Department of Botany, Aligarh Muslim University, Aligarh-202 001, India
Autotetraploidy was induced in Solarium americanum through colchicine treatment. The autotetra-ploids thus obtained were highly sterile and showed prevalence of quadrivalent formation in combination with trivalents, bivalents and univalents. The progeny of autotetraploids were triploids. They were vigorous in growth and highly sterile with several trivalents characteristic of an autotriploid.
The progeny of open-pollinated triploid had 2n=25 and 26 chromosomes. The plant with 25 chromosomes was a primary trisomic whereas the plant with 26 chromosomes was considered to be a double trisomic of a 2n + 1 + 1 type.
