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APOMIXIS AND POLYEMBRYONY IN PACHIRA OLEAGINEA (BOMBACACEAE)
Author(s) -
Baker H. G.
Publication year - 1960
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1960.tb07128.x
Subject(s) - polyembryony , biology , apomixis , seedling , endosperm , botany , ovule , germination , embryo , sowing , sporophyte , asexual reproduction , reproductive biology , leucaena , horticulture , ploidy , embryogenesis , pollen , biochemistry , gene , microbiology and biotechnology
B aker , H. G. (U. California, Berkeley.) Apomixis and polyembryony in Pachira oleaginea (Bombacaceae) . Amer. Jour. Bot. 47(4): 296—302. Illus. 1960.–Trees identified as Pachira oleaginea Decne. are now widely cultivated in tropical and subtropical Africa. Specimens from Achimota, Ghana, are shown to contain 1—5 embryos in a single seed. The flowers, which open at night, are self‐compatible but need to be pollinated for seed‐setting to occur. Maturation of the fruit takes about 2 mo. but the seeds germinate soon after shedding. One embryo in each seed is usually much the largest and the only one to become established as a seedling. There is no relation between seed‐size and numbers of embryos contained. Histological and cytogical studies show that adventitious embryony is responsible for the excess embryos following the formation of a normal sexually produced embryo (2 n =72) and endosperm (3 n =108). Adventitious embryos arise from single cells in the nucellus in the vicinity of the micropyle and appear to develop faster than the sexually produced embryo with consequent frequent apomictic reproduction. This is the first report of apomixis in the Malvales, which may have important practical consequences as P. oleaginea is a potential economic plant and may fruit only 3 yr. after sowing, rendering seed‐propagation feasible.