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Post by darthslater on Feb 8, 2011 19:20:37 GMT -5
If Ph1 and Ph3 major genes are introduced in a cross will disease tolerance be inherited?
How disease resistant will the offspring be?
Also, do both parents have to have these genes for resistance.
Or can a cross be selfed to get the results?
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Post by blane on Apr 2, 2011 20:50:20 GMT -5
This question needs to be addressed still....
If it was already covered in chat, or phone, I would still like to see some type...
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Post by frogsleapfarm on Apr 2, 2011 21:48:25 GMT -5
I believe that Ph3 is partially dominant, meaning that the level of resistance in homozygous Ph3/Ph3 plants is higher than in heterozygous plants. In a cross between a homozygous Ph3 line and a susceptible plant, the F1 progeny (heterozygous) will have moderate resistance. Homozygous Ph3 plants can be identified in the F2.
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PVP
Tomatophile
head spellerer
Only an Amateur
Posts: 798
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Post by PVP on Apr 2, 2011 22:49:36 GMT -5
Is Mountain Magic F1 heterozygous Ph3? How about Smarty F1 and Plum Regal?
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Post by frogsleapfarm on Apr 3, 2011 8:16:27 GMT -5
from a recent scientific paper on LB resistance in tomato "In tomato, three isolatespecific R genes have been reported: Ph1, Ph2, and Ph3. Ph1 is completely dominant, whereas Ph2 and Ph3 are incompletely dominant (Conover and Walter 1953; Gallegly 1960; Turkensteen 1973; Chunwongse et al. 1998; Moreau etal. 1998)." The three resistance genes are effective against different races of the pathogen. Here's a great summary power point presentation - www.ces.ncsu.edu/fletcher/programs/plantpath/2006-11-tomato-disease/TDW2006_presentations/Zitter_LB_EB_Breeding.pdfI believe all of the current LB resistant commercial hybrids are heterozygous for Ph3, but not sure about Defiant. |
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