ISSN:
1573-5060
Keywords:
apomeiosis
;
embryo-sac
;
Manihot esculenta
;
meiotic diplospory
;
apomixis
;
cassava
;
histology
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Embryo-sac formation in six cultivated Asian cassava clones and one unknown ‘wild type’, was histologically investigated to determine apomictic potential in the genus Manihot. All the 6 clones were found to possess one single sexual embryo-sac containing 6–8 nuclei at maturity. However, one clone, ‘Rayong 3’ possessed two functional embryo-sacs at 12 hours after controlled pollination (HACP). The larger embryo-sac was 6-nucleate (all 3 nuclei of the egg apparatus, 1 polar and 2 antipodal cells) and located towards the ‘false micropylar’ or the nucellar beak region. The smaller embryo-sac also contained a total of 6 nuclei and approximately 10 μm3 or 1/2 the volume of the former and located towards the chalazal pole. Percentage sexuality estimates indicated a 100% sexual reproduction in embryo-sacs of all the clones analysed. However, apomeiotic relationships indicate a low (0.3%) degree of meiotic diplosporous embryo-sac formation, thus suggesting facultative apomixis in cv. ‘Rayong 3’. This is the first embryological identification and evidence of apomeiosis and apomictic potential in cassava.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00029260
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