Sichuan Agricultural University Sichuan, China
Title: Mysterious meiotic behavior of autopolyploid and allopolyploid maize
Muhammad Zafar Iqbal has expertise in maize cytogenetic and allopolyploid’s evolution. His research contribution shed the light on evolution and relationship of subgenomes in genus Zea. He offered a new mechanism for origin and evolution of the genus Zea species on basis of his research findings. His laboratory is famous in China for classical cytogenetic techniques; Genomic in Situ Hybridization (GISH) and Fluorescent in Situ Hybridization (FISH). These techniques have been well utilized to understand the genomic relationships and evolutionary consequences of species.
This study was aimed to investigate the stability of chromosomes during meiosis in autopolyploid and allopolyploid maize, as well as to determine an association of chromosomes between maize (Zea mays ssp. mays Linnaeus, 1753) and Z. perennis (Hitchcock, 1922) Reeves & Mangelsdor, 1942, by producing a series of autopolyploid and allopolyploid maize hybrids. The intra-genomic and inter-genomic meiotic pairings in these polyploids were quantified and compared using dual-color genomic in-situ hybridization. The results demonstrated higher level of chromosome stability in allopolyploid maize during meiosis as compared to autopolyploid maize. In addition, the meiotic behavior of Z. perennis was relatively more stable as compared to the allopolyploid maize. Moreover, ten chromosomes of “A” subgenome in maize were homologous to twenty chromosomes of Z. perennis genome with a higher pairing frequency and little evolutionary differentiation. At the same time, little evolutionary differentiation has been shown by chromosomes of “A” subgenome in maize, while chromosomes of “B” subgenome, had a lower pairing frequency and higher evolutionary differentiation. Furthermore, 5IM + 5IIPP + 5IIIMPP and 5IIMM + 5IIPP + 5IVMMPP were observed in allotriploids and allotetraploids respectively, whereas homoeologous chromosomes were found between the “A” and “B” genome of maize and Z. perennis.