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Occurrence and distribution of ploidy levels of Oryza punctata KOTSCHY ex STEUD . in Africa With 5 Figures and 3 Tables
Author(s) -
Faluyi J. O.,
Nwokeocha C. C.
Publication year - 1993
Publication title -
feddes repertorium
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.24
H-Index - 25
eISSN - 1522-239X
pISSN - 0014-8962
DOI - 10.1002/fedr.19931040309
Subject(s) - biology , ploidy , polyploid , meiosis , pollen , sympatry , botany , oryza , bivalent (engine) , chromosome , oryza sativa , sympatric speciation , genetics , gene , chemistry , organic chemistry , metal
A total of 29 accessions consisting of local and other African accessions of Oryza punctata KOTSCHY ex STEUD . were studied for their agrobotanical characteristics, chromosome number and reproductive biology. Chromosome studies revealed normal meiosis with regular bivalent pairing suggesting that the polyploids are amphidiploid. Asynchrony of meiotic stages was observed in different anthers. The diploids showed economy of pollen production, earlier maturity, reduced biomass but high seed set. The distribution of ploidy levels in Africa shows that: the diploid is widespread. the ranges of the diploids and tetraploids overlap possibly with some degree of sympatry, tetraploids have spread beyond the range of diplods. All these suggest that the tetraploid is a young polyploid complex. The results of ecological and cytological observations are discussed in the light of the potentials for variability in the species.