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1.
In this work, the effect of microclimate at the tree level inside a polytunnel and in an uncovered orchard of Prunus avium was studied through the observation of leaf and fruit micromorphology and the accumulation of cuticular waxes. Records of
environmental parameters showed a significantly higher daytime temperature in the polytunnel (on an average 4°C), whereas
the night temperature did not differ between treatments. Furthermore, photosynthetic active radiation and UV-B radiation inside
the polytunnel were 43 and 97% lower, respectively, than the radiation measured outside. Leaves grown in the polytunnel had
lower contact angles and higher load of cuticular wax per unit area, irrespective of cultivar. The impact of the microclimate
was observed at the first sampling and did not increase with exposure time of leaves. Fruits of the cultivars ‘Souvenir’ and
‘Prime Giant’ grown outside had significantly less cuticular wax despite their delayed harvest time of 11 and 5 days, respectively.
The relationship of higher cuticular wax load and lower contact angles of protected leaves might have practical importance
for plant protection activities and the retention and uptake of leaf-applied agrochemicals. 相似文献
2.
Plants with leaves having numerous trichomes or domatia frequently harbor greater numbers of phytoseiid mites than do plant
with leaves that lack these structures. We tested the hypothesis that this pattern occurs, in part, with Typhlodromus pyri because trichomes increase the capture of pollen or fungal spores that serve as alternative food. Using a common garden orchard,
we found that apple varieties with trichome-rich leaves had 2–3 times more pollen and fungal spores compared to varieties
with trichome-sparse leaves. We also studied the effects of leaf trichome density and pollen augmentation on T. pyri abundance to test the hypothesis that leaf trichomes mediate pollen and fungal spore capture and retention and thereby influence
phytoseiid numbers. Cattail pollen (Typha sp.) was applied weekly to mature ‘McIntosh’ and ‘Red Delicious’ trees grown in an orchard and, in a separate experiment,
to potted trees of the same varieties. ‘McIntosh’ trees have leaves with many trichomes whereas leaves on the ‘Red Delicious’
trees have roughly half as many trichomes. With both field-grown and potted trees, adding cattail pollen to ‘Red Delicious’
trees increased T. pyri numbers compared to ‘Red Delicious’ trees without pollen augmentation. In contrast, cattail pollen augmentation had no effect
on T. pyri populations on ‘McIntosh’ trees. Augmentation with cattail pollen most likely supplemented a lower supply of naturally available
alternative food on ‘Red Delicous’ leaves and thereby enhanced predator abundance. These studies indicate that larger populations
of T. pyri on pubescent plants are due, in part, to the increased capture and retention of pollen and fungal spores that serve as alternative
foods.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Characterization of embryogenic mango cultures selected for resistance to Colletotrichum gloeosporioides culture filtrate and phytotoxin 总被引:3,自引:0,他引:3
S. Jayasankar R. E. Litz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(6-7):823-831
Embryogenic nucellar cultures of two polyembryonic mango cultivars, ‘Hindi’ and ‘Carabao’, were selected for resistance to
the culture filtrate and phytotoxin of a virulent strain of Colletotrichum gloeosporioides Penz. that was isolated from mango leaves. The cultures were recurrently selected either with progressively increasing concentrations
of culture filtrate or by continuous challenge with the same concentration of either culture filtrate phytotoxin. Mycelium
growth was inhibited when the pathogen was cocultured with the selected, resistant embryogenic cultures. Conditioned plant
growth medium containing macerated resistant embryogenic cultures did not inhibit mycelium growth, confirming that extracellular
antifungal compounds were involved in the defense response. Enhanced secretion of chitinase and glucanase was observed in
the plant growth medium in which resistant embryogenic cultures and regenerated somatic embryos were grown in comparison with
the controls.
Received: 6 February 1997 / Accepted: 4 November 1997 相似文献
4.
Effects of exogenous B supply on growth, B accumulation and distribution of two navel orange cultivars 总被引:3,自引:0,他引:3
Ou Sheng Shang W. Song Yun J. Chen Shu A. Peng Xiu X. Deng 《Trees - Structure and Function》2009,23(1):59-68
To investigate the effects of boron (B) on growth, B concentration and distribution of two navel orange cultivars, ‘Newhall’
(Citrus sinensis Osbeck) and ‘Skagg’s Bonanza’ (Citrus sinensis Osbeck) grafted on the rootstock trifoliate orange [Poncirus trifoliata (L.) Raf.], B at five levels was exogenously supplied to 1-year-old grafted plants of both cultivars under greenhouse conditions.
Plants were grown in sand:perlite (1:1, v/v) medium and were irrigated every 2 days with half-strength Hoagland’s No. 2 nutrient
solutions containing different B, 0.01, 0.05, 0.10, 0.25 and 2.50 mg l−1 (0.25 and 2.50 mg l−1 were considered as control and excess B treatment, respectively, and the other three B levels were considered as low B treatments).
After treatments for 183 days, leaves (from basal, middle, upper parts of the shoots), stem of scion, stem of rootstock and
root were separately sampled. Our results showed that plant growth (plant height, root volume and dry weights of various parts)
was inhibited in response to low or excess B supplies in both cultivars. It was found that B concentrations in the upper leaves
of both cultivars were substantially higher than those in the basal leaves when low concentrations (≤0.05 mg l−1) of exogenous B were applied, suggesting that B was preferentially translocated to the upper-younger leaves to support their
growth. Analysis of B distribution in different parts indicated that translocation of B from the root to the scion’s shoots
(stems and leaves of scion) may be restricted upon exposure to low B conditions. When B was inadequately supplied, growth
of ‘Skagg’s Bonanza’ was better than ‘Newhall’, implying that the former cultivar was more tolerant to low B status, which
may be due to the higher efficiency of B translocation from the root to the scion’s shoots. However, when the plants were
treated with excess B (2.50 mg l−1), both cultivars showed a similar degree of B toxicity. The probability of scion–rootstock interactions in relation to the
differential responses of growth and different efficiency of B translocation involved in the two orange cultivars following
the long-term low B stress were discussed. 相似文献
5.
Unopened leaves, petioles and fully opened leaves from micropropagation cultures of five Vitis rotundifolia Michx. varieties were cultured on induction medium to study their embryogenic response. Among the various explants tested,
the maximum number of varieties produced embryogenic cultures from unopened leaves followed by fully opened leaves and petioles.
Based on morphological differences, two types of embryogenic cultures were identified. Friable cultures typically arose as
proembryonic masses (PEM) on induction medium, whereas somatic embryo production without an intervening PEM stage was observed
in compact cultures. Of the five varieties tested, the highest frequency of embryogenic response was observed from fully opened
leaves of ‘Supreme’ and unopened leaves and petioles of ‘Delicious’. Attempts to initiate suspension cultures from varieties
resulted in proliferation and maintenance of ‘Alachua’ and ‘Carlos’ cultures in liquid medium for 16 weeks. Embryogenic potential
of varieties was studied on cultures growing on embryo development medium. The maximum number of cotyledonary stage somatic
embryos from 0.2 g proembryonic masses were observed in ‘Carlos’ (379.3) followed by ‘Alachua’ (350.0) and ‘Delicious’ (305.0).
Cotyledonary stage somatic embryos germinated when cultured on Murashige and Skoog medium containing 1 μM Benzyladenine (BA).
Although high embryo germination rates (80–100%) were observed in the varieties tested, plant recovery from germinated somatic
embryos ranged from 6–47%. Embryogenic cultures could be maintained on X6 medium and used in genetic engineering studies. 相似文献
6.
Mustapha Ennajeh Ahmadou Mohamed Vadel Habib Khemira 《Acta Physiologiae Plantarum》2009,31(4):711-721
In this study, we compared the efficacy of defense mechanisms against severe water deficit in the leaves of two olive (Olea europaea L.) cultivars, ‘Chemlali’ and ‘Meski’, reputed drought resistant and drought sensitive, respectively. Two-year old plants
growing in sand filled 10-dm3 pots were not watered for 2 months. Changes in chlorophyll fluorescence parameters and malondialdehyde content as leaf relative
water content (RWC) decreased showed that ‘Chemlali’ was able to maintain functional and structural cell integrity longer
than ‘Meski’. Mannitol started to accumulate later in the leaves of ‘Chemlali’ but reached higher levels than in the leaves
of ‘Meski’. The latter accumulated several soluble sugars at lower dehydration. ‘Chemlali’ leaves also accumulated larger
quantities of phenolic compounds which can improve its antioxidant response. Furthermore, the activity of three antioxidant
enzymes catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) increased as leaf RWC decreased. However, differences
were observed between the two cultivars for CAT and POD but not for APX. The activity of the first two enzymes increased earlier
in ‘Meski’, but reached higher levels in ‘Chemlali’. At low leaf hydration levels, ‘Chemlali’ leaves accumulated mannitol
and phenolic compounds and had increased CAT and POD activities. These observations suggest that ‘Chemlali’ was more capable
of maintaining its leaf cell integrity under severe water stress because of more efficient osmoprotection and antioxidation
mechanisms. 相似文献
7.
Mark N. Merzlyak Olga B. Chivkunova Tatiana V. Zhigalova K. Razi Naqvi 《Photosynthesis research》2009,102(1):31-41
Light absorption was quantified in the following systems: isolated chloroplasts and leaves of spinach (Spinacea oleracea L.), a mutant of geranium (Pelargonium zonale L.) widely differing in pigment content, and coleus (Coleus blumei Benth.) at different stages of leaf ontogenesis. For these species and pea (Pisum sativum L.), scattering-compensated absorption spectra of chloroplast suspensions are presented. Comparison of leaf and chloroplast
spectra showed considerable changes in the extent of the ‘package’ effect and the lengthening of the effective optical path
in a leaf. The difference between leaf and isolated chloroplast absorption could be quantitatively described by adapting Duysens’s
treatment of flattening. It was found that the accumulation of chlorophyll in leaves is accompanied by a monotonous enhancement
of the package effect. The results are discussed with special reference to the role of light scattering in leaf optics, light
utilization in photosynthesis and wavelength-dependent light gradients in a leaf. 相似文献
8.
Picrorhiza kurrooa Royle ex Benth., a high value medicinal herb of alpine Himalaya and a source of hepatoprotective picrosides, is listed as
‘endangered’ due to heavy collection from its natural habitat. The present report deals with successful propagation of this
species using both conventional and in vitro techniques. Vegetative propagation was achieved by rooting runner cuttings with indole-3-butyric acid (IBA) or α-naphtheleneacetic
acid (NAA) treatment before planting. Nearly 87% rooting success was achieved by treatment of cuttings with 50.0 μM IBA. Seeds were given a presoaking treatment with gibberellic acid (GA3), 6-benzylaminopurine (BAP) or a combination of both to influence germination. More than 11-fold improvement in germination
was recorded in seeds treated with 250.0 μM GA3. In vitro shoot multiplication was achieved through sprouting of axillary buds using nodal segment. Multiple shoots were formed following
culture for 3 weeks on Murashige and Skoog (MS; 1962. Physiologia Plantarum 15: 473–497) medium containing 1.0 μM BAP. Cent
percent rooting success, without basal callus formation, was observed when individual microshoots were placed in MS medium
supplemented with IBA. The plantlets raised using conventional as well as tissue culture methods were hardened and successfully
established in the experimental field located at 2450 m elevation. In addition, strategies have been discussed to encourage
cultivation and in situ conservation of this highly valued medicinal herb so as to reduce pressure on its natural populations. 相似文献
9.
Richard L. Bell Chinnathambi Srinivasan Delores Lomberk 《In vitro cellular & developmental biology. Plant》2009,45(6):708-714
The influence of the nutrient composition of plant tissue culture media on axillary shoot proliferation and their preconditioning
effect on subsequent adventitious shoot regeneration from pear leaves was investigated. The goal was to improve both micropropagation
and regeneration of ‘Bartlett’ and ‘Beurre Bosc’ pear cultivars. Driver–Kuniyuki walnut (DKW) and Quoirin and Lepoivre (QL)
nutrient media were found to be superior to Murashige and Skoog (MS) and Woody Plant Medium (WPM) for axillary shoot proliferation.
Shoots on WPM exhibited some chlorosis. Axillary shoot culture on DKW would be preferred to that on QL due to the production
of excessively short thin shoots on the latter medium. DKW also was superior to QL and MS for production of young expanding
leaves for use as explants in adventitious regeneration. Leaf explants derived from shoot proliferation cultures grown on
DKW or QL media produced more adventitious shoots than leaf explants from MS. 相似文献
10.
Cuticular wax is a hydrophobic barrier between the plant surface and the environment that effectively reduces the loss of water. The surface of Welsh onion leaves is covered with wax. To explain the relationship between wax composition and water loss, we conducted this experiment. The water permeability and wax composition of leaves were determined by chemical and GC-MS methods. We performed a comparative analysis of the differences between the two cultivars and analyzed the relationship between water permeability and waxy components. Overall, the permeability to water was higher in ‘Zhangqiu’ than in ‘Tenko’. The wax amount of ‘Tenko’ was 1.28-fold higher than that of ‘Zhangqiu’ and was primarily explained by the much larger amounts of ketones and alcohols in the former. Among the waxy components, C29 ketones were most abundant. There were substantial discrepancies in wax composition, total wax content, and water permeability between the two cultivars. The main reason for the discrepancy in water permeability may be the significantly lower aliphatic fraction in ‘Zhangqiu’ than in ‘Tenko’. This study makes a vital contribution to drought resistance research on allium plants. 相似文献
11.
Shoot tips and single node explants of two rootstocks (R.99 and 3309) and two varieties (‘Helwani’ and ‘Cabernet Franc’) of
grapevine cultured on DSD1 media for a period of 60 days, were irradiated with 0, 2, 5 and 7 Gy doses of gamma irradiation.
Shoot length of ‘Helwani’ and ‘Cabernet Franc’ was increased by 7 Gy irradiation. The 5 Gy dose increased the number of roots
in plants of the two rootstocks and ‘Helwani’. Root length of ‘Helwani’ and ‘Cabernet Franc’ at the 2 and 7 Gy doses were
significantly higher than those of the non-irradiated control. A similar effect was noticed on R.99 rootstock subjected to
5 Gy. Five Gy also increased the dry weight of the R.99 rootstock, whereas 2 and 7 Gy had a similar effect on ‘Helwani’ and
‘Cabernet Franc’. Number of leaves of plants exposed to 5 and 7 Gy was increased when compared with the non-irradiated control.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
Mokhtar Guerfel Alexandros Beis Tasos Zotos Dalenda Boujnah Mokhtar Zarrouk Angelos Patakas 《Acta Physiologiae Plantarum》2009,31(4):825-831
Differences in abscisic acid (ABA) accumulation between two olive cultivars were studied by enzyme-linked immunosorbent assay
in roots and leaves, leaf water potential (Ψl), stomatal conductance (g
s) as well as photosynthetic rate (A) were also determined in well-watered (WW) and water-stressed (WS) plants of two olive
cultivars ‘Chemlali’ and ‘Chetoui’. ‘Chemlali’ was able to maintain higher leaf CO2 assimilation rate and leaf stomatal conductance throughout the drought cycle when compared with ‘Chetoui’. Furthermore, leaf
water potential of ‘Chemlali’ decreased in lower extent than in Chetoui in response to water deficit. Interestingly, significant
differences in water-stress-induced ABA accumulation were observed between the two olive cultivars and reflect the degree
of stress experienced. Chemlali, a drought tolerant cultivar, accumulated lower levels of ABA in their leaves to regulate
stomatal control in response to water stress compared to the drought sensitive olive cultivar ‘Chetoui’ which accumulated
ABA in large amount. 相似文献
13.
M. J. van Steenis K. A. M. H. El-Khawass 《Entomologia Experimentalis et Applicata》1995,76(2):121-131
Life table data forAphis gossypii Glover (Homoptera: Aphididae), an important pest in glasshouse cucumber crops, were studied at 20, 25 and 30°C on two cucumber
cultivars (Cucumis sativus L.) in controlled climate cabinets. The development time on the cucumber cv. ‘Sporu’ ranged from 4.8 days at 20°C to 3.2
days at 30°C. Immature mortality was approximately 20% and did not differ between temperatures. Most mortality occurred during
the first instar. Reproduction periods did not differ among temperatures, but at 25 and 30°C more nymphs were produced (65.9
and 69.8 nymphs/♀, respectively) than at 20°C (59,9 nymphs/♀) because of a higher daily reproduction. Intrinsic rate of increase
was greatest at 25°C (r
m
=0.556 day−1). At 20 and 30°C the intrinsic rate of increase was 0.426 and 0.510, respectively. On cv. ‘Aramon’, the development time
ofA. gossypii was approximately 20% longer at all temperatures. Immature mortality did not differ between the two cultivars. The intrinsic
rate of increase on cv. ‘Aramon’ was 15% smaller than on cv. ‘Sporu’. The use of cucumber cultivars partially resistant to
aphids is discussed in relation to biological control of cotton aphid in glasshouses. Development time and immature mortality
on leaves of the middle and upper leaf layer of glasshouse grown cucumber plants (cv. ‘Aramon’) were comparable to development
in the controlled climate cabinets. On the lower leaves immature mortality was much higher (approximately 82%) than on leaves
of the middle (24.0%) and upper leaf layer (24.5%). Reproduction was less on the lower leaf layer (45.9, 70.5 and 70.1 nymphs/♀
on leaves of the lower, middle and upper leaf layer, respectively).
Aphids, successfully parasitized byAphidius colemani Viereck (Hymenoptera: Braconidae) only reproduced when they were parasitized after the third instar. Fecundity was 0.1 to
0.9 and 10.5 to 13.3 nymphs/♀ for aphids parasitized in the fourth instar or as adults, respectively. Reproduction of aphids
that were stung but survived the attack was lower than for aphids not stung. Average longevity of these aphids was equal to
the longevity of aphids not stung byA. colemani. 相似文献
14.
Open-top chambers were used to estimate the possible effects of global warming on δ13C of seven plant species grown in alpine meadow ecosystem. The δ13C values of plant species were lower after long-term growth in open-top chambers. In the course of experiment, temperature
significantly increased inside the chambers by 4°C. Plant species grown at a lower elevation above sea level had higher δ13C values as compared to those grown at a higher elevation. This was in accordance with the effect of open-top chamber on δ13C values in plants. Greater availability of CO2 and lower water vapor pressure at higher temperature inside the chambers, as indicated by an increase in discrimination against
13CO2, probably result in more negative δ13C values of plants because higher stomatal conductance increases availability of CO2 and causes greater discrimination against 13CO2. The plant species studied could be the indicator species for testing global warming by the change in carbon isotope ratios
at the two growth temperatures.
This text was submitted by the authors in English. 相似文献
15.
Ying Li Yuping Song Gongjun Shi Jianjun Wang Xilin Hou 《Acta Physiologiae Plantarum》2009,31(1):155-162
Changes in ascorbic acid content and antioxidant enzyme activities were investigated in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) leaves of ‘Wutacai’ and ‘Erqing’ exposed to excess copper (Cu). Cu treatment reduced the fresh weight of shoot and
root by 57% and 46% in ‘Wutacai’, and 60 and 54% in ‘Erqing’, respectively. The accumulation of copper in leaves was higher
in ‘Wutacai’ than that in ‘Erqing’. Compared to the control, ascorbic acid (AsA) contents were significantly decreased after
copper treatment in both cultivars, while they were higher in ‘Wutacai’ than in ‘Erqing’, which may explain the higher copper-tolerance
of ‘Wutacai’ with higher copper accumulation. The higher AsA contents of ‘Wutacai’ resulted from their lower activities of
degrading enzymes, such as ascorbate oxydase (AAO) and ascorbate peroxidase (APX), as well as the increasing activity of dehydroascorbate
reductase (DHAR) after copper treatment compared with ‘Erqing’. Copper stimulated superoxide dismutase (SOD) activity in both
cultivars, but for catalase (CAT), there was little difference between both cultivars. Peroxidases (POD) activity was decreased
after copper treatment in ‘Erqing’, while in ‘Wutacai’, it was significantly increased at 14 days, and POD activity was higher
in ‘Wutacai’ than that in ‘Erqing’ at 21 and 28 days. Therefore, the induced increasing activity of POD in ‘Wutacai’ also
played an important role in its copper tolerance. 相似文献
16.
Beata Kułek Jolanta Floryszak-Wieczorek Hanna Jackowiak 《Acta Physiologiae Plantarum》2004,26(1):95-102
The involvement of β-D-glucosidase activity in grey mould was studied in two ornamental plant species attacked by Botrytis cinerea.
β-D-glucosidase activity in the susceptible pelargonium cultivar ‘Shiva’ gradually increased with the disease development
in the leaf spots and their surroundings. The endogenic level of the studied hydrolase in the resistant pelargonium ‘Cascade’
was several times higher than in the susceptible cultivar ‘Shiva’ and in principle underwent no changes after inoculation.
The postinfection increase in the activity of β-D-glucosidase noted in the leaves of the susceptible poinsettia cultivar ‘Malibu
Red’ was evidently weaker in the intensity, but its tendencies were similar to those of the susceptible pelargonium cultivar.
In the leaves of the medium-resistant poinsettia ‘Coco White’ the constitutional level of β-D-glucosidase was 2-3-fold higher
in that cultivar than in the susceptible cv. ‘Malibu Red’. In attacked leaves of ‘Coco White’, the enzyme activity continued
to increase temporarily until the 3rd h after inoculation.
The process of healthy leaf senescence in both species had no significant influence on the change of the studied enzyme activity
which was generally low. A high activity of β-D-glucosidase was also observed in the homogenate prepared from mycelium and
in the fungal spores. 相似文献
17.
Response of strawberry to inoculation with arbuscular mycorrhizal fungi under very high soil phosphorus conditions 总被引:1,自引:0,他引:1
A field study was done to assess the potential benefit of arbuscular mycorrhizal (AM) inoculation of elite strawberry plants
on plant multiplication, under typical strawberry nursery conditions and, in particular, high soil P fertility (Mehlich-3
extractible P=498 mg kg−1). Commercially in vitro propagated elite plants of five cultivars (‘Chambly,’ ‘Glooscap,’ ‘Joliette,’ ‘Kent,’ and ‘Sweet
Charlie’) were transplanted in noninoculated growth substrate or in substrate inoculated with Glomus intraradices or with a mixture of species (G. intraradices, Glomus mosseae, and Glomus etunicatum) at the acclimation stage and were grown for 6 weeks before transplantation in the field. We found that AM fungi can impact
on plant productivity in a soil classified as excessively rich in P. Inoculated mother plants produced about 25% fewer daughter
plants than the control in Chambly (P=0.03), and Glooscap produced about 50% more (P=0.008) daughter plants when inoculated with G. intraradices, while the productivity of other cultivars was not significantly decreased. Daughter plant shoot mass was not affected by
treatments, but their roots had lower, higher, or similar mass, depending on the cultivar–inoculum combination. Root mass
was unrelated to plant number. The average level of AM colonization of daughter plants produced by noninoculated mother plants
did not exceed 2%, whereas plants produced from inoculated mothers had over 10% of their root length colonized 7 weeks after
transplantation of mother plants and ∼6% after 14 weeks (harvest), suggesting that the AM fungi brought into the field by
inoculated mother plants had established and spread up to the daughter plants. The host or nonhost nature of the crop species
preceding strawberry plant production (barley or buckwheat) had no effect on soil mycorrhizal potential, on mother plant productivity,
or on daughter plant mycorrhizal development. Thus, in soil excessively rich in P, inoculation may be the only option for
management of the symbiosis. 相似文献
18.
Effects of NaCl stress on germination, antioxidant responses, and proline content in two rice cultivars 总被引:1,自引:0,他引:1
Young Geol Sohn Byung Hyun Lee Kyu Young Kang Jeung Joo Lee 《Journal of Plant Biology》2005,48(2):201-208
We investigated the physiological and biochemical bases for salt tolerance in two rice (Oryza sativa L.) cultivars — relatively salt-tolerant ‘Dongjin’ and salt-sensitive ‘Kumnam’. Salinized hydroponic cultures were studied
at the germination and seedling stages. NaCI inhibited germination more severely in ‘Kumnam’ than in ‘Dongjin’. Increasing
the salt concentration also deterred growth to a larger extent in the former. Moreover, the leaves of ‘Kumnam’ exhibited greater
increases in lipid peroxidation and Na+ accumulation than those of ‘Dongjin’ under stress. The activities of constitutive and salt-induced superoxide dismutase (SOD,
EC 1.15.1.1) and ascorbate peroxidase (AP, EC 1.11.1.11) were also higher in ‘Kumnam’, while only catalase (CAT, EC 1.11.1.6)
activity was slightly higher in stressed plants of ‘Dongjin’. The positive correlation between leaf proline levels and NaCI
concentration was more evident in ‘Kumnam’. However, ‘Dongjin’ seeds, which had higher germinability in the presence of NaCI,
also contained more proline. These results suggest that the higher salt tolerance in ‘Dongjin’ seedlings could be ascribed
to their lower NaCI accumulations in the leaves. This presumably is due to reductions in the uptake or transport rates of
saline ions to the shoots from the roots. Finally, we believe that the higher germination rate by ‘Dongjin’ is caused by its
higher seed proline content. 相似文献
19.
Apart from the amount and distribution of food resources and predation pressure, we sought to clarify habitat spatial features
that affect group size and group density. To simulate animal groups interacting with one another, we made an agent-based model
in a computational space. Assuming no predation pressure, we change the resource conditions between the habitat (comprising
‘interior’ and ‘edges’) and the ‘exterior’. The results are as follows: when the group density is high throughout the habitat,
large groups tend to frequent the edges (i.e., the boundaries between the interior and exterior) even if food resources are
scarce in the exterior. Additionally, when the group density is high and the group size variation is small, both group size
and group density increase at the edges. These findings are discussed with reference to primates, particularly the Japanese
macaque (Macaca fuscata) as an example of group-living animal. 相似文献
20.
Summary Carbohydrate type and concentration and their interactive effects on in vitro shoot proliferation of three lingonberry (Vaccinium vitis-idaea ssp. vitis-idaea L.) cultivars (‘Regal’, ‘Splendor’, and ‘Erntedank’) and two V. vitis-idaea ssp. minus (Lodd) clones (‘NL1’ and ‘NL2’) were studied. Nodal explants were grown in vitro on medium with 2 μM zeatin and either glucose, sorbitol, or sucrose at a concentration of 0, 10, 20, or 30 gl−1. The interactive effects of carbohydrate type and concentration and genotype were important for shoot proliferation. The
best response was afforded by sucrose at 20 gl−1 both in terms of explant response and shoot developing potential, although glucose supported shoot growth equally well, and
in ‘NL1’ at 10 gl−1 it resulted in better in vitro growth than sucrose. Carbohydrate concentration had little effect on shoot vigor. The genotypes differed in terms of shoots
per explant, length, and vigor, leaves per shoot, and callus formation at the base of explants; this was manifested with various
types and concentrations of carbohydrate. Changing the positioning of explants on the medium from vertically upright to horizontal
increased the shoot and callus size, but decreased shoot height and leaves per shoot. Proliferated shoots were rooted on a
peat:perlite (1∶1, v/v) medium and the plantlets were acclimatized and eventually established in the greenhouse. 相似文献