硼对不同硼效率甘蓝型油菜品种细胞壁组成的影响

采用营养液培养技术 ,研究B对不同B效率油菜品种细胞壁组成的影响。结果表明 ,根系细胞壁提取率及细胞壁纤维素含量高于叶片 ,果胶含量低于叶片 ,半纤维素含量和叶片差异不大。缺B使细胞壁提取率升高 ,但对根系和叶片细胞壁组成的影响不显著。不同B效率油菜品种细胞壁组成在根系和下部叶中差异不大 ,上部叶片高效品种螯合剂可溶性果胶含量显著高于低效品种 ,碱溶性果胶含量显著低于低效品种 ;半纤维素和纤维素含量及果胶总量差异不大     

不同硼效率棉花品种木质部和韧皮部汁液中矿质养分的差异

溶液培养条件下研究硼对2个硼效率不同的棉花品种木质部、韧皮部中硼及其它矿质养分运输的影响。结果表明,缺硼使2个棉花品种木质部汁液硼含量及溢出量明显降低,低效品种降低幅度大于高效品种。供硼充足(0.5mg/L)时,2个棉花品种木质部汁液中硼浓度均小于培养液中硼浓度;缺硼(0.002mg/L)时,高效品种与低效品种木质部汁液硼浓度分别是培养液硼浓度的32.0和20.5倍。缺硼使2个棉花品种木质部汁液中钾、锰、铜、锌含量均升高,高效品种升高幅度较大;钙含量均降低,低效品种降低幅度较大;高效品种镁含量增高,低效品种降低。而2个棉花品种木质部各养分(钾、镁、钙、锰、铜、锌)溢出量均降低,低效品种降低更明显。无论在缺硼或供硼充足时,2个棉花品种韧皮部中硼浓度均极低,但韧皮部溢泌液中其它养分受缺硼影响品种间表现不同,高效品种韧皮部钾、镁、锰、铜溢出量升高,低效品种则降低;2个品种钙、锌溢出量均降低,低效品种降低幅度更大。     

缺硼对脐橙幼苗硼分配及叶片细胞壁组分硼含量的影响

【目的】 硼在维持细胞壁正常结构方面具有重要的作用,前期结果证实缺硼严重的脐橙叶片细胞壁结构改变程度也更大,但这种变化与细胞壁组分中硼的含量变化是否有关尚不清楚。本研究通过分析缺硼对脐橙幼苗各部分硼分配及叶片细胞壁组分硼含量的影响,明确缺硼症状表现及细胞壁结构变化程度与细胞壁各组分中硼含量变化之间的关系。 【方法】 以纽荷尔脐橙幼苗为试材,利用营养液培养方法进行缺硼处理,测定根、砧木茎、接穗茎、上部叶、下部叶、叶片细胞壁以及细胞壁各组分硼含量的变化情况。 【结果】 缺硼处理9周后上部叶出现叶片卷曲及叶片失绿等症状,而下部叶没有出现任何可见的症状。缺硼处理的脐橙幼苗各部位硼含量和硼吸收量均显著降低,缺硼降低了硼向地上部的相对分配比例且上部叶受到的影响程度更大。在硼正常供应条件下,上部叶和下部叶游离态硼、原生质体硼和细胞壁硼的含量和相对分配比例没有显著差异,说明硼在不同类型脐橙叶片细胞各组分中的分配是相对稳定的。缺硼后水溶性硼 (包括游离态硼和原生质体硼) 在脐橙上部叶和下部叶中都降到极低的水平,尤其是原生质体硼百分含量下部叶甚至是低于上部叶的。缺硼后细胞壁硼占总硼的比例则由22%左右增加到80%以上。与叶片中硼含量的变化趋势一致,缺硼以后虽然上部叶和下部叶细胞壁硼含量都显著降低,但上部叶降低的程度远大于下部叶。进一步分析细胞壁组分硼含量变化,发现缺硼显著降低了上部叶细胞壁中离子结合态果胶硼含量而对下部叶的无明显影响,其他组分硼含量的变化趋势下部叶和上部叶一致。 【结论】 原生质体硼含量的高低并不是决定缺硼症状的主要因素,离子结合态果胶与硼的结合能力对缺硼条件下细胞壁的结构及缺硼症状表现起着至关重要的作用。      

采用嫁接试验探讨不同甘蓝型油菜品种硼效率差异机理初报

溶液培养条件下,比较研究不同B效率甘蓝型油菜品种及其相互嫁接植株苗期对B吸收分配的差异.试验表明,缺B胁迫明显降低高效、低效油菜品种及其相互嫁接植株地上部B含量和累积量,高效品种降低幅度明显小于低效品种,两者相互嫁接植株降低幅度均居于高效品种与低效品种之间.无论缺B与否,高效品种和以高效品种为砧木的植株地上部B分配率分别有高于低效品种和以低效品种做砧木植株的趋势.推断甘蓝型油菜品种B效率差异是由根系吸收能力以及向地上部运输能力共同作用的结果.     

硼对不同硼效率棉花品种苗期叶片膜脂过氧化和多胺含量的影响

土培条件下研究缺硼对不同硼效率棉花品种苗期叶片膜伤害、保护酶活性及多胺化合物含量的影响。结果表明 ,遭受缺硼胁迫时 ,两棉花品种叶片膜透性和丙二醛含量增加 ,膜脂肪酸不饱和度下降 ,保护酶SOD、POD、CAT活性降低 ,但硼高效品种变化幅度比低效品种小。缺硼还导致两品种叶片中腐胺 (Put)含量显著降低 ,而低效品种降低幅度更大 ,但缺硼使高效品种叶片中精胺 (Spm)、亚精胺 (Spd)含量及多胺总量 (Spd +Spm +Put)显著升高 ,低效品种仅有升高趋势。推测硼高效品种在缺硼条件下保持较高的多胺含量是其保护酶活性较高、膜受伤害程度较轻的原因之一。     

不同硼效率甘蓝型油菜苗期对硼镁营养的反应

利用溶液培养研究硼低效和高效甘蓝型油菜(Brassica.napus)苗期对硼镁营养的反应。结果表明,低硼浓度下提高镁时,油菜的生长受影响不大,硼含量和累积量降低,镁含量和累积量及叶绿素上升。低镁浓度下提高硼时,油菜镁含量、镁积累量降低,且硼低效品种降低幅度大于硼高效;叶绿素降低幅度则硼高效大于硼低效品种。高硼浓度下提高镁时,硼镁含量和累积量及叶绿素含量均提高,提高幅度为硼高效品种大于低效品种。高镁浓度下提高硼时,硼镁表现出显著的相互促进,硼高效品种促进效应大于低效品种。在很大程度上镁影响油菜叶绿素a的含量,而硼影响油菜叶绿素b的含量。硼镁营养对锌含量无大的影响;在低镁浓度下,油菜低效品种锰含量显著增加。无论是低镁或高镁浓度下提高硼,硼高效和低效品种铁含量均有所增加,低效品种增加显著。     

不同硼效率棉花品种根系参数和伤流液组分的差异

溶液培养条件下研究硼对不同硼效率棉花品种根系参数、伤流量及伤流液组分的影响。结果表明,缺硼抑制棉花根系生长,根重、根体积、根长、活跃吸收面积、总吸收面积、活跃吸收面积占总吸收面积的比例以及伤流量均显著降低,高效品种降低幅度比低效品种小;缺硼还使高效品种根系比表面积升高,而低效品种无显著变化。缺硼显著影响不同棉花品种伤流液各组分含量,与低效品种相比,高效品种伤流液中有较多的NO3-、K+、无机磷、可溶性糖和游离氨基酸。说明缺硼条件下高效品种根系比低效品种具有更强的吸收、代谢活力,可能是其硼效率较高的主要原因之一。     

不同硼效率甘蓝型油菜品种中硼的形态及其相互关系

采用硼高效 (9589,9590)和硼低效 (9141,95105)甘蓝型油菜品种各 2个及其 4个杂交种 (95105 9589,95105 9590 ,91419589,9141 9590)作试材 ,研究了不同硼效率甘蓝型油菜品种及其F1代花期各部分叶片中硼的形态。结果表明 ,在B2 (0 .35mg/kg)处理下 ,硼高效品种上叶 ,中叶 ,下叶和花中水溶态硼含量和束缚态硼含量低 ,半束缚态硼含量高 ,而硼低效品种 3种硼形态的含量则与此相反 ;F1代基本居于二者之间 ,且趋向于高效品种 ;在B1(0 .2 0mg/kg)处理下 ,各叶片和花中各硼形态含量也呈现类似的特征 ,但存在例外 ,尤其在花中。B1和B2处理下 ,除B1处理上叶外 ,硼高效品种和F1代的花和叶片中水溶态硼和束缚态硼相对含量较低 ,半束缚态硼相对含量较高 ,硼低效品种与此相反。建立了硼形态之间的相互平衡关系 ,并把这种平衡关系同硼效率联系起来 ,表明硼形态和硼效率存在密切关系 ,可望由此揭示不同甘蓝型油菜品种硼效率差异的生理机制。     

硼对不同甘蓝型油菜品种细胞壁酶活性的影响

在溶液培养条件下,选用甘蓝型油菜硼高效和硼低效品种,研究硼对细胞壁酶活性的影响。结果表明,不同生育期缺硼均使油菜根系细胞壁过氧化物酶(POD) 活性显著升高;上部叶片细胞壁POD 活性显著下降;下部叶片处理间的差异不显著,但同一生育期细胞壁POD 活性硼高效品种显著高于硼低效品种。油菜根系细胞壁IAA 氧化酶活性,缺硼时两品种薹期和花期显著升高,苗期差异不显著;上部叶片细胞壁IAA 氧化酶活性缺硼时显著降低,硼高效品种花期差异不显著;缺硼对下部叶片细胞壁IAA 氧化酶活性影响不大,但低效品种花期该酶活性显著降低。     

硼镁营养对不同硼效率甘蓝型油菜品种苗期硼形态的影响

通过营养液培养试验,研究硼镁对不同硼效率甘蓝型油菜品种苗期硼形态的影响。结果表明,硼正常时,硼高效品种青油10号自由态和半束缚态硼含量较低效品种高,能参与转运的硼较多;硼低效品种95105束缚态(细胞壁)硼含量较高,自由态和半束缚态硼含量较低,转运、利用效率低。低硼时,硼高效品种根部束缚态硼减少,自由态和半束缚态硼增加,而叶中各形态硼分配合理,达到优化利用;反之,硼低效品种适应营养胁迫的能力较高效品种差。镁在一定程度上可以使硼向有利于其移动的形态转化,提高硼库容量,但在低硼、低镁时,却减少硼低效品种硼库容量,加剧地上部硼的缺乏。     

Differential Changes in Cell-Wall Content and Boron and Calcium Concentration in Newhall Navel Orange Grafted on Two Rootstocks Differing in Boron-Deficiency Responses

The study aimed to determine if the variability of the effect of boron (B) deficiency on Newhall navel orange grafted on trifoliate orange (deficient-B-sensitive) and on citrange (deficient-B-tolerant) can be explained on the basis of changes in cell-wall content and in cell-wall B and calcium (Ca) concentrations. The plants were cultured in the nutrient solution (with or without B) for 65 days. Boron deficiency increased the cell-wall content in old leaves (leaves from last season) of trifoliate orange but had no impact on citrange. Boron deficiency did not reduce B concentration in cell walls of old leaves of citrange-grafted plants but increased their Ca concentration. For trifoliate-orange-grafted plants, however, B deficiency decreased the B concentration in cell walls of old leaves and did not increase their Ca concentration. The changes of B and Ca concentrations between with and without B supply in pectin were in good agreement with the changes of those in cell walls. The relatively greater ability of citrange-grafted plants to maintain B and Ca in the cell wall may contribute to their tolerance to low external B.     

甘蓝型油菜硼营养高效在F1代的遗传研究

采用上培方法,研究了甘蓝型油菜不同硼效率品种为亲本的15个杂交组合农艺性状、棚的吸收、累积、分配和硼效率系数等性状在F1代的表现。结果表明,正反文杂交一代生育期短、抽更早,与高效亲本相近;对土壤轻度缺棚的反应也与高效亲本一致。土壤轻度缺硼时,苗期硼含量较低,累积吸收的单位棚量所形成的干物质重较高,蒙期茎中棚的相对含量高,有利于正反交杂交一代硼素向生长点的运转和再利用。硼效率系数与高效亲本达显著相关,说明甘蓝型油菜硼高效品种与低效品种间的杂交一代表现为硼高效,硼营养高效性状为显性。     

Effects of Boron and Calcium Supply on Calcium Fractionation in Plants and Suspension Cells of Rape Cultivars with Different Boron Efficiency

Abstract

In this study, the effects of boron (B) and calcium (Ca) supply on Ca fractionation in suspension cells and different tissues of rape (Brassica napus L.) plants of two cultivars with different B efficiency were studied, with a purpose to elucidate the mechanism by which B affects Ca concentration in plants. As Ca supply increased in nutrient solution or culture medium, the relatively easily extractable Ca fractions, that is H₂O and 80% ethanol extractable Ca in leaves, 1 mol L^?1 NaCl extractable Ca in upper leaves, roots and suspension‐cell were significantly increased. While the recalcitrant Ca fractions extracted by 2% acetic acid, 0.6 mol L^?1 HCl and Ca in the residue were not affected by Ca supply. Increasing B supply in nutrient solution or culture media significantly reduced 1 mol L^?1NaCl extracted Ca in suspension cell and roots of both cultivars, which were most likely related to the alteration of cell wall metabolism. Calcium extracted by 2% acetic acid, 0.6 mol L^?1 HCl and Ca in residue in suspension‐cell and roots of B inefficient cultivar Bakow were easily improved by B deficiency as compared to that of B efficient cultivar Tezao16. Increasing of these relative recalcitrant Ca fractions was related to the different response of cultivars to the B deficiency, which may reflected different extent that Ca deposited in the two cultivars due to impaired membrane integrity under B deficiency. The effects of B on Ca concentration in lower and upper leaves of the two cultivars were quite different and were the integrated effects of B on Ca metabolism, Ca transport in plants and growth of certain organ. Increasing B supply increased total Ca concentration in upper leaves of Bakow and reduced that of Tezao16, which might relate to the different adaptability of the two cultivars to comparatively higher B supply.     

Critical Levels of Boron in Cotton Plants

The lower and upper critical boron levels in cotton (Gossypium herbaceum-Etawa), which are not estimated, were determined to provide guideline values for estimating the boron status from deficiency to toxicity. Cotton plants were grown under greenhouse conditions in complete nutrient solution containing boron at levels ranging from 0 to 50 ppm. Plants were harvested after 40 days and analysed for B, Zn, Fe, Mn and Cu. The lower critical levels for boron in roots, young leaves and old leaves were 103, 61 and 78 ppm, while critical nutrient toxicity levels were 129, 80 and 91 ppm, respectively. For the Gossypium herbaceum-Etawa cultivar, the maximum growth was obtained when 1 ppm boron was applied as H₃BO₃ in the nutrient solution. High boron concentrations in the nutrient solution were associated with low content of Zn, Fe and Mn in the plants, while boron and Cu concentrations increased with boron supply. Significant correlations were found between B treatments and most response parameters measured.     

Boron stress inhibits beet (Beta vulgaris L.) growth through influencing endogenous hormones and oxidative stress response

Objective: This study aimed to evaluate the pleiotropic effects of boron stress on beet (Beta vulgaris L.) growth.

Methods: Beet seedlings were treated with varying concentrations of H₃BO₃ (0.05, 0.5, 2, and 30 mg/L) for 30 d for evaluation of diverse morphological parameters related to shoot and root growth. Transverse sections of beet leaves were observed under a microscope, and the leaf thickness was measured. Photosynthesis in beet was evaluated by measuring the photosynthetic rate, intercellular carbon dioxide concentration, and chlorophyll content; chloroplast morphology was observed by transmission electron microscopy. In addition, the levels of diverse endogenous hormones, as well as oxidative stress parameters, were also analyzed in beet leaves.

Results: We found that boron accumulated in different beet tissues but was observed mainly in mature leaves, followed by young leaves, mature petioles, young petioles, and roots. Boron stress (boron toxicity, 30 mg/L; boron deficiency, 0.05 mg/L) significantly inhibited beet shoot, root growth, and leaf expansion while promoting leaf thickening. Additionally, the levels of indole-3-acetic acid, gibberellin A3, and zeatin in beet leaves decreased significantly under boron stress, whereas the level of abscisic acid increased. Moreover, the levels of superoxide dismutase, peroxidase, catalase, malondialdehyde, and proline in beet leaves increased significantly under boron stress.

Conclusion: Together, our results indicate that boron stress significantly inhibited normal beet growth via the influence of endogenous hormone levels and oxidative stress responses.     

Effects of different boron concentration on the growth and physiological characteristics of two olive cultivars

This study investigated the effect of different boron concentrations on growth and physiological characteristics of olive plants. The absorption of some macronutrients and distribution of boron were also examined. This research was carried out in a completely randomized design with factorial arrangements including six boron levels (0.2, 10, 20, 30, 40 and 50 mg L^?1) and two cultivars (Amygdalolia and Konservolia), with four replications for each treatment. Two-year old seedlings were treated with Hoagland nutrient solution containing different boron (B) concentration for 4 months. Chlorophyll fluorescence, fresh and dry weight of leaves, stems and roots as well as absorption of macronutrients decreased in both cultivars as the boron level were increased. Diagnostic symptoms of boron toxicity appeared 45 and 75 days after planting for Amygdaloila and Konservolia at 30, 40 and 50 mg L^?1; and 40 and 50 mg L^?1 of boron, respectively. Our results showed that at a higher level of B, the Konservolia cultivar maintained more B concentration in its root than Amygdalolia cultivar; however, B content in young leaves of Amygdalolia was higher than Konservolia. It seems that Konservolia cultivar could accumulate B in its roots and prevents its translocation to the leaves through an internal tolerance mechanism; therefore, Konservolia shows greater tolerance to high concentrations of boron compared to Amygdalolia.     

VARIATION IN PHOSPHORUS EFFICIENCY AMONG BRASSICA CULTIVARS I: INTERNAL UTILIZATION AND PHOSPHORUS REMOBILIZATION

Plants have adapted a number of mechanisms to cope with widespread phosphorus (P) deficiency in arable lands. Crop species and even cultivars differ widely in one or more of these adaptive mechanisms hence, in P efficiency. Identification of these mechanisms is pre-requisite for long term breeding programs. Two independent experiments were conducted to study the possible mechanisms of P efficiency in Brassica cultivars. Eight Brassica cultivars (‘B.S.A.’, ‘Toria’, ‘Toria Selection’, ‘Brown Raya’, ‘Peela Raya’, ‘Dunkeld’, ‘Rainbow’, and ‘CON-1’) were selected on the basis of differences in growth under P deficiency from preliminary experiment. In the first experiment, cultivars were grown for 40 days in sand supplied either with sparingly soluble phosphate rock (PR) or soluble mono-ammonium phosphate (MAP). Cultivars differed significantly (P<0.05) for biomass production, P contents and P use efficiency. Low P availability in PR treatment resulted in significantly lower dry weights and P contents than those grown with MAP. The cultivars ‘Rainbow’, ‘Brown Raya’ and ‘Dunkeld’ accumulated more biomass (3.2 g/pot) and P contents (3.0 mg/pot) than other cultivars when grown with PR. Root dry weight was significantly correlated with shoot dry weight, shoot P content and total P content (r > 0.65) indicating significance of improved root growth for P acquisition. While in the second experiment cultivars were grown with adequate P for 30 days and then P was withdrawn from the nutrient solution by replacing fresh P free nutrient solution for 10 days. Induced P deficiency increased P contents in young leaves by two folds indicating remobilization of P from older leaves and shoot. Nonetheless cultivars varied for remobilization but differences in P remobilization could not explain the differences in P utilization efficiency among cultivars. Hence further experimentation to study root morphology, P uptake, and organic acid exudation by these cultivars in relation to P deficiency is recommended.