HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content

Fluorescent in situ hybridization (FISH) has been increasingly used to determine the physical locations of genes on chromosomes. Using FISH, Zhang and Sang show that Paeonia species have a relatively large number of rDNA loci and that these loci are all telomeric, suggesting that chromosomal location is critical to the tempo of concerted evolution. (see p. 735)

]Reference standards for plant DNA content

Johnston et al. address the need for a common set of standards for estimating DNA content of plant nuclei using flow cytometry. They suggest propidium iodide as the fluorochrome of choice and five plant species as an initial set of international standards. (see p. 609)

Clarifying Botrychium

Cryptic species of the subgenus Botrychium (Ophioglossaceae), commonly called the moonworts, are difficult to distinguish because of their small size and simple features. Hauk and Haufler report that isoenzyme analysis is a valuable taxonomic tool for clarifying relationships among 16 of the 24 currently recognized species. (see p. 614)

Pine genetics

Rehfeldt has studied a group of pines that are closely related, taxonomically tangled, and difficult to identify, the Ponderosae taxa, inhabiting the mountain islands of the southeastern United States and northern Mexico. He proposes three taxa, and his data indicate that the taxa have different genetic structures but that genetic variability in these isolated mountain populations is abundant. These pines have robust genetic systems that preclude endangerment. (see p. 741)

Delgado et al. have found high genetic variation for all known populations of Pinus rzedowskii, an endangered pine species from central Mexico first described in 1967 and subjected to habitation fragmentation since then. They propose that the high genetic variation results from the older members of this long-lived species and will decline abruptly when these individuals die. Increasing juvenile recruitment is a priority. (see p. 669)

This Article Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content