Growth and sodium accumulation in the tillers which appear on the upper nodes in rice (Oryza sativa L.) under saline conditions
2006
Sone, C.(Okayama Univ. (Japan). Faculty of Agriculture) | Tsuda, M. | Hirai, Y.
The mechanism of late-grown tillers which come out of the upper culm nodes in rice (Oryza sativa L.) under saline conditions was examined. A rice cultivar. Akihikari was grown in pots under flooding conditions. The panicles were excised below the neck node of the panicle at the heading stage. Salinity treatment consisted of adding 100 mM sodium chloride to water of pot at the excision of panicle (Na0), and 14 days after the excision (Na2). Tillers on the upper culm nodes grew in Na0 and Na2. Dry weight of tillers increased with decrease of dry weight of stock shoots that produced the tillers. So the sum of dry weights of the stock shoots and tillers did not change, indicating that tiller growth apparently depended on reserve of carbohydrate in the stock shoots. Sodium was accumulated gradually in the plant, while sodium content of internode and tiller were kept lower than those of leaf blade and leaf sheath. In the leaf blade and leaf sheath, the upper organs accumulated less sodium than the lower organs. The tillers on the upper nodes grew faster and had low sodium content in the early stages of tiller development in Na0. Therefore, it was concluded that tillers which come out of the upper culm nodes could grow under saline conditions because the sodium content of tiller, internode and the upper leaf sheath were kept at a relatively low level.
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