Silicon isotope fractionation between plant parts in banana: In situ vs. in vitro

• DOI: 10.1016/j.gexplo.2005.08.044
• Publication Date: 2005-11-10T07:17:48Z
• Authors: S. Opfergelt; D. Cardinal; C. Henriet; L. André; B. Delvaux
• Keywords: Petiole (insect anatomy)

We recently showed that silicon isotopic fractionation in banana (Musa acuminata Colla, cv Grande Name) was related to phytolith production, and therefore to silica content in plant. The present study focuses on isotopic fractionation between the different plant parts. Silicon isotopic compositions were measured using a Nu plasma multicollector plasma source mass spectrometer (MC-ICP-MS) operating in dry plasma mode. The results are expressed as 6 29 Si relatively to the NBS28 standard, with an average precision and accuracy of +/- 0.08 parts per thousand (+/- 2 sigma). On mature banana (Musa acuminata Colla, cv Grande Name) from Cameroon, 629 Si ranged from +0.13 parts per thousand in the petiole to +0.49 parts per thousand in the lamina, yielding to a 0.36 parts per thousand change towards heavier isotopic composition in the upper parts of the plant. This strongly accords with results obtained on in vitro banana plantlets cultivated in hydroponics, where the delta Si-29 increase from pseudostems to lamina is 0.26 parts per thousand. These preliminary results on in situ banana show a trend of intra-plant fractionation comparable with that of in vitro hydroponics banana plantlets and with previous data obtained on bamboo. (c) 2005 Elsevier B.V. All rights reserved.