Question

In a plant leaf color, leaf shape, and plant height are controlled by three linked genes. Wildtype plants are normal height with pointed, green leaves. Triple mutant plants are dwarf (d) with round (r), white (w) leaves. A female heterozygous for all three mutations is testcrossed and the following progeny phenotypes were observed:

wildtype	116
dwarf	350
dwarf, round	4
dwarf, round, white	120
round, white	325
round	35
white	3
dwarf, white	47

a. What are the parental genotypes?

b. Which gene is in the middle?

c. Construct a genetic map showing distances between adjacent genes.

d. Calculate the interference observed in this cross.