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1.
蚱蝉又名知了、黑蚱,属翅目蝉科。它对苹果幼树危害很大,成虫先用产卵器刺破枝条表皮与木质部,将卵产在枝条内部,使枝条表皮与木质部裂开,水分和养分输导受阻,产卵以上的枝段凋萎枯死。 相似文献
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不同土质中苹果幼树当年生根的解剖构造 总被引：4，自引：0，他引：4
对砂土、粘土中苹果幼树当年生根解剖构造的观察表明,砂土吸收根、生长根中柱占根面积百分比大于粘土;导管密度及导管占中柱面积百分比小于粘土;砂土输导根木质部占要面积百分比及导管总面积皆比粘土的小。 相似文献
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土壤有机质对苹果幼树根解剖构造的影响 总被引：1，自引：0，他引：1
土施有机肥后,对砂土与粘土中苹果幼树当年生根解剖构造的观察表明,吸收根及生长根中柱占根面积百分率提高,导管密度及导管占中柱占根面积百分率提高,导管密度及导管中柱面积百分率降低;输导根导管总面积及导管占木质部面积百分率增大;砂土及粘土中结果类似。 相似文献
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蚱蝉又名黑蝉、知了、秋蝉，属于同翅目，蝉科。蚱蝉分布全国各地，主要危害杨、柳、榆、槐、桐、椿、苹果、梨、桃、杏、李等150余种林木和果树。若虫在土内吸食树木根系汁液，削弱树势；成虫产卵于1年生枝梢木质部，造成外皮和木质开裂，破坏正常输导，引起枝条死亡。 相似文献
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折枝，就是在强旺枝条的下部剪伤，深度为枝条直径的1／3～1／2，再沿剪口上下纵向劈裂木质部5-8cm；扭伤则是对旺长枝条由基部将木质部旋转扭伤。红富士苹果幼树长势旺盛，在其生长季管理过程中，采取折枝和扭枝措施削弱枝条的输导能力，缓其长势，可以收到促花结果的良好效果，尤其扭枝较为常用。但有些果农却在冬剪时对红富士苹果强旺枝条采用折枝和扭枝措施。由于冬季树体处于休眠状态，生命活动极其微弱．一旦造成伤口很难愈合．加之红富士苹果幼树长势旺盛．枝条发育充实度差，极易失水，所以冬剪时实施折枝和扭枝技术很容易使枝条出现不同程度的抽条现象，严重者使枝条抽死。据调查，红富士3-5年生幼树冬季折枝抽条率为82％，死枝率为45％；扭枝抽条率为77％，死枝率39％。 相似文献
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1990年4月下旬,我们在苹果砧苗和接穗均不离皮的情况下,用带木质部芽接法芽接了53株,其成活率达98％,当年即成苗。9月份又对当年移栽过的和落叶早的苹果砧苗约1000余株进行了带木质部芽接,调查结果表明,成活率达96.5％,伤口愈合良好,当年可出半成品苗。实践证明苹果带木质部芽接法有许多优点: 相似文献
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3种柑橘实生砧木及其2种体细胞杂种根系解剖结构的比较 总被引：1，自引：0，他引：1
采用石蜡切片法和组织离析法分别对3种柑橘实生砧木和2种体细胞杂种的根系木质部和导管分子的解剖构造进行了比较。结果表明：（1）粗柠檬、红橘和枳3种实生砧木根系的木质部和韧皮部呈同心圆环状排列,而‘红橘+枳’和‘红橘+粗柠檬’两种体细胞杂种木质部和韧皮部呈“海星状”排列,结构异常。（2）导管所占的面积和密度,均以生长势较强的粗柠檬为大,以生长势较弱的枳为小;体细胞杂种没有明显规律。（3）柑橘导管分子属于孔纹导管,穿孔板均为单穿孔,大多分布于端壁上;导管分子两端具尾、倾斜、侧壁穿孔等性状的有无及其比例,反映出生长势的差异及其输导能力的强弱。（4）粗柠檬具有较好输导能力的导管分子结构,而枳较差;体细胞杂种根系的导管分子长度和直径都大于其亲本,在导管分子性状上,向不利于输导能力的较原始性状偏移。 相似文献
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Girdling and the reduction in shoot xylem sap concentrations of cytokinins and gibberellins in peach
J. G. M. Cutting M. C. Lyne 《The Journal of Horticultural Science and Biotechnology》2013,88(4):619-626
The effects of girdling at the beginning of pit hardening on peach shoot xylem sap cytoki- nin and gibberellin concentrations were studied. Girdling at the beginning of growth stage II of fruit development significantly reduced xylem sap concentration of zeatin-type cytokinins, gibberellin A, and/or gibberellin A3. Girdling also reduced shoot growth, both internodal length and node number, for about eight weeks after girdling until the girdle had healed over. The results support the hypothesis that reduced shoot growth is caused by reduced xylem transported, root supplied, promotive growth substances. 相似文献
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G. Browning 《The Journal of Horticultural Science and Biotechnology》2013,88(3):297-310
Two cationic, butanol-soluble, cytokinin fractions were resolved from purified coffee flower bud and xylem sap extracts. Dormant buds yielded only the more polar fraction and xylem sap collected during drought the less polar fraction, levels of the latter fraction decreasing as drought proceeded. When bud dormancy was broken by irrigation or rainfall, a rapid increase occurred in the more polar cytokinin of the xylem sap. Activity of both cytokinin fractions increased in the buds also, but more slowly at first. The pattern of changes in both bud and sap cytokinin indicate that, when water stress in coffee trees is relieved, cytokinin, which may be required by the buds for further development to anthesis, is released from within the xylem. This, it is suggested, explains why water stress usually must be relieved before the buds can emerge from dormancy. Using thin-layer chromatography, the more polar cytokinin was found to be chromatographically indistinguishable from zeatin riboside in the six different solvent systems tried, while the mobility of the less polar one was similar, but not identical, to 6γγ (dimethylallyl) amino purine. A technique for the sequential extraction of gibberellins, abscisic acid and cytokinin is described. 相似文献
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The rates of sap flow and xylem vessel features were studied in two-year-old nongrafted and grafted avocado (Persea americana Mill.) trees. Daily sap flow rates were measured with heat and balance stem gauges in clonal Duke 7 (D7) and Toro Canyon (TC) trees and ‘Hass’ clonal scions grafted onto clonal D7 (H/D7) and TC (H/TC) rootstocks. Vessel features as size, number and total vessel area were determined histologically in the stem of the scion and rootstock and the roots of the grafted trees. Significant differences in the sap flow rate were found among the rootstocks, where D7 had a 29% higher sap flow rate than did TC (grafted and nongrafted trees). There were no differences among xylem vessel features in the stems of any of the varieties. However in the roots, D7 had wider and fewer vessels then TC do. Also, D7 had a 19% higher total vessel area than TC. These results suggest that the differences in water consumption of ‘Hass’ on different rootstocks may be associated with differences in the efficiency of the roots to absorb water across conductive tissue which may be linked to differences in the area of xylem vessels in the root. 相似文献
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T. Brendon Johnson Robert M. Aug Craig D. Green Ann J. W. Stodola Joshua B. Olinick Arnold M. Saxton 《Scientia Horticulturae》2001,90(3-4):305-320
Recent findings suggest that stomatal conductance (gs) may be as closely linked to plant chemical variables as to hydraulic variables. To test this in an urban field setting, we examined seasonal gs in relation to a number of plant and environmental variables in five temperate, deciduous tree species. Stomatal conductance was generally more closely correlated with abscisic acid concentrations in xylem sap than with shoot water potential, shoot osmotic potential, pH of xylem sap or environmental variables. Seasonal gs was mostly poorly correlated with shoot water potential and osmotic potential. Among environmental variables, PPFD accounted for most variability in gs. We tested a model, developed previously in maize, that describes regulation of gs by abscisic acid concentration of xylem sap with leaf water status acting to modify stomatal sensitivity to the abscisic acid signal. This model explained somewhat more variation in gs than abscisic acid concentrations alone. Response surface models, especially those incorporating environmental variables, were most successful at explaining gs. Our findings with urban trees are consistent with the theory of regulation of gs by root-sourced abscisic acid. 相似文献
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对欧洲葡萄茎木质部截面上液流传导区域进行了定量研究。首先建立了一个木质部截面上导管总体分布的数量模型;然后对木质部截面上液流传导功能导管进行了区域定量研究;并且讨论了木质部不同年轮对液流传导的相对重要性和不同年龄茎干木质部液流传导的有效性估计;最后建议将欧洲葡萄植物木质部水导构造称为“外围散孔型”构造。 相似文献
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《Scientia Horticulturae》2005,103(3):317-327
The potential use of stem xylem chloride (Cl−) analysis as an indicator for sudden variation in Cl− uptake by the tree was examined. Three extraction techniques (xylem sap extracted by centrifuge, and water extraction of fresh or dry ground xylem) were linearly correlated to each other as well as to soil salinity. Chloride values in xylem sap extracted by centrifugation were about half (3–34 mM) of those found in water extraction of fresh or dry ground xylem (9–84 mM), reflecting some Cl− accumulation by existing living cells. Based on dry ground xylem, xylem Cl− concentration was not affected by time of day; however, when centrifuge extraction was used, daily values were highest at the beginning and end of the day, and lowest during mid-day. Additionally, Cl− concentration was not affected by stem thickness (5–25 mm) using the dry ground extraction method. Rootstock affected xylem Cl− content in the same way it affected leaf Cl− content; xylem Cl− content was highest for trees grafted on salt-sensitive rootstocks and vice versa. As opposed to leaf analysis in which Cl− concentration can only increase with time, xylem Cl− content always followed soil salinity variation, either increasing or decreasing. Thus, analysis of stem xylem water can be a valuable tool for detecting short-term variation in Cl− uptake. This method is important in trees since leaf analysis reflects the cumulative Cl− content and therefore does not always give the current transitory mineral uptake status. 相似文献
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Fabrício de Oliveira Reis Eliemar Campostrini Elias Fernandes de Sousa Marcelo Gabetto e Silva 《Scientia Horticulturae》2006
In papaya plants a study to quantify the water flow through the trunk is important for to promote a good water management in commercial orchard. The objective was to study the relationship between water flow through the trunk and temperature measurements determined by probes inserted in the papaya plant stem in laboratory. In addition, was possible to study the relationship between sap flow and instantaneous gas exchange in field conditions. We constructed an instrument that maintained a stable water flux through a 0.30 m stem section with a constant pressure, simulating the xylem sap flow through the stem. Water flux was adjusted by varying pressure of water in the stem section. The mathematical model used to fit the relation between K (Granier heat coefficient) values and sap flow density was the exponential model: u = 0.5511 × K1.9104. Field studies was conducted in a commercial orchard located in North of the State of Rio de Janeiro, with 12 plants in October 2002, and eight plants in January 2003. We verified that instantaneous transpiration, measured by a portable system of gas exchange (porometry), presented a good (R2 = 0.75) positive relationship with xylem sap flow. Estimates of papaya sap flow can be obtained by scaling portable photosynthesis system measurements with exposed leaves, however the relationship is non-linear in higher instantaneous transpiration rates. The causes of the non-linear relationship in higher transpiration are discussed. In addition, was possible to obtain a good (R2 = 0.76) relationship between net photosynthesis rate and xylem sap flow in papaya field-grown. 相似文献
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不同栽培袋材料对袋培黄瓜生长、产量及品
质的影响 总被引：1，自引：0，他引：1
以黄瓜品种津优30 为试材,以玉米秸秆∶牛粪∶炉渣=3V∶1V∶1V 为栽培基质,分别采用
底部（透水、不透水）编织袋、无纺布和双色膜为4 种栽培袋材料,进行日光温室黄瓜营养基质袋式栽培
试验,研究了不同栽培袋材料对黄瓜植株生长、伤流液、产量和品质的影响。结果表明：采用底部不透水
编织袋为栽培袋材料时,定值后40 d 及55 d 黄瓜的株高显著高于其他3 个处理,并且其植株地上部鲜质量、
地下部干质量、黄瓜伤流液中养分含量也显著高于其他3 个处理,果实可溶性蛋白、VC 含量都高于其他
处理。因此,底部不透水编织袋是适宜黄瓜袋培的栽培袋材料。 相似文献