Phylogenetic Relationships of Samydaceae and Taxonomic Revision of the Species of \u3ci\u3eCasearia\u3c/i\u3e in South-Central Asia

The flowering plant family Samydaceae was recently reinstated to include 14 genera and about 256 species of tropical trees and shrubs. Preliminary analyses of relationships in the family, however, indicated that the largest genus in the family, Casearia, is not monophyletic and that several smaller groups are probably misplaced. In order to affirm or refute those hypotheses, additional DNA sequence data with broader taxon sampling from the Old World were gathered for phylogenetic analysis. In particular, rapidly evolving plastid (matK, ndhF, psbA-trnH, trnL, and trnL-F) and nuclear (EMB2765 and GBSSI) DNA regions were sampled for characters. Four of these regions (matK, ndhF, EMB2765, GBSSI) could be confidently aligned across the family, and phylogenetic inferences were drawn from parsimony, likelihood, and Bayesian analyses primarily of these data. The results affirm the monophyly of Samydaceae and consistently recover four major clades, which are here circumscribed as four tribes, namely Lunanieae, Ryanieae, Samydeae, and Tetrathylacieae. The results also affirm that Casearia is not monophyletic. Rather, several small genera (Samyda, Laetia sensu stricto, Hecatostemon, and Zuelania) are nested within it. One previously recognized genus, Piparea, which is more closely related to Ryania, and Trichostephanus, should be reinstated. A key to the newly circumscribed tribes and genera is provided

Enhancing PCR Amplification of DNA From Recalcitrant Plant Specimens Using a Trelahose-Based Additive

Premise of the study: PCR amplification of DNA extracted from plants is sometimes difficult due to the presence of inhibitory compounds. An effective method to overcome the inhibitory effect of compounds that contaminate DNA from difficult plant specimens is needed. Methods and Results: The effectiveness of a PCR additive reagent containing trehalose, bovine serum albumin (BSA), and polysorbate‐20 (Tween‐20) (TBT‐PAR) was tested. PCR of DNA extracted from fresh, silica‐dried, and herbarium leaf material of species of Achariaceae, Asteraceae, Lacistemataceae, and Samydaceae that failed using standard techniques were successful with the addition of TBT‐PAR. Conclusions: The addition of TBT‐PAR during routine PCR is an effective method to improve amplification of DNA extracted from herbarium specimens or plants that are known to contain PCR inhibitors

New Names and Combinations in Neotropical Samydaceae

Nomenclatural changes are presented here to bring generic circumscriptions in line with recent advances in the understanding of phylogenetic relationships within Samydaceae and with the conservation of the name Casearia Jacq. over Samyda Jacq. and Laetia Loefl. ex L. Names of species formerly recognized in Hecatostemon S. F. Blake, Laetia sect. Laetia, Laetia sect. Casinga (Griseb.) Warburg, Samyda, and Zuelania A. Rich. are provided combinations or new names in Casearia, and the appropriate names for species of Casearia sect. Piparea (Aubl.) Benth., when recognized as the separate genus Piparea Aubl., are clarified. One new combination is also provided for Piparea

Enhancing PCR Amplification of DNA from Recalcitrant Plant Specimens Using a Trehalose-Based Additive

Premise of the study: PCR amplification of DNA extracted from plants is sometimes difficult due to the presence of inhibitory compounds. An effective method to overcome the inhibitory effect of compounds that contaminate DNA from difficult plant specimens is needed. Methods and Results: The effectiveness of a PCR additive reagent containing trehalose, bovine serum albumin (BSA), and polysorbate-20 (Tween-20) (TBT-PAR) was tested. PCR of DNA extracted from fresh, silica-dried, and herbarium leaf material of species of Achariaceae, Asteraceae, Lacistemataceae, and Samydaceae that failed using standard techniques were successful with the addition of TBT-PAR. Conclusions: The addition of TBT-PAR during routine PCR is an effective method to improve amplification of DNA extracted from herbarium specimens or plants that are known to contain PCR inhibitors