ASHS 2015 Annual Conference

Camellia azalea Wei. (syn. C. changii) was discovered in China in 1986.  Camellias typically bloom for two or three months and grow in phases of vegetative or reproductive growth.  C. azalea is very different in that it blooms every month of the year in a greenhouse setting.  This single ever-blooming characteristic makes C. azalea an attractive breeding parent.  From 2008 to 2014, 2401 controlled crosses were made with C. azalea as the maternal (770 crosses) or paternal (1631 crosses) parent.  Many different species and cultivars were used in these interspecific crosses with a wide range of compatibility ranging from 0 to over 60% fruit set.  Overall, fruit set occurred 19 or 8% of the time with C. azalea as the maternal or paternal parent.  The primary species used in crosses with C. azalea as the maternal parent were various C. japonica cultivars and straight species (351 crosses with 28.1% fruit set), C. albogigas (47 crosses with 8.5% fruit set) and C. × williamsii ‘Aida’ (43 crosses with 16.3% fruit set).  There were over 20 more species and non C. japonica cultivars that were also evaluated as paternal parents.  Amongst the C. japonica cultivars that were used as pollen parents at least 10 times, ‘Lady de Saumarez’ and ‘Longwood Centennial’ had the highest fruit set of 62.5 and 42.6%.  The primary species used in crosses with C. azalea as the paternal parent were C. japonica (466 crosses with 12.7% fruit set), C. wenshanesis (108 crosses with 8.3% fruit set), and C. sasanqua ‘Narumigata’ (104 crosses with 0% fruit set). There were over 30 more species and non C. japonica cultivars that were also evaluated as maternal parents.  Amongst the C. japonica cultivars that were used as seed parents at least 10 times, ‘Longwood Centennial’ and ‘Longwood Valentine’ had the highest fruit set of 58.3 and 50.0%.  Although fruit set occurred, many of the seeds inside the fruit were underdeveloped and considered non-viable.  A total of 487 seeds have been collected from these crosses and only 154 have been determined to be viable.  All viable seed have C. japonica as a straight species or cultivar as the maternal parent and 104 of these have germinated.  All seeds that were considered nonviable have been placed into an embryo rescue and somatic embryogenesis program.