油橄榄落吉规律及与氮素营养相关性研究

在我国油橄榄叶片寿命比原产地要短，为１－２年，落叶高峰期为１１月初至１２月底，而且不同年份落叶率有显著差异，施氮肥能显著降低油橄榄落叶率，但各施氮量之间差异不显著，落叶前叶片氮素营养水平极显著影响落叶率。     

油橄榄插穗二次处理生根研究

对已扦插50 d未生根的油橄榄插穗进行二次生根剂处理,研究了落叶后抽芽插穗的生根能力。结果表明,油橄榄叶片凋落抽芽后仍具有生根能力,6%B12+2%根旺处理3 h后扦插40 d,生根率可达51.1%,平均不定根数量为2.5条,平均不定根长1.2 cm,根系效果指数为0.103。油橄榄冬春季扦插易落叶,导致推迟生根或不生根,二次处理可以大幅度提高生根率,缩短育苗周期。油橄榄扦插育苗宜选择在夏秋季节进行。     

十堰市引种栽培油橄榄品种的叶片与果实表型性状分析

以十堰市引种栽培的6个不同油橄榄品种为研究对象,测定各品种的叶片及果实表型性状，采用方差分析比较不同油橄榄品种间的性状差异，采用Person相关分析研究各表型性状间的相关性，研究结果表明：不同油橄榄品种间的叶片及果实表型性状存在显著差异，‘皮削利’、‘鄂植-8号’和‘云台’果实较大，‘豆果’、‘阿尔波萨纳’与‘奇迹’果实较小；部分表型性状间相关性显著，可根据叶片性状初步筛选果肉率高的优良品种,为油橄榄品种鉴别及良种选育提供依据。     

油橄榄落叶过程中氧自由基和多胺含量的变化规律

油橄榄是原产地中海沿岸地区的重要木本油料树种。我国从１９６４年开始大面积引种，但在我国的主要引种栽培区，落叶很严重，即使１年生叶，当年冬天也开始落叶，影响了油橄榄开花座果和果实发育。油橄榄的落叶高峰期为１１月初至１２月底，叶片寿命为１～２年，而在原产...     

枝梢环剥对油橄榄莱星品种果实产量及叶片光合作用的影响

[目的]研究冬季半休眠期枝梢环剥对油橄榄成花、坐果及叶片碳氮营养、光合作用的影响,探讨环剥技术对油橄榄大小年结果的调控作用及环剥后较长时期内叶片光合作用调控机制.[方法]以16年生油橄榄'莱星'典型的大、小年树为试验材料,研究了冬季半休眠期枝梢环剥对油橄榄成花、坐果及叶片碳氮营养、光合作用的影响.[结果]冬季半休眠期枝梢环剥可显著提高油橄榄大、小年树次年花芽形成率和早期坐果率(花后30天),但对最终的坐果率、单个果实干鲜质量和果实产量无明显影响.环剥后30天,叶片可溶性糖含量显著升高,叶片淀粉含量明显升高,叶片全氮含量显著下降,叶片碳氮比值显著升高;叶片净光合速率(P_n)和气孔导度(G_s)显著下降,叶片胞间CO₂浓度(C_i)基本未变.之后,随处理时间延长,叶片中可溶性糖和淀粉含量积累效应基本消失时(处理后120 d),叶片P_n和G_s仍显著低于对照,叶片C_i显著高于对照.[结论]冬季半休眠期枝梢环剥可促进油橄榄成花,但果实产量无显著提高;莱星品种明显的结实大小年节律可能主要决定于其品种的发育节律和遗传本身.环剥后短期内叶片P_n的下降应与叶片中可溶性糖和淀粉积累有关.     

不同形态外源氮对马尾松与广玉兰落叶分解的影响

以马尾松及广玉兰落叶为试验材料,以浓度均为75 mg/kg的NH_4Cl、KNO_3、NH4NO_3溶液为试验处理液,采用分解袋方法,通过对落叶施加不同形态外源氮的方式模拟氮沉降,研究不同形态外源氮对马尾松及广玉兰落叶分解的影响。结果表明:施加外源氮素可以促进落叶的分解,外源氮对不同树种落叶分解的促进效果不同;广玉兰落叶在外源氮处理后分解率增加更为明显,161天后其各处理分解率均在马尾松落叶分解率的1.2倍以上。氮源形态对马尾松、广玉兰落叶分解率的影响均达极显著(马尾松F=1 262.9 P0.01,广玉兰F=165.3 P0.01),其中硝态氮处理效果最好,161天后马尾松和广玉兰落叶的分解率分别为9.79%和13.02%。分解时间对马尾松与广玉兰落叶分解率的影响均达极显著。     

6个油橄榄品种叶片解剖结构与抗旱性综合评价

为研究不同品种油橄榄叶片解剖结构的差异以及油橄榄叶片解剖结构与抗旱性的关系,以6个品种油橄榄的叶片为研究对象,根据不同品种叶片解剖结构特征及其栅海比、叶片紧密度等指标,观察研究了6个品种叶片的解剖结构,并采用模糊隶属函数和系统聚类法进行分析。结果表明:6个油橄榄品种抗旱能力表现强弱顺序为柯基﹥金叶佛樨榄﹥鄂植﹥佛奥﹥科拉蒂﹥软阿斯。     

不同调控措施对油橄榄促花保果的影响

为了寻找适合油橄榄促花保果的调控技术措施,以昆明市海口林场1964年从阿尔巴尼亚引种的油橄榄为试验对象,比较分析油橄榄在水肥管理、喷施植物生长调节剂、人工授粉单项及综合调控处理下的花果指标和果实性状的差异,探讨影响油橄榄开花结果的原因。结果表明,人工授粉调控和综合调控对油橄榄的花序数、花枝数、成花率、花枝率、幼果数、熟果数均有明显的提升作用。不同调控处理均显著提高了油橄榄的坐果率,水肥调控显著提高了油橄榄的果肉率。此外,油橄榄在果实成熟过程中均出现了明显的落果现象,但在不同调控处理下的落果效应比对照有所减轻。     

土壤含水量对油橄榄品种生长和结实的影响

【目的】分析土壤含水量对不同品种油橄榄生长和结实的影响,为油橄榄高效栽培提供理论依据。【方法】采用2因素4区组设计,观测土壤和含水量对3个油橄榄品种（豆果（C1）、田园1号TIANYUAN-1(C2)和柯基（C3））生长、生理和结实特性的影响。【结果】相对含水量不同的土壤中,3个参试油橄榄品种的生长、生理和结果指标差异均达极显著水平（P <0.01）。多重比较结果表明,不同土壤含水量对油橄榄品种的平均须根数、平均地径、平均新梢长度、平均叶片相对含水量、平均鲜果相对含水量和平均单株鲜果产量的影响,各水平之间差异均达显著水平（P <0.05）,对平均单果重的影响各水平之间差异不显著（P> 0.05）,说明油橄榄的生长指标（须根数、地径、新梢长度）和结果指标（单株鲜果产量）受不同土壤含水量和油橄榄品种两个因素的影响,而单果鲜重不受土壤相对含水量的影响。4个处理中,3个油橄榄品种豆果、田园1号和柯基的生长指标（平均须根数、平均地径、平均新梢长度）、生理指标（平均叶片相对含水量、平均鲜果相对含水量）和结果指标（平均果径、平均鲜果百粒重、平均单株鲜果产量）增长值顺序均为A2>...     

甘肃油橄榄园土壤养分丰缺状况

为了给油橄榄园土壤管理和合理施肥提供参考,通过对陇南白龙江沿岸低山河谷地区有代表性的126个油橄榄园的土壤进行取样测定,在前人研究的基础上,确定了甘肃油橄榄园土壤养分标准,并用该指标评价了果园土壤养分肥力的丰缺情况。结果表明:陇南油橄榄产区土壤肥力普遍存在的问题是有机质含量低,碱解氮、有效磷和速效钾亏缺,且各营养元素之间存在不同程度的差异;土壤p H值对土壤养分有效性影响较大,土壤p H值与有机质、碱解氮、有效磷含量呈显著或极显著负相关。     

氮素营养对枣树花和果实生长发育的影响研究

本文研究了氮素营养对枣树花和果实生长发育的影响，不同器官氮素水平有明显的季节变化规律，施氮肥不影响这种变化规律，但能提高各期不同器官的氮素水平，蕾期至盛花期叶片氮素水平极显著地影响枣花数量和质量。施氮肥能延长开花持续时间和座果时间，提高座果率，但施氮肥宜早，施氮肥对果实生长发育规律基本无影响，但能提高其生长速度，降低落果率。     

枣树生长发育前期高效叶面肥料的筛选

本试验就叶面肥料对枣树生长发育前期的影响进行了研究,结果表明:叶面施肥可增加枣树叶片厚度、叶面积、百叶重、花序数、枣吊长度及叶片数等。各种叶面肥的效果不尽相同,其中,"植物氨基酸液肥"的效果最好,"植物营养活力液"次之;矿质肥也有一定的效果。本文就枣树年周期中发育前期的发育特点及适宜的叶面肥料进行了讨论,并总结了叶面肥对不同指标的影响顺序。     

Competition control in juvenile hybrid poplar plantations across a range of site productivities in central Saskatchewan,Canada

The response of hybrid poplar plantations established on former agricultural land in Saskatchewan to competition from weeds on a range of site productivities was studied. The short-term impact of competition control on the growth of juvenile trees and how tree responses to competition control differed across the productivity gradient was of particular interest, as was the determination of which resource was most highly competed for and was most important in determining tree growth. Eight sets of paired plots in juvenile hybrid poplar plantations were established in central Saskatchewan across a range of site productivities. In each pair, one plot had complete weed control (weed-free) while in the other plot weeds were allowed to grow. The best soil predictor of tree growth was soil texture, represented by a combination of the percentage silt and clay, with finer textures showing better growth. Competition control significantly increased tree growth on all sites with the benefit being greatest on the higher productivity sites. Soil water appeared to be highly competed for between trees and weeds and was a dominant resource controlling growth. For soil nutrients, nitrogen and phosphorous were highly competed for between trees and weeds. However, leaf phosphorous concentration of the weed-free plots had a strong positive relation to tree growth while nitrogen did not, indicating that when trees are free of competition they can access sufficient nitrogen from these soils.     

Preformation in vegetative buds of Prunus persica: factors influencing number of leaf primordia in overwintering buds

We investigated the influence of bud position, cultivar, tree age, tree carbohydrate status, sampling date, drought and light exposure on the number of leaf primordia formed in dormant vegetative peach buds (Prunus persica (L.) Batsch) relative to the number of primordia formed after bud break (neoformed). During winter dormancy, vegetative peach buds from California and Italy were dissected and the number of leaf primordia recorded. Between leaf drop and bud break, the number of leaf primordia doubled from about five to about 10. Parent shoot length, number of nodes on the parent shoot, cross-sectional area of the parent shoot, bud position along the parent shoot and bud cross-sectional area were correlated with the number of leaf primordia. Previous season light exposure, drought and tree carbohydrate status did not affect the number of leaf primordia present. The number of leaf primordia differed significantly among peach varieties and tree ages at leaf drop, but not at bud break. Our results indicate that neoformation accounted for all shoot growth beyond about 10 nodes. The predominance of neoformed shoot growth in peach allows this species great plasticity in its response to current-season conditions.     

The ecological and functional correlates of nocturnal transpiration

Contrary to the conventional theory of optimal stomatal control, there is substantial transpiration at night in many tree species, but the functional significance of this phenomenon remains uncertain. To investigate the possible roles of nocturnal transpiration, we compared and contrasted the correlations of both nocturnal and diurnal sap flow with a range of traits in 21 temperate deciduous tree species. These traits included soil water affinity, shade tolerance, cold hardiness, nitrogen concentration of tissues, minimum transpiration rate of excised leaves, growth rate, photosynthetic capacity, stomatal length and density, and the water potential and relative water content of leaves at the wilting point. Nocturnal sap flow was higher in species with higher leaf nitrogen concentrations, higher rates of extension growth and lower shade tolerances. Diurnal sap flow was higher in species with higher leaf nitrogen concentrations and photosynthetic capacities on a leaf area basis. Because leaf metabolism and dark respiration, in particular, are strongly related to leaf nitrogen concentration, our findings suggest that nocturnal transpiration functions to sustain carbohydrate export and other processes driven by dark respiration, and that this function is most important in fast- growing shade-intolerant tree species.     

Photosynthetic light acclimation in peach leaves: importance of changes in mass:area ratio, nitrogen concentration, and leaf nitrogen partitioning

Photosynthetic light acclimation of leaves can result from (i) changes in mass-based leaf nitrogen concentration, Nm, (ii) changes in leaf mass:area ratio, Ma, and (iii) partitioning of total leaf nitrogen among different pools of the photosynthetic machinery. We studied variations in Nm and Ma within the crowns of two peach (Prunus persica L. Batsch) trees grown in an orchard in Portugal, and one peach tree grown in an orchard in France. Each crown was digitized and a 3-D radiation transfer model was used to quantify the intra-crown variations in time-integrated leaf irradiance, . Nitrogen concentration, leaf mass:area ratio, chlorophyll concentration, and photosynthetic capacity were also measured on leaves sampled on five additional peach trees in the orchard in Portugal. The data were used to compute the coefficients of leaf nitrogen partitioning among carboxylation, bioenergetics, and light harvesting pools. Leaf mass:area ratio and area-based leaf nitrogen concentration, Na, were nonlinearly related to , and photosynthetic capacity was linearly related to Na. Photosynthetic light acclimation resulted mainly from changes in Ma and leaf nitrogen partitioning, and to a lesser extent from changes in Nm. This behavior contrasts with photosynthetic light acclimation observed in other tree species like walnut (Juglans regia L.) in which acclimation results primarily from changes in Ma.     

Temporal changes in litterfall, litter decomposition and their chemical composition in Sasa dwarf bamboo in a natural forest ecosystem of northern Japan

We investigated the dynamics of litterfall and litter decomposition of Sasa dwarf bamboo (Sasa senanensis) and trees to clarify the characteristics of organic matter and nitrogen cycling between plant and soil in a natural cool-temperate mixed forest ecosystem dominated by an understory vegetation of Sasa. Mean annual Sasa litterfall over the 3-year study period was 164 g m^?2 year^?1, which accounted for approximately 29% of total litterfall. Litter decomposition of Sasa leaf and Sasa culm was significantly slower than that of tree leaf during first and second years. The slow decomposition rates of both Sasa litter types were caused by a significantly higher silicate than in tree leaf. Nitrogen concentration in litter increased as decomposition progressed, especially in Sasa leaf and tree leaf. As a result of the slow decomposition of both Sasa litter types, 111 and 73% of nitrogen to the initial amounts were retained in Sasa leaf and Sasa culm after 3 years, respectively. The amounts of retained nitrogen in Sasa leaf, Sasa culm, and tree leaf after 3 years were 1.29, 0.47, and 3.92 g N m^?2, respectively, indicating that the differences of litter decomposition rates among the litter types influence on the nitrogen cycling in forest ecosystem through the differences of the nitrogen release from litter.     

Interactive effects of nitrogen and water availabilities on gas exchange and whole-plant carbon allocation in poplar

Cuttings of balsam spire hybrid poplar (Populus trichocarpa var. Hastata Henry x Populus balsamifera var. Michauxii (Dode) Farwell) were grown in sand culture and irrigated every 2 (W) or 10 (w) days with a solution containing either 3.0 (N) or 0.5 (n) mol nitrogen m(-3) for 90 days. Trees in the WN (control) and wn treatments had stable leaf nitrogen concentrations averaging 19.4 and 8.4 mg g(-1), respectively, over the course of the experiment. Trees in the Wn and wN treatments had a similar leaf nitrogen concentration, which increased from 12.0 to 15.8 mg g(-1) during the experiment. By the final harvest, mean stomatal conductances of trees in the wN and wn treatments were less than those of trees in the Wn and WN treatments (1.8 versus 4.6 mm s(-1)). Compared to the WN treatment, biomass at the final harvest was reduced by 61, 72 and 75% in the Wn, wN and wn treatments, respectively. At the final harvest, WN trees had a mean total leaf area of 4750 +/- 380 cm(2) tree(-1) and carried 164 +/- 8 leaves tree(-1) with a specific leaf area of 181 +/- 16 cm(2) g(-1), whereas Wn trees had a smaller mean total leaf area (1310 +/- 30 cm(2) tree(-1)), because of the production of fewer leaves (41 +/- 6) with a smaller specific leaf area (154 +/- 2 cm(2) g(-1)). A greater proportion of biomass was allocated to roots in Wn trees than in WN trees, but component nitrogen concentrations adjusted such that there was no Wn treatment effect on nitrogen allocation. Compared with WN trees, rates of photosynthesis and respiration per unit weight of tissue of Wn trees decreased by 28 and 31%, respectively, but the rate of photosynthesis per unit leaf nitrogen remained unaltered. The wN and Wn trees had similar leaf nitrogen concentrations; however, compared with the Wn treatment, the wN treatment decreased mean total leaf area (750 +/- 50 cm(2) tree(-1)), number of leaves per tree (29 +/- 2) and specific leaf area (140 +/- 6 cm(2) g(-1)), but increased the allocation of biomass and nitrogen to roots. Net photosynthetic rate per unit leaf nitrogen was 45% lower in the wN treatment than in the other treatments. Rates of net photosynthesis and respiration per unit weight of tissue were 48 and 33% less, respectively, in wN trees than in Wn trees.     

Fertilization Response on Growth,Photosynthesis, Starch Accumulation,and Leaf Nitrogen Status of Cassia siamea Lam. Seedlings Under Nursery Conditions

Abstract

Nitrogen, phosphorus, and potash fertilizers in eight treatment combinations, including an unfertilized control treatment were given to Cassia siamea seedlings under nursery conditions. This study was carried out to identify the physiological basis of varying growth response due to fertilization. Nitrogenous fertilizer application increased seedling growth, whereas application of phosphorus or potash fertilizers, either separately or in conjunction, did not improve seedling growth. Starch level had increased considerably whenever there was decline in the leaf nitrogen status, even though the photosynthetic rate was reduced drastically. Starch concentration remained significantly higher in leaves of seedlings which showed poor growth because of treatment effects. Vector analysis of nitrogen concentration, content, and dry mass allowed simultaneous comparison of leaf nitrogen status. This analysis showed that nitrogenous fertilizer application signified dilution effect. P-fertilizer application alone leads to N-deficiency and in PK-fertilizer application, vectors shifted into a region of antagonistic effect. These results are useful in evaluating woody seedlings growth response due to fertilizer management under nursery conditions.     

毛竹叶片生物量、养分及与土壤的耦合特征

叶片对植物的生长、发育和生活史的完成具有极其重要的作用,叶生物量(叶量)及其养分含量将直接影响树体对光能的接收与利用,而土壤为植物的生长发育提供了所需的养分元素。本研究对不同年龄毛竹的叶量、叶片和土壤养分含量及其相互关系进行了研究。结果表明:(1)毛竹叶量随着径阶的增大而增大。(2)5块样地中,样地1和3的毛竹叶量明显高于其他3块样地,样地4的毛竹叶量最小。(3)毛竹叶片中镁含量随着年龄的变化差异不显著(p>0.05);氮、总磷、有机磷、钾、钙含量在1度毛竹叶片与其他年龄毛竹叶片含量差异显著(p<0.05);2度以上各年龄毛竹叶间氮含量差异显著(p<0.05);毛竹叶无机磷含量仅1度竹叶与4度竹叶含量差异显著(p<0.05);叶片中的氮磷比值(N/P)随年龄增加先增大后减小;相同年龄不同径阶毛竹的叶片养分含量虽有变化却不存在显著差异(p>0.05)。(4)竹叶中氮含量与有机磷、全磷、钾、钙含量呈极显著相关(p<0.01);总磷、无机磷、有机磷含量与钙、钾含量显著相关(p<0.05);钾与钙含量呈极显著负相关(p<0.01)。(5)毛竹林土壤pH值与叶片镁含量显著负相关(p<0.05);土壤中镁含量与叶片中钙含量显著负相关(p<0.05),而与叶片全氮、总磷、有机磷、镁含量呈极显著负相关(p<0.01)。