Dynamics of Root Systems in Crop and Pasture Genotypes over the Last 100 Years

This chapter is devoted to tongue root (ATR or RTR) harmony in Tungusic languages (a.o. Classical Manchu) and Mongolian languages (Khalka and Buriat), which all belong the Altaic language group. In addition to TR-harmony, most Tungusic and Mongolian languages also have a limited form of labial harmony, especially among low vowels. After discussing the Tungusic and Mongolian systems the chapter will focus on the behavior of high vowels, which do not participate in labial harmony, and are either transparent or opaque. A notable difference between Tungusic and Mongolic regards the fact that whereas [i] is transparent to labial harmony in Mongolic, it is opaque in Tungusic. High round vowels are opaque in both groups.

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Iron-Oxidizing Bacteria Are Associated with Ferric Hydroxide Precipitates (Fe-Plaque) on the Roots of Wetland Plants

Applied and Environmental Microbiology ◽

10.1128/aem.65.6.2758-2761.1999 ◽

1999 ◽

Vol 65 (6) ◽

pp. 2758-2761 ◽

Cited By ~ 174

Author(s):

David Emerson ◽

Johanna V. Weiss ◽

J. Patrick Megonigal

Keyword(s):

Ferric Hydroxide ◽

Root Systems ◽

Wetland Plants ◽

Positive Correlation ◽

Cell Numbers ◽

Iron Oxidizing Bacteria ◽

Soil Solutions ◽

Fe Plaque ◽

Ph Range

ABSTRACT The presence of Fe-oxidizing bacteria in the rhizosphere of four different species of wetland plants was investigated in a diverse wetland environment that had Fe(II) concentrations ranging from tens to hundreds of micromoles per liter and a pH range of 3.5 to 6.8. Enrichments for neutrophilic, putatively lithotrophic Fe-oxidizing bacteria were successful on roots from all four species; acidophilic Fe-oxidizing bacteria were enriched only on roots from plants whose root systems were exposed to soil solutions with a pH of <4. InSagittaria australis there was a positive correlation (P < 0.01) between cell numbers and the total amount of Fe present; the same correlation was not found for Leersia oryzoides. These results present the first evidence for culturable Fe-oxidizing bacteria associated with Fe-plaque in the rhizosphere.

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