Relationship between tipburn and leaf mineral composition in strawberry

Malformation of emerging leaves with distortion of leaf tips, a condition known as tipburn, is frequently observed in strawberry. Calcium (Ca) deficiency has been considered the main cause of tipburn. The aim of the present study was to analyse the relationship between leaf mineral composition and the incidence of tipburn in three short-day strawberry (Fragaria x ananassa Duch.) cultivars (‘Ventana’, ‘Camarosa’ and ‘Candonga’) submitted to different concentrations of Ca. The studies were conducted in a hydroponic system in a greenhouse. Calcium was added as Ca(NO₃)₂ at 2 mM, 3 mM, 4 mM and 5 mM. A completely randomized block design (4 Ca concentrations × 3 cultivars) with three replications was used. Each replicate consisted of 12 plants grown in a polyethylene bag (100 cm × 18 cm × 3 cm) filled with coconut peat. Crown diameter and tipburn incidence were evaluated throughout the experimental period, and at the end of the experiment leaf mineral composition was assessed. In general, plants with larger crown diameters had a greater incidence of tipburn. The ‘Candonga’ cultivar had the smallest incidence of tipburn, while the ‘Camarosa’ and ‘Ventana’ cultivars were more susceptible. There was no correlation between level of Ca applied and incidence of tipburn. The incidence of tipburn was associated with foliar K:Ca and K:Mg ratios. Ratios above 3.40 for K:Mg and 1.77 for K:Ca represented a risk of more than 50% of tipburn incidence, when overall means for all cultivars and levels of Ca were used.     

The influence of relative humidity and nutrition on leaf tipburn of strawberry

Leaf tipburn of strawberry, a localised calcium deficiency causing malformation of emerging leaves, was induced by high relative humidity and alleviated by diluting the nutrient solution or by reducing the level of potassium, magnesium or nitrate in otherwise standard solutions. Increasing the phosphate content of the solution had no effect, while supplementing the calcium nitrate to above sufficiency levels of calcium increased tipburn. Leaf calcium (% dry weight) decreased temporarily during leaf emergence and was lower in affected emerging leaves than in comparable healthy ones     

The relationship between leaf growth,calcium accumulation and distribution,and tipburn development in field-grown butterhead lettuce

The change in calcium (Ca) concentration with time, the distribution of Ca within various leaves, and leaf and tipburn development were studied in field-grown lettuce (Lactuca sativa L.) cultivar ‘Cobham Green’.Ca distribution between and within leaves followed two distinct patterns. The average concentrations in the outer leaves were always higher than in the inner leaves. The concentrations at the periphery of the outer leaves was always greater than in the midrib, whereas for the inner leaves the converse was true.Tipburn only occurred in the inner leaves; it developed on only those leaves and those parts of the leaf which expanded most rapidly.Thus, tipburn development appears to depend on the supply of Ca relative to the rate of leaf growth.     

The effect of boron on tipburn and auxin activity in lettuce

Lettuce plants (Lactuca sativa L.) grown in a boron deficient nutrient medium developed tipburn. Their leaves showed no overall increased auxin activity compared with those of control plants until they were 66 days old, when boron deficient plants showed a relative increase in the activity of one auxin. It is postulated that tipburn in lettuce may be caused by interacting factors including calcium and boron deficiences, and the ontogenetic age of the plant. Environmental and cultivar effects on the incidence of tipburn indicate that agronomic or genetic control measures may become feasible, if the mechanism controlling its expression can be further elucidated.     

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。     

不同浓度糖、硼、钙对苹果花粉萌发的影响

苹果花粉有自交不亲和且花粉萌发率低现象。为了提高人工授粉率,探寻最适宜苹果花粉萌发的培养基组分及浓度,以福岛、黄香蕉、美国八号、王林四个苹果品种花粉为试材,通过花粉离体培养法,分析了不同浓度的糖、硼、钙对花粉萌发率的影响。结果表明:蔗糖浓度在5%～15%之间,可以有效的提高四种苹果花粉萌发率,其中蔗糖浓度为10%时,萌发率极显著高于其他浓度处理及对照。硼酸浓度为0.03%时,可以有效的提高花粉萌发率。CaCl2浓度在0.01%～0.05%之间,对四种苹果花粉萌发率有不同程度的抑制作用;且外源钙不是苹果花粉萌发的必需物质。对于这四种苹果花粉萌发,培养基最佳组分及浓度是:10%蔗糖+0.03%硼酸。美国八号和王林在最佳培养基上的发芽率高达79.3%、78.8%。     

Fruit calcium content and lipoxygenase activity in relation to albinism disorder in strawberry

Nutrient elements and lipoxygenase (LOX) activity were determined in strawberry fruit to establish a relationship, if it exists, between nutrient ratios (N/Ca and K/Ca), and lipoxygenase activity with albinism disorder. About 33% strawberry fruit were affected by albinism. Etna had highest incidence of albinism (48.6%) and Sweet Charlie the lowest (16.2%). Dry matter content (%) was lower in albino fruit (5.23%) than normal fruit (7.36%). The concentration of N, P, and Mg did not differ significantly, but that of K (1.87 mg g⁻¹ fresh weight) was notably higher and of Ca (0.105 mg g⁻¹ fresh weight) was lower in albino fruit than normal fruit. Consequently, the nutrient ratios, N/Ca (9.78) and K/Ca (16.96) were higher in albino fruit than normal fruit. Cultivars differed widely in respect to dry matter (%), mineral content and nutrient ratios. LOX activity determined on dry weight or fresh weight basis was significantly higher in albino fruit than normal fruit, with significant differences among cultivars. Positive correlations existed between nutrient ratios and albinism incidence (r = +0.338), LOX activity and albinism incidence (r = +0.412), and LOX and nutrient ratios (r = +0.448). Thus, it appears from the study that calcium and LOX activity may not the basic cause of albinism in strawberry, but these may be involved in senescence or fruit ripening process, as LOX activity was lower in albino than in normal fruit.     

几种有机肥料在温室草莓上施用试验

目前,生产上应用有机肥料改善果实性状已成为重要的栽培技术之一.有机肥料是一种完全肥料,不仅含有大量元素和许多微量元素,还含有一些植物生长所必须的激素和多种有益土壤微生物,能够改善果实品质,提高产量,改良土壤等.为了摸清有机肥对草莓生长发育的影响,我们于2006年12月-2007年5月以草莓新品种'甜查理'为试材进行施肥试验,现总结如下.……     

Possible role of non-structural carbohydrates in flower induction in strawberry

Summary

Flower-induction is the event that initiates the transition of a vegetative apex into a floral apex in response to an environmental or developmental cue. Under flower-inducing conditions, biochemical or physiological changes can be recognised. One possible change that could occur is in sugar content. In this study, levels of non-structural carbohydrates (e.g., sucrose, glucose, fructose and starch) were measured in shoot tips, leaves and roots of strawberry (Fragaria ananassa cv. ‘Kordestan’) under flower bud-inducing conditions, and compared with non-induced plants. Runner plants were potted and grown for 4 weeks under non-inducing conditions (31º/25°C day/night; 16 h daylength). Half of the plants were then put under flower-inducing conditions (25°/15°C day/night; 8 h daylength) for 3 weeks. Samples for carbohydrate analysis were taken from induced and non-induced plants every 3 d over 3 weeks, and sucrose, glucose and fructose contents were determined by HPLC, and starch concentrations by the anthrone method. The most abundant soluble sugar, in all organs tested, was sucrose. Sucrose levels in shoot tips and leaves decreased at the beginning of the induction treatment, but soon increased to the levels recorded in non-induced plants. Fructose increased markedly in shoot tips of induced plants 3 d after the start of the short-day treatment, and declined thereafter. Starch contents in shoot tips, leaves and roots of non-induced strawberry plants were higher than those in induced plants on most sampling dates. From the results of this study, it appears that soluble carbohydrate contents in different organs of June-bearing strawberry may have a decisive role on flower-bud induction.     

The effect of trickle irrigation,misting and row position on the incidence of tipburn of field lettuce

The effect of trickle irrigation, with and without additional applications of night mist, just before maturity on the incidence and severity of tipburn in field lettuce was investigated. The mean incidence of tipburn for all treatments was much higher (84%) on the outer 2 rows of beds than on the inner 2 rows (47%). On the outer rows irrigation and misting had virtually no effect on tipburn, whereas on the inner rows irrigation reduced it from 72% (in control plants) to 39%, misting to 63% and misting + irrigation to 16%. It is believed that the combination of night misting and trickle irrigation of inner rows resulted in conditions conductive to root-pressure flow which translocated calcium ions to heart leaves of lettuce plants, thereby reducing tipburn injury. It is suggested that the increased severity and incidence of tipburn in the outer rows could have resulted from soil compaction in wheelings which would reduce root growth, soil aeration and root pressure.     

~(60)Coγ辐射对不同品种草莓离体叶片再生及芽生长的影响

以丰香和章姬草莓的无根无菌苗为试材,用10～40Gy 60Coγ射线辐照处理,以未辐照为对照,研究了60Coγ射线辐射对草莓叶片再生及植株继代增殖的影响。结果表明,叶片对辐射敏感,且丰香叶片比章姬叶片敏感,叶片再生的半致死剂量为10～20Gy;辐照后不同时间取叶接种,丰香叶片的不定芽再生率在剂量10Gy呈上升趋势,而其他剂量则几乎未见有变化,章姬在剂量10～30Gy,叶片的不定芽再生率提高较大,40Gy仍表现轻微下降;适宜的辐射剂量对草莓试管苗增殖有促进作用。     

Pre-harvest foliar application of calcium and boron influences physiological disorders,fruit yield and quality of strawberry (Fragaria × ananassa Duch.)

Studies were conducted in ‘Chandler’ strawberry to determine if pre-harvest foliar application of Ca, B or their combination influences physiological disorders, fruit yield and quality or not. For this, treatments consisted of (i) five sprays of calcium as CaCl₂ (first spray was performed at the petal fall stage and later at 7 days interval), (ii) three sprays of boron as boric acid (first spray at the beginning of flowering and later at 15 day interval), (iii) combination of (i) and (ii), and (iv) plants sprayed with water served as the control. Results indicated that fruit harvested from plants, which were sprayed either with Ca or Ca + B had significantly lesser incidence of albinism (6.7 and 6.5%), and grey mould (1.3 and 1.2%) than those harvested from plants sprayed either with B alone or in control. Although, B alone could not influence the incidence of albinism and grey mould, but it reduced fruit malformation (3.4 and 3.1%) significantly. Further, Ca, B or their combination had not influenced the individual berry weight, but marketable fruit yield differed significantly. The lowest marketable fruit yield (149.3 g/plant) was recorded in plants under control, and the highest (179.2 g/plant) in plants sprayed with Ca + B. Similarly, such fruit were firmer; had lower TSS, higher acidity and ascorbic acid content at harvest than those in control. Similarly, such fruit after 5 days storage were firmer and brighter, and have significantly lower TSS (7.9 and 7.8%); higher ascorbic acid content (43.7 and 45.0 mg/100 g pulp) and acidity (1.08 and 1.07%) than those in control or those receiving B alone. Incidence of grey mould was significantly lesser in fruit, which received Ca (2.2%) or Ca + B (1.9%) than those, which received either B (8.1%) alone or those in control (8.4%). Our studies indicated that pre-harvest foliar application of Ca + B is quite useful for reducing the incidence of disorders and getting higher marketable yield in ‘Chandler’ strawberry.     

Salinity effects on strawberry plants grown in rockwool. I. Growth and leaf water relations

Comparison of four everbearing or day-neutral cultivars of strawberry (Rapella, Ostara, Fern and Selva) grown under glasshouse conditions in rockwool showed Rapella to accumulate the greatest shoot dry weight and leaf number together with the production of few stolons but many relatively large fruits per inflorescence. Subsequent studies with cv. Rapella found that increasing the salinity of the irrigation supply from 2.5 to 5.7 and to 8.5 mS cm"1, by the addition of NaCl, progressively reduced leaf number emerged and final leaf area by up to 36% and 48% respectively, after 100 d of treatment. Shoot dry weight, excluding fruits, was reduced by up to 47%. The number of crowns (lateral branches) was reduced from 11 in the lowest salinity to 8 and 7 at the higher salinity levels. Leaf water potential, \)/w, was reduced by up to 0.23 MPa in young leaves and 0.36 MPa in older leaves. Leaf osmotic potential, xj/^, was decreased by up to 0.14 MPa in younger leaves following salinity treatment at 8.0 mS cm-1. Consequently leaf turgor was reduced more in older than in younger leaves. Inflorescence number was reduced from 27 to 20 and 17. Within the remaining inflorescences however, flower numbers, fruit numbers and duration of fruit ripening were not affected. A marked decrease in the fresh weight of the fruit was detected in both higher salinity treatments but fruit dry weight was only slightly reduced.     

The components of fruit size in strawberry

High Correlation coefficients have been found in the application of the formula:

$\text{Fresh weight of ripe berry}\text{(g)}\text{=}\text{(Total number of achenes?C)F}\text{(Number of achenes per cm}{}^2\text{of surface}$

to data for a large number of strawberries from nine cultivars. Of the terms in the equation (Total no. of achenes — C) was found to be different in different cultivars and to be related to the position of the berry on the inflorescence, but there was no constant relationship between the achene numbers in the different ranks of berry. Whether the numbers of achenes per berry can be altered by environmental or cultural treatments was not resolved. F, a term having the dimensions of weight per area, represents weight per unit area of berry surface and seems to be constant amongst plants of a cultivar subject to uniform treatment, but differs between cultivars and treatments.The number of achenes per cm² of surface on ripe berries is a measure of berry development in the fruiting season and may be affected by environmental and managerial factors and by internal competition between fruits and leaves on the same plant.The interactions of these factors on berry size enable two stages to be recognised at which size is determined, namely during flower formation, when achene numbers and possibly F are fixed, and during fruit development after pollination when the term for spatial distribution of achenes is settled.It is suggested that an examination of the effects of different treatments on each of the size components might enable a distinction to be drawn between the influence on yield of genetic characteristics on the one hand and intrinsically variable characteristics subject to external influence on the other hand, thus clarifying the type of research and/or development needed to enable growers to achieve maximum yields.     

Relationship between light,fruit and leaf mineral content with albinism incidence in strawberry (Fragaria x ananassa Duch.)

A study was conducted in strawberry to establish a relationship between shading, mineral nutrient of leaves and fruits with albinism incidence. Plants grown under shade produced albino fruits in higher proportion than those grown in open fields. Similarly, plants under shade produced smaller sized fruits and have lower fruit yield. Among cultivars, Etna had highest incidence of albinism (49.6%) and Sweet Charlie the lowest (14.4%). Dry matter content (%), concentration of five major nutrients, viz. N, P, K, Ca, Mg, S and N:Ca and K:Ca nutrient ratios did not differ significantly in the leaves of plants producing normal or albino fruits. However, in contrast, the concentration of K was notably higher (1.97 mg g⁻¹ fresh tissue weight) and that of Ca was lower (0.098 mg g⁻¹ fresh tissue weight) in albino fruits than normal ones. Consequently, the ratios of N:Ca (11.34) and K:Ca (20.08) were higher in albino fruits than normal ones. Cultivars also differed widely in respect to dry matter (%), mineral content and nutrient ratios. Thus, it appears that lower light intensity favours the development of albinism in strawberry, and it seems that calcium is not the basic cause of albinism, but increased vigour associated with overuse of N and K might be positively associated with it.     

Salinity and shading effects on leaf water relations and ionic composition of strawberry plants grown on rockwool

Summary

Strawberry plants were grown in rockwool under glasshouse conditions at NaCl salinities of 2.6,5.9 and 8.6 mS cm^-1 and at total irradiances of 2.1 and 4.9 MJ m^?2d^?1. Increasing salinity and irradiance reduced leaf water potential (ψω), osmotic potential (ψπ) and turgor potential (ψτ). There was an interaction between salinity and irradiance on with the lowest ψπ recorded for the unshaded leaves. Increased salinity altered the ionic composition of the leaf. Chloride concentration was increased from 0.03 to 0.61 % (D.W.) while NO₃ content in the leaf sap was reduced from 10.51 to 3.60 mg ml^-1 as salinity increased from 2.6 to 8.6 mS cm^?1. Expressed on a fresh-weight basis, the concentration of K was reduced at high irradiance whereas Ca and Mg were enhanced. On a dry-weight basis K, Na, Ca and Mg were unaffected by salinity treatment. Net photosynthesis was reduced by high salinity but only in plants grown in unshaded conditions.     

日光温室条件下桃、草莓、葡萄套栽技术

日光温室桃树下间作草莓,边行套栽葡萄,可充分利用温室内土地面积,也可有效利用温室边空闲地,是立体栽培的新模式,高产高效的新技术。     

缺硼胁迫对不同基因型葡萄硼效率及硼积累、分配的影响

【目的】评价缺硼胁迫下不同基因型葡萄的硼效率大小,揭示造成葡萄硼效率差异的原因。【方法】以葡萄属4个种7个基因型为试材,采用营养液试验,研究缺硼胁迫对不同基因型葡萄幼苗的生长状况及硼积累、分配的影响。【结果】毛葡萄‘花溪-9’、‘花溪-4’和葛藟葡萄‘习水-4’为硼高效基因型,而毛葡萄‘福泉-1’、‘农院-11’和欧洲葡萄‘红地球’、欧美杂交种‘水晶’为硼低效基因型。与对照相比,缺硼胁迫对硼高效基因型地上部或根系生长的抑制作用小于硼低效基因型。缺硼处理降低了不同基因型葡萄体内硼含量和硼积累量,其中,硼高效单株‘花溪-9’的根系和茎中的硼含量为对照的97.89%和95.28%,全株的硼积累量降幅小于50%,而硼低效植株‘福泉-1’只有51.38%和66.66%,且硼积累量降幅均大于50%。缺硼胁迫下,硼高效单株(‘花溪-9’、‘花溪-4’和‘习水-4’)根系和茎干中硼的再分配能力强于硼低效单株或品种的(‘福泉-1’、‘红地球’和‘水晶’)。缺硼胁迫下,不同葡萄基因型的硼效率与葡萄的生物量及根系特性关系密切。【结论】原产贵州喀斯特山区的野生葡萄种群整体硼效率高于欧洲葡萄和欧美杂种,但野生葡萄种内存在差异。缺硼胁迫对硼高效基因型的抑制作用小于硼低效基因型,不同基因型葡萄的硼效率差异取决于硼在植株内的移动性和再分配能力。     

The effects of some chemical treatments on leaf water conductance of cut,flowering stems of Chrysanthemum morifolium

The leaf water conductance of cut, flowering stems of Chrysanthemum morifolium was measured by diffusion porometry. The stems were placed in solutions of chemicals which have commonly been used in flower preservatives, or which might be expected to affect the physiology of the leaves.In the environmental conditions of our experiments (18° C; 0.8 kPa; 5 W m^?2 visible radiation for 8 h) sucrose (6 %) and abscisic acid (0.001 %) lowered leaf water conductance. Silver nitrate (0.003 %) or 8-hydroxyquinoline sulphate (0.02 %) either had no effect or increased leaf water conductance. We conclude that the latter two substances increase the vase life of cut flowers by affecting the physiology and pathology of the stem rather than the stomatal physiology of the leaf. The leaves of stems standing in high concentrations of sucrose accumulated sucrose and were frequently damaged as a result.The results are discussed with regard to the water relations of the cut flower and the possible use of anti-transpirants.     

花期叶面喷施B和Ca对油橄榄完全花比率和坐果率的影响

【目的】在油橄榄花期叶面喷施硼和钙肥,研究叶面喷施硼、钙及硼-钙交互作用对油橄榄完全花和坐果率的影响。【方法】选甘肃陇南主栽的3个油橄榄品种(‘莱星’‘鄂植8’‘城固32’),采用完全正交试验,在花期前、中、后分别喷施不同浓度硼和钙的叶面肥,调查完全花比率和坐果率,并观察了硼和钙对花粉萌发的影响。【结果】花期叶面喷施硼和钙对各品种油橄榄完全花及坐果率的交互影响均不显著。但‘鄂植8’和‘城固32’在0.10%的硼酸因素下,完全花比率较对照分别提高了8.9%和11.5%;‘城固32’在0.05%的硼浓度下的坐果率较对照提高了154.2%;‘鄂植8’和‘城固32’在0.00%、0.25%的钙浓度处理下,其坐果率均显著高于更高浓度的处理,高浓度的钙反而对果实坐果率有显著抑制作用;‘莱星’的处理间差异均不显著。培养基50~75 mg·L~(-1)的硼酸对油橄榄花粉萌发促进作用最好,而培养基添加钙则抑制花粉萌发,且硼和钙存在一定的拮抗作用,因此高浓度的钙不利于油橄榄花受精和果实坐果。【结论】油橄榄不同品种对花期喷施硼和钙的响应程度不同,适量的硼(0.5%~1.0%)对油橄榄开花坐果有促进作用,而高浓度硼(大于1.00%)和高浓度钙(大于0.25%)均不利于油橄榄开花坐果,在油橄榄花期的叶面施肥中应谨慎使用外源高浓度钙。