膳食补硒是人类摄入硒的主要途径,通过硒生物强化技术能有效提高作物硒含量。本研究以甜荞品种西农9976为试验材料,亚硒酸钠为硒源,采用大田试验,设置纯硒施用量0(Se0)、5(Se5)和20 g hm^(-2)(Se20)3个水平。于2020—2021年连续两个作...膳食补硒是人类摄入硒的主要途径,通过硒生物强化技术能有效提高作物硒含量。本研究以甜荞品种西农9976为试验材料,亚硒酸钠为硒源,采用大田试验,设置纯硒施用量0(Se0)、5(Se5)和20 g hm^(-2)(Se20)3个水平。于2020—2021年连续两个作物生长季,研究不同外源硒浓度下甜荞光合特性、干物质积累与转运、农艺性状及产量的变化规律及其对各器官硒含量、硒转运因子及籽粒硒利用率的影响。结果表明,叶面喷施亚硒酸钠使甜荞叶片叶绿素相对含量(SPAD)、净光合速率(Pn)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)和水分利用效率(WUE)较对照平均增加13.12%、11.50%、5.48%、5.95%和5.77%,改善了叶片光合物质生产能力;喷硒处理显著增加甜荞叶片光系统Ⅱ的最大光化学效率(Fv/Fm)、实际光化学效率(Φ_(PSII))及光化学淬灭系数(qp),降低非光化学淬灭系数(NPQ),使其增强对光能的捕获及转化能力,减少无效光能损失,提高对高光的利用能力。两个施硒量下,甜荞茎部和叶部的干物质积累量较Se0处理显著上升而分配比例显著下降;籽粒的干物质积累量和分配比例均得到提高;茎部和叶部的干物质转运量、移动率和对籽粒的贡献率分别在Se5和Se20浓度下出现最大值。喷硒处理使甜荞千粒重、单株粒数和产量较对照分别提高3.1%~11.3%、13.5%~32.0%和4.9%~23.2%。甜荞各部位硒含量和转运因子在Se20处理下出现最大值,而籽粒硒的利用率在Se5处理下较高。综上所述,叶面喷施亚硒酸钠能改善甜荞光合作用和叶绿素荧光参数,增加各器官干物质积累量,并促进干物质向籽粒转运,从而提高甜荞籽粒产量。此外,叶面喷硒后甜荞各部位硒含量显著提高,Se5处理下荞麦籽粒硒利用率最高,且籽粒硒含量符合国家谷物富硒标准,适合于黄土高原地区推广使用。展开更多
Recently, a new bacterial top rot disease of maize has frequently appeared in many areas of Yunnan Province, China. The pathogen of the disease was identified as Klebsiella pneumoniae （KpC4）, which is well known to ...Recently, a new bacterial top rot disease of maize has frequently appeared in many areas of Yunnan Province, China. The pathogen of the disease was identified as Klebsiella pneumoniae （KpC4）, which is well known to cause pulmonary and urinary diseases in humans and animals and occasionally exists as a harmless endophyte in plants. To evaluate the viru- lence of the maize pathogen to maize and mice, we inoculated maize and mice with routine inoculation and intraperitoneal injection respectively according to Koch＇s postulates. The results showed that KpC4 and the clinical strain K. pneumoniae 138 （Kp138） were all highly pathogenic to maize and mice and the strain re-isolated from diseased mice also caused typical top rot symptoms on maize by artificial inoculation. It is highlighting that a seemingly dedicated human/animal pathogen could cause plant disease. This is the first report of K. pneumoniae, an opportunistic pathogen of human/animal, could infect maize and mice. The findings serve as an alert to plant, medical and veterinarian scientists regarding a potentially dangerous bacterial pathogen infecting both plants and animals/humans. The maize plants in the field could serve as a reservoir for K. pneumoniae which might infect animals and probably humans when conditions are favorable. The new findings not only are significant in the developing control strategy for the new disease in Yunnan, but also serve as a starting point for further studies on the mechanism of pathogenesis and epidemiology of K. pneumoniae.展开更多
文摘膳食补硒是人类摄入硒的主要途径,通过硒生物强化技术能有效提高作物硒含量。本研究以甜荞品种西农9976为试验材料,亚硒酸钠为硒源,采用大田试验,设置纯硒施用量0(Se0)、5(Se5)和20 g hm^(-2)(Se20)3个水平。于2020—2021年连续两个作物生长季,研究不同外源硒浓度下甜荞光合特性、干物质积累与转运、农艺性状及产量的变化规律及其对各器官硒含量、硒转运因子及籽粒硒利用率的影响。结果表明,叶面喷施亚硒酸钠使甜荞叶片叶绿素相对含量(SPAD)、净光合速率(Pn)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)和水分利用效率(WUE)较对照平均增加13.12%、11.50%、5.48%、5.95%和5.77%,改善了叶片光合物质生产能力;喷硒处理显著增加甜荞叶片光系统Ⅱ的最大光化学效率(Fv/Fm)、实际光化学效率(Φ_(PSII))及光化学淬灭系数(qp),降低非光化学淬灭系数(NPQ),使其增强对光能的捕获及转化能力,减少无效光能损失,提高对高光的利用能力。两个施硒量下,甜荞茎部和叶部的干物质积累量较Se0处理显著上升而分配比例显著下降;籽粒的干物质积累量和分配比例均得到提高;茎部和叶部的干物质转运量、移动率和对籽粒的贡献率分别在Se5和Se20浓度下出现最大值。喷硒处理使甜荞千粒重、单株粒数和产量较对照分别提高3.1%~11.3%、13.5%~32.0%和4.9%~23.2%。甜荞各部位硒含量和转运因子在Se20处理下出现最大值,而籽粒硒的利用率在Se5处理下较高。综上所述,叶面喷施亚硒酸钠能改善甜荞光合作用和叶绿素荧光参数,增加各器官干物质积累量,并促进干物质向籽粒转运,从而提高甜荞籽粒产量。此外,叶面喷硒后甜荞各部位硒含量显著提高,Se5处理下荞麦籽粒硒利用率最高,且籽粒硒含量符合国家谷物富硒标准,适合于黄土高原地区推广使用。
基金funded by the Maize Production System of Yunnan Province,China(2015KJTX002)
文摘Recently, a new bacterial top rot disease of maize has frequently appeared in many areas of Yunnan Province, China. The pathogen of the disease was identified as Klebsiella pneumoniae （KpC4）, which is well known to cause pulmonary and urinary diseases in humans and animals and occasionally exists as a harmless endophyte in plants. To evaluate the viru- lence of the maize pathogen to maize and mice, we inoculated maize and mice with routine inoculation and intraperitoneal injection respectively according to Koch＇s postulates. The results showed that KpC4 and the clinical strain K. pneumoniae 138 （Kp138） were all highly pathogenic to maize and mice and the strain re-isolated from diseased mice also caused typical top rot symptoms on maize by artificial inoculation. It is highlighting that a seemingly dedicated human/animal pathogen could cause plant disease. This is the first report of K. pneumoniae, an opportunistic pathogen of human/animal, could infect maize and mice. The findings serve as an alert to plant, medical and veterinarian scientists regarding a potentially dangerous bacterial pathogen infecting both plants and animals/humans. The maize plants in the field could serve as a reservoir for K. pneumoniae which might infect animals and probably humans when conditions are favorable. The new findings not only are significant in the developing control strategy for the new disease in Yunnan, but also serve as a starting point for further studies on the mechanism of pathogenesis and epidemiology of K. pneumoniae.
