枝叶凋萎病对杨梅根际菌根的影响

探讨了枝叶凋萎病对其根围菌根的生长及侵染能力的影响.结果表明,较之健康杨梅的须根和菌根,发生枝叶凋萎病的杨梅其根部须根受到严重破坏,内部菌根菌丝多数崩解,根围土壤内的菌根孢子多数破裂、内容物泄露,病树根围分离到的饱满孢子与从健康杨梅树根围分离到的孢子相比其侵染西瓜和三叶草的能力大大下降,具体原因尚需进一步研究.     

methods during the silvopastoral-system establishment in midwestern USA: Cattle performance and tree damage

Silvopastoral systems offer an alternative to the conventional cow-calf segment of the beef industry in the Midwestern region of the United States. Little information exists for transitioning from a conventional pasture-based beef operation to a silvopastoral system utilizing multiple deciduous tree species. Nine pastures approximately 1 ha in size were established with a mixture of cool-season grasses and legumes to investigate tree protection methods and cattle performance. Four tree species (Juglans nigra, Gleditsia triacanthos, Quercus rubra, & Carya illinoensis) were planted within six of these pastures. Three methods of protection were tested, and included a no protection control (Con), foliar application of 0.20% denatonium benzoate (TreeGuard™), or a single strand of electrified poly-wire (EF) in each of the two grazing years. Cattle damage to young trees was prominent during the two years for Con and TreeGuard™. EF offered acceptable protection. Red oak trees suffered the highest degree of damage from livestock. Establishing trees within grazed pastures did not hinder performance of beef cattle. Transitioning from conventional pastures to silvopastures can be accelerated utilizing an electrified fencing system to prevent cattle damage. This revised version was published online in August 2006 with corrections to the Cover Date.     

红叶小檗的繁育技术

红叶小檗(Berberis thunbergii var. atropurpurea Chenault)适应性强,耐修剪,观赏价值高,在园林绿化中广泛应用。文章从选地整地、扦插枝条选择、繁殖方法、幼苗抚育等方面总结红叶小蘖育苗技术,以期为提高红叶小檗繁育水平提供参考。     

Variation in quality and decomposability of red oak leaf litter along an urban-rural gradient

 This study tested whether urban land use can affect the chemistry and decomposability of Quercus rubra L. (red oak) leaf litter in forests within and near a large metropolitan area. Cities may affect the quality of leaf litter directly through foliar uptake of atmospheric pollutants, and indirectly through alterations in local climate and changes in soil fertility caused by pollutant loads and altered nutrient cycling regimes. Using a microbial bioassay, we tested whether red oak leaf litter collected from urban and suburban forests in and near New York City differed in decomposability from litter of the same species collected from rural forests 130 km from the city. We found that oak litter from the urban forests decayed 25% more slowly and supported 50% less cumulative microbial biomass in a laboratory bioassay than rural litter. Rural litter contained less lignin and more labile material than urban litter, and the amounts of these chemical constituents were highly correlated with the decay rate coefficients and integrated microbial growth achieved on the litter. The specific causes of the variation in litter chemistry are not known. The results of this study suggest that decomposer activity and nutrient cycling in forests near large cities may be affected both by altered litter quality and by altered biotic, chemical and physical environments. The sensitivity of the microbial bioassay makes it useful for distinguishing differences in within-species litter quality that result from natural or anthropogenic variation in the environment. Received: 7 January 1999     

杨梅叶抑菌活性成分初步分离与鉴定

用石油醚、氯仿、乙酸乙酯和正丁醇分别对杨梅叶甲醇提取物进行了萃取,得不同萃取相。测定了其对番茄灰霉病菌Botrytis cinerea、番茄早疫病菌Alternaria solani、水稻立枯丝核Rhizoctonia solani、小麦禾谷镰刀菌Fusarium graminearum、 黄瓜炭疽病菌Colletotrichum lagenarium、玉米大斑病菌Setosphaeria turcica等植物病原菌的抑菌活性。结果表明,乙酸乙酯相和正丁醇相的抑菌活性较好。对乙酸乙酯相进一步分离得到7个化合物,经电喷雾质谱(ESI-MS)、核磁共振氢谱(1H NMR)和碳谱(13C NMR)鉴定其分别为已知化合物山楂酸( 1 )、3-O-反-对-香豆酰基马斯里酸( 2 )、3-O-没食子酰二氢杨梅素( 3 )、斛皮素-7-O-鼠李糖甙( 4 )、杨梅素3-O-鼠李糖甙( 5 )、杨梅素-3-O-鼠李糖(3-O-没食子酰)甙( 6 )和杨梅素-3-O-鼠李糖(2-O-没食子酰)甙( 7 )。孢子萌发法测定结果表明,化合物 3~6 对番茄灰霉病菌和玉米大斑病菌的孢子萌发具有较好的抑制作用,EC50值分别在3.44~4.59 mg/L和8.85~11.6 mg/L之间。     

毒死蜱在杨梅果实中的残留及消解动态

为探明毒死蜱在杨梅果实中的残留消解动态和最终残留量,于2013-2015年在浙江省临海市进行了毒死蜱在杨梅果实中的残留消解动态和最终残留量试验。结果表明:于杨梅春梢（幼果）生长期,在树冠均匀喷施48%毒死蜱乳油800倍液1次的施药条件下,毒死蜱在‘东魁’和‘临海早大梅’2个品种果实中的消解动态基本一致,均符合一级动力学方程,半衰期为4.60~5.78 d,降解速度较快。综合3年试验结果,施药后23 d,毒死蜱在杨梅果实中的残留量为0.26~0.45 mg/kg,低于中国（苹果、梨、荔枝和龙眼）及日本（其他浆果）最大残留限量标准（MRL,1 mg/kg）;施药后34 d,毒死蜱在杨梅果实中的残留量为0.074~0.28 mg/kg,低于香港草莓中MRL值（0.3 mg/kg）;但施药后44 d,毒死蜱在果实中的残留量为0.073~0.13 mg/kg,仍高于欧盟蓝莓及桑椹中毒死蜱的MRL值（0.05 mg/kg）。膳食风险评估结果表明,施药后23、27、34和44 d采收的杨梅果实中毒死蜱对2~6岁、7~14岁、18~30岁和60~70岁4类人群的膳食摄入风险商值及急性膳食风险均较低,处于安全水平。     

早熟杨梅新品种‘早炭梅8801号’

 ‘早炭梅8801号’是从‘荸荠种’中选出的杨梅新品种。该品种6月10日果实开始成熟, 比荸荠种提早10～15 d, 果实比荸荠种早熟株系大17.86%, 树冠覆盖面积产量3.5 kg/m² , 可在生态环境较恶劣的低丘红壤区域作为多功能品种栽培。果实鲜食加工兼用, 适应性强, 高产稳产。     

红壤退化地杨梅林土壤对养分补偿的响应

2016年在福建省长汀县河田镇车寮村杨梅园以东魁杨梅(Myrica rubra cv.DongKui)林为试验材料,在了解当地东魁杨梅的栽培情况及对林下土壤养分分析的基础上,开展复合肥、菌肥、磷肥、菌肥+磷肥4种土壤养分补偿试验,分析0～20、20 ～ 40 cm土层对不同土壤养分补偿方式的响应.结果 表明:在pH值响...     

贵州矮杨梅营养器官总黄酮测定方法及含量积累规律

矮杨梅为我国特有,其植物体中含有大量的天然黄酮类化合物,对其测定方法和积累规律进行考察和探讨。结果表明,对总黄酮测定方法进行考察得出,线性回归方程为Y=8.5257X-0.0184,相关系数r=0.9996;在0~60 min范围内于波长510 nm条件下测定,结果准确、重现性好(RSD=0.34),回收率高(RSD=2.13%)。相同生育期的总黄酮含量变化规律为:雌株除营养期外均为根>茎>叶;雄株则为营养期和孕花期茎>叶>根,盛花期和果期根>茎>叶。不同生育期矮杨梅总黄酮含量动态变化规律为:雌株根为果期最高,营养期次之,孕花期最小;茎为盛花期>果期>营养期>孕花期;叶为营养期>果期>孕花期>盛花期。雄株根为果期>盛花期>孕花期>营养期;茎和叶为孕花期>果期>营养期>盛花期。     

玉屏县种植杨梅的气候适应性分析

为玉屏县发展布局“一村一特,一镇一品,一县一业”的特色经果业提供科学依据,利用玉屏县1971-2008年的温度、降水、湿度等气候资料,对杨梅种植与其原产地的气候情况进行比较分析.结果表明,玉屏县温度、降水量、相对湿度等气候条件均适宜杨梅的生长发育.实际生产中,玉屏县较高的相对湿度和多雾有利于杨梅的生长发育和果实优良品质...