Here is the info from the PVR patent application
Origin and Breeding Open pollination: ‘Australian Blood’ lime was identified from progeny of open-pollinated seedlings grown from seeds of a zygotic seedling of Rangpur lime grown adjacent to a row of Citrus australasica var. sanguinea seedlings (red-flesh finger limes). Rangpur lime is a citrus rootstock cultivar that yields acid mandarin-like fruits. It has the botanical name of Citrus x limonia (Watson et al, 1984). The seedlings from which the ‘Australian Blood’ lime was identified were culled from other seedlings of the zygotic Rangpur lime seedling based on the obvious Citrus australasica habit and characteristics that they displayed. As a consequence of these characteristics, it is assumed that the pollen parent of the Australian Blood lime was a seedling of C. australasica var. sanguinea. The seedlings with C. australasica habit and characteristics were rowed out for field evaluation and monitoring for growth habit, fruit yield and characteristics. The Australian Blood lime was selected in 1990 when 12 trees were propagated as rooted cuttings for further evaluation. Selection criteria: it was selected for the culinary qualities of its striking red, highly aromatic acid fruits. ‘Australian Blood’ lime will be propagated vegetatively by grafting or budding to standard citrus rootstocks.
Breeder: Dr. S.R. Sykes, CSIRO Plant Industry (Horticulture Unit), Merbein, VIC.
This info from here,
http://www.gondwananativelimes.com.au/australian_native_red_lime.htmlSome other articles say that Ellendale Mandarin is the other parent. Not sure why this is reported.
There are a couple of assumptions in the above, i.e. that a red Finger lime was the parent, assumed because the Blood Lime has red pigmented fruit.
This may not be 100% correct, as another non red/red Finger lime could possibly contribute red genes to an orange fruited Rangpur.
As far as I know some of the Finger Lime parents used by CSIRO came from from the USA collections, possibly seed introductions.
I did grow one of these Finger Limes some years ago, from CSIRO budwood. It was a cherry red small fruit, with cherry flavour.
Not sure if that was the assumed parent.
ps The CSIRO Merbein is now closed. Not sure if the PVR patent has expired yet ??
I once saw some F2 selections from Blood Lime at a Farm Field Day, looked like bigger bumpy finger limes.