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1.
M. El.-D. Ibrahim S. Prochézka V. Borkovec 《Journal of Agronomy and Crop Science》1988,160(5):339-344
The transport and distribution of 14C- sucrose and 14C- BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period of kernel formation. While M C-sucrose was transported and accumulated intensively in the developing ear, 14C- BA was transported much less and only a small part of it was found in the ear. With the ear development the accumulation of both 14 C-sucrose and 14 C-BA in the ear increased but the 14 C-BA distribution pattern (ratio of the internode/kernel and the rest of the ear) did not change significantly. In the period of one to two weeks after anthesis the accumulation of 14 C-sucrose and 14 C-BA was higher in the kernels of the Slavia cv., i.e. in the cultivar with a higher mass of kernels. 相似文献
2.
Maize ( Zea mays L.) plants were grown in the field and labelled with 14 CO2 at four leaf positions from silking up to maturity. The ear leaf was the most important source of labelled photosynthates to the ear, followed by the first leaf blade above and below the ear. The movement of labelled assimilates from the second leaf blade below the ear was predominantly downwards. The ear became an important sink soon after silking and continued in importance till harvest.
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of14 C, which was mostly deposited in the stem. 相似文献
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of
3.
Investigations about the distribution of assimilates during flowering in broad beans ( Vicia faba L.)
The distribution of assimilates during flowering was studied on single plants exposed to14 CO2 in the field. The plants were harvested 1, 3, 15 days after exposition and at ripening. Results:
1. At the begin of flowering the nodes with flowers assimilated much14 C with a tendency of higher contents in the more above situated nodes. The concentration of 14 C was similar in blades, stalks and flowers.
2. The assimilates incorporated after 24 hours were only to a small amount translocated afterwards. Only 3 % went to the apical region. An intensive restorement out of the blades took place at the time of ripening.
3. In the midst of flowering the concentration of14 C was lower in the nodes with open flowers than in those with shut or with pods. At that time pods are already strong sinks that withdraw assimilates from blades and stalks.
4. At the time when large and small pods are growing on the lower and middle nodes, the nodes in the apical region will be deprived of assimilates (effects of dominance).
5. Roots and nodules had low but stable contents and concentrations of14 C during flowering. These descended distinctly at ripening. 相似文献
The distribution of assimilates during flowering was studied on single plants exposed to
1. At the begin of flowering the nodes with flowers assimilated much
2. The assimilates incorporated after 24 hours were only to a small amount translocated afterwards. Only 3 % went to the apical region. An intensive restorement out of the blades took place at the time of ripening.
3. In the midst of flowering the concentration of
4. At the time when large and small pods are growing on the lower and middle nodes, the nodes in the apical region will be deprived of assimilates (effects of dominance).
5. Roots and nodules had low but stable contents and concentrations of
4.
Genotypic differences in the translocation of temporarily stored 14 C from the stem to the grains in spring wheat (Triticum aestivum L.)
In three field experiments with two spring wheat genotypes (Kolibri and breeding line 93117 ), changes in the total nonstructural carbohydrates (TNC) of the stem were observed after anthesis. Maximum values were measured in the third or fourth week following anthesis when stems contained 300 to 400 mg TNC. Thereafter TNC content declined up to maturity.
Flag leaves of individual shoots or all plants in micro-plots were labelled with14 C 5 days prior to anthesis, at anthesis or 5 days after anthesis to observe long term movements of assimilates during grain filling. After a chase period of two to three days, 60 to 80 % of total 14 C recovered in the shoot was in the stem. From total l4 C recovered two to three days after labelling, Kolibri had translocated 12.5 to 27.0 % into the grains by maturity whereas this portion was significantly higher for the breeding line 93117 (22.5 to 43.9 %). It was concluded that genotypes differ in the translocation of soluble carbohydrates from the stem to the grains. These differences were not related to parameters describing the 'source-sink' relationship, such as leaf area, grain number or grain size. However, the lower translocation rates of Kolibri coincided with a lower TNC concentration in the stem dry matter. This was due to a higher stem weight at anthesis, a longer period of stem elongation and a higher incorporation of assimilates into structural carbohydrates in non elongating stem parts after anthesis. It was therefore suggested that the accumulation of TNC in the stem and the remobilisation of these reserves for grain filling are determined partly by factors related to the carbohydrate metabolism in the stem. 相似文献
In three field experiments with two spring wheat genotypes (Kolibri and breeding line 93117 ), changes in the total nonstructural carbohydrates (TNC) of the stem were observed after anthesis. Maximum values were measured in the third or fourth week following anthesis when stems contained 300 to 400 mg TNC. Thereafter TNC content declined up to maturity.
Flag leaves of individual shoots or all plants in micro-plots were labelled with
5.
The effects of exposure in the vegetative phase of growth to 5- or 10-day spells of soil drought (30% field water capacity) on assimilation, dissimilation and accumulation of 14 C and on dry matter growth were studied in two maize hybrids, nos. 8344 and 8388 (Garst Seed Co.) of high and low drought tolerance. Under control water regime in soil there was no difference in 14 CO2 uptake and dry matter growth between hybrids. After five days of drought 14 CO2 assimilation dropped by about 75% referred to unit weight of dry matter in hybrid 8344 and by 56% in hybrid 8388. After 10 days of drought 14 CO2 assimilation rate was reduced by 75% in both hybrids. Soil drought increased the 14 C dissimilation. There were no significant differences between hybrids in all treatments, with the exception of 5 days drought; after this treatment the dissimilation rate of hybrid 8344 was higher than that of 8388. Changes of translocation of 14 C and its accumulation in particular organs occurred in drought treated plants; the amount of 14 C accumulated in roots of plants of hybrid 8344 increased, while that of hybrid 8388 decreased. Changes of 14 C accumulation in roots were positively correlated to changes of dry matter of those organs. One day after 10 days of drought assimilation and dissimilation rates in both hybrids were about 60% of controls. 相似文献
6.
The effect of the application of abscisic acid (ABA, 10−4 mol 1−1 ), benzyl adenine (BA, 10−6 mol - 1−1 ), N6 -m-hydroxybenzyl-adenosine (HBA, 10−6 mol - 1−1 ) and combinations of these cytokinins with ABA on the transport of 14 C-sucrose into the developing kernels of winter wheat, their number and mass, was studied. Growth substances were applied in the period 10 to 5 days before anthesis and their effects were examined 4 and 18 days after anthesis on ears that were detached 10 days before anthesis and then cultivated on a complete nutrient solution. The stimulating effect of HBA on the transport of 14 C-sucrose, number of kernels and their mass was higher than that of BA. ABA partly decreased the stimulating effect of cytokinins and reduced up to several days after anthesis the transport of 14 C-sucrose to the developing kernels, their number and mass. The results revealed that a higher level of cytokinins in the period before anthesis could effectively interact with the inhibiting effect of ABA in that period and influence the accumulation of assimilates in the kernels. 相似文献
7.
J. Ko&#;cielniak F. Janowiak J. Biesaga-Ko&#;cielniak 《Journal of Agronomy and Crop Science》1993,170(3):163-170
Seedlings of a maize hybrid sensitive to chilling initially grew in the growth chamber of the phytotron at 20/ 17°C (day/night) and after the formation of the fourth leaf, the soil temperature was lowered to 5°C. Under such growth conditions the dynamics of dry weight change, gas exchange and the distribution of 14 C-assimilates in seedlings were examined. The low soil temperature inhibited daily growth of dry weight of whole seedlings more than their photosynthesis. Simultaneously, it was also responsible for a greater increase in dissimilative losses.
During 37 hours (day-night-day), following exposure to14 CO2 , dissimilation in seedlings in cool soil (5°C) and in non-chilling conditions amounted to 35.1 % and 23.4 % of assimilated 14 C (AC), respectively. At lower soil temperature relatively high dissimilative losses were observed on the first day after exposure (23.5 %), lower at night (9.9 %) and the lowest on the following day - merely 1.7 % AC. Higher losses of 14 C under chilling conditions occurring on the first day were a result of limited photosynthetic refixation of 14 CO2 At night, however, they were associated with a prolonged period of intensive translocation of assimilates to the stem. It was assumed that an excessive accumulation of assimilates in leaf blades might be an additional factor responsible for increased dissimilative losses at low temperature during the first twenty-four hours. In the third period of measurements, as a result of a limited transport of 14 C, dissimilative losses were lower than in previous ones and were not dependent upon soil temperature. 相似文献
During 37 hours (day-night-day), following exposure to
8.
Effect of plant growth regulators Naphthalene acetic acid (NAA), Gibberellic acid (GA3 ) and Kinetin on 14 CO2 assimilation, partitioning of 14 C into major biochemical fractions and translocation of assimilates was studied in different parts of Indian Mustard ( Brassica juncea ) at late ripening stage. Leaves, stem and pod walls are photosynthetically active and are important sources for seed filling. NAA and kinetin increased the 14 CO2 assimilation rate in all the three photosynthetically active parts. All the three growth regulators increased the export of 14 assimilates out of source organs and increased the movement of assimilates into the reproductive parts (pods). The increased movement of photoassimilates into the developing pods may be due to the stimulation of sink activity by the growth regulators which resulted in the higher demand for photoassimilates. It was suggested that growth regulators may increase yield by altering distribution of assimilates in the mustard plants. 相似文献
9.
Field bean planes cultivar Nadwiślański were submitted to soil drought (30 % of field soil water capacity) for 5 days at the stage of pod formation (A) and of rapid pod growth (B) and then exposed for 20 minutes to 14 CO2 . Radioactivity of leaves, stems, roots, and pods or pod shells and seeds was measured 1, 5, 24 and 48 hours after exposition.
In both stages soil drought reduced by about five times total CO2 assimilation, mainly owing to lower activity of the photosynthetic apparatus and also, though less so, to reduced leaf growth. Photosynthetic activity referred to the dry weight of the leaves dropped to 22-35% of controls. Accumulation of photosynthetates in generative organs was much less depressed than 14 CO2 assimilation. 48 hours after exposition to 14 CO2 of drought treated plants, the contents of 14 C of pods in phase A, and seeds in phase B, amounted to respectively 24% and 36% of assimilated 14 C and equalled 91.5% and 74% of the corresponding values for controls.
The progressive decline of radioactivity in leaves and stems after14 CO2 exposition was distinctly correlated to the rise of radioactivity of generative organs both in soil drought treated plants and in controls. Slightly lower values of correlation coefficients in drought treated plants may indicate impairment under drought conditions of synchronization in processes of unloading and accumulation of assimilates.
In plants drought treated in phase A the ability to dissimilate14 C was reduced to about 59% of that in controls, but when drought was applied in phase B, dissimilation rate was about three times as high. 相似文献
In both stages soil drought reduced by about five times total CO
The progressive decline of radioactivity in leaves and stems after
In plants drought treated in phase A the ability to dissimilate
10.
Influence of high temperature stress on photosynthesis and allocation of carbon into different biochemical fractions in mature leaves of Indian mustard [ Brassica juncea (L) Czern] was investigated. Heat stress reduced 14 CO2 fixation and inhibited the translocation of carbon from the leaves. Allocation of 14 C into starch and residue fractions was significantly lower in heat stressed plant leaves. Starch content was significantly reduced in heat stressed plants. 相似文献
11.
Pflanzenwachstum durch CO2 /HCO3 -Eintrag über die Wurzel 总被引：1，自引：0，他引：1
W. Schäfer 《Journal of Agronomy and Crop Science》1988,160(4):228-234
Plant Growth after Application of CO2 /HCO3 to the Roots
After applying H14 CO3 to the root system of summer wheat in hermetically sealed pots, absorption and incorporation of HCO3 in the sugar-, starch-, and fibre-fraction (approximately 50 % of the absorped 14 C) could be shown. This fraction reached 0.44–1.21 % of total C-assimilation of the shoot during growing stage F9/F10 on the Feeke-scala. 1/3 of the HCO3 -fraction resting in the soil was bound organically indicating that microorganisms may be able to utilize exogenous anorganic CO2 /HCO3 for their photosynthesis. 相似文献
After applying H
12.
S. Ito T. Hara Y. Kawanami T. Watanabe K. Thiraporn N. Ohtake K. Sueyoshi T. Mitsui T. Fukuyama Y. Takahashi T. Sato A. Sato & T. Ohyama 《Journal of Agronomy and Crop Science》2009,195(5):368-376
Rice ( Oryza sativa cv. Koshihikari) seedlings were grown in a sandy dune soil in pots with a basal dressing of N (0.5 g N), P and K. Two N treatments were applied, a +N treatment in which a top dressing of 15 N-labeled 0.5 g N was supplied on July 20 and a −N treatment in which no additional fertilizer was supplied. During the grain-filling stage from August 6 to 13, plants were subjected to one of three temperature treatments; controlled low temperature, LT (day/night 28/23 °C), controlled high temperature, HT (35/30 °C) and uncontrolled glasshouse temperature, UT (day/night averages, 38/26 °C). All plants were then exposed to 13 CO2 for 1 h on August 11 in a growth chamber at 25 °C. On August 13, all plants were harvested and the 13 C and 15 N abundances and starch and sugar concentrations in the ears, shoots and roots were determined. The 13 C content of the ear was lower in UT than in LT irrespective of the +N or −N treatment. The translocation of 15 N to the ears was also slightly depressed in UT compared with LT. Under high-temperature conditions (HT and UT), the starch content per plant was reduced for −N, but for +N, it was not significantly different among the temperature treatments. A high accumulation of sucrose was observed in all plant parts under UT conditions. It is suggested that extreme high day temperatures during the grain-filling period may reduce starch synthesis in the grains and, especially so under N-deficient conditions. High temperatures also induce an accumulation of sucrose and a decrease in carbon and nitrogen transport from the shoots to the ears via the phloem. 相似文献
13.
H. Stützel W. Aufhammer A. Rautenkranz B. Wagner J. Falfus E. Nalborczyk 《Journal of Agronomy and Crop Science》1993,170(3):177-186
Yield formation and yield components of a conventional and an epigonal genotype of white lupin ( Lupinus albus )
Differences in yield formation and yield structure of two contrasting Lupinus albus growth types, the conventional, freely branching cultivar Kalina and the epigonal. little branching cultivar Ep I were analyzed. Both cultivars were grown in field experiments at Hohenheim in 1987 and 1988 with a combined variation of population density (30–120 plants/m2 ) and plant distribution. In addition, assimilate distribution within the plant was studied using a 14 C-labelling experiment. – The contributions of branches to light interception of the crops during the generative phase were > 90 % in Kalina as compared to about 30 % in Ep 1 . Relative 14 C uptake of branches was in a similar range, but great proportions of the 14 C taken up by branches was translocated to main stems. No genotype x plant density interactions with respect to grain yield were recorded, indicating that yield formation at main stems and branches was affected by cropping conditions similarly in both genotypes. This applies to the conditions of the experiments, where stress effects were absent. Under these conditions, the conventional genotype showed agronomic, but no physiological disadvantages. 相似文献
Differences in yield formation and yield structure of two contrasting Lupinus albus growth types, the conventional, freely branching cultivar Kalina and the epigonal. little branching cultivar Ep I were analyzed. Both cultivars were grown in field experiments at Hohenheim in 1987 and 1988 with a combined variation of population density (30–120 plants/m
14.
Effect of Soil Moisture and Potassium Fertilizer on Shoot Water Potential, Photosynthesis and Partitioning of Carbon in Mungbean and Cowpea 总被引：3，自引：0，他引：3
The effect of different rates of potassium (K+ ) on shoot water potential, photosynthesis and carbon movement (using 14 C) at the V3/4 growth stages was studied in mungbean ( Vigna radiata L. Wilczek), a drought-susceptible legume, and cowpea ( Vigna unguiculata L. Walp), a drought-tolerant legume, grown under low- and high-irrigation regimes under controlled conditions. Soil moisture and K+ affected all measured parameters in the two species. The rate of photosynthesis was higher at reduced water stress when K+ was applied. The impact was greater in cowpea, which had an inherently high rate of carbon assimilation. Mungbean and to a lesser extent cowpea allocated greater quantities of carbon to roots under dry conditions, especially with added K+ . The distribution of 14 C into other plant parts was also increased at higher rates of K+ application under both soil moisture regimes. Thus, application of K+ seems to have a beneficial effect in overcoming soil moisture stress and increasing physiological parameters and carbon partitioning in these two important tropical food legumes. 相似文献
15.
Zhang Qinzheng Xi Haifu Lan Xiafua Zhu Xuequn Liu Yinhua 《Journal of Agronomy and Crop Science》1991,166(3):152-156
Rape plants were labelled by applying (NH4 )2 35 SO4 to soil. Changes in content of 35 S in various constituents in pods and grains were determined during siliquae development to exploit formation and accumulation of glucosinolates in oilseed rape. Content of 35 S in glucosinolates expressed as μmol S/g.d.w. and its relative amounts in extractable forms in young siliquae were in constant level within one week after flowering, but either absolute content or relative content of 35 S in glucosinolates increased largely by two weeks after flowering, thereafter the distribution of extractable 35 S in glucosinolates of siliquae and grains increased linearly as proceeding of its development, 35 S in extracts of grains almost was in form of glucosinolates after 8 weeks from flowering. Amounts of both 35 S in glucosinolates and dry matter per pod increased linearly with time after flowering. According to the changes of amounts of 35 S in other constituents per pod, it could be supposed that glucosinolates accumulated in seeds might be transported from other organs together with nutrients. 相似文献
16.
N. Keutgen G. W. Roeb F. Führ H. J. Reisener 《Journal of Agronomy and Crop Science》1995,175(5):297-305
Accumulation of assimilates in stem-rust-infected wheat leaves
Using wheat plants (cv. 'Prelude'), the effects of stem-rust infection on photosynthesis and assimilate partitioning were studied with the aid of the short-lived carbon isotope11 C. Photosynthesis of strongly infected leaf parts declined by about 30 % within 1 day. This rapid inhibition was caused by the formation of appressoria and the growth of infection tubes into the stomata, leading to a reduction in gas exchange. Further decline of photosynthesis to 5–10 % was accompanied by the degradation of chlorophyll. Nevertheless, during sporulation, the dry weight of the infected leaf area increased by about 50 %. With the use of 11 C, the reduced export of photosynthate from the infected leaf part and the capture of labelled compounds from the apical leaf section were quantified. The enhanced storage of assimilates in stem-rust-infected leaves can be attributed to the increase in invertase activity. 相似文献
Using wheat plants (cv. 'Prelude'), the effects of stem-rust infection on photosynthesis and assimilate partitioning were studied with the aid of the short-lived carbon isotope
17.
The role of leaves, stem and reproductive parts in 14 CO2 fixation and subsequent photosynthate translocation was studied in Indian mustard ( Brassica juncea L.) at three growth stages. The data indicated that leaves, stem and pods are important sources of photosynthates for seed filling. At bud emergence stage leaves are the principle site of 14 CO2 , fixation. The contribution of leaves declines at subsequent stages, where as the contribution of pod walls increased from bud emergence stage to ripening stage. The contribution of the stem remains more or less constant at all three growth stages studied. Although stem can fix 14 CO2 , at bud emergence and flowering stages it imported 14 C-photosynthates from leaves. However, stem exported photosynthates during subsequent growth stages. 相似文献
18.
Effect of heat stress on 14 CO2 assimilation and translocation by different parts was investigated in Indian mustard ( Brassica juncea (L.) Czern.]. Heat stress reduced 14 CO2 assimilation by leaves, stem and pods. Export of radioactive carbon from upper and lower leaves, upper and lower stem and stem of terminal raceme was inhibited in response to heat stress. Import of 14 C-photosynthates into pods was also inhibited by heat stress indicating reduction in sink strength of the developing pods. 相似文献
19.
Analysis of Wheat Cultivar Differences in Grain Yield, Grain Nitrogen Yield and Nitrogen Utilization Efficiency. 总被引：1，自引：0，他引：1
More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha-1 was applied before planting or 100 N kg ha-1 before planting and then 50 N kg ha-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha-1 ) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application. 相似文献
20.
Zhang Qinzheng Lan Xiafua Xi Haifu Zhu Xuequn Liu Yinhua 《Journal of Agronomy and Crop Science》1991,166(2):96-100
The conversion of SO2- 4 -S and changes in content of S in various constituents in leaves of rape seedlings transplanted were investigated by using (NH4 )2 35 SO4 as a tracer to exploit formation and accumulation of glucosinolates in oilseed rape. Seedlings grown under sandy culture absorbed 35 SO2- 4 which was added to the cultural solution and incorporated into amino acids, glucosinolates and proteins rapidly. Distribution of extractable 35 S with 70 % methanol in glucosinolates in leaves declined with time from labelling, while those in amino acids rised correspondingly. Per cents of 35 S incorporated into bound form in total 35 S increased linearly and those of 35 S into glucosinolates and amino acids decreased with time within five days from labelling. After that the relative amounts of 3S S in three constituents was basically constant. Content on dry weight basis of labelled glucosinolates and amino acids expressed as μmol S/g.d.w. increased linearly with time from labelling with absorption of 35 SO2- 4 from soil by the seedlings under soil culture. Compared with seedlings grown under sandy culture, more 35 S was incorporated into glucosinolates in leaves of seedlings grown under soil culture. 相似文献