Exogenous and endogenous factors acting on the spatial distribution of a chrysomelid in extensively managed blueberry fields

相似文献   

Impact of soil stockpiling on ericoid mycorrhizal colonization and growth of velvetleaf blueberry (Vaccinium myrtilloides) and Labrador tea (Ledum groenlandicum)

Soil stockpiling is a common practice prior to the reclamation of surface mines. In this study, velvetleaf blueberry and Labrador tea plants were grown from seed in fresh soil, stockpiled soil (1 year), and autoclaved stockpiled soil (1 year) obtained from the Canadian boreal forest. After 7 months of growth, the root colonization intensity with ericoid mycorrhizal (ERM) fungi in both plants growing in stockpiled soil was lower compared to plants growing in the fresh soil. The diversity of ERM fungal species in roots also decreased due to soil stockpiling and Pezoloma ericae was absent from the plants growing in stockpiled soil. Changes in the ERM root colonization in plants growing in stockpiled soil were accompanied by decreases in root and shoot dry weights. Leaf chlorophyll, nitrogen, and phosphorus concentrations of velvetleaf blueberry were higher in fresh soil compared to 1‐year stockpiled soil. Plants grown in the autoclaved stockpiled soil became colonized by the thermotolerant ERM fungus Leohumicola verrucosa and showed higher root and shoot biomass compared to the nonautoclaved stockpiled soil. The results point to the importance of ERM fungi for growth of ericaceous plants, even under favorable environmental conditions and adequate fertilization, and suggest that reduced ERM colonization intensity and ERM fungal diversity in roots likely contributed to the negative effects of soil stockpiling on growth of velvetleaf blueberry and Labrador tea.     

Isolation of a Peptidyl Factor, α Substance-IA,Inducing Sexual Agglutinability in Saccharomyces cerevisiae

After a eleven-steps purification, a peptidyl factor named α substance-Ia was isolated in pure form from a culture filtrate of α type cells of the heterothallic Saccharomyces cerevisiae. The substance induced the sexual agglutinability in a haploid cells belonging to the opposite mating type at concentrations from 0.4 to 0.8 ng/ml.     

蓝莓腐霉根腐病的病原菌

在山东青岛新发现一种蓝莓根腐病害,症状最初出现在根部,病根腐烂坏死,根状茎维管束和皮层变黑,导致根数量减少,叶片变黄、变红,植株生长不良,严重时叶片全部脱落,植株死亡。通过组织分离法和菌丝段分离法获得纯化菌株HMQAU 180018,经柯赫氏法则验证,综合形态学特征及ITS区和cox I基因序列分析,菌株HMQAU 180018被鉴定为畸雌腐霉Pythium irregulare。这是国内首次描述畸雌腐霉引起蓝莓根腐病的报道。     

Mathematical modeling of the indole-3-butyric acid applications on rooting of northern highbush blueberry (<Emphasis Type="Italic">Vaccinium corymbosum</Emphasis> L.) softwood-cuttings

The objective of the present study is to develop a mathematical model to predict the effect of indole-3-butyric acid (IBA) on mean rooting (%) and mean root growth of northern highbush blueberry cultivars (Vaccinium corymbosum L.). The best estimating equations for the rooting (%) and root growth are formulized as: RG = (5.672183) + [0.002851 × (IBA)] − [2.0E⁻⁶ × (IBA)2] + (−0.27211 × Cv.) and R = (82.00649) + [0.030801 × (IBA)] − [2,4E⁻⁵ × (IBA)2] − [2.36218 × (Cv.)] where RG is root growth, R is rooting, IBA is indole-3-butyric acid (ppm) and Cv. is cultivar. Cultivars are Ivanhoe [1], Jersey [2], Rekord [3], Northland [4], Berkeley [5] and Bluejay [6]. The numbers given in square brackets represent the blueberry cultivars for the equations. Multiple regression analysis was carried out until the least sum of squares (R2) was obtained. R ² value 0.90 for rooting and 0.95 for root growth. Standard errors were found to be significant at the p < 0.001 level. The actual rooting differed to the blueberry cultivars and it was between 57.76 and 83.23% while estimated rooting percentage calculated by the produced mathematical model was between 59.04 and 83.80%.     

越桔两种蛀干害虫的发生与防治

咖啡豹蠹蛾Zeuzera coffeae Nietner和樟泥色天牛Uraecha angusta(Pascoe)是江苏地区的美国兔眼越桔上2种主要蛀干害虫。前者在枝干中向顶端方向蛀食,排出圆粒状虫粪;后者向植株基部方向蛀食,排出粉末状虫粪,均造成枝干枯死。咖啡豹蠹蛾发生量较大,是主要虫种。防治这2种蛀干害虫,应采用保护利用天敌、改善果园生态环境、促使树体健壮生长等综合管理措施。     

木质化程度对兔眼蓝浆果不同品种插条扦插生根的影响

在常规扦插条件下,兔眼蓝浆果(Vaccinium ashei Reade)的‘园蓝'('Gardenblue')、‘梯芙蓝'('Tifblue')、‘顶峰'(‘Climax')和‘杰兔'(‘Premier')等4个品种的硬枝插条均不能生根;而春季3月份开始在全光照间歇弥雾条件下扦插6个月后,上述各品种的硬枝插条的生根率分别达到84%、52%、62%和79%. 在全光照间歇弥雾条件下,未木质化的绿枝插条也未能生根;木质化程度不同的绿枝插条均能生根,品种间生根率差异显著,‘园蓝'和‘杰兔' 的生根率显著高于‘梯芙蓝'和‘顶峰';各品种内木质化程度不同的绿枝插条之间的生根率差异显著,木质化程度越低,生根率越高.木质化程度不同的插条还在生根部位、生根数量、插条萌芽和插条基部腐烂等方面存在差异.     

Mineral composition and accumulation of silicon in tissues of blueberry (Vaccinum corymbosus cv. Bluecrop) cuttings

Research was carried out with the objective of investigating the mineral composition and Si accumulation in tissues of young cuttings of blueberry (Vaccinum corymbosus L. cv. Bluecrop). Blueberry cuttings were irrigated every day for 1 hour (140 ml per pot) with river water containing 0.66 to 1.0 mol m^–3 SiO₂, and after 7 months of growth their mineral composition and silicon distribution were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mean contents of N, K, Mg, Cu and Zn in young leaves were the same as those in old ones. On the other hand, the mean contents of P, Ca, Si, Fe and Mn in old leaves were higher than those in young leaves. Although Si is not known to be an essential element for growth of blueberries, it was the element that accumulated the most in leaves, with a mean content of 32.0 and 60.0 mg g^–1 dry weight in young and old leaves, respectively. The mean Si content in young leaves was 3.1, 56.7, 4.8, 4.9 and 85 times higher than the mean contents of N, P, K, Ca and Mg, respectively, and was 5.4, 60.0, 8.8, 6.8 and 100 times higher than in old leaves. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis of dry ash samples showed that Si accumulated in many parts of the leaves, forming phytoliths in the upper epidermis, including some parts of the palisade mesophyll, in the lower epidermis around the stomata, including guard cells, and in some parts of the spongy mesophyll, and in the veins. There were also silica bodies of unknown origin on the upper epidermis.     

兔眼蓝浆果品种果实养分测定

对南京地区引自美国的１２个兔眼蓝浆果品种果实主要营养成分包括可溶性固形物、糖、酸、水溶性维生素、氨基酸、矿质元素进行了测定,并与原产地进行了比较。大多数品种果实糖分含量高而酸度低,糖酸比高,风味甜而微酸。Ｂ族维生素含量明显高于苹果、柑橘和黑莓。氨基酸含量品种间差异大,Ｄｅｌｉｔｅ、Ｗｏｏｄａｒｄ、Ｃｅｎｔｕｒｉｏｎ和Ｇａｒｄｅｎｂｌｕｅ含量最高。Ｇａｒｄｅｎｂｌｕｅ大部分矿质元素,特别是Ｃａ、Ｆｅ、Ｚｎ、Ｋ的含量较高,Ｐｒｅｍｉｅｒ和Ｗｏｏｄａｒｄ的Ｓｅ含量高,Ｃｌｉｍａｘ的Ｚｎ含量高。考虑到品种的适应性,特别是丰产性表现,认为Ｇａｒｄｅｎｂｌｕｅ和Ｔｉｆｂｌｕｅ二品种在南京地区发展前途较大。     

Effect of electrostatic spray parameters on the viability of two bacterial biocontrol agents and their deposition on blueberry flower stigmas

The fungus Monilinia vaccinii-corymbosi infects blueberry flowers via the stigma-style ovary pathway to cause mummy berry disease. Previous laboratory experiments documented considerable activity of stigma-applied biofungicides containing the bacteria Bacillus subtilis and, to a lesser extent, Pseudomonas fluorescens against flower infection by the pathogen. However, adequate and targeted delivery of the biocontrol agents to the stigmatic surfaces of open flowers in the field has remained problematic. Here we consider the application of the biofungicides Serenade AS (containing B. subtilis QST713) and BlightBan A506 (containing P. fluorescens A506) to blueberry flowers by air-assisted electrostatic spraying. In laboratory experiments with typical field-use rates, viability of B. subtilis and P. fluorescens was unaffected by different levels of induction-charging voltage (0–1.2 kV) and atomizing pressure (138–276 kPa) applied to an electrostatic spray-charging nozzle, showing that the bacteria in both formulations readily survived exposure to the intense electrical fields and near-sonic atomizing air shear encountered during electrostatic spraying. Electrostatically charged application significantly (P<0.0001) increased deposition of B. subtilis on the stigmatic surfaces of detached blueberry flower clusters by a factor of 4.5 compared with conventional hydraulic spraying; a similar comparison showed that population densities of P. fluorescens on the stigma were increased by a factor of 2.9, but this effect was not statistically significant (P=0.1487). For Serenade, the increased coverage and/or retention on the flower stigma, along with the excellent bacterial survival, portend well for electrostatic application for mummy berry disease control in the field.