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1.
The application of gibberellic acid (0, 5, 20 and 80 µg) to seedlings of Syringa vulgaris L. about two weeks after germination increased significantly the total length, the length of internodes and the dry weight (d.w.) of shoots and the net assimilation rate. GA3 also had a small but significant positive effect on the number of pairs of leaves, especially at high temperatures; it increased the girth, but this effect was not significant.

GA3 reduced significantly the d.w. of roots and leaves but did not affect the leaf/root ratio. GA3 had no effect on the total plant d.w. or the relative growth rate.

The effect of GA3 on shoot growth was dependent on temperature and on the stage of growth. One and two weeks after its application it had the maximum relative effect at high temperatures (21–24 °C) but at the end of the experiment (8.5 weeks) the maximum effect was reached at 12 °C; it decreased with increasing temperature and was not significant at 24 °C. By this stage there were, however, no statistical interactions between temperature and GA3 for total length and for d.w. of shoots, roots, leaves and of the whole plant.

Increasing temperatures over the range 12–24 °C resulted in increases in the following characteristics: the number of pairs of leaves; length of internodes, diameter and total length of the shoot; the d.w. of shoots, roots, leaves and of the whole plant; the d.w. ratios of leaves/roots and shoots/roots; and the relative growth rate and net assimilation rate. High temperatures reduced the root/whole plant dry weight ratio. The effect of temperature on the number of pairs of leaves was linear, and results at alternating temperatures (24°/18° and 21°/15 °C, 8 hr/16 hr) did not deviate significantly from values expected on the basis of mean daily temperature.  相似文献   

2.
Summary

Experiments were conducted to optimize nutritional and cultural requirements for initiation and growth of roots on papaya in vitro. Axillary shoots were obtained from plants which had been sub-cultured monthly for two years. Root initiation was enhanced when 1 to 2 mm of stem base was removed and shoots were growing actively before transfer to the rooting medium. Decreasing daylength during incubation from 24 h to 12 h promoted root initiation. Within the day temperature range of 22 to 29°C, optimum rooting occurred at 27°C and higher temperatures produced higher mean root weights per shoot. High concentrations of growth factors and the absence of sucrose in the medium both reduced root initiation, however, varying the concentration of sucrose and removing growth factors affected mean root weight per shoot. All media contained a modified de Fossard et al. (1974) basal medium plus 10 μM IBA.  相似文献   

3.
The problem was studied whether tomatoes, grown in a hot and arid climate, benefit from grafting on egg-plant, which is highly efficient in water uptake. Growth and development of tomato (T), tomato grafted on its own rootstock (TT) and tomato grafted on egg-plant rootstock (TE) were compared at air temperatures of 28°C during the day and 18°C during the night (2818) and at 28°C constantly (2828), at soil temperatures of 14, 21 and 28°C with the following soil moisture regimes: wet (W1), medium (W2) and dry (W3).At 2818 and 2828 water consumption was about equal, but the transpiration ratio at 2828 was twice as high as that at 2818. The latter conditions gave a much stronger plant with more fruits. At a soil temperature of 14°C water use was strongly reduced. The transpiration ratio increased with the soil temperature. Differences in plant type were small. At the highest soil temperature of 28°C fruit growth was strongly reduced. At lower soil moisture levels less water was used and the transpiration was lower. Plant type was correlated herewith.Vegetative growth of TT was weaker than of T, but generative growth was stimulated. The strong E rootstock stimulated vegetative growth at high air and soil temperature, but fruit growth was very poor under these conditions; at a low soil temperature of 14°C vegetative growth was also reduced.The hope that the E rootstock would be beneficial for fruit growth at high temperatures was not fulfilled.An additional experiment in a growth-room at 23°C showed that under conditions of moisture stress there was no difference in water potential between leaves of TT and TE.  相似文献   

4.
The effect of a wide range of soil temperatures (6–26°C) on growth and flowering of Chrysanthemum morifolium Ram. ‘Horim’ were studied at the favourable air temperature of 18°C. Shoot growth was severely reduced at soil temperatures below 10°C which may be explained by poor root growth, while flowering was enhanced by approximately 2 days compared to higher soil temperatures. Increasing the soil temperature to 18°C was beneficial. Further increase had no positive effect on growth. Measurements of net photosynthetic rates revealed no effect of lowering soil temperatures from 18 to 6°C.Mother plants grown at 18°C air temperature revealed no effect of soil temperatures ranging from 13 to 21°C on number and fresh weight of the cuttings. Neither did mother plants grown at the less favourable air temperatures of 12 or 15°C. Cutting production was, however, affected by air temperature.  相似文献   

5.
Six-week-old tomato plants were subjected to 5 root-zone temperatures, ranging from 12 to 36°C, and 4 light levels in a factorial design. Large increases in shoot dry weight, leaf area and fruit development resulted from soil warming to 24°C when plants were grown under high light conditions. Shoot growth and fruit weight were reduced at 24°C root temperature under low light conditions. Total plant photosynthesis, leaf area index, net assimilation rates and leaf chlorophyll content were related to plant growth and flower development for the various treatments. Our experiments have shown an interaction between root-zone temperature and light levels for greenhouse tomatoes. Soil warming caused large increases in shoot dry weight and fruit development when light was not limiting plant growth, but had deleterious effects on flowering and fruit set under shaded conditions.  相似文献   

6.
Gas exchange of lettuce plants, pre-grown in growth chambers at different irradiances (18, 37, 70 W m?2) and temperatures (6, 14, 22°C) were measured in the range of 2–22°C. In weak light (18 W m?2) there was no increase in CO2 uptake above 2°C, and even in 70 W m?2 the highest rates were obtained at about 10°C only. The response of net photosynthesis of lettuce to temperature is diminished as a result of morphological plant adaptations, i.e. specific leaf area or top-to-root weight ratio. The temperature optimum for dry-matter production is much higher than that for CO2 uptake. Therefore, photosynthesis is an unsuitable criterion for temperature control in greenhouses.  相似文献   

7.
Summary

This study addresses the effects of air temperature and plant growth regulators on anthocyanin synthesis, sugar content and phenylalanine ammonia-lyase (PAL) activity in chicory (Cichorium intybus L.). Anthocyanin in chicory was synthesised at the highest level under 15°/10°C (day/night) temperatures, followed by 20°/15°C, and 25°/20°C; while synthesis was inhibited > 90% at 30°/25°C, resulting in an almost green colour. Sugar contents paralleled anthocyanin development under the same temperatures. The plant growth regulators, abscisic acid (ABA), ethephon and uniconazole all stimulated anthocyanin synthesis, with uniconazole treatment showing the greatest effect. Gibberellic acid (GA3) inhibited anthocyanin development, while GA3 in combination with uniconazole alleviated this inhibition.

PAL activity was higher at 15°/10°C or 20°/15°C (day/night) temperatures when plants were treated with ABA, ethephon or GA3, than at 25°/20°C and 30°/25°C (day/night) temperatures. These results suggest that, under lower temperatures, plant growth regulators may play an important role in anthocyanin synthesis and PAL activity in chicory.  相似文献   

8.
Abstract

Four European (Vitis vinifera L.) winegrape cvs., ‘Semillon’, ‘Pinot Noir,’ ‘Chardonnay’, and ‘Cabernet Sauvignon’, and one American (Vitis aestivalis Michx.) winegrape cv. ‘Cynthiana’, were subjected to three temperature regimes in growth chambers set at 20/15°C, 30/ 25°C, or 40/35°C, for 16/8 hr day/night to determine the influence of temperatures on vine growth and development. In general, the best temperature for shoot and root growth 28 days after temperature treatments was 20/15°C for ‘Semillon’, ‘Cabernet Sauvignon’, and ‘Cynthiana’, and 30/25°C for ‘Pinot Noir’ and ‘Chardonnay’. Although 40/35°C reduced number of leaves, shoots, tendrils, and internodes, total leaf area (LA), and total shoot biomass of all the cultivars, the reduction was more pronounced in ‘Cynthiana’ than in the European cultivars. The average reduction in number of leaves at 40/35°C for the European cultivars was 47%, compared with 92% for ‘Cynthiana’. The two types of grapes adapted differently to high temperature. Shoot growth in the European cultivars continued under high temperature, whereas growth ceased in ‘Cynthiana’. Roots of ‘Cynthiana’, however, were less susceptible to the adverse effect of high temperatures than were the shoots. This study shows that the European cultivars were relatively more tolerant to high temperature than the American cultivar and they have a potential for production of wine in the climate of south central Kansas.  相似文献   

9.
Summary

Floral induction in tropical trees generally follows a check in vegetative growth. However, it is not easy to identify the environmental factors involved in flowering, which normally occurs during the dry season when temperatures are also often lower. The separate and combined effects of temperature and water supply on floral induction were investigated in ‘Hass’ avocado (Persea americana), ‘Lisbon’ lemon (Citrus limon). ‘Wai Chee’ litchi (Litchi chinensis) and ‘Sensation’ mango (Mangifera indica). Low temperatures (15°/10°C or 15°/10°C and 20°/15°C compared with 30°/25°C and 25°/20°C) generally decreased vegetative growth and induced flowering in well-watered avocado, litchi and mango. A pre-dawn leaf water potential (ψL) of ?1.7 to ?3.5 MPa compared with ?0.4 to ?0.7 MPa in control avocado and litchi, and a pre-dawn relative water content (R.W.C.) of 90-93% compared with 97% or above in control mango plants also reduced or eliminated vegetative growth, but did not induce flowering. Low temperatures (15°/10°C compared with 20°/5°C, 25°/20°C or 30°/25°C) and water stress (pre-dawn ψL of ?2.0 to ?3.5 MPa compared with ?0.7 to ?0.8 MPa in controls) reduced or eliminated vegetative growth in lemon. In contrast to the response in avocado, litchi and mango, flowering in lemon was very weak in the absence of water stress at 15°/10°C or outdoors in Brisbane in subtropical Australia (Lat. 28°S), and was greatest after a period of water stress. The number of flowers increased with the severity and duration of water stress (two, four or eight weeks) and was generally greater after constant rather than with cyclic water stress. In lemon and litchi, net photosynthesis declined with increasing water stress reaching zero with a midday ψL of ?3.5 to ?4.0 MPa. This decline in carbon assimilation appeared to be almost entirely due to stomatal closure. Despite the reduction in midday CO2 assimilation, starch concentration increased during water stress, especially in the branches, trunk and roots of lemon. Leaf starch was uniformly low. The number of flowers per tree in lemon was strongly correlated with starch in the branches (r2=77%, P<0.01) and roots (r2=74%, P<0.001). In litchi, starch was lower than in lemon roots and was not related to flowering.

In separate experiments to test the interaction between temperature and water supply, low day/night temperatures (23°/18° and 18°/15°C compared with 29°/25°C) reduced vegetative growth and induced flowering in avocado, litchi and mango. None of these species flowered at 29°/25°C or as a result of water stress (ψL of ?1.5 MPa compared with ?0.3 MPa for avocado and ?2.0 MPa compared with ?0.5 MPa for litchi, and R.W.C, of 90-93% compared with 95-96% in mango). In contrast, in lemon, flowering was very weak (<10 flowers per tree) in the absence of water stress (pre-dawn ψL of ?2.0 MPa compared with ?0.5 MPa) and was only heavy (>35 flowers per tree) after stressed trees were rewatered. There were slightly more flowers at 18°/15°C than at 23°/18° and 29°/25°C in control plants, but no effect of temperature in stressed plants. Starch concentration in the roots of avocado, lemon, litchi and mango was generally higher at 18°/15°C and 23°/18°C than at 29°/25°C. Water stress increased the starch concentration in the roots of lemon and litchi and decreased it in avocado. There was no effect in mango. There was a weak relation (r2=57%, P<0.05) between the number of flowers per tree in lemon and the concentration of starch in the roots. In contrast, there was no significant relationship between flowering and starch levels under the various temperature and water regimes in the other species. In another experiment, only vegetative growth in litchi and mango occurred at 30°/25°C and only flowering at 15°/10°C. Six weeks of water stress (pre-dawn ψL of ?2.5 MPa compared with ?1.0 MPa or higher in litchi, and R.W.C, of 90-93% compared with 95% or higher in mango) in a heated glasshouse (30°C days/20°C night minimum) before these temperature treatments did not induce flowering.

Temperatures below 25°C for avocado and below 20°C for litchi and mango are essential for flowering and cannot be replaced by water stress. The control of flowering in lemon over the range of day temperatures from 18°C to 30°C differed from that of the other species in being mainly determined by water stress. Flowering was generally weak in well-watered plants even with days at 18°C. Starch did not appear to control flowering.  相似文献   

10.
Summary

Rooting and growth responses of miniature rose cuttings were investigated in an experiment in which four propagation temperatures, two photosynthetic photon flux densities (PPFDs) with five auxin (IBA) concentrations, cutting sizes and cutting positions, were combined factorially in a response-surface design. Most prominently, temperature, cutting size and auxin and their interactions, influenced root and shoot growth. A propagation temperature of 24.6°C, and IBA concentrations between 10–3 and 10–1M, depending on temperature, were optimal for root formation. Root formation in extra short cuttings was delayed at low IBA concentrations. Regarding root formation, IBA could substitute for increased temperature as well as for increased cutting size. Onset of axillary bud growth was fastest at 24.6°C, and delayed in extra short cuttings. Application of IBA at 10–4 to 10–3M was optimal for axillary bud growth. By increasing the IBA concentration both time to flowering and plant height increased at 24.6°C. In cuttings from higher positions on stock plants, axillary shoots enhanced their growth to flowering, became shorter, and weighed less, suggesting occurrence of positional effects (topophysis). The growth rate increased with increasing IBA concentration, as well as from medial to low positioned cuttings. Increasing propagation PPFD from 46 to 72 µmol m–2s–1 did not affect the parameters. Time to axillary bud growth and time to first flower were related to time-to-visible root. Fast formation of roots apparently resulted in fast axillary bud growth. In time-to-visible root and axillary bud growth, the smallest variation between plants was found at optimal ranges for temperature, IBA concentration and cutting size, and further factors optimal for root formation and axillary bud growth provided the most synchronized plant development.  相似文献   

11.
Net photosynthesis and dark respiration from whole plants of various tomato genotypes were measured in a closed system. At low irradiance (27 W m?2) and low external CO2 concentration (550 mg m?3), net photosynthesis of 10 genotypes was found to vary between 0.122 and 0.209 mg CO2 m?2 s?1. Correlation was observed between net photosynthesis, net uptake on a daily basis (8 h photoperiod at 20°C and 16 h nyctoperiod at 10°C), specific leaf weight and leaf area ratio. At high irradiance (243 W m?2), high external CO2 concentration (1480 mg m?3) and ambient temperatures of 10, 18, 20 and 26°C, four genotypes were analysed. ‘F6 I.V.T.’ had the highest rate of photosynthesis at 10°C, while ‘Sonatine’ ranked high at 26°C. Dark respiration increased with temperature, except in the case of ‘Bonabel’ where the effect of temperature was slight.  相似文献   

12.
Summary

Increasing need for salt-tolerant turfgrasses continues due to population growth in arid and semi-arid regions where potable water is limited, while soil and existing water sources are salty. Bermudagrass (Cynodon spp. L. C. Rich) is widely used in these areas. Therefore, this experiment was conducted to evaluate the salt-tolerance of ten cultivars of bermudagrass under a high saline soil and water environment. Five salinity levels of irrigation water (3.30, 6.93, 10.2, 14.8 and 17.8 dS m–1) were prepared and 30 pots were surfaced-irrigated at each salinity level for 1 year. Overall top growth, root growth, K content and K:Na ratio were reduced by 75%, 45%, 77% and 94.5%, respectively; while leaf-firing, shoot Cl and shoot Na concentrations were increased by 4%, 498% and 356%, respectively, when the salinity increased from 3.3 dS m–1 to 17.8 dS m–1. Regarding the salt-tolerance of cultivars, ‘Tifway’ was superior in top growth, percentage leaf-firing, Na uptake and K:Na ratio, ‘ISF2’ in root growth, and ‘Tifdwarf’ in Cl uptake. Although ‘Tifway’ showed the greatest reduction in root dry weight, it had the lowest level of leaf-firing and lowest reduction in top growth, which could be due to having the lowest Na uptake. Cultivars exhibited marked differences in their response to salinity; however, no mortality was observed, indicating that all cultivars tolerated the salinity levels used in the experiment.  相似文献   

13.
The effects of temperature and the root system on growth and establishment were assessed for rhizomes of three Alstroemeria cultivars.-The numbers of lateral rhizomes, aerial shoots and tubers produced by rhizome ‘splits’ were not significantly affected by increase in temperature in the range of 8 to 18°C. Significant increases in root system and rhizome dry weight were seen for cv. Butterfly and in aerial shoot dry weight for all three cultivars used. Increasing temperature significantly decreased the number of plants establishing from rhizome ‘splits’ obtained from plants grown in glasshouse soil. For maximum rhizome production a temperature of between 13 and 18°C was found to be required. A second experiment employing rhizome ‘splits’ from container-grown plants showed no effect of temperature on plant establishment. The presence or absence of the rootsystem on the ‘splits’ at planting was found to be important in plant establishment, with removal of the root system producing a significant decrease in the number of plants establishing. It is suggested that the rootsystem, and damage sustained by it prior to planting, are more important than temperature for the successful establishment of plants of Alstroemeria.  相似文献   

14.
Summary

Dry-matter accumulation and partitioning in plants of Zantedeschia ‘Best Gold’ were quantified under a range of temperature and photosynthetic photon flux (PPF) regimes using plant growth analysis. Initiation of tuber growth did not require an obligate environmental trigger. Under both PPF regimes, relative growth rate of the tuber (RGRt) increased linearly with increasing temperature (13 to 28°C) up to a maximum at 28°C, with a base temperature of 3.2 ± 1.1°C. Optimum temperature for tuber growth was found to be PPF dependent, but maximum tuber dry mass was calculated as occurring under low PPF (348 µmol m–2 s–1) at 24.5 ± 0.1°. Mechanisms of acclimation under both PPF regimes suggested that tuber growth was principally source limited. Source limitation was expressed either in terms of: 1) enhanced inter-sink competition for assimilates, as occurred under the low PPF regime, where leaf area development was in direct competition with tuber growth (RGRt) or, 2) efficiency of dry-matter accumulation by the leaf area present, as occurred under the high PPF regime, where large increases in RGRt were correlated with increased net assimilation rate (NAR). Use of the daily increment of dry matter into tuber tissue (TMP) provided a more sensitive measure of short-term changes in partitioning than the conventionally used term, harvest index.  相似文献   

15.
There was no effect of irradiance level on surviving percentages of shoot tip explants of the pear rootstock BP10030, but low irradiance stimulated the initial growth of the explant. Irradiance had a strong effect on shoot multiplication. With an increase in photosynthetic photon flux (PPF) from 10 to 80 μmol m?2s?1, shoot number and length and shoot fresh and dry weights increased. The greatest number of shoots and the longest ones were obtained with a 16 h photoperiod, while the highest fresh and dry weight of shoots were produced with a 24 h photoperiod. Rooting percentage and the number of roots were markedly promoted under 80 μmolm?2s?1 PPF. Photoperiods of 8, 16 and 24 h produced similar effects on rooting percentages and the numbers of roots. Four to seven days of darkness were the optimum for rooting. Rooting percentage and the number of roots increased with increased temperature during darkness between 5 and 25°C. A further increase in dark temperature up to 30°C reduced rooting percentage and root number.  相似文献   

16.
The growth of radish cultivars ‘Saxa’, ‘Saxerre’, ‘Serra’, ‘Istar’, ‘Cherrybelle’ and ‘Robino’ was compared at 7 and 12°C under winter glasshouse conditions. ‘Serra’ alone produced marketable storage roots by 63 days at 7°C, but root weight was no greater at 12 than at 7°C; only ‘Robino’ produced significantly larger roots at the higher temperature. Under-soil heating applied to ‘Cherrybelle’ and ‘Robino’ grown at an air temperature of 7°C increased root growth, particularly in ‘Cherrybelle’. Daminozide treatment at 7°C increased total and storage root weight and root:shoot ratio of both cultivars. At 12°C, the only significant effect of daminozide treatment was reduced shoot weight in ‘Robino’.  相似文献   

17.
Summary

Shoot tips of two almond scion cultivars, ‘Ne Plus Ultra’ and ‘Nonpareil 15-1’, and one almond/peach hybrid rootstock were successfully cryopreserved using a one-step vitrification technique. Three week old in vitro cultures were cold-hardened at 4°C on the multiplication medium (Murashige and Skoog for ‘Ne Plus Ultra’ and the hybrid rootstock; Almehdi and Parfitt for ‘Nonpareil 15-1’) for three weeks. Shoot tips, 2–2.5 mm long, were excised and precultured for 1 d at 4°C on the same basal medium, without plant growth regulators, supplemented with 0.7 M sucrose. After the preculture, the shoot tips were incubated in vitrification solution at 25°C for 45 min for the almond scion cultivars and 60 min for the hybrid rootstock, and then stored under liquid nitrogen (LN) for at least 3 d. After rapid thawing at 30°C, the shoot tips were washed with the appropriate liquid basal medium containing 1.0 M sucrose and then cultured on the same basal medium, solidified with agar, but excluding NH4NO3 or (NH4)2SO4. Shoot regeneration was usually observed within 2–3 weeks. Survival after LN, recorded as the percentage of shoot tips that produced at least one new shoot four weeks after thawing, was 87.5, 60.0 and 72.5% for ‘Ne Plus Ultra’, ‘Nonpareil 15–1’ and the hybrid rootstock respectively. The one-step vitrification method is a promising simple technique for cryopreserving almond scion and rootstock shoot tips from in vitro cultures.  相似文献   

18.
Under controlled environment conditions the influence of four soil temperatures (7°, 14°, 21°, and 28°C) on vegetative development and flower-bud formation of apple trees (cvs ‘Rode Boskoop’ and ‘Elstar’) were evaluated in the first year after budding. Relative air humidity was high, air temperature was 20°C. Broadly speaking, for both cultivars shoot growth clearly increased with increasing soil temperature. The effects on growth were mainly reflected in the number (not length) of the lateral shoots; the growth of the main shoot was little influenced by soil temperature. At 7°C the lateral shoots usually occurred higher along the main stem than at the higher temperatures. Flowering on the parent stem and on the lateral shoots was little affected by the soil temperatures tested. In general, flower-cluster quality was rather poor. If only clusters having more than four well-developed flowers are considered, flowering was favoured by higher soil temperatures; at 28°C, especially, cluster quality was much better than at the other soil temperatures. It is concluded that soil temperature is important in controlling the degree of lateral shoot-formation as well as the formation of well-developed flower clusters.  相似文献   

19.
Summary

Trichoderma harzianum strain T-22 (T22) is one of the most effective strains of this fungus that is able to colonise the roots of most plant species across a wide range of soil types. This fungus is used as a biocontrol agent during crop production, and for the improvement of the rooting and acclimatisation phases in plant nurseries. In vitro-cultured shoots of GiSeLa6® (Prunus cerasus P. canescens) and of GF677 (P. amygdalus P. persica), two important Prunus varieties used as commercial rootstocks, were inoculated with T22. The results showed that early inoculation of the fungus (at the stage of shoot transfer to root-inducing medium) seriously damaged both GiSeLa6® and GF677 plants; whereas, following later inoculation (7 d after shoot transfer to root-inducing medium), the plants survived and showed significant increases in shoot growth and root development. In particular, root lengths in GiSeLa6® and GF677 plants increased by 180% and 136%, respectively, compared to non-inoculated controls. Microscopic analysis revealed T22 hyphae spreading on the root surface in GiSeLa6® (fungus colonisation frequency = 20%), but not in GF677 roots. Our results demonstrate that the application of T22 during the rooting phase resulted in greater shoot lengths, as well as increased numbers of leaves, roots, and stem diameters. These morphological characteristics could increase the quality and viability of nursery planting material and provide advantages during the plant acclimatisation phase.  相似文献   

20.
Summary

Effects of root damage during the transplant process on growth and nitrogen (N) uptake were studied with one-year-old bench-grafted Malus domestica Borkh ‘Fuji’ on M.26 rootstock apple nursery plants. Plants were potted after grafting and grown outside for one season. At the end of the season uniform trees were selected and randomly divided into four groups. One group of plants were moved into a 2°C cold room with soil and container intact (IR Treatment). Plants in other groups were removed from pots and stored as bareroot in the same cold room for three months. In the spring, bareroot plants were either: (1) transplanted with about 10% of the root system damaged during transplant (TP Treatment and Control-CK); or (2) root pruned by 25% (by volume) prior to transplant (RP treatment). Five trees from each treatment received 1 g of 15NH415NO3 at 12, 41 and 76 d after repotting. Control (CK) trees received no N. Trees were harvested 10 d after each N application, and plant growth and total N and 15N content of different tissues were determined. Root pruning reduced plant total biomass and root biomass at the first two harvests, but the plants from the RP treatment had highest total plant biomass and root biomass at the third harvest. There was no significant difference in the new stem and leaf growth among IR, RP and CK treatments at harvests but the TP treatment reduced new shoot biomass. Plants with intact roots (IR) had the higher total N content while control plants (CK) had the lowest. Root pruning reduced 15N uptake rate at the first two harvests but promoted it at the third harvest. Our results suggest that plant growth and nutrient uptake was suppressed by root pruning/damage during transplanting only in the early season, and the negative effects on growth and N uptake were offset later in the season by compensative root regeneration.  相似文献   

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