Main features of Polygenic inheritance using character of carolia length of Nicotiana longiflora

i) The two parents were inbred and almost homozygous. But there was variation for corolla length within each of two parents. This variation can’t be genetic but it is due to environmental factors because plants within parental lines are expected to hace same genotype.

ii) . F1 was intermediate between those of two parents.

iii) The amount of variations in F1 was comparable to that in parents. Again, all F1 plants will have identical genotype. So, variation produced will be again due to environment.

iv) The F1 mean was close to that of F1 and intermediate between those of two parents. There was much greater variation for corolla length in F2 than in either of segregation and recombination of polygenes governing corolla length.