Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent year...Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.展开更多
This paper applied the theory and method of non linear dynamic to study the integrated environ economic system( EES ). The results of the numerical computational experiment and theoretical inductions showed that the...This paper applied the theory and method of non linear dynamic to study the integrated environ economic system( EES ). The results of the numerical computational experiment and theoretical inductions showed that the system behaviour pattern of the EES will be changed with the variation of the force power level. When the force DP become higher, the system loss its stability gradually, until the chaos occurs. Based on these results, this paper presented an explanation for the long wave economic fluctuation, and proposed in order to guarantee the sustainable development of the specific EES, the DP value of the system should be limited within a reasonable range.展开更多
西藏当雄错盐湖是一个碱性的富锂、硼资源盐湖,对其碳酸盐沉积物的研究有助于了解盐湖形成过程中沉积环境的变化以及锂、硼资源的富集过程。为此,本文从当雄错盐湖碳酸盐剖面自上而下采集了31件样品。对这些样品开展了铀系年龄、XRD、主...西藏当雄错盐湖是一个碱性的富锂、硼资源盐湖,对其碳酸盐沉积物的研究有助于了解盐湖形成过程中沉积环境的变化以及锂、硼资源的富集过程。为此,本文从当雄错盐湖碳酸盐剖面自上而下采集了31件样品。对这些样品开展了铀系年龄、XRD、主-微量元素、碳-氧同位素测定以及介形类的鉴定分析。铀系年龄结果表明剖面沉积开始于(3788±120)a BP,结束于约2220 a BP。碳酸盐沉积的微量元素和稀土元素特征表明,其沉积水体为缺氧、还原环境下的咸水环境,沉积物形成于干旱、寒冷的气候环境,湖泊水体具有半开放-半封闭性质,但封闭程度较高。约3430 a BP时,当雄错水体盐度发生了较大改变。结合沉积物中介形类Candona gyrongensis的出现和沉积物的碳氧同位素特征,推测有地下淡水注入导致湖泊水体变淡和还原性减弱。当雄错水体的盐度在2220 a BP之前仍相对较低,湖水浓缩达到盐湖阶段的时间在2220 a BP以后。展开更多
基金The research was supported by the State Key Basic Research and Development Plan of China(2004CB 117200,2002CB111300)the Hi-Tech Research and De-velopment Program of China(2004AA21111)+1 种基金the China Scholarship Council,the Sino-Polish Scientific and Technological Cooperation 2004 2006(3 1-23B)the National Natural Science Foundation of China(30000107).
文摘Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.
文摘This paper applied the theory and method of non linear dynamic to study the integrated environ economic system( EES ). The results of the numerical computational experiment and theoretical inductions showed that the system behaviour pattern of the EES will be changed with the variation of the force power level. When the force DP become higher, the system loss its stability gradually, until the chaos occurs. Based on these results, this paper presented an explanation for the long wave economic fluctuation, and proposed in order to guarantee the sustainable development of the specific EES, the DP value of the system should be limited within a reasonable range.
文摘西藏当雄错盐湖是一个碱性的富锂、硼资源盐湖,对其碳酸盐沉积物的研究有助于了解盐湖形成过程中沉积环境的变化以及锂、硼资源的富集过程。为此,本文从当雄错盐湖碳酸盐剖面自上而下采集了31件样品。对这些样品开展了铀系年龄、XRD、主-微量元素、碳-氧同位素测定以及介形类的鉴定分析。铀系年龄结果表明剖面沉积开始于(3788±120)a BP,结束于约2220 a BP。碳酸盐沉积的微量元素和稀土元素特征表明,其沉积水体为缺氧、还原环境下的咸水环境,沉积物形成于干旱、寒冷的气候环境,湖泊水体具有半开放-半封闭性质,但封闭程度较高。约3430 a BP时,当雄错水体盐度发生了较大改变。结合沉积物中介形类Candona gyrongensis的出现和沉积物的碳氧同位素特征,推测有地下淡水注入导致湖泊水体变淡和还原性减弱。当雄错水体的盐度在2220 a BP之前仍相对较低,湖水浓缩达到盐湖阶段的时间在2220 a BP以后。
