F2 to F3 question

**Patrina_Pepperina** · February 26, 2007

Hi Tom

I have a question for you relating to the Dwarf Project for the following scenario:

New Big Dwarf (F) x Paul Robeson (M) gives a dwarf:non dwarf ratio of approximately 1:3 in the F2 generation. In the F3s it appears that there is a higher ratio of dwarfs:non dwarfs when growing out seeds from dwarf plants.

What about seeds from indeterminates in the F2 generation - will some of the F3 seeds from an indeterminate parent give dwarf seedlings?

Patrina

Rena · February 26, 2007

Patrina, I came here to ask the same thing. I am growing out some f3s from an ind witty plant and I have be staring down the seedlings (I think 2 could be dwarf) but they are so itty I am probably wrong. The ind Witty plant gave a yellow/green ripe fruit so I am curious what will happen.-Rena

gardenpaws_VA · May 5, 2007

I put this in the dwarf project thread as well, but since the topic has come up here, one (out of eight) F3 seedlings of Tylenol's orange indeterminate F2 (Doc line) is definitely as dwarf as the F3 seedlings from his dwarf RL9 F2. It's short, stocky, and rugose.

pierre rutten · May 30, 2007

As Tom did not reply here are the facts.

We are speaking of progenies of a dwarf x non dwarf cross.

Dwarf:non dwarf ratio of approximately 1:3 in the F2 generation points strongly to dwarf being a single gene recessive. All confirmed facts.

A recessive gene is expressed only when no dominant gene is present. Dominant to dwarf here is non dwarf. All F1 are non dwarf. It is because each F1 seed got a dwarf gene from the mother plant and a non dwarf gene from the pollen.

Then all dwarfs are homogeneous (and true breeding) for dwarfness. Unless crossed all seedlings from a dwarf should be dwarves also. That F3 from dwarf F2 are all dwarves is just right. All non dwarf seedlings from a dwarf mother are crossed. Allways.

**Patrina_Pepperina** · June 4, 2007

Thanks folks! So it appears that dwarf F2s will always give dwarf F3s (unless some crossing has occurred), and indeterminate F2s can still segregate further giving a few dwarf F3s. This ties in with other results where segregation still occurs for leaf form, ie. some RL dwarf F2s have given a small number of PL dwarf F3s.

Very interesting!

Patrina

February 26, 2007	#1
Patrina_Pepperina Cross Hemisphere Dwarf Project™ Moderator Join Date: Jan 2006 Location: New South Wales, Australia Posts: 3,094	F2 to F3 question Hi Tom I have a question for you relating to the Dwarf Project for the following scenario: New Big Dwarf (F) x Paul Robeson (M) gives a dwarf:non dwarf ratio of approximately 1:3 in the F2 generation. In the F3s it appears that there is a higher ratio of dwarfs:non dwarfs when growing out seeds from dwarf plants. What about seeds from indeterminates in the F2 generation - will some of the F3 seeds from an indeterminate parent give dwarf seedlings? Patrina __________________ Truth is colourful, not just black and white. PP: 2005

May 5, 2007	#3
gardenpaws_VA Tomatovillian™ Join Date: Apr 2006 Location: Northern Virginia, USA - zone 7+ Posts: 161	I put this in the dwarf project thread as well, but since the topic has come up here, one (out of eight) F3 seedlings of Tylenol's orange indeterminate F2 (Doc line) is definitely as dwarf as the F3 seedlings from his dwarf RL9 F2. It's short, stocky, and rugose. Last edited by gardenpaws_VA; June 7, 2007 at 11:17 PM. Reason: remove a typo

June 4, 2007	#5
Patrina_Pepperina Cross Hemisphere Dwarf Project™ Moderator Join Date: Jan 2006 Location: New South Wales, Australia Posts: 3,094	Thanks folks! So it appears that dwarf F2s will always give dwarf F3s (unless some crossing has occurred), and indeterminate F2s can still segregate further giving a few dwarf F3s. This ties in with other results where segregation still occurs for leaf form, ie. some RL dwarf F2s have given a small number of PL dwarf F3s. Very interesting! Patrina __________________ Truth is colourful, not just black and white. PP: 2005

February 26, 2007	#2
Rena Tomatovillian™ Join Date: Feb 2006 Location: Warm Springs, GA Posts: 1,421	Patrina, I came here to ask the same thing. I am growing out some f3s from an ind witty plant and I have be staring down the seedlings (I think 2 could be dwarf) but they are so itty I am probably wrong. The ind Witty plant gave a yellow/green ripe fruit so I am curious what will happen.-Rena

May 30, 2007	#4
pierre rutten Tomatovillian™ Join Date: Jun 2006 Location: France Posts: 16	As Tom did not reply here are the facts. We are speaking of progenies of a dwarf x non dwarf cross. Dwarf:non dwarf ratio of approximately 1:3 in the F2 generation points strongly to dwarf being a single gene recessive. All confirmed facts. A recessive gene is expressed only when no dominant gene is present. Dominant to dwarf here is non dwarf. All F1 are non dwarf. It is because each F1 seed got a dwarf gene from the mother plant and a non dwarf gene from the pollen. Then all dwarfs are homogeneous (and true breeding) for dwarfness. Unless crossed all seedlings from a dwarf should be dwarves also. That F3 from dwarf F2 are all dwarves is just right. All non dwarf seedlings from a dwarf mother are crossed. Allways.