flowers only during long days while N. tobacum
flowers only during short days. If raised in the laboratory under different photoperiods, they can be induced to flower at the same time and can be cross fertilized to produce self-fertile offsprings.
What is the best reason for considering N. sylvestris
and N. tobacum
to be separate species?
- They are physiologically distinct
- They are morphologically distinct
- They can interbreed in nature
- They are reproductively distinct