Mechanism of salt tolerance in wild Oryza species.

野生稻（Oryza）种干物质生产及其生理响应。通过与对照品种的比较，研究了红叶花（latifolia）和红叶花（O. officinalist）对盐胁迫的抗性。耐盐的Pokkali和耐盐的O. rufipogon。officinalis对盐度的抗性与O. latifolia相当。不同品种的根、叶鞘、叶片各部位干物质产量在NaCl处理后下降程度不同。100mM NaCl处理下，阔叶树和officinalis的单位干物质顶叶Na^+含量分别比pokali提高了6.0倍和5.2倍。耐盐野生稻品种叶片Na^+含量的积累模式与耐盐品种Pokkali不同。野生稻种下叶Na^+积累量大于上叶Na^+积累量。在盐度条件下测定了碳同化和析氧速率。盐处理后21 d，野生稻的碳同化率几乎没有下降。另一方面，盐胁迫增加了析氧速率。光合活性结果表明，野生稻具有显著的耐盐能力。

The dry matter production and physiological response of wild Oryza species(O. latifolia and O. officinalist) to salinity stress were investigated by comparing with check varieties of O. sativa L. cv. Pokkali(salt-tolerant) and O. rufipogon(salt-susceptible). O. officinalis showed resistance to salinity as high as O. latifolia. The degree of decline in dry matter production of each part(root, leaf sheath, leaf blade) was different among the varieties after NaCl treatment. Top leaf Na^+ content per unit of dry-matter under 100mM NaCl condition in O. latifolia and O. officinalis increased 6.0 times and 5.2 times, respectively, as compared with Pokkali. Accumulation pattern of leaf blade Na^+ content in salt tolerant wild Oryza species were different from that in salt tolerance varieties, Pokkali. The wild Oryza species accumulated more Na^+ in lower leaf blade than in upper leaf blade. Carbon assimilation and oxygen evolution rate was examined under salinity conditions. The carbon assimilation rate of the wild Oryza species hardly decreased at 21 day after salt treatment. On the other hand, the oxygen evolution rate increased by salinity stress. The result of photosynthetic activity indicates that wild Oryza species has notable salt tolerance ability.