cheesmanii x martian giant

Minnesota Mato · August 21, 2011

I crossed a cheesmanii with a martian giant in hopes to get a larger fruited tomato with a high beta-carotene content. the F1 gen was slightly larger then the cheesmanii and red. This spring I planted 45 F2 gen plants and am getting slightly bigger fruit with a few variations. As the fruits ripen I mark each plant as to its color, red or orange. With almost all plants accounted for 50% are red and 50% are orange. If red is dominant shouldn't 75% of the plants be red and 25% be orange? how many genes control color in tomatoes ? Also how many generations does it usually take to recover some good size if one parent was pretty small?
craig

dice · August 26, 2011

If you grew out another 45 F2 plants, you might find that all 45
of them produce red fruit. The 75/25 split is only the probability.
What actually happens depends on exactly which F2 seeds were
actually grown out at the same time.

There could be something else going on with other, linked genes,
like you suspect, but it could be as simple as that.

I have no idea how many you would need to grow to find a bigger
fruited one (probably several genes involved in that).

What was the DTM, compared to other plants of well-known cultivars
that you might have been growing at the same time? (Martian Giant
is kind of late ripening.)

August 21, 2011	#1
Minnesota Mato Tomatovillian™ Join Date: Aug 2011 Location: minnesota Posts: 175	cheesmanii x martian giant I crossed a cheesmanii with a martian giant in hopes to get a larger fruited tomato with a high beta-carotene content. the F1 gen was slightly larger then the cheesmanii and red. This spring I planted 45 F2 gen plants and am getting slightly bigger fruit with a few variations. As the fruits ripen I mark each plant as to its color, red or orange. With almost all plants accounted for 50% are red and 50% are orange. If red is dominant shouldn't 75% of the plants be red and 25% be orange? how many genes control color in tomatoes ? Also how many generations does it usually take to recover some good size if one parent was pretty small? craig

August 26, 2011	#2
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	If you grew out another 45 F2 plants, you might find that all 45 of them produce red fruit. The 75/25 split is only the probability. What actually happens depends on exactly which F2 seeds were actually grown out at the same time. There could be something else going on with other, linked genes, like you suspect, but it could be as simple as that. I have no idea how many you would need to grow to find a bigger fruited one (probably several genes involved in that). What was the DTM, compared to other plants of well-known cultivars that you might have been growing at the same time? (Martian Giant is kind of late ripening.) __________________ -- alias