The story thus far: Our plucky heroes have traced Triticum monococcum C68-101, the wild parent of a tetraploid wheat (Line 149) with interesting salinity tolerance genes, to the University of Sydney. Maybe. Kinda. Sort of. But they keep digging, and their perseverance is not long in being rewarded. We hear again from Ray Hare.
You may remember that you asked me back in March to track down the source details of the T. monococcum used as the donor of the sodium exclusion genes Nax1 and 2. At last after some detective work I have a fairly good set of identifiers that match up.
The original seed, that was obtained by the University of Sydney, came as part of a collection of monococcums from Dr Ralph Riley of the Plant Breeding Institute, Cambridge. Prof. Eldrid Baker assembled this collection of Triticum species back in the 1960’s. C68-101 is an accession identifier in the University of Sydney Wheat register with the accession number NS 3637. It is also known as “Triticum aegilopoides – 3″. All of the entries in the University species collection have now been lodged with the Australian Winter Cereals Collection where this monococcum accession has the AUS number 98382.
I have not been able to trace the original collection location. It is likely to be Israel or a neighbouring country. PBI Cambridge had links with the Hebrew University. I have seen no shortage of all manner of Triticum species in Syria, Lebanon, Jordan and Israel.
I would be fairly confident that other monococcums have these Nax genes. We checked out two others from this set and each one showed Na exclusion activity. We simply had to select one accession to conduct our studies.
As I said before, the A genome diploids remain rather under researched. Who knows what may come from this ploidy level. It is quite possible that few diploids were involved in the original formation of the progenitor tetraploids and some of this A genome variation has been lost in the formation of the hexaploids. The total variation in the A genome in hexaploids is likely to be small when referenced back to that in the monococcums. I have seen good isozyme variation evidence that clearly supports this belief, in the order of a few orders of magnitude.
I am happy to be of additional assistance.