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The effects of acid extracts of tomato ( Lycopersicon esculentum Mill.) and carrot ( Daucus carota L.) juice wastes from the food industry on the growth of five species of crops and four weeds were examined. The acid extract of the tomato juice waste promoted the shoot and root growth of tomato, Chinese cabbage, corn, and radish, but not the growth of oat seedlings. The extract did not promote the shoot growth of weeds tested, and it inhibited the root growth of the weeds that included barnyardgrass ( Echinochloa oryzicola Ohwi), southern crabgrass ( Digitaria ciliaris Koel.) and Japanese barnyard millet ( Echinochloa utilis Ohwi). The carrot juice waste was also examined as another waste from the food industry. The effect of the acid extract of carrot juice waste showed significant promoting effects on the root growth of Chinese cabbage; however, the effects on other plants were lower than that of tomato juice waste. It also did not inhibit the growth of weeds. These results suggested that the acid extract from tomato juice waste is useful as plant-growth substances because they have a promoting effect on the shoot and root growth of crops, and an inhibitory effect on the root growth of some weeds.  相似文献   
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ABSTRACT:   The timing of molting and metamorphosis was monitored for Panulirus japonicus phyllosoma larvae cultured in the laboratory. Larvae cultured under natural light–dark cycle molted synchronously within approximately 1.0 h before and after sunrise, except for a short period after hatching; the timing of molting changed with time of sunrise. When three artificial light–dark cycles were introduced, larvae molted around the start of lighting, irrespective of the light–dark cycles. In the event of a sudden change in the start or end of lighting, molting was regulated by an endogenous rhythm. The start of lighting had a greater impact on the timing of molting than the end of lighting, suggesting that sunrise is probably the critical signal for phase-setting in molting rhythm. Metamorphosis to the puerulus stage occurred within 0.4 h before and 1.2 h after sunset under a natural light–dark cycle, and the timing of metamorphosis was also changed artificially by regulating the end of lighting.  相似文献   
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使用12个分别持有不同抗病基因(Xa1,Xa2,Xa3,Xa4,Xa5,Xa7,Xa8,Xa10,Xa11,Xa13,Xa14和Xa21)的近等基因系水稻白叶枯病鉴别品种及3个对照品种(IR24,Toyonishiki和Sigadagabo),鉴别了从云南省收集的138个菌株。结果根据致病谱可以将这些菌株分成A-J共10组。A组菌株仅对Toyonishiki和Sigadagabo两个对照品种致病,J组菌株则能对9个鉴别品种和3个对照品种致病。对不同海拔采集的菌株进行致病力分析的结果表明,从大理、武定等较高海拔粳稻种植区采集的菌株致病力较弱,在鉴别品种上病斑的平均长度不到50mm;而元江、景洪、潞西等低海拔杂交稻种植区采集的菌株致病力较强,在鉴别品种上的病斑平均长度超过100mm。从高海拔稻区到低海拔稻区,病菌致病力有逐步增强的趋势。  相似文献   
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