Cytogenetic and molecular analysis of an apomictic cassava hybrid and its progeny

Abstract

ABSTRACT. An interspecific hybrid between cassava and Manihot glaziovii acquired an apomixis gene from the parent M. glaziovii. This hybrid was exposed to open pollination during three subsequent generations. Seven sibs and the maternal progenitor of the fourth generation were genotyped using six microsatellite loci previously developed for cassava. All sibs were identical with each other and with their maternal progenitor. Sibs of selfed M. glaziovii proved to be identical when examined with these microsatellite loci. The chromosome complement of the apomictic clone was 2n = 38. We observed multi-embryonic aposporic embryo sacs.

Apomixis in different ploidy levels of cassava

“…It can also be a polygenic trait since it was manifested in polyploid type while it was absent in the diploid one. This is in agreement with the findings reported earlier (Nassar et al 2007, 2009, 2010).…”

Review Apomixis in cassava: advances and challenges

“…In this case, additional chromosomes in the aneuploid F 2 plant (2n = 38) have allowed for homozygosity and dosages necessary for the action of these genes. The connection between apomixis and aneuploidy was confirmed in more recent research (Nassar, 2002(Nassar, , 2003bNassar et al, 2000Nassar et al, , 2009). …”

“…Collevatti (2005a, 2008) and Nassar et al (1998bNassar et al ( , 2006Nassar et al ( , 2009 analyzed a large number of samples of parents, F 1 and F 2 hybrids of M. glaziovii x cassava, namely 307. According to their results, heterozygosis was low for all loci; F 2 samples of mother plant were all sibs with loci different from each other and from the maternal plant.…”

Cytogenetic and anatomic behavior of cytochimeras and total polyploids in cassava

“…This may suggest recessive genes for control of this character in Manihot (Nassar, 2002;Nassar et al, 2009).…”