Induction of Autotetraploid Plants of Sorghum versicolor

Abstract

Autotetraploid plants of S. versicolor (Anderss.) (2n=10) were induced by colchicine treatment. Seedling treatment with 0.01% colchicine solution for 6hr led to 8.3% tetraploid plant induction, and seed germination with 0.01% colchicine solution for 5 days led to 6.6% tetraploid plant induction. These were considered the most effective and convenient induction methods. Tetraploid S. versicolor plants grew more vigorously, were taller, and had a longer vegetative growth period and larger glumes and seeds compared to their diploid counterparts. Thousand-seed weight was 11.3g for tetraploids and 7.8g for diploids, indicating a 44.8% increase for the former. Cytological observations of meiotic configurations revealed that the unequal distribution of chromosomes of tetraploid S. versicolor plants was one of the major reasons causing partial sterility of the plants.