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Fusion_power · June 20, 2014

I've mentioned this cross several times and finally today had a few ripe fruits. The background for this cross is my search for high septoria tolerance which led me to grow several wild species from TGRC in 2013. I found 3 plants that were exceptional.

LA0417 is S. Pimpinellifolium which is fully cross compatible with domestic tomato. It showed better than average tolerance to septoria and was the best of the S. Pimpinellifolium lines I grew.

I also observed good tolerance in LA2869 which is S. Habrochaites. This line is self incompatible which is typical of S. Habrochaites. The tolerance was good, but not exceptional, there was some leaf damage toward the end of the season.

The best tolerance was LA2175 which is S. Habrochaites and happens to be a self-compatible line. These plants were totally unharmed by septoria and were still fruiting at the end of the season.

I put several plants in 1 gallon pots late last year and attempted crosses. Piennolo del Vesuvio was one of the potted plants. It is a potato leaf variety so was extra easy to tell if crosses took given that the male lines are all regular leaf. This spring, I grew a few seedlings from Piennolo and had 3 regular leaf. I put these into my garden. Two of them are from LA0417 and the 3rd is from a large fruited variety. I had tried some pollen of Black From Tula and Aunt Ruby's German Green so one of those is the probable parent.

Today I picked 2 ripe fruit and there is about a gallon nearly ripe on the LA0417 derived plants. Flavor is good though not quite as sweet as I like. Texture is more like Piennolo, a bit mushy on the inside. Aroma is clean, slightly pungent, good fragrant essence of tomato. As an F1 cross, the results this year do not predict results for F2 plants. I will save a few hundred seed and see what next year brings.

Septoria tolerance of the F1 plants is mid-range, not as good as LA0417, but significantly better than susceptible plants growing in my garden. I expect the tolerance to be based on multiple genes therefore will be slow to concentrate into a stable line.

Why are crosses like this useful? Because the "immune system" of wild species is much more robust than domestic tomato. A few generations of growing and stable large fruited plants can be developed that will bring useful new resistance genes into plants gardeners will enjoy growing.

June 20, 2014	#1
Fusion_power Tomatovillian™ Join Date: Feb 2006 Location: Alabama Posts: 2,250	Piennolo del Vesuvio X LA0417 septoria tolerance I've mentioned this cross several times and finally today had a few ripe fruits. The background for this cross is my search for high septoria tolerance which led me to grow several wild species from TGRC in 2013. I found 3 plants that were exceptional. LA0417 is S. Pimpinellifolium which is fully cross compatible with domestic tomato. It showed better than average tolerance to septoria and was the best of the S. Pimpinellifolium lines I grew. I also observed good tolerance in LA2869 which is S. Habrochaites. This line is self incompatible which is typical of S. Habrochaites. The tolerance was good, but not exceptional, there was some leaf damage toward the end of the season. The best tolerance was LA2175 which is S. Habrochaites and happens to be a self-compatible line. These plants were totally unharmed by septoria and were still fruiting at the end of the season. I put several plants in 1 gallon pots late last year and attempted crosses. Piennolo del Vesuvio was one of the potted plants. It is a potato leaf variety so was extra easy to tell if crosses took given that the male lines are all regular leaf. This spring, I grew a few seedlings from Piennolo and had 3 regular leaf. I put these into my garden. Two of them are from LA0417 and the 3rd is from a large fruited variety. I had tried some pollen of Black From Tula and Aunt Ruby's German Green so one of those is the probable parent. Today I picked 2 ripe fruit and there is about a gallon nearly ripe on the LA0417 derived plants. Flavor is good though not quite as sweet as I like. Texture is more like Piennolo, a bit mushy on the inside. Aroma is clean, slightly pungent, good fragrant essence of tomato. As an F1 cross, the results this year do not predict results for F2 plants. I will save a few hundred seed and see what next year brings. Septoria tolerance of the F1 plants is mid-range, not as good as LA0417, but significantly better than susceptible plants growing in my garden. I expect the tolerance to be based on multiple genes therefore will be slow to concentrate into a stable line. Why are crosses like this useful? Because the "immune system" of wild species is much more robust than domestic tomato. A few generations of growing and stable large fruited plants can be developed that will bring useful new resistance genes into plants gardeners will enjoy growing.