硼、钙和农药对草莓花粉萌发和花粉管生长的影响

采用花粉液体培养法研究温度、硼、钙及农药对草莓花粉萌发和花粉管生长的影响。结果表明,(1)草莓花粉萌发和花粉管生长适宜的温度为25～30℃。(2)外源硼酸为草莓花粉萌发必需物质,适宜质量浓度为0.3g/L,低质量浓度促进花粉萌发和花粉管生长,而高于0.3g/L则起抑制作用。(3)外源钙为非必需物质,但适量的外源钙离子有利于花粉萌发,适宜质量浓度为0.3g/L,高钙抑制花粉萌发。(4)在培养液中分别加入常规浓度的7种农药,每处理几乎无花粉萌发,加入1/10常规体积分数的7种农药中,只有一遍净、速克灵、奥美特等3种农药处理有少量花粉萌发,说明农药对花粉萌发和花粉管生长有强烈抑制作用。     

Effects of Boron Stress on copper enzyme activity in tomato

Moderate B deficiency in plants has been reported to enhance Cu deficiency by keeping these plants in the vegetative growth stage. In this study, ascorbate oxidase activity was used as an index of the effect of B stress on Cu activity. When T3238FER (B‐inefficient) and Rutgers (B‐efficient) tomatoes (Lycopersicon esculentum Mill.) were grown in nutrient solutions at various B levels, B‐stressed plants had higher ascorbic acid oxidase activity than B‐sufficient plants. This activity was significantly higher in T3238FER than in Rutgers. Ascorbic acid oxidase activity may be directly or indirectly related to the role of B in plant growth and may be responsible for the more efficient use of B by Rutgers than by T3238FER tomato.     

Catalase peroxidase and IAA‐oxidase activities and O‐diphenolics contents in sunflower leaves grown with different boron levels

Cataiase, peroxidase and IAA‐oxidase activities, so as odiphenolics content in sunflower leaves grown in hydroponics with 4 B levels (0.05; 0.25; 0.5 and 2.0 ppm) were determined. The biochemical assays were made when visual symptons were clearly developed.

Cataiase activity significantly increased in B deficient leaves. Peroxidase, IAA‐oxidase activities and o‐diphenolics content did not significantly change with B levels. The lag period for IAA‐oxidase activity was significantly reduced in B deficient and toxic leaves with respect to the normal ones. These results are in accordance with the hypothesis that one of the B action could be to enhance cataiase activity, the “in vivo” decrease of H₂O₂ levels beeing the cause of the variation in other enzymatic activities related with that substrate.     

Localization of boron in membranes

Abstract

A spectrofluorometric analysis for boron with carminic acid has been made of protoplast membranes, protoplasts, and hypocotyls of mung bean seedlings (Vigna radiata L., c.v. Berken). When expressed on a protein basis, a major part of the boron is localized in the membranes.     

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.     

Influence of Gyttja on Shoot Growth and Shoot Concentrations of Zinc and Boron of Wheat Cultivars Grown on Zinc‐Deficient and Boron‐Toxic Soil

Abstract

Greenhouse experiments were carried out to study the influence of gyttja, a sedimentary peat, on the shoot dry weight and shoot concentrations of zinc (Zn) and boron (B) in one bread wheat (Triticum aestivum L., cv. Bezostaja) and one durum wheat (Triticum durum L., cv. Kiziltan) cultivar. Plants were grown in a Zn‐deficient (DTPA‐Zn: 0.09 mg kg^?1 soil) and B‐toxic soil (CaCl₂/mannitol‐extractable B: 10.5 mg kg^?1 soil) with (+Zn = 5 mg Zn kg^?1 soil) and without (?Zn = 0) Zn supply for 55 days. Gyttja containing 545 g kg^?1 organic matter was applied to the soil at the rates of 0, 1, 2.5, 5, and 10% (w/w). When Zn and gyttja were not added, plants showed leaf symptoms of Zn deficiency and B toxicity, and had a reduced growth. With increased rates of gyttja application, shoot growth of both cultivars was significantly enhanced under Zn deficiency, but not at sufficient supply of Zn. The adverse effects of Zn deficiency and B toxicity on shoot dry matter production became very minimal at the highest rate of gyttja application. Increases in gyttja application significantly enhanced shoot concentrations of Zn in plants grown without addition of inorganic Zn. In Zn‐sufficient plants, the gyttja application up to 5% (w/w) did not affect Zn concentration in shoots, but at the highest rate of gyttja application there was a clear decrease in shoot Zn concentration. Irrespective of Zn supply, the gyttja application strongly decreased shoot concentration of B in plants, particularly in durum wheat. For example, in Zn‐deficient Kiziltan shoot concentration of B was reduced from 385 mg kg^?1 to 214 mg kg^?1 with an increased gyttja application. The results obtained indicate that gyttja is a useful organic material improving Zn nutrition of plants in Zn‐deficient soils and alleviating adverse effects of B toxicity on plant growth. The beneficial effects of gyttja on plant growth in the Zn‐deficient and B‐toxic soil were discussed in terms of increases in plant available concentration of Zn in soil and reduction of B uptake due to formation of tightly bound complexes of B with gyttja.     

Seasonal Changes of Mineral Nutrients in Fruit and Leaves of ‘Newhall’ and ‘Skagg's Bonanza’ Navel Oranges

In southern Jiangxi province of China, ‘Newhall’(Citrus sinensis Osbeck) navel orange presented a conspicuous symptom of boron (B) deficiency in mature leaves, whereas B deficiency symptoms were not manifested on ‘Skagg's Bonanza’(C. sinensis Osbeck) navel orange. In this study, changes in concentrations of B, calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), and zinc (Zn) were comparatively investigated in the structural parts of the fruit (rind and pulp) and leaves (old leaves from last season and spring-flush leaves from current year) of ‘Newhall’ and ‘Skagg's Bonanza’ navel orange during the growing season. Two peaks of B concentrations were observed in the rind of the two cultivars during fruitlet growth and fruit enlargement, respectively. Boron concentrations were relatively high in the rind during fruitlet growth, and then decreased in both rind and pulp, whereas, during middle and late fruit enlargement significant increases were found for B in both rind and pulp of the two cultivars. Boron concentrations in old leaves of ‘Newhall’ decreased progressively and remained relatively low, whereas that of ‘Skagg's Bonanza’ was relatively high and changed slightly as the season progresses. Both Ca and K concentrations were above the critical threshold values, while their dynamics were reverse to that of B in fruit and leaves during certain times. Old leaf Mg concentrations of samples at 140 days after full bloom from the two cultivars and spring-flush leaves from ‘Newhall’ were below the threshold limit for sufficiency. In addition, Mg in old leaves was much lower from ‘Newhall’ than from ‘Skagg's Bonanza’. Spring-flush leaf concentrations of Mn and Zn and Mn concentrations in old leaves from ‘Newhall’ were relatively lacking during middle and late season, which accelerated the occurrence of B deficiency symptoms on mature leaves of ‘Newhall.’     

Performance improvement of nonformaldehyde wrinkle resistant finished cotton fabrics treated with dialdehydes

Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index (WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialdehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.     

主要栽培措施对烤烟总氮含量的影响

采用五因素二次正交回归旋转组合设计,以株距(X1)、氮肥用量(X2)、打顶时间(X3)、硼肥浓度(X4)、IAA浓度(X5)为研究对象,建立了株距、氮肥用量、打顶时间、硼肥浓度、IAA浓度与烤烟总氮含量的数学模型;解析了数学模型,并给出各因子的理想搭配模式及其适宜取值范围。结果表明:最适宜的栽培组合为株距50 cm,氮肥用量80 kg/hm2,打顶时间为现蕾后10 d,硼肥浓度为6 g/kg,IAA浓度为30 mg/kg。     

外源硼缓解铅对蜈蚣萍毒害作用的研究

[目的]探讨了外源硼缓解植物重金属毒害的机制。[方法]以水生植物蜈蚣萍为材料,研究了外源硼对不同浓度铅胁迫下植物叶内O2-.产生速率、叶绿素、可溶性蛋白含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响。[结果]随铅浓度的升高,叶绿素和可溶性蛋白含量逐渐下降,抗氧化酶系统的平衡被打破,O2-.产生速率急剧上升。而外施硼有效维持了抗氧化酶系统的平衡,降低了O2-.产生速率,并且提高了铅胁迫下蜈蚣萍叶内可溶性蛋白和叶绿素含量。[结论]外源硼有效缓解了植物的铅毒害。