In pumpkin Hlarge hh small O bright orange oooff white R r

In pumpkin: H_-=large, hh small O_- = bright orange, oo-off white R_- = resistant to caterpillars, rr-susceptible Map: O--5mu--H 10mu R Interference-o.6 cross: ohR//oHr x ohr//ohr.//= haplotypes How many plants producing bright orange, large and resistant pumpkins do you expect out of 1000 progeny? 2 3 4 1 5

Solution

Answer: 1

Explanation:

Interference = 1- Coefficent of Coincidence (COC)

0.6 = 1-COC

COC = 0.4

COC = Observered double crossovers / Expected double crossover

Expected double crossover = 5 * 10 = 50/1000 = 0.05

Observered double crossovers = COC * Expected double crossover

= 0.4 * 0.05 = 0.02

Observed double crossovers = 0.02 out of 1000 population= 2

Double crossover genotypes are OoHhRr (Bright orange, large and resistant pumpkins) & oohhrr (Off white, small and susceptible). Only one of each double crossover combination of plant is produced.