[Objective] The aim was to study the effect of different kinds of exogenous auxin on the growth of rice roots under cadmium stress.[Method] Oryza sativa L.cv Zhonghua No.11 was used as experimental materials to detect...[Objective] The aim was to study the effect of different kinds of exogenous auxin on the growth of rice roots under cadmium stress.[Method] Oryza sativa L.cv Zhonghua No.11 was used as experimental materials to detect the effect of different kinds of exogenous auxin on the growth of rice roots.[Result] The results showed that 0.1 mmol/L Cd treatment could not only increase primary,adventitious and lateral root length but also lateral root number,whereas the shoot growth was inhibited.When supplemented with different concentrations of NAA,IAA,IBA and 2,4-D,the growth of root system varied and similar change trend had been found.At the auxin concentration of 10^-9-10^-7 mol/L in particular 10^-8 mol/L,all four kinds of auxin promoted the elongation growth of primary and adventitious roots,but inhibition was observed when auxin was higher than 10^-7 mol/L.The decreased shoot growth caused by Cd could not be counteracted by supplementing with the four kinds of auxin.However,at the auxin concentration of 10^-9-10^-8 mol/L,NAA could improve rice growth under Cd stress condition.The formation and development of lateral roots on primary and adventitious roots was not only similar but also different after applying the same concentration of four auxins.[Conclusion] The addition of suitable amount of auxin under cadmium stress （such as 10^-9-10^-8 mol/L of NAA and so on） could ease the damage of cadmium on plants to a certain extent.展开更多
Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve...Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that： （1） water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control ＋ rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; （2） water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control; （3） all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting ＋ rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.展开更多
Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate ...Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate the effects of nitrate (NO3-) on rice lateral root growth and nitrogen (N) uptake efficiency under upland condition, three treatments, including root-split culture and whole plant culture in N sufficient and deficient conditions, were used in a vermiculite culture experiment. Root-split treatment showed that the growth of lateral roots was stimulated by localized nitrate supply. However, in whole plant culture, elongation of lateral roots was induced by NO3- deficiency. The effects of NO3- on rice lateral root growth were genotype-dependent. Similar N concentration, soluble sugar concentration and N content in shoot were observed in both root-split treatment and whole plant culture under NO3- sufficient condition, suggesting that the nitrogen requirement for rice normal growth could be satisfied with only half of roots supplied with NO3-. In the root-split treatment, N uptake was positively correlated with the average of lateral root length (ALRL) in NO3--supplied side, suggesting that the ALRL is important for rice root N uptake in the environment where the nitrogen nutrient is limiting factor. No significant correlation was observed between N uptake and ALRL in whole plant culture under N sufficient condition, which implies that the length of lateral roots may not be the main factor to determine tire rice root N uptake in nutrient-rich zone. Morphological and metabolic evidence in this study provided some prospects for genetic improvement of root system characters to improve the efficiency of nutrient absorption in rice.展开更多
[Objective] This study aimed to investigate the effects of nutrient and water stress on the secretion of organic acids from roots of two-year-old Larix olgensis. [Method] Different nutrient and water stress conditions...[Objective] This study aimed to investigate the effects of nutrient and water stress on the secretion of organic acids from roots of two-year-old Larix olgensis. [Method] Different nutrient and water stress conditions were designed to investi- gate the types and quantities of organic acids secreted from roots of two-year-old L. olgensis. [Result] Under nutrient and water stress, the types of organic acids secreted from roots of two-year-old L. olgensis increased, which varied with different stress levels. In addition, nutrient and water stress also increased the secretory vol- ume of organic acids from roots of two-year-old L. olgensis. The increment in total amount of organic acids reached the maximum under Level 1 （high stress）. Among different types of organic acids, the increment in secretory volume of citric acid reached the maximum, followed by malic acid, while oxalic acid presented relatively small increment. Furthermore, the increment in secretory volume of these three organic acids all reached the maximum under Level 1. [Conclusion] The proportion of the secretory volume of each organic acid accounting for the total amount of organic acids varied slightly, but the overall order was unchanged.展开更多
[Objective] This study aimed to investigate the effect of superoxide radical on root system growth and auxin distribution in rice （Oryza sativa L. cv Zhonghua No.11）. [Method] With rice Zhonghua No.ll as the experim...[Objective] This study aimed to investigate the effect of superoxide radical on root system growth and auxin distribution in rice （Oryza sativa L. cv Zhonghua No.11）. [Method] With rice Zhonghua No.ll as the experimental material, the effects of DDC （SOD inhibitor） and Tiron （superoxide radical scavenger） on the root system growth, superoxide radical generation and root system auxin distribution in rice were analyzed. [Result] The growth and elongation of primary and adventitious roots were significantly promoted by DDC, while Tiron significantly inhibited the growth and elongation of shoots, primary roots and their lateral roots, and also suppressed the formation and growth of the adventitious roots as well as the elongation of their lateral roots. The superoxide radical was increased with the induction of DDC, while Tiron decreased the accumulation of superoxide radical. Increased accumulation of auxin in the vascular bundle and behind the elongation zone was observed in DDC- treated roots, while the treatment with Tiron resulted in a decrease of auxin in the same position. [Conclusion] This study indicated that the regulation of rice root sys- tem growth by superoxide radical was closely related with the accumulation and distribution of auxin.展开更多
To solve the problems of microbial contamination and no rooting during the tissue culture of Huperzia serrata, wild seedlings of Huperzia serrata were cultured by indoor hydroponics or soil cultivation methods, then t...To solve the problems of microbial contamination and no rooting during the tissue culture of Huperzia serrata, wild seedlings of Huperzia serrata were cultured by indoor hydroponics or soil cultivation methods, then the stem tips were used in tissue culture. The above operation significantly reduced microbial contamination during tissue culture process. Different types and concentrations of hormones were added into the basic medium MS to screen the optimal formula for induced plantlet growth and rooting. It was found that 1/2MSCO was the best medium on which stem, leaves and roots of tissue culture plantlets of Huperzia serrata grew quickly. At the same time, sand planting was a convenient and effective approach for gemmae propagation of Huperzia serrata, the survival rate of seedlings germinated from gemmae was nearly 100%.展开更多
基金Supported by National Natural Science Foundation of China(30671126)~~
文摘[Objective] The aim was to study the effect of different kinds of exogenous auxin on the growth of rice roots under cadmium stress.[Method] Oryza sativa L.cv Zhonghua No.11 was used as experimental materials to detect the effect of different kinds of exogenous auxin on the growth of rice roots.[Result] The results showed that 0.1 mmol/L Cd treatment could not only increase primary,adventitious and lateral root length but also lateral root number,whereas the shoot growth was inhibited.When supplemented with different concentrations of NAA,IAA,IBA and 2,4-D,the growth of root system varied and similar change trend had been found.At the auxin concentration of 10^-9-10^-7 mol/L in particular 10^-8 mol/L,all four kinds of auxin promoted the elongation growth of primary and adventitious roots,but inhibition was observed when auxin was higher than 10^-7 mol/L.The decreased shoot growth caused by Cd could not be counteracted by supplementing with the four kinds of auxin.However,at the auxin concentration of 10^-9-10^-8 mol/L,NAA could improve rice growth under Cd stress condition.The formation and development of lateral roots on primary and adventitious roots was not only similar but also different after applying the same concentration of four auxins.[Conclusion] The addition of suitable amount of auxin under cadmium stress （such as 10^-9-10^-8 mol/L of NAA and so on） could ease the damage of cadmium on plants to a certain extent.
基金Supported by Science and Technology Plan Project of Hunan Province(2013NK3036)Science and Technology Projects of Changsha Tobacco Company(12218,12231)~~
文摘Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that： （1） water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control ＋ rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; （2） water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control; （3） all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting ＋ rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.
文摘Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate the effects of nitrate (NO3-) on rice lateral root growth and nitrogen (N) uptake efficiency under upland condition, three treatments, including root-split culture and whole plant culture in N sufficient and deficient conditions, were used in a vermiculite culture experiment. Root-split treatment showed that the growth of lateral roots was stimulated by localized nitrate supply. However, in whole plant culture, elongation of lateral roots was induced by NO3- deficiency. The effects of NO3- on rice lateral root growth were genotype-dependent. Similar N concentration, soluble sugar concentration and N content in shoot were observed in both root-split treatment and whole plant culture under NO3- sufficient condition, suggesting that the nitrogen requirement for rice normal growth could be satisfied with only half of roots supplied with NO3-. In the root-split treatment, N uptake was positively correlated with the average of lateral root length (ALRL) in NO3--supplied side, suggesting that the ALRL is important for rice root N uptake in the environment where the nitrogen nutrient is limiting factor. No significant correlation was observed between N uptake and ALRL in whole plant culture under N sufficient condition, which implies that the length of lateral roots may not be the main factor to determine tire rice root N uptake in nutrient-rich zone. Morphological and metabolic evidence in this study provided some prospects for genetic improvement of root system characters to improve the efficiency of nutrient absorption in rice.
基金Supported by National Natural Science Foundation of China(31370613)Major State Basic Research Development Program of China(973 Program)(2011CB403202)+1 种基金Project of General Administration of Quality Supervision,Inspection and Quarantine of China(2009IK177)Fundamental Research Fund for the Central Universities(DL12CA01)~~
文摘[Objective] This study aimed to investigate the effects of nutrient and water stress on the secretion of organic acids from roots of two-year-old Larix olgensis. [Method] Different nutrient and water stress conditions were designed to investi- gate the types and quantities of organic acids secreted from roots of two-year-old L. olgensis. [Result] Under nutrient and water stress, the types of organic acids secreted from roots of two-year-old L. olgensis increased, which varied with different stress levels. In addition, nutrient and water stress also increased the secretory vol- ume of organic acids from roots of two-year-old L. olgensis. The increment in total amount of organic acids reached the maximum under Level 1 （high stress）. Among different types of organic acids, the increment in secretory volume of citric acid reached the maximum, followed by malic acid, while oxalic acid presented relatively small increment. Furthermore, the increment in secretory volume of these three organic acids all reached the maximum under Level 1. [Conclusion] The proportion of the secretory volume of each organic acid accounting for the total amount of organic acids varied slightly, but the overall order was unchanged.
基金Supported by the National Natural Science Foundation of China(30671126)the Science and Technology Development Plan of Zibo City(109036,111089)~~
文摘[Objective] This study aimed to investigate the effect of superoxide radical on root system growth and auxin distribution in rice （Oryza sativa L. cv Zhonghua No.11）. [Method] With rice Zhonghua No.ll as the experimental material, the effects of DDC （SOD inhibitor） and Tiron （superoxide radical scavenger） on the root system growth, superoxide radical generation and root system auxin distribution in rice were analyzed. [Result] The growth and elongation of primary and adventitious roots were significantly promoted by DDC, while Tiron significantly inhibited the growth and elongation of shoots, primary roots and their lateral roots, and also suppressed the formation and growth of the adventitious roots as well as the elongation of their lateral roots. The superoxide radical was increased with the induction of DDC, while Tiron decreased the accumulation of superoxide radical. Increased accumulation of auxin in the vascular bundle and behind the elongation zone was observed in DDC- treated roots, while the treatment with Tiron resulted in a decrease of auxin in the same position. [Conclusion] This study indicated that the regulation of rice root sys- tem growth by superoxide radical was closely related with the accumulation and distribution of auxin.
文摘To solve the problems of microbial contamination and no rooting during the tissue culture of Huperzia serrata, wild seedlings of Huperzia serrata were cultured by indoor hydroponics or soil cultivation methods, then the stem tips were used in tissue culture. The above operation significantly reduced microbial contamination during tissue culture process. Different types and concentrations of hormones were added into the basic medium MS to screen the optimal formula for induced plantlet growth and rooting. It was found that 1/2MSCO was the best medium on which stem, leaves and roots of tissue culture plantlets of Huperzia serrata grew quickly. At the same time, sand planting was a convenient and effective approach for gemmae propagation of Huperzia serrata, the survival rate of seedlings germinated from gemmae was nearly 100%.
