Das Kaushik, Baruah Kushal Kumar
Department of Crop Physiology, Assam Agricultural University, Jorhat, Assam 785 013, India.
Physiol Plant. 2008 Oct;134(2):303-12. doi: 10.1111/j.1399-3054.2008.01137.x. Epub 2008 Jun 28.
Plant-mediated transport is the primary route of methane (CH(4)) emission from the reduced paddy field to the aboveground atmosphere. Experiments were conducted at North Bank Plain Agro-climatic Zone of Assam, India, during monsoon rice-growing season (July to December 2006) to elucidate the influences of anatomical and morphophysiological characteristics of rice (Oryza sativa L.) cultivars on methane emission from submerged agroecosystem. Ten rice cultivars were grown in light-textured loamy soil under rainfed uniform field condition. Among the 10 cultivars, 5 were traditional rice genotypes commonly grown in the agroclimatic zone and the other 5 were improved high-yielding varieties. Wide variation in CH(4) flux was recorded among the rice cultivars, which may be regulated by the difference in anatomical and morphophysiological characteristics of rice plant. Microscopic analysis of stem portion showed that high- and medium-CH(4)-emitting cultivars recorded higher size of the medullary cavity. Leaf area and transpirational rates were also found to be higher in high-CH(4)-emitting varieties. Scanning electron microscopic analysis revealed higher stomatal frequencies in high-methane-emitting cultivars. Data presented in this study suggest that variation in anatomical and morphophysiological characteristics among different rice genotypes may influence CH(4) emission from paddy fields.
植物介导的传输是还原稻田向地上大气排放甲烷（CH₄）的主要途径。在印度阿萨姆邦北岸平原农业气候区的季风水稻种植季节（2006年7月至12月）进行了实验，以阐明水稻（Oryza sativa L.）品种的解剖学和形态生理特征对淹水农业生态系统甲烷排放的影响。在雨养均匀田间条件下，将10个水稻品种种植在质地较轻的壤土中。在这10个品种中，5个是该农业气候区常见种植的传统水稻基因型，另外5个是改良的高产品种。水稻品种间记录到的CH₄通量差异很大，这可能受水稻植株解剖学和形态生理特征差异的调节。茎部的显微镜分析表明，高甲烷排放和中等甲烷排放品种的髓腔尺寸更大。高甲烷排放品种的叶面积和蒸腾速率也更高。扫描电子显微镜分析显示，高甲烷排放品种的气孔频率更高。本研究提供的数据表明，不同水稻基因型间解剖学和形态生理特征的差异可能影响稻田的CH₄排放。
