世界泥盆系洛霍考夫阶和布拉格阶牙形刺生物地层有较明显的地理分区性,区域对比较困难,中国缺少连续的布拉格阶与洛霍考夫阶灰岩相剖面,牙形刺生物地层的研究,仍很不完善。广西南宁大沙田剖面是目前所知布拉格阶灰岩最多的剖面,在其下...世界泥盆系洛霍考夫阶和布拉格阶牙形刺生物地层有较明显的地理分区性,区域对比较困难,中国缺少连续的布拉格阶与洛霍考夫阶灰岩相剖面,牙形刺生物地层的研究,仍很不完善。广西南宁大沙田剖面是目前所知布拉格阶灰岩最多的剖面,在其下部发现了牙形刺Eognathodus irregularis,E.nagaolingensis,E.sulcatus mu morphs,Masaraella pandora(Murphy,Matti et Walliser,1981)W morphotype P element,其时代为布拉格期早期,大致相当于北美的Eognathodus irregularis-Gondwania profunda带和欧洲的E.sulcatus带。中布拉格期牙形刺Pseudogondwania kindlei带,还没有确立。晚布拉格期的牙形刺Polygnathus pirenniae带的存在和时限范围也没有在大沙田剖面得到确定。但大沙田剖面那高岭组的时代属布拉格期早期是肯定的。展开更多
Cadmium(Cd)contamination in soil poses a huge threat to plants even at low concentrations;Broussonetia papyrifera has great potential in remediation of soil heavy metal contamination.However,whether exogenous indole-3...Cadmium(Cd)contamination in soil poses a huge threat to plants even at low concentrations;Broussonetia papyrifera has great potential in remediation of soil heavy metal contamination.However,whether exogenous indole-3-acetic acid(IAA)application and arbuscular mycorrhizal fungi(AMF)have synergistic effects on Cd tolerance of B.papyrifera remains unclear.To investigate the effects of AMF inoculation and IAA application on the tolerance of B.papyrifera to Cd stress,two experiments were conducted:the first to investigate the effect of AMF(Rhizophagus irregularis)inoculation on the tolerance of B.papyrifera to Cd stress and the second to investigate the combined effects of AMF inoculation and IAA application on the tolerance of B.papyrifera to Cd stress.Parameters including endogenous hormone concentration,antioxidant defense response,malondialdehyde(MDA)content,and gene expression related to antioxidant enzyme system and hormone were measured.The results indicated that AMF alleviated Cd toxicity of B.papyrifera by reducing MDA content and improving antioxidant enzyme activities and Cd absorption capacity.Furthermore,the combination of AMF inoculation and IAA application had a synergetic effect on the tolerance of B.papyrifera to Cd stress through upregulating BpAUX1 and BpAUX2,which might contribute to root growth and root xylem synthesis,and by upregulating BpSOD2 and BpPOD34 to enhance the antioxidant enzyme system.This work provides a new insight into the application of IAA in the remediation of soil Cd pollution by mycorrhizal plants.展开更多
Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace ch...Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace chemical fertilizers(NPK)with biostimulants as an important approach to enhance the productivity and sustainability of agriculture.Here,we evaluated the effect of separating and/or combining arbuscular mycorrhizal fungi(AMF)with compost(C)in comparison to the use of NPK on the growth,physiological and biochemical of tomatoes under DS.The findings showed that DS significantly reduced the growth and physiological attributes of tomatoes.Furthermore,the treatment of AMF and C showed better results in agro-physiological and fruit quality compared to the NPK and control under DS.The combination of AMF and C(C+AMF)increased leaf water potential by 18.8%,stomatal conductance by 14.1%,fresh fruit weight by 25.0%,shoot dry matter by 104%and root dry matter by 56.1%compared to the control under DS.The study revealed that C+AMF caused a significant increase in sugar,protein and activity of polyphenoloxidase and peroxidase in leaves and fruits,and an opposite trend was observed in the case of malonaldehyde and hydrogen peroxide compared to NPK and control under DS.In conclusion,it is recommended to utilize the combination of AMF with compost to enhance the growth,yield,osmotic adjustment,and antioxidant capacity of tomato plants.This approach can boost their resilience to water stress and improve overall fruit quality.展开更多
文摘世界泥盆系洛霍考夫阶和布拉格阶牙形刺生物地层有较明显的地理分区性,区域对比较困难,中国缺少连续的布拉格阶与洛霍考夫阶灰岩相剖面,牙形刺生物地层的研究,仍很不完善。广西南宁大沙田剖面是目前所知布拉格阶灰岩最多的剖面,在其下部发现了牙形刺Eognathodus irregularis,E.nagaolingensis,E.sulcatus mu morphs,Masaraella pandora(Murphy,Matti et Walliser,1981)W morphotype P element,其时代为布拉格期早期,大致相当于北美的Eognathodus irregularis-Gondwania profunda带和欧洲的E.sulcatus带。中布拉格期牙形刺Pseudogondwania kindlei带,还没有确立。晚布拉格期的牙形刺Polygnathus pirenniae带的存在和时限范围也没有在大沙田剖面得到确定。但大沙田剖面那高岭组的时代属布拉格期早期是肯定的。
基金supported by the National Natural Science Foundation of China(Nos.32001289 and 32071639)the Laboratory of Lingnan Modern Agriculture Project,China(No.NZ2021025)。
文摘Cadmium(Cd)contamination in soil poses a huge threat to plants even at low concentrations;Broussonetia papyrifera has great potential in remediation of soil heavy metal contamination.However,whether exogenous indole-3-acetic acid(IAA)application and arbuscular mycorrhizal fungi(AMF)have synergistic effects on Cd tolerance of B.papyrifera remains unclear.To investigate the effects of AMF inoculation and IAA application on the tolerance of B.papyrifera to Cd stress,two experiments were conducted:the first to investigate the effect of AMF(Rhizophagus irregularis)inoculation on the tolerance of B.papyrifera to Cd stress and the second to investigate the combined effects of AMF inoculation and IAA application on the tolerance of B.papyrifera to Cd stress.Parameters including endogenous hormone concentration,antioxidant defense response,malondialdehyde(MDA)content,and gene expression related to antioxidant enzyme system and hormone were measured.The results indicated that AMF alleviated Cd toxicity of B.papyrifera by reducing MDA content and improving antioxidant enzyme activities and Cd absorption capacity.Furthermore,the combination of AMF inoculation and IAA application had a synergetic effect on the tolerance of B.papyrifera to Cd stress through upregulating BpAUX1 and BpAUX2,which might contribute to root growth and root xylem synthesis,and by upregulating BpSOD2 and BpPOD34 to enhance the antioxidant enzyme system.This work provides a new insight into the application of IAA in the remediation of soil Cd pollution by mycorrhizal plants.
文摘Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace chemical fertilizers(NPK)with biostimulants as an important approach to enhance the productivity and sustainability of agriculture.Here,we evaluated the effect of separating and/or combining arbuscular mycorrhizal fungi(AMF)with compost(C)in comparison to the use of NPK on the growth,physiological and biochemical of tomatoes under DS.The findings showed that DS significantly reduced the growth and physiological attributes of tomatoes.Furthermore,the treatment of AMF and C showed better results in agro-physiological and fruit quality compared to the NPK and control under DS.The combination of AMF and C(C+AMF)increased leaf water potential by 18.8%,stomatal conductance by 14.1%,fresh fruit weight by 25.0%,shoot dry matter by 104%and root dry matter by 56.1%compared to the control under DS.The study revealed that C+AMF caused a significant increase in sugar,protein and activity of polyphenoloxidase and peroxidase in leaves and fruits,and an opposite trend was observed in the case of malonaldehyde and hydrogen peroxide compared to NPK and control under DS.In conclusion,it is recommended to utilize the combination of AMF with compost to enhance the growth,yield,osmotic adjustment,and antioxidant capacity of tomato plants.This approach can boost their resilience to water stress and improve overall fruit quality.
