Genetic Ratio Exercise
Try counting the following genetic ratios. If you have questions or comments, contact a friendly maize researcher.
Ratio 1, orp2-N1186B, orange pericarp2 (duplicate factor with orp1): pericarp orange over orp1 orp2 kernels; roots fluoresce blue in UV light; weak seedlings that respond to tryptophan feeding. Photo: selfed ear of an orp1/orp1, +/orp2 plant segregating 3:1 for orange pericarp, orp2. See also related images and information here by filtering with orp.
Ratio 2, orp1-1186A, orange pericarp1: selfed ears segregating for duplicate factors orp1 and orp2. Top: +/orp1 +/orp2 showing 15 normal to one orp. Bottom: orp1/orp1, +/orp2 showing 3 normal to one orange pericarp kernel. See also related images and information here by filtering with orp.
Ratio 3: selfed ear of B1:Peru/b1, R1/r1 showing 15:1 segregation for colorless aleurone (b1 b1 r1 r1) with some kernels showing r-mottling (b1 b1 R1/r1/r1) and others showing dilution effect of B1:Peru in single dose (originally designated R2 because it is a duplicate gene to R1). Ear also segregating for pr1, recessive for red kernels. See also related images and information here by filtering with b1.
Ratio 4, c2, colorless2: colorless aleurone, reduced plant color; C2-Idf dominant inhibitor; duplicate factor with whp1 for pollen color and for anthocyanins; encodes chalcone synthase. Photo: segregating ear shows full colored C2 C2 (C2 or c2), dilute C2 c2 c2, and colorless c2 c2 c2 kernels in a ratio of 2:1:1. See also related images and information here by filtering with c2.
There are many alternative images showing segregations for kernel traits. Go hereand filter with su1 or pro1 or sh1, for example.
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Last updated 1:43 pm, Dec 03, 2014.