I have found this a hard subject to make simple. But here goes...

Tomato late blight resistance genes are non-allelic

Quote:
Non-allelic genes are genes located at different loci on the same
chromosome or on different chromosomes altogether.


The gene, Ph-3, Chromosome 9
Ph-1 (chromosome 7
Ph-2 (chromosome 10).

Reports are that
Quote:
WV106
carried a single dominant allele conditioning a high level
of resistance to P. infestans tomato race 0 (T0)
(Ph-1)

and that WV700 possessed one or more dominant resistance genes (but is associated with Ph-2)


Quote:
Researchers at the AVRDC identified resistance to late blight from Solanum pimpinellifolium L. accession L3708. Segregation data obtained for resistance do not support the hypothesis of single gene control of the full resistance trait, but suggest that more than one gene is involved, and that these genes interact in an epistatic manner. Differential responses were also observed between the resistant CU-R lines and the resistant CLN-R lines, which were independently bred from L3708. RFLP analysis confirmed the Ph-3 gene derived from L3708 is located on chromosome 9.



The meaning of (genes interact in an epistatic manner )
epistatic (not comparable)

1. (genetics) Of or pertaining to epistasis, the interaction between genes.

I have a lot of self doubt about my work with Late Blight resistance. Since I had great results with sinlgle dominance with WV 700 with my particular strain of it for years 2004-2007. But 2008 is a year that needed homozygous Ph-2 and Ph-3 clones. Mountain Magic has heterozygous genes as a hybrid and it did not survive to the end of the infestation process. Only my most homozygous clone (Ph-2 and Ph-3)survived totally. I will be testing some seedlings from the recent hybrid of WV 700 X homozygous Ph-1 and 2 for this fall. The hybrid would be homozygous for Ph-2 but only heterozygous for Ph-1.


The good news is that I am transferring the genes Ph-2 and Ph-2 into a wide variety of clones such as Black Pineapple, Black Prince, Green Sleeves, WV 700, and many, many more. I've got to remind myself to sow a huge compilation of varieties soon.

The kind of work I am doing with require that I do a large extension collaboration. I will be exploring ideas to that effect soon.

Tom Wagner

CULTIVATED SPECIES ACCESSIONS WITH TUBER FLESH COLOR

PI #

SOLANUM SPECIES

DESCRIPTION

I am putting this list up on the blog to show that I am involved in many types of research. The list below of potatoes from South America will be dug this August 28 in Vancouver, WA.

I have already collected the inter-mated crosses and the tremendous amount of open pollinated berries from a vast majority of these. The tubers will be of some importance to grow again, but the TPS will be invaluable for many years to come. I could plant many acres of transplants grown just from the berries of this group.

Yes the potatoes will be video taped also as they are dug

PI 310490* (phureja)

YELLOW RED

PI 310493*(phureja)

YELLOW

PI 225667*(phureja)

DEEP YELLOW

PI 225667* (phureja)

YELLOW - PURPLE RING

PI 225673*(phureja)

DEEP YELLOW

PI 225677*(phureja)

DEEP PURPLE FLESH - PURPLE MOTTLED ON WHITE FLESH

PI 225686*(phureja)

WHITE - PURPLE RING

PI 225686*(phureja)

DEEP YELLOW

PI 225688(phureja)

YELLOW - PURPLE SPLASH

PI 225689(phureja)

YELLOW - PURPLE SPLASH

PI 225689*(phureja)

YELLOW - PURPLE

PI 225689(phureja)

BRIGHT YELLOW

PI 225689*(phureja)

DEEP PURPLE - DARK YELLOW

PI 225693* (phureja)

DEEP YELLOW

PI 225693*(phureja)

DEEP YELLOW

PI 225694*(phureja)

DEEP YELLOW

PI 225705*(phureja)

DEEP YELLOW

PI 225710*(phureja)

DEEP YELLOW

PI 320355*(phureja)

DEEP PURPLE

PI 320355(phureja)

YELLOW SKIN - DEEP PURPLE

PI 320370(phureja)

YELLOW - RED CENTER

PI 320370*(phureja)

DEEP YELLOW - RED PHLOEM

PI 320373*(phureja)

DEEP YELLOW

PI 320373*(phureja)

DEEP YELLOW

PI 320377*(phureja)

DARK PURPLE SKIN - YELLOW FLESH

PI 320377*(phureja)

DARK YELLOW

PI 320377(phureja)

DEEP PURPLE

PI 320379*(phureja)

DEEP YELLOW

PI 320379* (phureja)

DEEP YELLOW - RED RING

PI 320379*(phureja)

DEEP YELLOW - RED RING

PI 320387(phureja)

DEEP YELLOW

PI 320390(phureja)

PURPLE CENTER

PI 320390*(phureja)

YELLOW

PI 320391*(phureja)

DARK YELLOW

PI 320391*(phureja)

DARK YELLOW

PI 320391*(phureja)

DEEP PURPLE CENTER

PI 320391*(phureja)

DEEP YELLOW

PI 498171*(phureja)

DEEP YELLOW

PI 498171*(phureja)

YELLOW - RED

PI 292110*(stenotomum)

DEEP YELLOW - NEAT SHAPE

PI 205527(stenotomum)

PI 234007* (stenotomum)

DEEP PURPLE

PI 234007*(stenotomum)

DEEP PURPLE

PI 234015(stenotomum)

PI 209421(andigena)

PURPLE FLESH

PI 209421*(andigena)

PI 186179*(andigena)

RED FLESH

PI 214441*(andigena)

BRIGHT YELLOW

PI 217448* (andigena)

BRIGHT YELLOW

PI 280868*(andigena)

LIGHT RED

PI 280871*(andigena)

YELLOW

PI 280921*(andigena)

YELLOW

PI 280952* (andigena)

INTERESTING TUBER

PI 281004*(andigena)

YELLOW

PI 281007(andigena)

PURPLE RING

PI 281012* (andigena)

PURPLE MOTTLED

PI 281079*(andigena)

WHITE SKIN - PURPLE CENTER

PI 281080*(andigena)

PURPLE SKIN - PURPLE RING

PI 281080*(andigena)

PURPLE/WHITE SKIN - DEEP YELLOW

PI 281189(andigena)

RED SPLASH

PI 281189* (andigena)

PURPLE SPIKE IN MIDDLE

PI 281189 (andigena)

PURPLE SPIKE IN MIDDLE

PI 281206* (andigena)

YELLOW - RED

PI 281219 (andigena)

DEEP YELLOW

PI 29211 (andigena)

DEEP YELLOW

PI 473260* (andigena)

YELLOW - RED SPLASH

PI 473260* (andigena)

YELLOW - RED CIRCLE

PI 473260*(andigena)

YELLOW - RED CIRCLE

PI 473260*(andigena)

RED SKIN - RED CENTER

PI 473276*(andigena)

PURPLE - YELLOW

PI 473276* (andigena)

YELLOW

PI 473276*(andigena)

YELLOW

PI 498310*(andigena)

PURPLE SPOTTING

PI 498310*(andigena)

PURPLE CENTER

PI 498310 (andigena)

DEEP PURPLE