Forces applied tlhrough the cohesion of wvater have been generally accepte(d as the cause of the rise of the transpirationi streaml since the early publications of Dixon and( Joly (8). The water absorbing forces of the leaf mlesophyll cells caln be shown to be adequate to lift w!ater to the height of the leaves. The cohesion theorv assumiies that the (liffusion of water from the non-collapsible...

[1] In late summer 2004, the Integrated Ocean Drilling Program (IODP) conducted one of the most transformational missions in the almost 40 year history of scientific ocean drilling: the Arctic Coring Expedition (ACEX) [Backman et al., 2006; Moran et al., 2006a]. This technically challenging expedition [Moran et al., 2006b] to the Lomonosov Ridge near 88 N recovered the first long-term Cenozoic ...

Isolated oceanic islands are characterized by patterns of biological diversity different from that on nearby continental mainlands. Isolation can provide the opportunity for evolutionary divergence, but also set the stage for hybridization between related taxa arriving from different sources. Ferns disperse by haploid spores, which are produced in large numbers and can travel long distances in ...

Plants of Juniperus communis L. var. communis, J. c. var. depressa Pursh, J. c. var. hemispherica J. & C. Presl, J. communis var. megistocarpa Fern. & St. John, J. c. var. nipponica (Maxim.) Wils., J. c. var. oblonga hort. ex Loudon and J. c. var. saxatilis Pall. were sampled and DNA fingerprinting (RAPDs, Random Amplified Polymorphic DNAs) was performed. Based on 191 RAPD bands, there was litt...

Arsenic-contaminated soil is one of the major arsenic sources for drinking water. Phytoremediation, an emerging, plant-based technology for the removal of toxic contaminants from soil and water, has been receiving renewed attention. Although a number of plants have been identified as hyperaccumulators for the phytoextraction of a variety of metals, and some have been used in field applications,...

Dinitrogen fixation by Nostoc azollae residing in specialized leaf pockets supports prolific growth of the floating fern Azolla filiculoides. To evaluate contributions by further microorganisms, the A. filiculoides microbiome and nitrogen metabolism in bacteria persistently associated with Azolla ferns were characterized. A metagenomic approach was taken complemented by detection of N2 O releas...

Chile, a long and narrow country in South America, is situated between the Andes mountains to the east and the Pacific Ocean to the west. It is bordered by Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the south (Fig. 1). Chilean territory includes the Pacific islands of Juan Fern andez, Salas y G omez, Desventuradas and Easter Island in Oceania. C...

Allelopathic effects of juglone and walnut leaf extracts from Persian walnut (Juglans regia L.) on yield, growth, chemical and plant nutrient element composition of the day-neutral strawberry (Fragaria × ananassa L.) cultivar Fern were investigated as part of an effort to identify tolerant species to plant adjacent to walnut. Strawberry plants were treated with juglone (5-hydroxy-1.4 naphthoqui...

Amplified fragment length polymorphism (AFLP) was employed to analyze the population genetics of relict tree fern Sphaeropteris brunoniana. A total of 132 individuals from ten natural populations in China and Laos were collected for this study. Using two selective primers, 234 reliable bands were generated, of which 221 (94.4%) were polymorphic. Genetic analysis indicated an unexpectedly high l...

Hybridization is an important evolutionary force in plants, but the mechanisms underlying it have not been well studied for many groups. In particular, the drivers of non-random patterns of interspecific gene flow (asymmetrical hybridization) remain poorly understood, especially in the seed-free vascular plants. Here, we examine patterns of asymmetrical hybridization in two widespread fern hybr...