B-chromosome Paradigms in Genetic System of Poppy (<i>Papaver somniferum</i> L.)

Abstract

Summary 2B chromosomes are reported here in Papaver somniferum L., cultivar Vivek, which had previously not been reported. The present piece of work investigates the influence of B-chromosomes on the genetic system of the plant and it proposes that variations are present not only between carrier and non-carrier plants but also between carrier and non-carrier pollen mother cells (PMCs) of the carrier plants. Morphologically B and non B carrier plants were indistinguishable but they showed a significant effect on the endophenotype of the plant without depriving it of its vigor. The study deals with a brief investigation on the genomic behavior of B-chromosomes and their influence on A-chromosome s chiasma frequency and pollen fertility. In comparison to noncarrier plants, an increase in chiasma frequency with mild reduction in fertility has also been observed in B-carrier plants. With regard to earlier investigations, the possible mechanism of action of B-chromosomes has been discussed. Owing to their particular properties, B-chromosomes might be used to elucidate wider issues of genome organization and evolution in plants and make sense of them.