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1.
The relative importance of growth rate and calcium concentration in sweet
pepper fruits ( Capsicum annuum L.) for the induction
of blossom-end rot (BER) was investigated in (1) four pollination
treatments in one cultivar, (2) four cultivars with the same fruit load and
(3) three fruit load treatments in four cultivars. For fruits with the same
pollination treatment those eventually developing BER had a higher initial
fruit growth rate than those not developing BER. Within the same experiment
both the growth rate of the young fruit and BER increased with the number
of seeds. The Ca concentration of the pericarp in mature fruits was
negatively related to both fruit size and BER incidence. Differences in
levels of BER between different pollination experiments could not be
explained solely by differences in growth rate of the young fruit, but
related to different Ca concentrations in the mature fruits. In the spring,
but not in the summer, cultivars more susceptible to BER had a larger final
size but lower Ca concentration in the young fruit than the resistant ones.
By lowering the fruit load in the summer both the final fruit size and the
BER incidence increased, but the Ca concentrations of both proximal and
distal pericarp in the young fruit of all cultivars were not consistently
affected. Despite a correlation between growth rate and low Ca
concentration in the fruit, the incidence of BER may only be predicted from
separate effects of fruit growth and of Ca concentration of fruit. The data
indicated that at a higher growth rate a higher Ca concentration is
required to prevent the induction of BER. The usefulness of the total Ca
concentration of the fruit for determining the critical Ca concentration in
the induction of BER is discussed. Key words: Capiscum
annuum L., sweet pepper, blossom-end rot, calcium, growth rate,
pollination, fruit load.
相似文献
2.
Blossom-end rot is generally considered a calcium-related physiological disorder. The results of the previous studies show that several factors such as plant conditions can be effective on the blossom-end rot incidence. Therefore, the present study was undertaken to investigate the effect of the sink/source ratio on the incidence of the blossom-end rot of two greenhouse tomato ( Solanum lycopersicum L.) cultivars: ‘Grandella’ and ‘Isabella’. To this end, four treatments were applied: saving one fruit per truss (1F), two fruits per truss (2F), three fruits per truss (3F), and no fruit pruning (control). The results showed that the tomato cultivar ‘Isabella’ was more susceptible to the blossom-end rot than ‘Grandella’. Decreasing the sink/source ratio increased the incidence of the blossom-end rot and the relative fruit growth rate. The correlation between the blossom-end rot incidence and the relative fruit growth rate showed that the fruit growth rate could be regarded as an important factor in the incidence of this disorder. Endogenous auxin and cytokinin concentrations acted as the regulators of the fruit growth rate and influenced it. Slowing down the relative growth rate by keeping proper sink/source ratio based on tomato cultivar is, therefore, an effective, cheap and healthy way to control the incidence of the blossom-end rot, especially in organic farming. 相似文献
3.
Summary The uptake and distribution of potassium was examined in tomato plants, cv. Amberley Cross and Moneymaker, grown in peat/loam and given a nutrient feed either adequate or deficient in potassium.Detailed studies were also made of the distribution of potassium in various parts of tomato plants, cv. Amberley Cross, grown in sand and supplied with nutrient feeds containing four and seven concentrations of potassium. In these plants the concentration of potassium in stem, petiole and laminar tissue increased from the base to the apex of plants, irrespective of the potassium concentration in the nutrient feed. There was also a gradient of decreasing potassium concentration along leaves, from proximal to distal laminae. The concentration of potassium in all plant parts increased with increasing nutrient supply of potassium, petioles showing a greater response to nutrient potassium than laminar tissue.Marginal chlorosis and/or necrosis were observed when the potassium concentration in fully expanded leaves fell below 1.2 per cent of the dry weight for cv. Amberley Cross or 1.5 per cent for cv. Moneymaker. A 50 per cent incidence of chlorosis and/or necrosis occurred in leaf laminae containing 0.74 per cent potassium.Leaves rarely showed deficiency symptoms when the concentration of potassium in the petioles was higher than that in adjacent laminar tissue. However, chlorosis and/or necrosis occurred when the potassium concentration in petioles fell below that in laminae. In the diagnosis of the potassium status of tomato plants, the most suitable tissue for sampling for potassium analysis is considered to be the petioles of young fully expanded leaves. 相似文献
4.
An internal blackening disorder may cause substantial losses in the value of tomatoes grown for processing. The disorder resembles an internal form of blossom-end rot and appears to be more common in dry seasons. In an experiment to test whether the internal blackening is caused by water deficit and whether it is indeed blossom-end rot, plots of cv. Cannery Row were irrigated to keep the soil moisture deficit <50 mm and others were sheltered from rain and not irrigated from early flowering onwards. Shoot growth (total and fruit dry mass) was measured destructively at intervals, and root growth and death nondestructively using minirhizotrons. There was a greater incidence of internal blackening and blossom-end rot, and lower Ca concentrations, in the fruit of non-irrigated plants. Root growth and root death were accelerated in these plants around the time that internally-blackened fruit were set. Although the internal blackening syndrome shared some features with blossom-end rot some differences were apparent in this experiment. It is suggested that internal blackening could have resulted from increased root competition for photosynthate, leading to abnormal seed development. Root turnover was appreciable (30–40% of the roots survived 28 days). This suggests there may be substantial errors in contemporary models of dry matter partitioning in tomato crops. 相似文献
5.
Studies of Ca uptake and distribution in relation to environmental variables were used to relate Ca status of tomato fruit to blossom-end rot (BER) incidence. Ca uptake was highly correlated with solar radiation and root temperature. The rate of Ca uptake decreased linearly with increasing salinity. High humidity reduced Ca import by the leaves but increased that by the fruit. While total plant dry weight was reduced more than fruit dry weight by salinity, total Ca uptake and the Ca content of the fruit were decreased similarly. Thus, the concentration of calcium in the fruit was substantially reduced by salinity. The distal half of the fruit contained less Ca than the proximal half. The lowest % Ca was found in the distal placenta and locular tissues, where BER first develops. The incidence of BER was often stimulated more by high salinity achieved with the addition of major nutrients than with NaCl. The cause of BER is usually an interaction between the effects of irradiance and ambient temperature on fruit growth and the effects of environmental stress on calcium uptake and distribution within the whole plant. 相似文献
6.
Summary Tomato plants ( Lycopersicon esculentum cv. Amberley Cross) were grown in sand culture and were fed with four concentrations of potassium nitrate in combination
with two levels of sodium nitrate. After six weeks the plants were scored for the presence and absence of a symptom of potassium
deficiency, namely, marginal chlorosis and/or necrosis in the young, fully-expanded leaves. These leaves were also analysed
for K and Na. Marginal chlorosis and/or necrosis occurred in plants given a nutrient solution containing 0.5 meq K/I or less
and supplied with either of the sodium nitrate levels. However, the symptoms occurred more frequently in plants receiving
the lower level of sodium nitrate. The laminae on plants receiving the lower concentration of sodium nitrate had a 50 per
cent incidence of chlorisis and/or necrosis when the tissue potassium content was 0.74 per cent of the dry wt, while those
laminae on plants receiving the higher level did not show a 50 per cent incidence until their potassium fell to 0.64 per cent
of the dry wt. 相似文献
7.
Regulation of the uptake and distribution of calcium in thetomato plant was investigated in plants grown in recirculatingnutrient solutions at electrical conductivities of 2,7,12 and17 millisiemens (mS). Despite an increased calcium content inthe nutrient solution at high conductivity (717 mS),the accumulation of calcium by fruit was progressively reducedby increasing salinity, particularly in the distal half. Theincidence of blossom-end rot in fruit (BER) also increased withsalinity. The uptake of water and 45Ca by plants was substantially reducedin the high salinity treatment (17 mS) and, to a lesser extent,by high relative humidity (90 per cent r.h. at 20 °C). Further,the translocation of 45Ca from roots to shoots was reduced byhigh salinity, while the percentage distribution of 45Ca tothe apex was reduced by high humidity. Only approx. 2 per centof the 45Ca taken up by a plant was imported by the truss. The uptake of 45Ca and its distribution among pedicel, calyxand berry by detached fruit in 24 h showed that fruit from highsalinity plants had a reduced uptake and a lower accumulationof 45 Ca in the berry than in the calyx. In addition, plants grown at high conductivity had a lower rateof xylem sap exudation from decapitated plants. The fruit ofthese plants had a smaller xylem cross-sectional area in thefruit pedicel and a smaller calyx than those of the low conductivitytreatment. Calcium, translocation, tomato, fruit, blossom-end rot 相似文献
8.
Factors affecting the uptake and distribution of calcium (Ca)by detached tomato ( Lycopersicon esculentum Mill.) fruit wereinvestigated in seven cultivars with different susceptibilitiesto blossom-end rot (BER), a physiological disorder caused byCa deficiency. Plants were grown with different levels of salinityin the root zone or under shade to induce BER. In addition,fruit grown at different salinities were treated with CME, aninhibitor of auxin transport to alter IAA movement. The basipetalmovement of indole-3-acetic acid (IAA) out of detached fruit(i.e. IAA efflux) was determined concurrently with 45Ca uptaketo assess the possible involvement of IAA in Ca import or theincidence of BER. High salinity in the root zone during fruitdevelopment decreased both the uptake and distribution of 43Cato the blossom-end of the detached fruit. Shading and the applicationof CME reduced 45Ca uptake to a lesser extent. IAA efflux, however,was not consistently reduced by these treatments. Neither theuptake and transport of 45Ca within, nor the efflux of IAA from,detached fruit was related to the cultivar susceptibility toBER. The proposed role of IAA on the uptake and distributionof Ca by tomato fruit is assessed. Key words: Tomato, calcium, IAA, blossom-end rot, salinity 相似文献
9.
Solution culture was used to investigate whether the high solution Na concentrations and Na:Ca ratios found in sodic soils could directly affect the early growth and nutrient uptake of cotton ( Gossypium hirsutum L.). Cotton was grown in nutrient solutions with three Na:Ca ratios (46:1, 4:1 and 0.2:1 m M) and three electrical conductivities (EC) (2.5, 4.25 and 6 dS m ?1) combined in a factorial design with four replicates. Most cotton growth parameters (including shoot and root dry weight, fruit number and weight) were unaffected by increasing solution EC or Na:Ca ratio, but at the highest Na concentration (56.6 m M), plant height was reduced. It was concluded that young cotton has the ability to tolerate solution Na concentrations up to those found in moderately sodic soils. Increasing solution Na:Ca increased plant root and shoot concentrations and plant accumulation for Na, and decreased them for Ca. Increasing EC also increased plant Na concentration and accumulation. Shoot K and P concentrations decreased with EC, but actually increased as the sodicity (Na:Ca ratio) of the nutrient solution increased. The results suggest that the low K and P concentrations commonly found in cotton grown in sodic soils are not a direct result of Na:Ca ratio in the soil solution. 相似文献
11.
The possible causes of blossom-end rot (BER) in tomato fruitwere investigated by comparing the uptake of calcium by theroots, the distribution of 45Ca within the fruit and the vascularbundle network in the fruit of susceptible cultivars (Calypsoand Spectra) with those of a less susceptible cultivar (Counter)grown in a range of salinities (electrical conductivity of 5,10 and 15 mS cm 1). The daily calcium uptake rates at5 mS cm 1 as estimated from the xylem exudation of thedecapitated stem stump in young plants of Calypso and old plantsof Spectra, were lower than that of Counter. The uptake of 45Caby, and the transport to, the distal part of the detached fruitof susceptible cultivars, especially Calypso, were less thanin Counter at 10 mS cm 1. The number of vascular bundlesin both proximal and distal fruit tissues was similar in allcultivars and was only slightly reduced by salinity. However,the number of bundles containing lignified xylem vessels, asdetected by safranin staining, was reduced substantially bysalinity, particularly in Calypso. The estimated area of thefruit tissue served by individual xylem bundles in the BER susceptiblefruit grown at high salinity was greater than in Counter. Theincidence of BER in all trusses was linearly related to theproduct of average daily irradiance and daily temperature throughoutthe year. Temperature appears to be the major environmentalfactor which induces BER, regardless of cultivars and salinitytreatment. The most likely causes of BER in susceptible cultivarsare the interactions of (a) light and temperature on fruit enlargement,(b) inadequate xylem tissue development in the fruit and (c)competition between leaves and fruit for the available Ca. Key words: Lycopersicon esculentum, calcium transport, susceptibility to blossom-end rot, root exudation, xylem 相似文献
12.
Summary A study conducted in pots to evaluate the effect of different Mg/Ca ratios (2, 4, 8 and 16) and electrolyte concentrations
(20 and 80 meq/l) at SAR 10 in irrigation water on the nutrient uptake and yield of wheat crop in two soils revealed that
the average grain and dry matter yields of wheat decreased significantly with an increase in Mg/Ca ratio in irrigation water,
but the magnitude of decrease was greater at higher electrolyte concentration than at lower electrolyte concentration. The
concentration of Na in both straw and grain of wheat increased and that of K decreased with an increase in Mg/Ca ratio and
electrolyte concentration of irrigation water, which led to higher Na/Ca and Na/K ratios in the plant. Further, the concentration
of Ca and Mg both in straw as well as in grain increased with increasing electrolyte concentration of the irrigation water.
An increasing proportion of Mg in saline irrigation water resulted in decreased concentration of Ca and increased concentration
of Mg in both straw and grain of wheat crop. It was also noticed that the increasing proportion of Mg over Ca in the poor
quality irrigation water increased the P content of both straw and grain of wheat crop. 相似文献
13.
To ensure that narrow-leafed lupin ( Lupinus angustifolius L.) meets feed quality standards, the concentration of alkaloids must be kept under the maximum acceptable limit of 200 mg kg –1 DM. One of the factors that may affect seed alkaloid concentration is soil nutrient deficiency. In this paper, we report the results of glasshouse and field experiments that tested the effect of potassium (K) deficiency on seed alkaloid concentrations. In the glasshouse, seed alkaloid concentrations increased by 385, 400 and 205% under severe K deficiency in sweet varieties (Danja, Gungurru and Yorrel, respectively) of L. angustifolius. The concentration of alkaloids in Fest, the bitter variety, was always high regardless of soil K status. At all levels of applied K (0–240 mg kg –1 soil), lupanine was the predominant alkaloid in sweet varieties, whereas 13-hydroxylupanine prevailed in the bitter variety. Seed yield of all varieties increased exponentially with increasing amounts of applied K, reaching a maximum at 60 mg K kg –1 soil. In the field, application of K to deficient soils decreased seed alkaloid concentration at Badgingarra, Western Australia (WA) but not at Nyabing, WA, in 1996. In both field trials, seed yield and mineral content were not affected by the amounts of K fertiliser applied. These findings highlighted the need for adequate K fertilisation of deficient soils in WA to avoid the risk of producing low quality lupin seed with high alkaloid concentrations. K deficiency is involved in stimulating alkaloid production in sweet varieties of L. angustifolius. 相似文献
14.
In a greenhouse study, increases in dry weight and N, P, K, Ca, and Mg content of seedlings from a preplanting application
of 0.16 meq K/100 g of Caddo silt loam topsoil were markedly greater on soil containing 0.06 meq K, than on soil containing
0.09 meq K/100 g. Except for further increasing K and reducing Ca content of seedlings, applications of 0.32 and 0.48 meq
K/100 g added little to growth or nutrient accumulation. Additions of 1 to 5 meq Ca/100 g either did not affect or slightly
reduce dry weight and uptake of all nutrients except Ca. Potassium and calcium treatments did not interact to influence growth
or nutrient uptake. Dry weight and accumulation of N, P, and K were all associated with the amount of K available; Ca accumulation
was related only to available Ca. 相似文献
15.
Tomato plants ( Lycopersicon esculentum Mill. var. DRK) were grown hydroponically to determine the effect of an uneven distribution of nutrients in the root zone on blossom end rot (BER) and Ca and K concentrations in the fruits. The plants were grown in rockwool with their root system divided into two portions. Each portion was irrigated with nutrient solutions with either the same or the different electrical conductivity (EC) in the range 0 to 6 dS m –1. Solutions with high EC supplied to both sides of the root system significantly increased the incidence of BER. However, when only water or a solution of low EC was supplied to one portion, BER was reduced by 80%. Fruit yields were significantly higher ( P<0.01) for plants that received solutions of the uneven EC treatments (6/0 or 4.5/0 EC treatment). Plants supplied with solutions of uneven EC generally had higher leaf and fruit concentrations of Ca but lower concentrations of K than those supplied with solutions of high EC. There was no difference in Ca concentration at the distal end of young fruits of the uneven EC treatment but it was reduced in the high EC treatments. The concentration of K in the mature fruits of the uneven EC treatments was lower than that of the high EC treatments and higher or similar that of the 3/3 or 2.5/2.5 EC treatments (controls). A clear relationship was found between the incidence of BER and the exudation rate. High rate of xylem exudation was observed in the uneven EC treatments. Reduction of BER in the uneven EC treatments is most likely to be the effect of high exudation rate on Ca status in the young fruits. It was concluded that high EC of solution had positive effects on Ca concentration and incidence of BER provided that nutrient solution with low EC or water is supplied to the one portion of the root system. 相似文献
16.
Foliar concentrations of starch and major nutrients N, P, K, Ca, and Mg along with specific leaf weight (SLW) were determined in the potato (Solaruan tuberosum L. ) cvs "Denali", "Norland” and "Russet Burbank" grown for 35 days under the CO2 concentrations of 500, 1 000, 1 500 and 2 000 μmol' mol-l at both 16 and 20 ℃ air temperature. The starch concentration, pooled from the three cuhivars, increased with increasing CO2 concentration at both 16 and 20 ℃, and was consistently higher at 16 ℃ than at 20 ℃. The SLW (g·m-2) was positively related to the foliar starch concentration on the basis of leaf area or dry weight. The concentrations of N, P, Ca, and Mg in leaves were negatively related to starch concentration under 14% starch on a dry weight basis. Above 14%, there was no significant relationship between nutrient and starch concentrations. The similar patterns were seen when the SLW and nutrient concentrations were expressed on a starch-free basis. In contrast, the leaf concentration of K was not closely related to the starch concentration. The results indicated that the changes in SLW and concentrations of N, P, Ca, and Mg in potato leaves only partially resulted from the changed starch concentration. 相似文献
17.
The effect of soil nutrient content on fruit yield and fruit quality is very important. To explore the effect of soil nutrients on apple quality we investigated 200 fruit samples from 40 orchards in Feng County, Jiangsu Province. Soil mineral elements and fruit quality were measured. The effect of soil nutrient content on fruit quality was analyzed by artificial neural network (ANN) model. The results showed that the prediction accuracy was highest (R 2 = 0.851, 0.847, 0.885, 0.678 and 0.746) in mass per fruit (MPF), hardness (HB), soluble solids concentrations (SSC), titratable acid concentration (TA) and solid-acid ratio (SSC/TA), respectively. The sensitivity analysis of the prediction model showed that soil available P, K, Ca and Mg contents had the greatest impact on the quality of apple fruit. Response surface method (RSM) was performed to determine the optimum range of the available P, K, Ca, and Mg contents in orchards In Feng County, which were 10∼20 mg⋅kg −1, 170∼200 mg⋅kg −1, 1000∼1500 mg⋅kg −1, and 80∼200 mg⋅kg −1, respectively. The research also concluded that improving the content of available P and available Ca in orchard soil was crucial to improve apple fruit quality in Feng County, Jiangsu Province. 相似文献
18.
AimsHigh pH, and high bicarbonate (HCO3−) and calcium (Ca) availability characterise calcareous soils. High [Ca] only partially explains why some Lupinus species are calcifuge, so we explored high [HCO3−] and high pH. MethodsWe grew six Lupinus genotypes in hydroponics with pH 5, 6.5 and 8a (adjusted by KOH), and 8b (adjusted by KHCO3). Leaf symptoms and areas, root appearance and biomass were recorded; whole leaf and root nutrient concentrations, and leaf cellular phosphorus (P), Ca and potassium (K) concentrations were determined using elemental X-ray microanalysis. ResultsChlorosis was observed in young leaves at high pH for L. angustifolius and L. cosentinii, and P deficiency at high pH for all genotypes. High pH decreased iron (Fe) and zinc (Zn) uptake in all genotypes. It also decreased lateral root growth, the uptake of P, K, Ca, and manganese (Mn) by all sensitive species; and translocation of P, Fe, Zn, Mn, and Ca to leaves in most sensitive species. However, leaf [Ca], leaf [K], [K] within each measured cell type, and translocation of K and Ca to leaves of L. pilosus and L. cosentinii at pH 8 were greater than at pH 5 and 6.5. Compared with pH 8a, all L. angustifolius genotypes translocated more P, Fe, Zn, Mn and K from roots to leaves at pH 8b. High pH did not affect the leaf cell types that accumulated P and Ca, but decreased the leaf cellular [P]. ConclusionsLupinus angustifolius and L. cosentinii were sensitive to high [HCO3−] and/or high pH; L. pilosus was relatively tolerant. High pH decreased lateral root growth and nutrient uptake, inhibiting growth of sensitive species. High [HCO3−] diminished the negative effect of pH 8 on nutrient translocation to leaves in most L. angustifolius genotypes. This knowledge provides critical insights into the habits of Lupinus species to guide breeding of calcicole plants. 相似文献
19.
Although gibberellins (GAs) have been shown to induce development of the physiological disorder blossom-end rot (BER) in tomato fruit ( Solanum lycopersicum), the mechanisms involved remain largely unexplored. BER is believed to result from calcium (Ca) deficiency, but the relationship between Ca content and BER incidence is not strong. Our objectives were to better understand how GAs and a GA biosynthesis inhibitor affect BER development in tomato fruit. Tomato plants of two BER-susceptible cultivars, ‘Ace 55 (Vf)’ and ‘AB2,’ were grown in a greenhouse environment and subjected to Ca-deficiency conditions. Plants were treated weekly during fruit growth and development with 300 mg L ?1 GA 4+7, 300 mg L ?1 prohexadione-calcium (Apogee ®, a GA biosynthesis inhibitor), or water beginning 1 day after flower pollination. GA 4+7 treatment induced an increase in BER incidence in both cultivars up to 100%, whereas ‘Ace 55 (Vf)’ and ‘AB2’ plants treated with Apogee did not show BER incidence. The number of functional xylem vessels was higher in the placental and pericarp tissue of tomato fruit treated with Apogee at the early stages of fruit growth. Treatment with Apogee also increased fruit pericarp Ca concentration. GA 4+7 treatment enhanced the expression of the putative CAX and Ca-ATPase genes, that code for proteins involved in Ca movement into storage organelles. The lowest water-soluble apoplastic Ca concentration and the highest membrane leakage values were observed in the pericarp of GA 4+7-treated fruit. These results suggest that GAs consistently reduced fruit Ca uptake and water-soluble apoplastic Ca concentration, leading to leakier plasma membranes and an increase in BER development in fruit tissue of both tomato cultivars. 相似文献
20.
BACKGROUND: The incidence of blossom-end rot (BER) is generally associated with a calcium (Ca) deficiency in the distal portion of tomato fruits. The visible symptom is a necrotic lesion, which is presumed to be a consequence of cell death and the subsequent leakage of solutes into the extracellular space. Environmental factors that affect either fruit cell expansion or Ca delivery to the distal portion of the fruit influence the occurrence of BER. However, since no absolute, critical fruit Ca concentration for the occurrence of BER has been identified, it is now important to define the role of Ca in fruit cell physiology and to seek the cause of BER at the cellular level. HYPOTHESIS: Here, it is suggested that BER is initiated by a cellular dysfunction in the distal portion of a young fruit during rapid cell expansion. It is proposed that insufficient Ca(2+) is available for critical apoplastic and cytoplasmic functions when the cellular Ca demand imposed by vacuolation exceeds the Ca delivery to an expanding cell. A local Ca deficiency, therefore, may result in aberrant intracellular Ca(2+) signals, a weakening of cell walls and a loss of cellular integrity. Ultimately it may lead to cell death and the visible symptoms of BER. Several experimental strategies are suggested to confirm the occurrence of aberrant Ca(2+) concentrations in cells contributing to BER. PERSPECTIVE: Many genetic and genomic resources are becoming available for tomato. Ultimately, these will allow genes affecting the occurrence of BER to be identified. Such knowledge will inform breeding strategies to eliminate BER. In the meanwhile, increasing the apoplastic Ca concentration in susceptible fruit tissue should provide a simple and reliable, practical solution for the prevention of BER in tomatoes. It is suggested that current horticultural practices, such as the manipulation of the mineral composition of the feed or the growth environment, are not completely effective in reducing BER because they affect apoplastic Ca concentration in fruit tissue indirectly. Therefore, spraying Ca directly onto young fruits is recommended for the prevention of BER. 相似文献
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