Patent Application
20160120083
Citrus sinensis
‘OLL-4’
The present invention relates to a new and distinct variety of sweet orange tree named ‘OLL-4’. ‘OLL-4’ is a somaclone regenerated from embryogenic callus (tissue culture) of ‘OLL’ (‘Orie Lee Late’) sweet orange, with high-quality fruit that usually matures in the standard ‘Valencia’ time period. ‘OLL’ (unpatented) is believed to be an irradiation-induced mutant line originating from ‘Pineapple’ sweet orange in an abandoned USDA trial attempting to generate a seedless ‘Pineapple’ orange. ‘OLL’ attracted attention because it never dropped fruit, a serious problem with ‘Pineapple’, and held quality late into the summer. Propagations of ‘OLL’ were not uniform and included some trees of poor growth and productivity, as well as robust high-yielding trees. In efforts to generate genetically stable clones from the ‘OLL’ selection, tissue cultures (embryogenic callus) were established for the creation of somaclones. At present, ‘OLL-4’ has been the highest yielding somaclone, and is the only remaining somaclone showing no Huanglongbing (HLB) disease symptoms. Trees of ‘OLL-4’ sweet orange topworked onto HLB-infected root/scaffold trees (‘Swingle’ and ‘Carrizo’) are also growing off quite well, but it is too early to determine the actual level of HLB tolerance. Topworked trees demonstrated true-to-typeness, as well as new trees grafted to experimental rootstocks also planted at St. Cloud, Fla.
‘OLL-4’ produces round oranges with internal and external color similar (or better) to that of ‘Rhode Red Valencia’ (Table 1). Fruit of ‘OLL-4’ holds on the tree exceptionally well, and maintains quality into the summer. Fruit of ‘OLL-4’, like all of the ‘OLL’ oranges, peel easier than ‘Valencia’, which, combined with the attractive external color, provides excellent crossover potential as fresh fruit, thereby expanding the available fresh orange portfolio for Florida. ‘OLL’ seedling trees (including ‘OLL-4’) have shown good drought tolerance in the greenhouse, as overgrown trees in small pots rarely wilt compared to other sweet orange seedlings. This apparent improved stress tolerance may be useful against HLB disease. Limited yield data is available, but the original tree of ‘OLL-4’ has been the highest yielding tree among the ‘OLL’ somaclones over the past 3 years, producing more than five 90-lb. boxes of fruit per year, with a maximum of 6.13 boxes in 2014 (Table 1). Trees on ‘Swingle’ citrumelo appear to yield better than standard ‘Valencia’. Production of lbs solids on ‘OLL-4’ is not the highest among the ‘OLL’ somaclones (Table 2), but has been as good as or better than traditional ‘Valencia’. ‘OLL’ oranges, including ‘OLL-4’, have not exhibited the undesirable low ratios associated with ‘Valencia’ during the past two seasons (Tables 2 and 3). Alternate bearing has not been an issue on ‘OLL-4’. Sensory (taste panel) analyses have indicated that ‘OLL-4’ has a favorable ‘Valencia’-like flavor profile (Table 3). Top-worked and grafted trees of ‘OLL-4’ on various rootstocks are growing off quite well.
‘OLL-4’ is illustrated by the accompanying photographs, which show the tree's form, foliage and fruit. The colors shown are as true as can be reasonably obtained by conventional photographic procedures. The photographs are of a tree approximately 13 years old.
Phenotypic Description of Citrus sinensis ‘OLL-4’
The following detailed description sets forth the distinctive characteristics of ‘OLL-4’. The present botanical description is that of the variety grown on a 13-year-old tree growing on ‘Swingle’ citrumelo rootstock (C. paradisi×Poncirus trifoliata) at St. Cloud experimental block, and a top-worked tree at the same location. The colors (except those in common terms) are described from the R.H.S. Colour Chart published by The Royal Horticultural Society in London (second edition), in association with the Flower Council of Holland.
