Meiotic behavior of B chromosome in two species of <i>Trigonella</i> L. from Bangladesh

Abstract

Meiotic study revealed the presence of B chromosomes in two species of Trigonella L. Meiotic abnormalities, pollen fertility, and chiasma frequency were taken into consideration to investigate the effects of B chromosomes. Several meiotic abnormalities were observed as a consequence of chromatin stickiness and abnormal spindle activity such as asynchronous condition, precocious movement, clumping, chromosome breakage, vagrant chromosome, cytomixis, polar tendency, unequal distribution, laggard chromosome, tri-polarity and disturbed polarity. Stickiness of the chromosome was found to be dominant over the other meiotic abnormalities in both metaphase-I/II and anaphase-I/II. Here, B chromosomes showed a neutralizing effect on meiotic abnormality and had an inert control over chiasma frequency thus producing fertile pollen. Nowadays, studying B chromosomes became an important fact because the contribution of B chromosome in plants is not well known to all.