Origins of Genotypic Variation in North American Dandelions Inferred from Ribosomal DNA and Chloroplast DNA Restriction Enzyme Analysis

Evolution ◽  
1993 ◽  
Vol 47 (1) ◽  
pp. 136 ◽  
Author(s):  
Lynn Mertens King
Keyword(s):  
Chloroplast Dna ◽  
Ribosomal Dna ◽  
Restriction Enzyme ◽  
North American ◽  
Genotypic Variation ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Dna Restriction

Hybridization and the origin of the arctic grass Poa hartzii (Poaceae): evidence from morphology and chloroplast DNA restriction site data

1997 ◽  
Vol 75 (11) ◽  
pp. 1978-1997 ◽  
Author(s):  
Lynn J. Gillespie ◽  
Laurie L. Consaul ◽  
Susan G. Aiken
Keyword(s):  
Chloroplast Dna ◽  
Restriction Enzyme ◽  
The Arctic ◽  
Hybrid Origin ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Dominant Type ◽  
Morphological Studies ◽  
Poa Secunda ◽  
Dna Restriction

The hypothesized hybrid origin of Poa hartzii Gand. (Poaceae) was investigated by analysis of morphological and molecular data. This endemic nearctic caespitose grass has been considered to be a hybrid between two of the three sympatric arctic species, Poa glauca M. Vahl, Poa arctica R. Br., and Poa abbreviata R. Br. Field observations and morphological studies indicate that Poa hartzii is a morphologically distinct apomictic species that reproduces and disperses by seed. Restriction enzyme analysis of polymerase chain reaction amplified chloroplast DNA revealed the presence in Poa hartzii of two very different haplotypes. One haplotype is identical to the dominant type found in Poa glauca, while the second is identical to the haplotype of Poa secunda J. Presl., located south of the arctic region. These results are consistent with an hypothesis of ancient hybrid origin involving Poa glauca and Poa secunda, but not Poa arclica nor Poa abbreviata. They are also consistent with an hypothesis of cytoplasmic transfer via hybridization and introgression from Poa glauca to an ancestral Poa hartzii in the Poa secunda complex. Direction of transfer is suggested by the widespread occurrence of the Poa secunda haplotype in Poa hartzii and by closer morphological similarity with Poa secunda than Poa glauca. The origin of Poa hartzii provides an excellent example of reticulate evolution and the importance of hybridization in the speciation of arctic grasses. Key words: Poa hartzii, arctic Poa, chloroplast DNA, restriction enzyme analysis, hybridization, introgression.

scholarly journals Molecular Confirmation that Sterile Cytoplasm Has Been Introduced into Open-pollinated Grano Onion Cultivars

1994 ◽  
Vol 119 (1) ◽  
pp. 90-93 ◽  
Author(s):  
M.J. Havey ◽  
O.H. Bark
Keyword(s):  
New Mexico ◽  
Chloroplast Dna ◽  
Allium Cepa ◽  
Restriction Enzyme ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Recent Introduction ◽  
Seed Mixtures

Open-pollinated (OP) onion (Allium cepa L.) cultivars are primarily in normal (N) fertile cytoplasm; however, specific cultivars possess both N and sterile (S) cytoplasm or are exclusively in S cytoplasm. It is unclear whether the presence of S cytoplasm in OP cultivars is due to ancient or recent introduction or both. Restriction-enzyme analysis of the chloroplast DNA established that S cytoplasm has been introgressed into OP onion cultivars since its discovery in 1925. `Valencia Grano' (released in 1927), `New Mexico Early Grano' (1931), `Texas Early Grano (TEG) 502' (1947), and `Temprana' (1979) are in N cytoplasm; S cytoplasm was introduced into the population `TEG 502 PRR', and subsequent selections (`NuMex BR1' and `NuMex Sunlite') are in S cytoplasm. The inbred `TEG 951 C' and `Texas Grano 1015Y' possess a mixture of N and S cytoplasm and, because these two onions originated from self-pollinations of single plants, bulb or seed mixtures or both must have occurred.

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