The Transference of Apomixis Genes from Manihot Neusana Nassar to Cassava, M. Esculenta Crantz

Review Apomixis in cassava: advances and challenges

“…However, recurrent selection has proven to increase its rate to up to 11% judging from polyembryo frequencies (Nassar et al, 2000). This result supports the hypothesis that apomixis in cassava is controlled by multiple factors; accumulation of such factors in a certain genotype might result in a higher level of apomixis.…”

“…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). …”

“…neusana was found to have a 1.5% apomixis rate; while this feature was found to be absent in cassava and the F 1 generation. In Nassar et al (2000), normal embryo sacs were found to contain 8 nuclei (Figure 2A). Two embryo sac components were found for the first time, as they grew side by side in an F 2 individual ( Figure 2B).…”

“…The finding of apomixis transfer from M. glaziovii in the 1990s was followed by a report of its transfer from M. neusana (Nassar et al, 2000;Nassar, 2003a). First and second generations and parental plants of cassava x M. neusana hybrids were analyzed embryologically and cytogenetically.…”

“…These plants were studied cytogenetically and anatomically. Embryo sacs were also analyzed by clearing in toto (Nassar et al, 2000). Anatomical study of these progenies showed aposporic embryo sacs in all of them (Figure 3).…”