Investigating the parentage of ‘Orri’ and ‘Fortune’ mandarin hybrids

Germplasm characterization is now possible with improved molecular analysis tools with a greater ability todetect polymorphisms. Previously citrus cultivars were primarily described according to their morphological or horticultural traits, but trueness-to-type can now be confirmed using molecular markers, thereby limiting S02inadvertent cultivar misidentification. However, following routine testing the reported parentage of twomandarin hybrids is now questioned. 'Orri' mandarin is derived from 'Orah' mandarin hybrid by inducedmutation, and was bred by Spiegel-Roy and Vardi (The Volcani Center, Israel) with 'Temple' tangor and 'Dancy' mandarin reported as the parents. 'Orri' is prized in many markets for its excellent organoleptic qualities, andother favorable traits. With 'Dancy' as the pollen parent, at least some degree of susceptibility of 'Orri' toAlternaria Brown Spot (ABS) might be expected, but more likely to have inherited a high degree of susceptibility;yet it appears to be immune to ABS. SSR analysis provided evidence that excludes 'Dancy' as the pollen parentof 'Orah'. Further testing has revealed the likely candidate as the pollen parent. 'Fortune' mandarin was apopular late-maturing mandarin cultivar until the high incidence of ABS rendered the cultivar uneconomicalto produce. This exceptionally late, high quality, attractive cultivar is reported to have originated from aclementine mandarin x 'Dancy' cross made by Furr (USDA, Indio, California). 'Fortune' is used as a femaleparent in breeding programs. However, two independent molecular marker studies revealed that the pollenparent of 'Fortune' is actually 'Orlando' tangelo and not 'Dancy'. In both cases, the pollen parent of 'Orri' and'Fortune' mandarin hybrids appears to not be 'Dancy' as published. This information will assist geneticists andbreeders to re-interpret heritability studies on ABS susceptibility of mandarins and their hybrids.