核桃实生苗叶片养分含量及氮代谢关键酶活性对氮素水平的响应

以一年生核桃实生苗为试材,设置不同氮处理(N1:5g·株^-1、N2:10g·株^-1、N3:15g·株^-1和N4:20g·株^-1),以清水处理为对照(N0),研究了核桃实生苗株高、地径、叶片养分含量及氮代谢关键酶活性,以期为核桃实生苗生产过程中科学施肥策略的制定及养分的高效管理提供参考依据。结果表明:不同氮水平处理后核桃实生苗的株高、地径呈先升后降的趋势,阿克苏种源地与和田种源地核桃实生苗的株高、地径分别在N2、N3处理达到峰值。核桃实生苗叶片蛋白质含量及硝酸还原酶活性在不同处理下表现出先升后降的变化趋势,经N2处理后达到峰值,蛋白质含量分别为(A:26.2427mg·g^-1、H:25.4360 mg·g^-1)、硝酸还原酶活性分别为(A:34.9824μg·g^-1·h^-1、H:34.1990μg·g^-1·h^-1),均显著高于N0;同时,氮素促进谷氨酰胺合成酶活性的升高。氮素促进2个种源地核桃实生苗叶片中N、P、K元素的积累,当施氮量超过N3处理后P元素的积累被抑制,均显著高于对照,分别是对照的1.31倍和2.00倍。因此,氮素在核桃实生苗的生长发育过程中起着关键的作用,适宜的施氮量可促进核桃实生苗的生长、对氮素的同化以及营养元素含量的积累。     

基于主成分分析立地条件对核桃幼苗生长影响的研究

为探明不同立地条件对核桃幼苗生长的影响，以“辽宁1号”核桃种子为试验材料，应用主成分分析的方法，研究了不同立地条件土壤相关指标与核桃叶片营养元素的关系。结果表明，山坡(未改造)核桃叶片内的含磷量最高，山顶核桃幼苗叶片中铁元素含量较高；在核桃幼苗生长状况方面，山坡(客土)的核桃幼苗株高最高，山谷的核桃幼苗干径显著高于其他3种立地条件上的核桃幼苗。结合相关性分析得出，土壤中的钙、铜含量与核桃幼苗的发芽率呈显著正相关关系，铁含量与核桃幼苗的株高呈显著负相关关系，土壤中钙、铁、铜含量与核桃幼苗的干径呈显著正相关关系；土壤的pH与叶片中钾、钙的含量呈正相关关系，但与叶片中铁、锰、铜含量呈显著负相关关系，叶片中磷、钾、钙与土壤中磷含量呈显著正相关关系(P<0.05)。最后经过主成分分析得出，山谷的含水量、有机质及氮等矿质元素含量适中适宜核桃幼苗的生长，其次是山坡(未改造),然后是山坡(客土),最后是山顶。     

矮化中间砧对华红苹果致矮机理初探

试验研究了不同矮化中间砧对3年生华红苹果树生长势和叶片POD活性、IOD活性、可溶性糖含量、比叶重及净光合速率的影响。结果表明,不同矮化中间砧华红树体生长势依次为:SH38相似文献   

不同矮化砧木叶片酶活性与内源激素含量的差异

以乔化砧、半矮化砧、矮化砧3类矮化程度不同的苹果砧木为试材,研究比较了不同砧木叶片内酶活性及内源激素含量的差异.结果表明:不同矮化程度的砧木之间叶片内的POD(过氧化物酶)、IOD(吲哚乙酸氧化酶)活性差异较大,并且乔化砧木的酶活性显著低于半矮化、矮化砧木的酶活性;不同砧木间春季叶片内源激素IAA(生长素)、ABA(脱落酸)、GA(赤霉素)和ZR(玉米素)的含量差异较大,并且春季矮化砧木叶片的IAA/ABA比值显著低于半矮化与乔化砧木.因此,可以利用叶片内POD、IOD活性与春季叶片的IAA/ABA比值预测砧木的矮化性.     

菖蒲抗氧化系统保护酶对水体萘污染的响应

用人工配制不同浓度的含萘废水培养菖蒲,比较了其根部和叶片中超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和过氧化氢酶(CAT)活性的变化。结果表明:随着萘浓度的提高,菖蒲根部SOD活性显著下降,而叶片SOD活性极显著上升;根部POD活性上升不明显,但叶片POD活性极显著下降;根部和叶片CAT活性极显著或显著下降。菖蒲不同部位的不同抗氧化保护酶对萘污染的反应各不相同,叶片的反应要比根部更显著。     

紫玉兰对模拟酸雨的胁迫响应

以1a生盆栽紫玉兰实生苗为试验材料,采用人工模拟酸雨的方法观测酸雨胁迫时紫玉兰的生长情况及其生理响应。结果表明:pH 3.5是酸雨对紫玉兰叶片隐性伤害的临界点。在轻度酸雨(pH3.5)胁迫下,随着酸雨酸度增加,紫玉兰叶片内可溶性蛋白含量增加,超氧化物岐化酶(SOD)、过氧化物酶(POD)活性随酸度增加而增加;当pH3.5时,随酸度增加,可溶性蛋白含量有所下降,SOD、POD活性急剧下降。相关性分析表明,紫玉兰叶片内过氧化氢酶活性与丙二醛含量呈显著负相关。     

供磷水平对核桃苗木根系发育、幼苗生长及光合性能的影响

以当年生核桃实生苗为试材,采用土培方法,研究了不同供磷水平对核桃实生苗根系的形态和活力、苗木生长、叶绿素含量和光合性能的影响,为幼龄核桃栽培的磷养分管理提供科学依据。结果表明:核桃根系的长度、表面积、体积、直径及活力,苗木的高度与地径,叶绿素含量与光合性能均随磷肥施用量的增加呈显著增加的趋势,施磷量增至45 mg·kg~(-1)时以上指标达最大值,若再增加磷肥用量各指标呈逐渐下降的趋势。适量施用磷肥有利于提高核桃苗木根系的长度、表面积、体积和直径;显著增强了根系活力和吸收能力;极显著地促进了干物质累积和苗木生长;提高了苗木叶片叶绿素含量和光合性能,提升了核桃实生苗的同化能力。综合分析认为,施用45 mg·kg~(-1)的磷素时有利于培育出根系发达、生长迅速、光合能力强的核桃苗木。因此,在培育核桃实生苗时应采用该施肥标准进行磷肥管理。     

红托竹荪母种菌丝生长特性及胞外酶活性

采用木屑培养基培养红托竹荪(Dictyophora rubrovolvata)母种90d,培养过程中观察测定菌丝生长特性,从第40天开始测定5种胞外酶活性。结果表明:漆酶(laccase)和纤维素酶(cellulase,CL)活性较高,漆酶活性为31.2~52.7U/mL,CL活性为10.7~31.9U/mL;中性木聚糖酶(neutral xylanase,NEX)活性较低,为0.2~0.4U/mL;多酚氧化酶(polyphenol oxidase,PPO)和过氧化物酶(peroxidase,POD)活性分别为3.3~11.7U/mL和2.5~13.5U/mL。线性相关分析表明:母种菌丝生长状态、生长速度和胞外酶活性有相关性,菌丝变红程度与漆酶活性呈显著负相关,与POD活性呈极显著负相关,漆酶活性与生长速度呈显著正相关。     

不同坡度和不同坡向对金花茶生长量的影响

2015年从广西防城港引进1年生的金花茶扦插苗,2016年6月,在海南省屯昌县海南省枫木实验林场设计了不同坡度和不同坡向对金花茶生长指标影响的试验。结果表明,在缓坡种植时金花茶成活率、金花茶叶片增长量和地径增长量都显著高于在斜坡和平坡种植。种植在背阳处比向阳处的成活率较高;种植在背阳处时,株高增长量、叶片增长量和地径增长量较高。在不同的种植条件对比中,金花茶在更适宜在缓坡背阳条件下种植。     

方位及冠层对核桃内果皮木质素形成及相关酶活性的影响

【目的】明确核桃果实发育过程中不同光照强度对内果皮中木质素、相关酶活性影响的动态变化规律。【方法】以核桃品种’新新2号’为试验材料,研究了树冠不同方位、不同冠层对内果皮中木质素含量、相关酶活性的变化规律,并进行了相关性分析。【结果】在不同方位、不同冠层上,木质素含量随着核桃果实的生长发育呈持续增加趋势;PAL、POD酶活性强弱的排序依次为:南面上层>南面中层>南面下层>北面上层>北面中层>北面下层>中部上层>中部中层>中部下层;PPO酶活性强弱的排序依次为:北面下层>北面中层>北面上层>中部下层>中部中层>中部上层>南面下层>南面中层>南面上层。相关性分析表明,木质素含量与POD酶活性呈极显著正相关(p<0.01,r=0.808**),与PPO酶活性呈负相关。【结论】树冠南面和上层接受的光照强度最大,木质素含量最高,PAL、POD酶活性最强;PPO酶活性最低;木质素含量与POD酶活性呈极显著正相关(p<0.01,r=0.808**),表明光照强度诱导了核桃果实内果皮中木质素的积累及相关酶活性的增强。     

苹果新根生理生化特性研究

以盆栽３年生新红星／怀来海棠（Ｍａｌｕｓｍｉｃｒｏｍａｌｕｓ）为试材，研究了生长根和吸收根的还原能力、碳氮物质代谢、吲哚乙酸氧化酶（ＩＯＤ）、过氧化物酶（ＰＯＤ）和超氧化物歧化酶（ＳＯＤ）的周年动态变化。结果表明，两类新根均于春、夏、秋形成３次吸收高峰，但还原能力的高峰只于夏秋季出现，其中夏季高峰最大；淀粉、糖、蛋白质含量及ＩＯＤ、ＰＯＤ活性随新梢旺长而降低，随新梢缓慢或停止生长而积累，氨基酸含量、ＳＯＤ活性相反；吸收根的吸收能力、淀粉、糖、蛋白质含量、ＰＯＤ、ＩＯＤ活性均显著高于生长根，但吸收根中氨基酸含量、ＳＯＤ活性却小于生长根，因而两类新根的代谢特点和功能不同，其发生数量和比例影响树势和植株的生长发育     

Apple rootstock studies: growth of trees on three clonal rootstocks planted with or without roots

Trees of Cox's Orange Pippin on M.IXa, M.26 and MM. 106 were planted either normally with roots or without roots to simplify the planting operation. Pruning treatments were superimposed, the trees being cut back at planting, left unpruned the first year and cut back the second year, or left entirely unpruned. All trees survived. After two growing seasons the trees were lifted and weighed. Removal of all roots before planting reduced shoot growth, trunk girth increment, final tree weight and incremental weight. However, on all rootstocks, trees planted without roots and left unpruned were similar in size when lifted to those planted with roots and cut back at planting in the orthodox manner.

In a complementary trial lasting one season Cox's Orange Pippin trees on M.26 were planted with or without roots. All trees were cut back at planting, and four times of planting were compared. The mid-April planting included trees that had been stored at 2.8 °C and trees that had been bedded-in outdoors. There were no tree losses attributable to removal of the roots before planting. Removing the roots at planting again reduced growth and weight of tree at lifting. Month of planting had no effect upon shoot growth or trunk girth increment.

The results are discussed, together with their practical implications in relation to mechanical tree planting for high density orchards.     

发酵果树枝碎屑对苹果幼树根系特征及叶片光合蒸腾的影响

以2年生盆栽红富士苹果[Malus × domestica Borkh.‘Red Fuji’/Malus hupehensis Rehd.]幼树为试材,将苹果枝干碎屑发酵后施入盆土,定期调查苹果叶片光合与蒸腾速率、干周生长量、根系活力以及根系构型等指标。结果表明,向土壤施入质量比为2%和4%的发酵果树枝碎屑可以提高苹果幼树叶片净光合速率和根系活力,增加干周增长量,对叶片蒸腾速率和水分利用效率的影响不明显;2%的处理还能够增加新根数量,提高新根表面积和体积,促进新根加粗和加长生长,增大根系分形维数,促使根系结构复杂化,而施入4%的发酵果树枝碎屑则降低新根数量、体积和长度。综合分析表明,施用2%的发酵果树枝碎屑促进幼树根系和树干生长的整体效果好于4%的处理。     

Studies in Biennial Bearing II. A Review of the Literature

Apple trees were lifted at three-year intervals until 18 years after planting, and cut into constituent parts of roots, rootstock, trunk and branches. Pruning weights and crop were also recorded. Vegetative growth rate reached a peak before heavy cropping had started but, by half-way through the period, cropping dominated tree growth and eventually 80–85% of the trees’ accumulated fresh weight production was in crop. All the vegetative constituents of the trees were highly correlated with each other even when the age-of-tree effects were removed. However, removing the age-of-tree effects resulted in non-significant correlations between crop and vegetative variates. Trunk and rootstock weights were proportional to trunk girth², branch weight was approximately proportional to girth³, and roots had a relationship intermediate between those of trunk and branch. Crop was proportional to girth raised to a power between four and five.     

氮素浓度对“新温185号”核桃细根密度和分布的影响

以新疆核桃主栽品种"新温185号"为试材,通过设置不同施氮处理,采用根钻取样法和图像扫描分析法,对不同氮素供应水平下核桃细根(直径≤2mm)的空间分布和细根根长比例进行了研究。结果表明:在垂直方向上,细根根长密度随着土层深度的增加呈现出先增大后减小的变化趋势,0～70cm深度土层是"新温185号"核桃细根集中分布区域;在水平方向上,距离树干150cm以内是核桃细根集中分布区域,细根根长密度随着与树干距离的增加而减小;各施氮处理核桃细根根长密度显著高于对照,随着施氮量的增加,核桃细根根长密度和总根长中细根长度比例呈现出先升高后降低的变化趋势,表现为中氮处理(单株施氮量1.2kg)>高氮处理(单株施氮量1.8kg)>低氮处理(单株施氮量0.6kg)>对照(单株施氮量0kg)。"新温185号"核桃的栽培应加强距离树干150cm以内0～70cm深度土层的水肥管理,适量施氮能够促进细根形成,氮素亏缺和过量均不利于细根生长。     

不同油豆角品种过氧化物酶活性及其同工酶酶谱分析

应用过氧化物酶同工酶技术,通过相似系数比较和聚类分析,比较7个油豆角品种不同器官过氧化物酶(POD)的活性,并对其亲缘关系进行探讨。结果表明:不同品种POD活性不同,同一品种不同器官的POD活性也不同,根部的POD活性高于叶的,而叶片的高于茎的;不同器官POD酶谱不同,同一器官不同品种的酶带数也不尽相同;‘油豆子’、‘俏春大荚油豆王’和‘齐研五号架油豆’亲缘关系比较近;‘俏春3号地油’与‘油豆子’的亲缘关系最远。     

不同有机生态型基质配比对辣椒生长发育的影响

以菇渣、锯木屑和珍珠岩3种基质为材料,研究了其不同配比对辣椒生长发育的影响。结果表明,菇渣、锯木屑和珍珠岩的体积含量分别为30%、50%和20%,即3种基质的配比为3∶5∶2时,能显著促进辣椒的生长,增加株高和茎粗,促进叶片发育,提高叶绿素含量。同时还能明显增强叶片体内SOD（超氧化物歧化酶）和APX（抗坏血酸氧化酶）活性,但对POD（过氧化氢酶）和CAT（过氧化物酶）活性的影响则不大。     

Effect of Seed Coat Removal Treatments on Seed Germination and Seedling Attributes in Mango Varieties

A field experiment was carried out at the Indian Institute of Horticultural Research, Bengaluru during 2011–12 to study the effect of seed coat removal on seed germination and vigor of polyembryonic mango seedlings. In seed coat removal, the cultivar Muvandan recorded the maximum germination percent (85.4%), extent of polyembryony (2.76), and maximum number of leaves (10.3), whereas Bappakkai recorded maximum plant height (22.4 cm), stem girth (0.64 cm), leaf area (249.2 cm²), fresh weight (18.5 g) and dry weight (8.4 g), vigor index-I (1831.5 cm), and vigor index-II (685.7 g). With respect to treatments, seed coat removal was superior in all of the parameters, namely, initiation of germination (16.7 days), germination percent (78.3%), extent of polyembryony (2.50), plant height (19.5 cm), stem girth (0.62 cm), number of leaves per plant (8.7), leaf area (288.3 cm²), fresh weight (16.2 g) and dry weight (7.3 g), vigor index-I (1559.0 cm), and vigor index-II (581.8 g) compared to seed coat intact. There were no significant differences among the interactions of different treatments and cultivars.     

Apple Mosaic Viruses Host Reactions and Strain Interference

The annual growth of an apple tree in the vegetative condition is distributed in a definite pattern between leaves, stems and roots ; when a crop is borne, this constitutes an additional end-point for growth materials. The disturbances in the pattern of vegetative growth caused by this additional region of utilization are described. Two-year-old apple trees were deblossomed at flowering or defruited on 30th May, and their growth was compared with that of cropping trees. The increments in weight were estimated by samples taken at treatment times.

After deblossoming, the trees made extra growth in terms of dry weight, more and larger leaves, and longer stems. The periods of greatest and least growth were the same as for cropping trees. Defruiting also resulted in extra growth, but this came later, and so was out of phase with the growth of fruiting trees. This extra vegetative growth (including more trunk thickening and root growth as well as leaves and new shoots) weighed more than the crop on the fruiting trees. Defruiting had slightly less effect than deblossoming.

The diversion of metabolites to the crop changed the pattern of growth in the rest of the tree. Cropping trees had 50% more leaf proportionate to total vegetative increment, and 50% less root, than deblossomed ones. The intervening regions varied roughly according to their position. Despite this greater leafiness of cropping trees, they produced significantly more total dry matter (vegetative growth plus crop) per unit area of leaf.

These results are attributed to the greater demanding power of the growing crop in diverting photosynthates from the lower parts of the tree and in increasing the rate of removal of photosynthates from the leaves.