In vitro culture of Liriodendron tulipifera

Liriodendron tulipifera L. (yellow-poplar, tulip-poplar, tuliptree), a native of eastern North American, is one of two extant species of Liriodendron (Magnoliaceae). The other, L. chinense (Hemsl.) Sarg. (Chinese tuliptree), is native to central mainland China. The natural range of yellow-poplar is throughout the eastern United States and into southern Ontario, Canada. Although it grows on a wide variety of sites, it is most abundant and reaches its largest size in the lower Ohio river valley and in the mountains of North Carolina, Tennessee, Kentucky and West Virginia [12]. Yellow-poplar is an early stage successional species on most sites, but its rapid growth rate and the large size of mature trees (up to 60 m), make it a dominant canopy tree. Yellow-poplar possesses many desirable traits which make it one of the most important hardwood species in the United States. Besides rapid growth, it is also known for its straight form, self-pruning ability and wood of exceptional working quality [49]. Large amounts of the wood are used for furniture (mostly hidden parts), plywood, corestock, millwork, siding and other light construction lumber. It is also used for pulping and for products such as chipboard and flakeboard [36]. Bees are a primary pollinator of yellow-poplar, producing a popular honey. Finally, with its symmetrical leaves and yellow, green and orange flowers, yellow-poplar is widely planted both in the United States and abroad as an ornamental species. A number of horticultural cultivars have been described for the species [39].