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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. 相似文献
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—大白菜干烧心病发生过程中心叶组织Ca^2＋定位及超微结构变化 总被引：7，自引：2，他引：5
采用电镜细胞化学技术，研究了人为诱导大白菜干烧心病发生过程中心叶组织细胞的Ｃａ２＋定位和超微结构变化。结果表明，正常植株叶片细胞内钙主要分布于液泡、细胞壁和叶绿体的膜片层结构中；试验处理植株随着缺钙天数的增加，细胞壁膜上的钙被释放沉淀到细胞间隙，叶绿体片层膜上的Ｃａ２＋释放到胞液中。缺钙后期，细胞内钙沉淀明显减少。同时细胞结构改变，质膜内陷，叶绿体膜和内膜系统破坏；随后细胞壁中胶层解体，可见症状出现时，细胞内隔消失，细菌侵入细胞间隙 相似文献
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A.P. Everaarts M. Blom-Zandstra 《The Journal of Horticultural Science and Biotechnology》2013,88(5):522-528
SummaryInternal tipburn of cabbage (Brassica oleracea var. capitata) is a serious quality defect. The discolouring and desiccation of inner head leaves may render whole yields useless. The disorder is regarded as a localized calcium ficiency. The ficiency is not caused by reduced calcium availability to the plant, but rather by calcium transport characteristics within the plant. Because of the absence of transpiration from the inner head leaves of the cabbage plant, calcium is transported to the meristematic tissues in the head mainly by root pressure flow or because of meristematic sink activity during the night. High growth rates are known to increase the incidence of internal tipburn. Probably because of the increased demand for calcium per unit of time, the result of disruption in the calcium transport to the head is more serious. Conditions of even transpiration between day and night, whether high or low, reduce root pressure flow to the head and thereby may induce development of internal tipburn. A combination of high growth rates and low root pressure flow during periods of prolonged dry, sunny weather with high transpiration rates during the day as well as during the night, may be especially important in inducing internal tipburn, because of insufficient calcium influx in the cabbage head under such conditions. As initiation of calcium deficiency in growing tissue is a subcellular process, visible symptoms of internal tipburn may be expressed only later. Growers are primarily advised to cultivate internal tipburn resistant cultivars. Recommendations to limit the occurrence of internal tipburn are formulated. 相似文献
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P. Palencia F. Martinez E. Ribeiro M. Pestana F. Gama T. Saavedra A. de Varennes P.J. Correia 《Scientia Horticulturae》2010
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. 相似文献
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大白菜干烧心病的形态结构及生理生化变化 总被引：8，自引：1，他引：7
以人为诱发大白菜(Brassica Campestris L.ssp.pekinensis(Lour)Olsson.)干烧心病的方法,研究了该病发生发展过程中叶片形态结构及生理生化的变化。结果表明:随着叶片中钙含量的下降,干烧心病症逐渐出现。在此过程中,光合强度降低,膜受损伤,糖含量及电解质外渗率渐增,粘液外溢于叶表;解剖结构观察可见质膜内陷,有囊状小泡形成,细胞器逐步解体;随之,可溶性果胶剧增,胞壁损伤,最后细胞解体死亡,残存固形物充塞了胞壁内外。对叶片排水器黑变与干烧心病发生的独立性检验,表明二者无相关性。 相似文献
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紫色大白菜育种思路初探 总被引：4，自引：0，他引：4
应用大白菜与紫色小白菜亚种间杂交转育紫色性状,获得2份紫色大白菜中间材料。比较了转育获得的紫色大白菜与普通大白菜的外叶颜色、球内叶颜色以及包球的球色等。结果表明,转育紫色小白菜获得的紫色大白菜材料只在叶片的正面表现紫色,而叶片的反面依然表现绿色;剖开后的剖面表现为紫色、白色和黄色相间排列的几种颜色。研究认为,该类型的紫色材料可以在小白菜、半包球大白菜,如快菜类型和娃娃菜等紫色品种中应用,所育成的大白菜品种可以作为拼盘搭色时凉拌或做汤食用,效果会更佳。桔红心品种的VC含量在4种球色大白菜品种中最高。初步探讨了国内外紫色大白菜研究的育种思路和应用进展。 相似文献
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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. 相似文献
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白菜采后衰老生理的研究 总被引：8，自引：0，他引：8
‘早油冬’白菜采后在(20±1) ℃、85％～95％相对湿度条件下贮藏时，乙烯释放量呈下降趋势，失重率迅速升高，呼吸速率先下降后上升，于第6天形成呼吸高峰。外叶叶绿素、可溶性蛋白质和类胡萝卜素含量下降比内叶快。外叶贮藏中SOD和CAT活性变化较大，4 d后迅速下降，特别是CAT活性降幅更大；POD活性先逐渐增加，6 d后急剧上升，MDA含量先缓慢增加，4 d后急剧上升，表明活性氧代谢失调，膜脂过氧化加剧。内叶SOD和CAT变化很小，并保持较高水平，POD活性无显著上升，MDA略呈下降趋势，表明活性氧的产生与清除相平衡，从而防止了活性氧积累和膜脂过氧化加强。结论：白菜的衰老是活性氧代谢失调的结果，外叶比内叶容易衰老。 相似文献
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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. 相似文献
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SummaryThe aim of this study was to provide an overview of the causes and control of calcium (Ca)-deficiency disorders in vegetables. Ca-deficiency is usually related to the inability of the plant to translocate adequate Ca to the affected part. Many vegetables develop unique symptoms: for example blackheart in celery, tipburn in lettuce, chervil, onion, fennel, chinese cabbage and other cabbages, blossom end rot (BER) in tomato. Ca-deficiency disorders in vegetables can be controlled by various means. The growing medium influences the development of Ca-deficiency symptoms in plants. Restriction of the root volume is one factor that favours the development of Ca-deficiency symptoms in leafy vegetables, but reduces the incidence of BER in pepper. Ca-deficiency can also be avoided by using reasonable levels of nitrogen in the nutrient solution. Cations depress Ca-uptake and distribution, while anions depress the development of tipburn in plants. Ca-deficiency can be avoided by using the recommended level of salinity for each crop. Too high a salinity level increases the symptoms of Ca-deficiency in plants. Watering helps to prevent Ca-deficiency injury, as when growing vegetables outdoors. Maintaining an optimum soil moisture level helps to promote adequate movement of Ca to the roots and into the plant. A low relative humidity during the day-time increases the Ca-contents of leaves in leafy vegetables with an open growing point, but reduces the Ca contents of fruit and the inner leaves of leafy vegetables with a closed growing point. Avoiding too long a duration of supplementary lighting, too high a light intensity, and the use of high-pressure sodium lamps can prevent Ca-deficiency injury in plants. Shading may influence the incidence of BER, by reducing the appearance of symptoms of BER. Growing plants under a far-red wavelength filter helps to prevent Ca-deficiency disorders. Avoiding high or low temperatures also prevents Ca-deficiency injury. A negative DIF value (DIF = the difference between the day-time and night-time temperatures; a negative DIF means the night temperature is higher than the day temperature) may influence the incidence of tipburn injury by reducing its appearance. Air flow to the affected parts of plants can help to avoid the symptoms of Ca-deficiency. Ca sprays also help to prevent Ca-deficiency disorders in plants. Mulches can be used to protect plants against Ca-deficiency. Some crop varieties are less susceptible to Ca-deficiency. The plant growth regulator, Cultar (paclobutrazol, an inhibitor of gibberellin-biosynthesis), may influence the symptoms of Ca-deficiency in plants by reducing the appearance of the disorders. Planting a little later than the optimum date can avoid Ca-deficiency symptoms in leafy vegetables in Nordic countries. Harvesting a little earlier than the optimum date can also avoid Ca deficiency- symptoms in leafy vegetables. 相似文献
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Kale (Brassica oleracea var. acephala), Chinese cabbage (B. campestris ssp. pekinensis), chikale (B. campestris ssp. pekinensis × B. oleracea var. acephala hybrid) and turnip (B. campestris spp. rapifera) were studied. The proper plant size (number of true leaves) for the beginning of vernalization treatment was determined. All vernalization experiments commenced when the plants were 4 weeks old, with 5–7 true leaves. Plants were classified as bolters either through the visible appearance of flower buds at the apex, or by making longitudinal cuts through the apex if the flower buds were not visible. Cut plants with a pointed apex were classified as bolters. A definite relationship between the number of true leaves and bolting was observed for kale, the more difficult biennial species. 相似文献
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大白菜结球中前期^14C运转与分配特性的研究 总被引：1，自引：1，他引：0
以鲁白３号为试材，对大白菜结球中前期１４Ｃ示踪的试验结果表明，在标记２４小时内，１４Ｃ可被运转到植株的各个部位，尤以外叶和球叶的交界处较多。２４小时后，莲座叶内的１４Ｃ逐步向外运输，在球叶、根和茎三者间进行再分配。内部球叶由于不断生长，对１４Ｃ的竞争能力最强，其总放射性强度也最高。根系因为此时基本停止生长［３］，根内的１４Ｃ放射性强度也较高，而茎中的放射性强度相对较低。由此认为结球中前期，即产品器官旺盛生长期之前加强肥水管理是提高商品菜产量的关键时期。 相似文献
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Influence of prohexadione-calcium on growth and gibberellins content of Chinese cabbage grown in alpine region of South Korea 总被引：2，自引：0，他引：2
Sang-Mo Kang Jung-Tae Kim Muhammad Hamayun In-Cheon Hwang Abdul Latif Khan Yoon-Ha Kim Joon-Hee Lee In-Jung Lee 《Scientia Horticulturae》2010
We investigated the effect of prohexadione-calcium (Pro-Ca) on growth characteristics and endogenous gibberellins content of Chinese cabbage grown in the alpine region of South Korea. Pro-Ca was applied at the rates of 200 ppm and 400 ppm, after 10, 15 and 20 days of transplanting seedlings in to the field. Application of Pro-Ca through foliage improved quality and quantity of yield by promoting Chinese cabbage head yield, number of head leaves, total soluble sugar content and compactness of head. The leaf size was reduced, while the chlorophyll content increased under the influence of elevated Pro-Ca application, when measured after 40 days of transplantation. The endogenous bioactive GA1 and GA4 contents of Chinese cabbage drastically decreased with elevated Pro-Ca, indicating that gibberellins (GAs) biosynthesis was blocked by this chemical. Current study suggests that both of GAs biosynthesis pathways are operational in Chinese cabbage, although non-C13-hydroxylation pathway was found to be the major pathway. GAs were quantified by gas chromatography/mass spectroscopy-selective ion monitoring (GC/MS-SIM). 相似文献