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Apomixis and Sexuality in Eragrostis curvula 1
Author(s) -
Voigt P. W.,
Bashaw E. C.
Publication year - 1972
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1972.0011183x001200060039x
Subject(s) - apomixis , biology , obligate , sexual reproduction , meiosis , asexual reproduction , reproduction , botany , plant reproduction , ploidy , genetics , pollen , pollination , gene
Weeping lovegrass, Eragrostis curvula (Schrad.) Nees, reproduces by obligate apomixis (diplospory). Eventual success in the breeding of this important forage and conservation species depends on the identification of sexual types and their successful manipulation. The objective of this study was to examine megasporogenesis and embryo sac development in plants producing variable progenies (presumed sexuals) compared with development apomictic plants. Offspring of the presumed sexual plants were also examined cytologically. The study indicated that the plants producing variable progenies were indeed sexual. The best indicator of sexuality was evidence of meiosis and the presence of a tetrad of megaspores. The number of nuclei in mature embryo sacs was not always a good indicator of mode of reproduction. It was apparent that diplospory is genetically controlled. Based on the cytological results from the offspring of the sexual plants, we propose, as a working hypothesis, that mode of reproduction in Eragrostis curvula is controlled by only a few genes and that sexuality is either dominant or epistatic to apomixis. Because apomixis is apparently obligate in this species, we believe that, through hybridization of sexual and apomictic strains, diplospory can be effectively manipulated in a lovegrass breeding program.