摘要
Brown spot (BS), caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg) on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L.) plants (cv. Metica-1) grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids), were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites
摘要译文
褐斑病（BS），由真菌引起的蠕孢，是对BS的开发研究镁（Mg）的作用由riceWe承包的最重要的疾病之一，引起蠕孢和疾病发展对水稻的光合性能的影响（水稻苜蓿植物（cvMetica-1）含有0or 4营养液长大BS严重性MgAssessments 0毫米，叶Mg和颜料浓度（总叶绿素和类胡萝卜素），分别在120小时接种后进行，除了气体交换的参数，在用4M镁比与0mMThe增加供给的那些叶镁伴随着在BS严重性降低供给植物中观察到的Mg更高叶浓度用4M提供镁叶绿素和更好的光合performancePlants较高浓度的碳同化较高的平均值，气孔导度和与0mm的MgConversely提供的植物相比，内部叶CO2浓度时，类胡萝卜素的浓度在具有较高的Mg流量供给植物低级这些结果表明，镁抑制疾病的严重程度，并通过允许更好的气孔导度保留光合性能，因此，在羧化位点的CO2更高的可用性
MOREIRA, Wiler Ribas et al.. Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae.[J]. Scientia Agricola, 2015,72(4): 328-333