Publication details
Study of prezygotic and postzygotic barriers of crossability in the genus Lotus.
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Breeding and seed production for conventional and organic agriculture |
| MU Faculty or unit | |
| Citation | |
| Field | Plant cultivation |
| Keywords | Lotus - interspecific hybridization - prezygotic barriers - postzygotic barriers |
| Description | Lotus corniculatus L. is a crucial component of meadow and pasture vegetation and can be used as a fodder crop. Its growth is limited by differences in maturation and pod shattering, which also affect the seed yield. Shattering resistance is a characteristic of high heritability and, in Lotus, is considered to be controlled by more than one gene. Classical breeding approaches to reduce shattering through recurrent selection were unsuccessful. The problem of pod shattering can be solved by means of interspecific hybridization with various distantly related indehiscent Lotus species. Our work was aimed at the study of prezygotic and postzygotic barriers of crossability between L. corniculatus and sources of the indehiscent seed pod trait, such as L. uliginosus (2n=2x and 4x). The growth of the pollen tubes up to the ovary was observed after the crosses of L. corniculatus x L. uliginosus (2n=2x and 4x). This means that prezygotic barriers were not detected in this combination. In L. corniculatus, L. uliginosus (2x, 4x), the method of clearing treatment of plant tissues by chloral hydrate was used. Clearing of immature seeds and inner embryos up to heart stage was carried out after modifications of a known procedure. The optimal length of fixation was 24 h and the optimal length of action of chloral hydrate was 48 h. For other embryo stages, this method has not been sufficiently optimised so far. Even if enlargement of immature seeds occurred, postzygotic barriers after interspecific crosses of L. corniculatus x L. uliginosus (2x) covered defects of embryo sac and no hybrid embryo was traced. In the interspecific combination of L. corniculatus x L. uliginosus (4x), globular stage embryo was detected. |
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