and dwarf-sized cultivars ('Chime' and 'Murasaki'). For three consecutive fall-winter seasons of the study, 'Chime', 'Greray', and 'Lemon-Lime' heavenly bamboo did not fruit at any of the study sites. Among the three sites, 'Murasaki' had 97.7% to 99.9% fruit reduction, 'SEIKA' had 97.7% to 100% fruit reduction, and 'Twilight' had 95.9% to 100% fruit reduction compared to the wildtype at respective sites. Seeds collected from low fruiting cultivars ('Murasaki', 'SEIKA', and 'Twilight') had 33.3% to 66.7% viability, as determined by tetrazolium tests. In comparison, 'Emerald Sea' produced as much, if not more, fruit as the wildtype, especially in northern Florida, with seed viability ranging from 6.7% to 29.0% among sites. Nuclear DNA content of cultivars were comparable to the wildtype, suggesting they are diploids. These findings identified four low to no fruiting heavenly bamboo cultivars recommended for landscape use ('Lemon-Lime', 'SEIKA', 'Murasaki', and 'Greray').