Rubidoux pummelo hybrid #2
Citrus hybrid RUTACEAE
Received as budwood from Citrus Clonal Protection Program.
Putatively bred at USDA Date and Citrus Station, Indio, and released to UCR when station closed.
Recent information reports the parentage as Redblush grapefruit x Webber tangelo
Rootstocks of accession
Carrizo citrange, C-35 citrange
Season of ripeness at Riverside
January to May
Notes and observations
4/2022, MR: "Reviewing the recent cross records caused me to pursue the parentage of Rojo Blanco. I believe that this selection is a Redblush x Webber tangelo hybrid made by USDA. The source tree was likely LREC Field 53 8-28 or Field 53 9-21 or 9-22. All of these had the same code, USDA code 52-58-3. We did not originally know the identity - the map I received was blank. After Darwin Atkins retired in 2012 I received some paper files he had and one of these listed the parentage of the previously "blank" hybrids in these rows. My notes on the tree call it "pink Oroblanco" type.
When these rows in field 53 were removed (2010) it was propagated to Field 92E where it is identified as "USDA grapefruit hybrid, F53-9-21". Probably it was that tree from which budwood was sent to CCPP. CCPP should have a record. The only reason to question this is that Yoko's analysis of genome ancestry does not show any regions of Rojo Blanco homozygous for mandarin alleles. I would expect some of these, but perhaps they are "hidden" in the 20% of the genome that could not be assigned.
4/2022, RRK: "USDA 52-58 was indeed listed as Redblush X Webber."