Effects of manganese toxicity on leaf CO2 assimilation of contrasting common bean genotypes
Effects of manganese toxicity on leaf CO2 assimilation of contrasting common bean genotypes
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DOI：
10.1111/j.1399-3054.1997.tb01076.x
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发表时间：
1997-12-01
影响因子：
6.4
通讯作者：
Lynch, JP
中科院分区：
文献类型：
--
作者：
González, A;Lynch, JP
以菜豆为材料，对3个菜豆品种叶片光合作用相关参数进行了测定。对锰毒害的耐受性不同。通过两个短期的水培试验，研究了过量锰对成熟和未成熟叶片CO2同化的影响。锰毒害只降低了未成熟叶片的总叶绿素含量，从而降低了叶片对CO2的吸收。至少在为期4天的试验中，表现出锰毒特征的棕色斑点的成熟叶片在吸收二氧化碳的能力方面没有受到任何损害。叶片组织中高水平的锰不影响气孔导度和蒸腾作用。气孔导度和蒸腾速率只有在严重失绿的叶片中才能观察到。品种间的差异表现为较敏感的ZPV-292黄化加剧，其次是A-283，耐性的CALIMA黄化程度较低。由于单位叶绿素的CO2同化量在高锰植株和对照植株之间没有差异，因此我们得出结论，锰毒对CO2同化的负面影响可以通过叶片叶绿素含量的降低来解释。
Parameters related to leaf photosynthesis were evaluated in three genotypes of common bean (Phaseolus vulgaris L.) with contrasting tolerance to Mn toxicity. Two short-term studies in solution culture were used to assess the effect of excess Mn on CO2 assimilation in mature and immature leaves. Mn toxicity decreased total chlorophyll content only in immature leaves, with a consequent reduction of leaf CO2 assimilation. Mature leaves that showed brown speckles characteristic of Mn toxicity, did not suffer any detriment in their capacity to assimilate CO2, at lease in a 4-day experiment. Stomatal conductance and transpiration were not affected by the presence of high levels of Mn in leaf tissue. Lower stomatal conductance and transpiration rates were observed only in leaves with advanced chlorosis. Differences among genotypes were detected as increased chlorosis in the more sensitive genotype ZPV-292, followed by A-283 and less chlorosis in the tolerant genotype CALIMA. Since CO2 assimilation expressed per unit of chlorophyll was not different between high-Mn plants and control plants, we conclude that the negative effect of Mn toxicity on CO2 assimilation can be explained by a reduction in leaf chlorophyll content.