Assessing the chromosomal stability during cell division in the interspecific hybrids of pearl millet × Napier grass hybrid CO (BN) 5

Abstract

Pennisetum glaucum, with 2n = 2x = 14 chromosomes and genomes AA and Pennisetum purpureum with 2n = 4x = 28 chromosomes and genomes A’A’BB belongs to two different gene pools are however sexually compatible and undergoes hybridization that favors the introgression of favorable alleles into development of Pearl Millet × Napier (PMN) hybrids. But the major problem lies in their interspecific hybrids that produces sterile pollen grains due to triploidy (2n = 3x = 21). This current study describes meiotic behavior of PMN hybrid CO (BN) 5 of TNAU origin along with its parental lines. Pearl millet parent variety (IP 20594) used as female parent presented normal and regular meiotic behavior with seven bivalents. In Napier parent (FD 437) normal bivalent formation was noticed, however, univalents ranging from 1- 3 and laggards during anaphase-I were also observed in few pollen mother cells. The hybrid, presented a high frequency of abnormalities that were characterized by irregular chromosomal segregation and tetrad formation with micro nuclei.