THE CYTOLOGY OF STELLARIA LONGIPES
Stellaria longipes Goldie s.1. is a polyploid species complex with euploid and aneuploid chromosome numbers ranging from 2n = 51 to 107, the most frequent being 52, 78 and 104. Almost all the cytotypes show a near normal pollen and seed production and fertility. Meiotic irregularities in most plants...
| Published in: | Canadian Journal of Genetics and Cytology |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1974
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/g74-056 http://www.nrcresearchpress.com/doi/pdf/10.1139/g74-056 |
| Summary: | Stellaria longipes Goldie s.1. is a polyploid species complex with euploid and aneuploid chromosome numbers ranging from 2n = 51 to 107, the most frequent being 52, 78 and 104. Almost all the cytotypes show a near normal pollen and seed production and fertility. Meiotic irregularities in most plants are few and confined to the occurrence of a small number of univalents, trivalents and multivalents. Crosses between the main cytotypes are readily produced and usually show a near normal level of fertility in pollen and seed. All the naturally occurring cytotypes, together with several additional ones, have been produced in the artificial crosses. During pollen formation in some of the artificial hybrids, as well as in wild plants, a varying number of fertile monads and diads are produced. It is concluded that the range of chromosome numbers occurring in nature has arisen by hybridity between octoploids (2n = 104) and tetraploids (2n = 52), though it is probable that many of these hybrids are not of recent origin. The distribution of the cytotypes is discussed in relation to glaciation and it is noted that the octoploid tends to predominate near the edge of the range of distribution. |
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