A molecular and embryonic study of apomixis in cassava (Manihot esculenta Crantz)
- 118 Downloads
In cassava, apomixis fixes heterosis and avoids transmission of systemic pathogens which complicate vegetative propagation of the crop. A combination of evidence from maternal inheritance of RAPD markers and the structure of the embryonic sac in large progeny sets of two distinct genotypes have further confirmed the occurrence of apomixis in cassava. We could advance further on earlier reports of the detection of apomixis in four ways: (1) we could arrive at an estimate of the rate of facultative apomixis in the range of 2%; (2) we detected the occurrence of apomixis in a second genotype, derived from a different interspecific cross; (3) apomictic behavior was demonstrated in an F1 individual and (4) parallel embryonic evidence was generated that corroborate the potential occurrence of apomixis by apospory. The fact that apomixis was detected in an F1 interspecific hybrid hints to the possibility of directly transferring genes for apomixis from a wild relative to cultivated cassava.
Unable to display preview. Download preview PDF.
- Asker, S., 1979. Progress in apomixis research. Hereditas 91: 231- 240.Google Scholar
- Doyle, J.J. & J.L. Doyle, 1987. Isolation of plant DNA from fresh tissues. Focus 12: 13-15.Google Scholar
- FAO, 1994. FAO Yearbook. Rome.Google Scholar
- Grattapaglia, D., C. Costa e Silva & N.M.A. Nassar, 1996. Strict maternal inheritance of RAPD fingerprints confirm apomixis in cassava (Manihot esculentaCrantz). Can J Plant Sci 76: 379-382.Google Scholar
- Nassar, N.M.A., 1980. Attempts to hybridize wild Manihotspecies with cassava. Econ Bot 34: 13-15.Google Scholar
- Nassar, N.M.A., 1994. Development and selection of apomixis in cassava, Manihot esculentaCrantz. Can J Plant Sci 74: 857-858.Google Scholar
- Ogburia, M.N. & T. Adachi, 1994. An improved cleared-pistil technique for rapid in totoobservation of embryo sac malformation in cassava (Manihot esculentaCrantz). Proceedings of the Second International Scientific Meeting Cassava Biotechnology Network, Indonesia, pp. 117-127.Google Scholar
- Young, B.A., R.T. Sherwood & E.C. Bashaw, 1979. Cleared-pistil and thicksectioning techniques for detecting aposporous apomixis in grasses. Can J Bot 57: 1668-1672.Google Scholar