Cross-breeding program in the genus Camellia involving the “everblooming” camellia (C. azalea C.F. Wei)

A. Lenzi, S. Biricolti, R. Vivoli, F. Bulleri, A. Baldi
For the flowering ornamental plants industry, blooming time and flowering duration are crucial since they strictly influence commercialization. The species used as ornamentals in the genus Camellia, among which C. sasanqua Thumb. and especially C. japonica L. are the most common, are known to have quite a short flowering period. In Italy, the cultivation of different cultivars of these two species allows for camellia flowering from the end of August (C. sasanqua) to April (C. japonica), leaving throughout the year a gap in the market of four-five months. For this reason, great expectations have arisen among collectors and nurserymen after the introduction from China, in recent years, of C. azalea C.F. Wei, a species capable of blooming all year long in the origin area. C. azalea shows good ornamental characteristics, but grows very slowly and is hard to propagate, making it difficult to be cultivated on a commercial scale. Based on this background, C. azalea has been used in a cross-breeding program carried out at the University of Florence (Italy) with the aim of obtaining hybrids with re-flowering capability, or at least blooming in the late spring and/or in summer, and ease of propagation. C. azalea was crossed with 33 different genotypes of the genus Camellia, mainly cultivars of C. japonica. For 15 parental combinations C. azalea was used as both female and male parent, bringing to 48 the total number of cross combinations. Overall, 860 crosses were carried out by manual pollination from November 2013 to April 2018. Forty-five fruits and 95 seeds were obtained from 12 cross combinations. Seedlings were achieved from 50 seeds, deriving from six cross combinations. Plants are now under observation. Five have already developed flowers, but the goal of a full summer bloom has not been achieved yet.
Lenzi, A., Biricolti, S., Vivoli, R., Bulleri, F. and Baldi, A. (2021). Cross-breeding program in the genus Camellia involving the “everblooming” camellia (C. azalea C.F. Wei). Acta Hortic. 1331, 35-42
DOI: 10.17660/ActaHortic.2021.1331.4
flowering ornamentals, Camellia azalea, blooming time, re-flowering, hybrid, new ornamental products

Acta Horticulturae