Post by Joseph Lofthouse on Aug 31, 2010 18:31:42 GMT -5
I have spent the last few weeks in my corn breeding patch, detasseling. pollinating, and trying to identify the sweetest ears, which presumably are homozygous for the sugary enhancing gene.
My identification strategy for BC1 plants (F1/F2 backcrossed to se+) is as follows:
Cut the end of the cob off a couple inches from the tip.
Taste the kernels. If they are not sweet, or only somewhat sweet, move on to the next cob.
If the kernels taste sweet then squeeze the juice of individual kernels onto the sample plate of a refractometer and measure the percent sugar. If 5 tested kernels in a row measure around 23% sugar then mark the cob for saving as "probably homozygous for se".
I am also finding a number of cobs with around 17% sugar. I am marking these with a different color flag, and consider them to be "very interesting for further work."
So far I have identified high sugar cobs in the following strains:
Astronomy Domine (2 ears out of 100)
LISP Ashworth (15 ears out of 100)
Spero's Red & Gold
Spero's 51A
In particular the AD result over-represents the amount of se in the general population, because I sorted through many hundreds of seeds attempting to identify se+ by the nature of the seeds wrinkles and shape.
I grew 3 rows of Ashworth. One that I had selected based on finely wrinkled and gently rounded kernels (se+?). And two rows with the rest of the seed. There were lots on non-se+ cobs in the first row, but statistically se+ cobs showed up 3X more often in the selected seed than in the non-selected seed, so there might be some hope for the selection criteria.
The worst tasting cob award for the season goes to Red & Gold. Uugh!!! There were a lot of great tasting cobs in Red & Gold, but that one was something else.
Runner up goes to a variety which I think was mislabeled as "Rainbow Inca". It looked more like an indian dent corn before I planted it, and it tastes like an indian dent corn now.
I'll be testing more varieties as they mature in the next few weeks.
Regards,
Joseph
My identification strategy for BC1 plants (F1/F2 backcrossed to se+) is as follows:
Cut the end of the cob off a couple inches from the tip.
Taste the kernels. If they are not sweet, or only somewhat sweet, move on to the next cob.
If the kernels taste sweet then squeeze the juice of individual kernels onto the sample plate of a refractometer and measure the percent sugar. If 5 tested kernels in a row measure around 23% sugar then mark the cob for saving as "probably homozygous for se".
I am also finding a number of cobs with around 17% sugar. I am marking these with a different color flag, and consider them to be "very interesting for further work."
So far I have identified high sugar cobs in the following strains:
Astronomy Domine (2 ears out of 100)
LISP Ashworth (15 ears out of 100)
Spero's Red & Gold
Spero's 51A
In particular the AD result over-represents the amount of se in the general population, because I sorted through many hundreds of seeds attempting to identify se+ by the nature of the seeds wrinkles and shape.
I grew 3 rows of Ashworth. One that I had selected based on finely wrinkled and gently rounded kernels (se+?). And two rows with the rest of the seed. There were lots on non-se+ cobs in the first row, but statistically se+ cobs showed up 3X more often in the selected seed than in the non-selected seed, so there might be some hope for the selection criteria.
The worst tasting cob award for the season goes to Red & Gold. Uugh!!! There were a lot of great tasting cobs in Red & Gold, but that one was something else.
Runner up goes to a variety which I think was mislabeled as "Rainbow Inca". It looked more like an indian dent corn before I planted it, and it tastes like an indian dent corn now.
I'll be testing more varieties as they mature in the next few weeks.
Regards,
Joseph