Non-Mendelian transmission of apomixis in maize-Tripsacum hybrids caused by a transmission ratio distortion
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ArticlePublication details: 1998Subject(s):
In:
Heredity v. 80, no. 1, p. 40-47649234Summary: Apomixis is a mode of asexual reproduction through seeds. The apomictic process bypasses both meiosis and egg cell fertilization: producing offspring that are exact genetic replicas of the mother plant. In the Tripsacum agamic complex, all polyploids reproduce through the diplosporous type of apomixis, and diploids are sexual. In this paper, molecular markers linked with diplospory were used to analyse various generations of maize-Tripsacum hybrids and backcross derivatives and to derive a model for the inheritance of diplosporous reproduction. The results suggest that the gene or genes controlling apomixis in Tripsacum are linked with a segregation distorter-type system promoting the elimination of the apomixis alleles when transmitted through haploid gametes. Hence, this model offers an explanation of the relationship between apomixis and polyploidy. The evolutionary importance of this mechanism, which protects the diploid level from being invaded by apomixis, is discussed.
| Item type | Current library | Collection | Call number | Copy number | Status | Date due | Barcode | Item holds | |
|---|---|---|---|---|---|---|---|---|---|
| Article | CIMMYT Knowledge Center: John Woolston Library | CIMMYT Staff Publications Collection | CIS-2644 (Browse shelf(Opens below)) | 1 | Available | 649234 |
Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0018-067X
Apomixis is a mode of asexual reproduction through seeds. The apomictic process bypasses both meiosis and egg cell fertilization: producing offspring that are exact genetic replicas of the mother plant. In the Tripsacum agamic complex, all polyploids reproduce through the diplosporous type of apomixis, and diploids are sexual. In this paper, molecular markers linked with diplospory were used to analyse various generations of maize-Tripsacum hybrids and backcross derivatives and to derive a model for the inheritance of diplosporous reproduction. The results suggest that the gene or genes controlling apomixis in Tripsacum are linked with a segregation distorter-type system promoting the elimination of the apomixis alleles when transmitted through haploid gametes. Hence, this model offers an explanation of the relationship between apomixis and polyploidy. The evolutionary importance of this mechanism, which protects the diploid level from being invaded by apomixis, is discussed.
English
R97-98ANALY|9808|anterior|EE|ABC|1998kelly|FINAL9798|3
FR-INA-PG 1997 GRIMANELLI D rf
CIMMYT Staff Publications Collection