巨尾桉生理性缺硼症的诊断与防治

通过土壤和新梢的测试分析,确定巨尾桉生理性缺硼症除表现为“新梢畸形、上部枝条呈丛枝状,树皮爆裂、叶脉变粗”外,还可因同时缺锌表现为“主梢基部膨大,顶梢枯死,新梢韧皮部疏松、褐变”等症状。采用沟施硼砂(20g.株-1)或喷施0.1%硼酸溶液进行防治,效果良好,在定植前下基肥时补充硼砂(15g.株-1)和硫酸锌(10g.株-1)可有效预防该病的发生。     

Alleviation of alternate bearing phenomenon in mango (Mangifera indica L.) trees using boron and nitrogen fertilization

Abstract

This investigation was conducted during two successive seasons (2014/2015) and (2015/2016) using 15?years old productive mango (Mangifera indica) trees cv. Zebda. The trees were grown at AlMalak Valley Farm, El-Sharkeya Governorate- Egypt (30–51° North; 32–53° East). Trees were planted 8?×?8 meter within and between rows in sandy soil under drip irrigation system using the Nile water. The objective of this study is to alleviate alternate bearing in cv. Zebda using mineral nutrients (nitrogen in the on year and boron in the off year). Treatments included three concentrations of nitrogen (1000, 1250, 1500?g/tree/year) and three concentrations of boron (0.0, 250, 500?mg L^?1). Nitrogen was applied to the soil as ammonium sulfate and boron was applied as foliar spray of boric acid. The extra amount of nitrogen fertilizer (250 and 500?g N/tree) was applied at three installments in (May, June and July). Treatment was arranged in a factorial Completely Randomized Block Design with three replicates for each treatment. Results show that the on-year nitrogen fertilization significantly increased mango tree vegetative growth (number of shoot/branch, shoot length, shoot thickness, number of leaves/meter and leaf area) and yield. The average yield in the on year is 85.5?kg/tree at 1250?g N/tree but 67.4?Kilogram/tree at 1000?g N/tree (the control treatment). While in the off year boron foliar application resulted in a significant increase in flowering, initial fruit set, final fruit set and fruit yield. The average yield in the off year is 47?kg/tree at 250?mg L^?1 boron but 9?kg/tree at 0.0?mg L^?1 boron rate (the control treatment).The interaction treatment of 250?mg L^?1 boron + 1500?g nitrogen/tree is the best treatment as it resulted in the highest values for all the tested parameters. The average yield of this treatment is 53.5?kg/tree. This treatment helps alleviate alternate bearing phenomenon by 41% and obtain the highest economic yield in the off-year, i.e. increased yield by 5.9 fold.     

Boron-Calcium Synergically Alleviates Aluminum Toxicity in Wheat Plants (Triticum aestivum L.)

The effects of B and Ca treatments on root growth, nutrient localization and cell wall properties in wheat ( Triticum aestivum L.) plants with and without Al stress were investigated. Seedlings were grown hydroponically in a complete nutrient solution for 7 d and then treated with B (0, 40 μM), Ca (0, 2,500 μM), and Al (0, 100 μM) in a 500 μM CaCl₂ solution for 8 d. The cell wall materials (CWM) were extracted with a phenol: acetic acid: water (2:1:1 w/v/v) solution and used for subsequent pectin extraction with trans -1,2-diami-nocyclohexane- N,N,N,N -tetraacetic acid (CDTA) and Na₂CO₃ solutions. Boron, Ca, and B + Ca treatments enhanced root growth by 19.5, 15.2, and 27.2%, respectively, compared to the control (pH 4.5). Calcium and B+Ca treatments enhanced root growth with Al stress by 43 and 54%, respectively, while B did not exert any effect. The amounts of CWM and pectin per unit of root fresh weight increased by Al treatment, whereas the Ca and B+Ca treatments slightly reduced the contents of these components. Seventy-four percent of total B, 69% of total Ca, and 85% of total Al were located in the cell wall in the B, Ca, and Al treatments, respectively and 32% of total B, 33% of total Ca, and 33% of total Al were located in the CDTA-soluble and Na₂CO₃-soluble pectin fractions. A more conspicuous localization of B was observed in the presence of Al. Aluminum treatment markedly decreased the Ca content in the cell wall as well as pectin fractions, mainly in the case of the CDTA-soluble pectin fraction. Boron + Ca treatment decreased the Al content in the cell wall and pectin fractions compared to the Ca treatment alone in the presence of Al. It is concluded that the B+Ca treatment enhanced root growth and, B and Ca uptake, and helped to maintain a normal B and Ca metabolism in the cell walls even in the presence of Al.     

硅、镁、硼肥对甘蔗产量和产糖量影响的研究

在硅、镁、硼营养较缺乏的甘蔗田，进行硅肥、镁肥、磷肥的施肥效应试验，结果表明：硅、镁、硼肥及其不同施肥水平对甘蔗的株高、茎径、锤度、产量和产糖量有明显的影响。施用硅肥使甘蔗锤度、产量和理论产糖量分别比对照增加0.42～1．11，11．04～14．96t／hm^2和1．84～2．10t／hm^2；施用镁肥分别比对照增加0.93～1．26，4．02～9．55t／hm^2和0．99～1．53t／hm^2；施用硼肥分别比对照增加0．41～1．20，5．00～10．00t／hm^2和0．80～1．82t／hm^2。     

硼对棉花叶片解剖结构的影响

在土培条件下,研究了缺硼和硼中毒对棉花叶片解剖结构的影响。结果表明:缺硼真叶及子叶的叶脉维管束明显增长,输导组织严重受损,细胞畸形,细胞数显著增加,且叶片加厚,但栅栏组织所占比例及其细胞中的内含物减少并解体,导致总叶绿粒和线粒体降低,可能是减弱光介强度的重要原因之一。硼中毒仅影响叶缘及叶尖的解剖结构,表现为栅栏细胞叶绿粒减少,海绵细胞衰老坏死,表皮细胞排列紊乱、缺硼及硼中毒对解剖结构的变化与外观症状一致。     

不同硼效率油菜品种细胞壁果胶硼的结合位点

用果胶酶水解油菜上部叶细胞壁中提取的果胶，用二乙氨乙基(DEAE)—琼脂糖(Sepharose)色谱柱层析分离含硼化合物，研究硼在不同硼效率甘蓝型油菜品种(Brussica na pus)细胞壁果胶中的结合位点。结果表明：硼在不同油菜品种、不同提取剂提取的果胶酶解液中均只有1个色谱峰，该峰与鼠李半乳糖醛酸聚糖-Ⅱ(RG-Ⅱ)的特种糖残基-3-脱氧-D-甘露-2-辛酮糖酸(KDO)色谱峰重合，所有酶解液中硼和KDO出峰的位置基本相同，只是峰的高低不同，证明RG-Ⅱ可能是硼在油菜细胞壁中的唯一结合位点，RG-Ⅱ在不同油菜品种细胞壁中的结构基本相同，但含量不同。     

油菜的硼素效应研究

本文以杂交油菜秦油二号（F1）和常规油菜中油821为试材，以第四纪红土发育的三熟制稻田土为研究对象，较系统地考察了硼素对油菜的生理、生物学和品质效应，结果表明：施硼能极显著地提高根系活力和降低叶片的细胞透性；能有效地提高叶绿素含量，增加叶片厚度和叶片气孔数；有效角果数、角果表观粒数和含油量显著增加，增产效果达极显著水平；对菜籽品质有不同程度的影响，但正负效应随品种（组合）而异，施硼的副效应均主要表现在千粒重显著减小和菌核病成倍增加。     

不同硼营养下甘蓝型油菜体内游离氨基酸成分变化分析

本文研究了不同供硼水平（缺硼、正常供硼、硼过量）对油菜幼苗叶片及花药内游离氨基酸成分的影响。实验结果表明，缺硼和硼过量都会造成植株生长异常，幼苗干物重显著下降，植株幼苗叶片与花药内蛋白水解酶的活性升高，而游离氨基酸总量增加，同时，氨基酸的组分也发生了明显的变化。不适宜供棚（缺硼、硼过量）使幼苗叶片内辅氨酸含量明显升高，与之相伴随的是一些氨基酸含量的下降，而花药内脯氨酸含量有所减少。     

条施调酸材料对石灰性土壤调酸及马铃薯锌硼吸收的影响

【目的】研究条施调酸材料的调酸效应及其对马铃薯锌、硼吸收的影响,为调酸材料在马铃薯上的应用提供依据。【方法】以马铃薯为材料,采用田间试验,设置根区施用磷酸一铵（MAP）、硫磺(S)、混合调酸剂(磷酸一铵和硫磺按质量比1∶1混合,MS）,以不施用调酸材料为对照,分析调酸材料施入石灰性土壤后土壤pH值、锌硼有效性以及马铃薯叶片、块茎锌硼含量的变化,研究3种调酸材料根区条施后的调酸效应及对土壤锌硼有效性和马铃薯锌硼吸收的影响。【结果】施入调酸材料能显著降低石灰性土壤pH值,在马铃薯整个生育期调酸效应总体表现为MS＞MAP＞S。施用调酸材料能提高淀粉积累期马铃薯根区土壤有效锌和有效硼含量,MAP、S、MS处理土壤有效锌含量较对照分别提高了58.82%,9.80%和37.25%,土壤有效硼含量较对照分别提高了53.01%,57.83%和61.45%。施用调酸材料后,苗期马铃薯叶片锌、硼积累量分别增加了48.44%~60.83%和40.73%~58.68%,块茎膨大期分别增加了31.43%~39.88%和22.40%~33.06%;在淀粉积累期,MS和S处理马铃薯叶片锌积累量较对照分别降低了51.85%和30.25%,而MAP处理则较对照增加了4.79%,MAP、S、MS处理马铃薯叶片硼积累量较对照分别减少了20.67%,41.78%和38.21%。收获期施用调酸材料后,MAP、S、MS处理马铃薯块茎锌含量较对照分别降低了9.47%,4.94%和14.81%,S、MS处理马铃薯锌积累量较对照分别降低了5.88%和21.08%,而MAP处理提高了30.39%;MAP、S、MS处理马铃薯块茎硼含量较对照分别提高了14.97%,15.51%和63.10%,硼积累量分别提高了67.74%,16.13%和51.61%。【结论】调酸材料降低了石灰性土壤pH值和马铃薯块茎锌含量,但提高了马铃薯块茎硼含量;从调酸效应和马铃薯块茎吸收来看,磷酸一铵与硫磺配施最有利于马铃薯对土壤中微量元素锌硼的利用。     

Boron toxicity of strawberry

Abstract

Radlands Crimson strawberries were grown in a glasshouse with 7 rates of applied boron. Wood shavings mulches with different boron concentrations were also applied as separate treatments. Boron toxicity symptoms were produced in leaves by boron rates of 0.32 kg ha^‐1 and greater on a soil containing 1.6 ug B g^‐1 of hot water extractable boron. Concentrations greater than 123 μg B g^‐1 in old leaves were associated with boron toxicity symptoms.

In the B rate experiment, soil boron concentrations greater than 1.9 μg B g^‐1 soil were associated with leaf toxicity symptoms which increased in severity with increasing soil boron concentrations up to 4.1 μg B g^‐1 soil. Wood shavings mulch containing 17 μg B g^‐1 caused boron toxicity symptoms in older leaves whereas mulches containing less than 6 μg B g^‐1 did not produce toxicity symptoms.