共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
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
3.
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
4.
Rapid discrimination of commercial strawberry cultivars using Fourier transform infrared spectroscopy data combined by multivariate analysis 总被引:1,自引:0,他引:1
Suk Weon Kim Sung Ran Min Jonghyun Kim Sang Kyu Park Tae Il Kim Jang R. Liu 《Plant biotechnology reports》2009,3(1):87-93
To determine whether pattern recognition based on metabolite fingerprinting for whole cell extracts can be used to discriminate
cultivars metabolically, leaves and fruits of five commercial strawberry cultivars were subjected to Fourier transform infrared
(FT-IR) spectroscopy. FT-IR spectral data from leaves were analyzed by principal component analysis (PCA) and Fisher’s linear
discriminant function analysis. The dendrogram based on hierarchical clustering analysis of these spectral data separated
the five commercial cultivars into two major groups with originality. The first group consisted of Korean cultivars including
‘Maehyang’, ‘Seolhyang’, and ‘Gumhyang’, whereas in the second group, ‘Ryukbo’ clustered with ‘Janghee’, both Japanese cultivars.
The results from analysis of fruits were the same as of leaves. We therefore conclude that the hierarchical dendrogram based
on PCA of FT-IR data from leaves represents the most probable chemotaxonomical relationship between cultivars, enabling discrimination
of cultivars in a rapid and simple manner.
The authors Suk Weon Kim and Sung Ran Min contributed equally to this work. 相似文献
5.
Yujie Sun Brian Christensen Fulai Liu Huiqun Wang Renate Müller 《Plant Growth Regulation》2009,59(1):83-91
Phalaenopsis frequently exhibits bud drop during production and in response to adverse postharvest conditions. The effect of exogenous
ethylene on bud drop of mini Phalaenopsis was studied and ethylene sensitivity of four cultivars was compared. Water content, membrane permeability and ABA (abscisic
acid) content in floral buds and flowers were determined after ethylene treatment. Exogenous ethylene induced flower bud drop
in all tested Phalaenopsis cultivars and the different cultivars showed distinct differences in ethylene sensitivity. The cultivar Sogo ‘Vivien’ exhibited
the highest bud drop, water loss and change in membrane permeability in floral petals, while Sogo ‘Berry’ showed the lowest
sensitivity. The ethylene inhibitor 1-MCP (1-methylcyclopropene) reduced ethylene-induced floral bud drop in the cultivar
Sogo ‘Yenlin’. ABA content in floral buds was increased in response to ethylene and 1-MCP pretreatment inhibited the ethylene-induced
increase in ABA levels efficiently. This finding suggests that the observed increase in ABA content during bud drop was mediated
by ethylene. The interaction between ABA and ethylene is discussed. 相似文献
6.
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
7.
The effects of water deficit on photochemical parameters and activities of superoxide dismutase, catalase, ascorbate peroxidase
and glutathione reductase were investigated in two olive cultivars differing in drought tolerance — ‘Chemlali’ and ‘Chetoui’.
After 30 days without irrigation, leaf water potential fell to −5.5 MPa that was accompanied by a marked decrease in net photosynthesis
in ‘Chetoui’ olive cultivar. Maximal efficiency of PSII photochemistry (Fv/Fm) decreased slightly in ‘Chemlali’ (28 %) and substantially in ‘Chétoui’ (47 %). Both cultivars showed a similar decline (about
25 %) in the photochemical quenching coefficient, but only the drought-sensitive olive cultivar exhibited an enhancement (31
%) of non-photochemical fluorescence quenching under water deficit conditions. The quantum yield of electron transport decreased
in both olive cultivars. ‘Chemlali’ showed a higher protection against oxidative stress, as judged from the lower levels of
the malondialdehyde production. Catalase activity was higher in ‘Chetoui’. Glutathione reductase activity was increased similarly
in both olive cultivars under water stress. Ascorbate peroxidase activity was enhanced in ‘Chemlali’ under water stress, but
was unaffected in ‘Chetoui’. While, superoxide dismutase activity was inhibited in both cultivars under water stress, but
higher activity was detected in ‘Chemlali’. Thus, the ability to increase ascorbate peroxidase and a higher superoxide dismutase
activity might be an important attribute linked to the drought tolerance in ‘Chemlali’ olive cultivar. 相似文献
8.
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
9.
The response of two rice cultivars to external Na/Ca ratio 总被引:1,自引:1,他引:0
The response of the rice cultivars ‘M9’ and ‘M-201’ to nutrient cultures salinated at −0.4 MPa with varying ratios of Na and
Ca was studied. Although the dry matter production of both cultivars was sensitive to the Na/Ca ratio, this correlation was
significant only for M-201. Calcium nutrition was severely affected by the composition of the external solution, and the laminae
exhibited Ca-deficiency symptoms at Na/Ca molar ratios of 78 and 198. Sodium concentration in the shoot decreased as the Na/Ca
ratio in the external solution decreased. Patterns of Na and Cl distribution in the shoot tissues were similar; both ions
were accumulated preferentially in the tillers and older leaves. The Na-induced inhibition of Ca uptake and transport appears
to be more limiting to shoot growth of M9 and M-201 than Na toxicity per se. 相似文献
10.
Tadeusz Zaj c Stanisław Grzesiak Bogdan Kulig Milan Polá ek 《Acta Physiologiae Plantarum》2005,27(4):549-558
In three year field experiments (2001 – 2003) the growth, yield and productivity of 8 flax cultivars were compared. Cultivars
‘AC Linora’, ‘Flanders’, ‘Linola™ 947’, ‘Norlin’ and ‘Omega’ were obtained from Canada, ‘Barbara’ and ‘Hungarian Gold’ from
Hungary and ‘Opal’ from Poland. Apart from the estimation of the yield of aboveground parts dry matter and seed yield the
determinations of the primary index value of growth analysis were done and on their basis the indices LAI, LAD, RGR, CGR and
HI were calculated.
The obtained yield results of the examined flax cultivars show significant genotypic — environmental relationships pertaining
to the dynamics of dry matter accumulation and the amount of seed yield. Meteorological conditions in the successive years
significantly influenced the particular phases of growth and development of cultivars and the factor which increased the amount
of dry matter was the air temperature during the period of plant emergence — budding. During the vegetative season with a
large amount of rainfall the average seed yield was about 40 % lower than compared with a year of average precipitation and
a warm second part of the second period of flax vegetation. Among the analyzed cultivars a stable yield in all the years was
characteristic for cultivars ‘Flanders’, ‘Barbara’ and ‘AC Linora’ (that cultivar, however, during a wet year yielded at a
low level). The assimilation leaf surface of the linseed quickly increased during the period from budding to flowering and
the accumulation of dry matter of the aboveground parts lasted up to the green maturity. In the successive years of the experiment
there were observed significant (linear or logarithmic regressions) relationship between the yield of dry matter and the indices
of growth analysis. The biggest values of the CGR indicator were observed for the period from budding to flowering. The maintaining
of a high CGR value after plant flowering in the year with a favourable course of climatic parameters was beneficial for a
better yield of all flax cultivars. The low values of the RGR index after flowering of cultivar ‘Hungarian Gold’ and ‘Opal’
strictly corresponded to their low yield of seed and straw biomass. 相似文献
11.
Shimpei Uraguchi Masako Kiyono Takuya Sakamoto Izumi Watanabe Katsuji Kuno 《Planta》2009,230(2):267-276
The contributions of cadmium (Cd) accumulation in cell walls, antioxidative enzymes and induction of phytochelatins (PCs)
to Cd tolerance were investigated in two distinctive genotypes of black oat (Avena strigosa Schreb.). One cultivar of black oat ‘New oat’ accumulated Cd in the leaves at the highest concentration compared to another
black oat cultivar ‘Soil saver’ and other major graminaceous crops. The shoot:root Cd ratio also demonstrated that ‘New oat’
was the high Cd-accumulating cultivar, whereas ‘Soil saver’ was the low Cd-accumulating cultivar. Varied levels of Cd exposure
demonstrated the strong Cd tolerance of ‘New oat’. By contrast, low Cd-accumulating cultivar ‘Soil saver’ suffered Cd toxicity
such as growth defects and increased lipid peroxidation, even though it accumulated less Cd in shoots than ‘New oat’. Higher
activities of ascorbate peroxidase (EC 1.11.1.11) and superoxide dismutase (EC 1. 15. 1. 1) were observed in the leaves of
‘New oat’ than in ‘Soil saver’. No advantage of ‘New oat’ in PCs induction was observed in comparison to Cd-sensitive cultivar
‘Soil saver’, although Cd exposure increased the concentration of total PCs in both cultivars. Higher and increased Cd accumulation
in cell wall fraction was observed in shoots of ‘New oat’. On the other hand, in ‘Soil saver’, apoplasmic Cd accumulation
showed saturation under higher Cd exposure. Overall, the present results suggest that cell wall Cd accumulation and antioxidative
activities function in the tolerance against Cd stress possibly in combination with vacuolar Cd compartmentation. 相似文献
12.
The effects of post harvest application of ethylene, abscisic acid (ABA), indole-3-butyric acid (IBA) treatments or dark storage
on root induction and continued growth of regenerated roots in Pelargonium cuttings were investigated using hydroponics in the greenhouse. Ethylene markedly increased rooting percentage in ‘Greco’
and ‘Surfing’, reduced the number of roots per cutting in ‘Surfing’ and had no effect on the total root lengths in the two
cultivars. Ethylene treatment reduced fresh root mass in ‘Surfing’, increased dry root mass and reduced root water content
in both cultivars. ABA (50 μM) enhanced rooting percentage in ‘Greco’, reduced the number of roots per cutting, reduced total
root lengths and fresh root mass in both cultivars. ABA increased dry root mass and reduced root water content in ‘Surfing’
but this effect was not apparent in ‘Greco’. Storing cuttings in the dark for 4 days had no effect on rooting percentage and
number of roots per cutting in ‘Greco’ and ‘Surfing’. However, dark storage reduced total root lengths in ‘Surfing’ and reduced
fresh root mass in ‘Greco’. Dark storage had no effect on dry root mass and water content in both cultivars. Applying 4 μl l−1 IBA in the rooting solution induced maximum (100%) root induction in ‘Surfing’. However, IBA reduced the number of roots
per cutting in ‘Greco’, reduced total root lengths and fresh root mass in the two cultivars. IBA treatment profoundly increased
and reduced dry root mass and root water content, respectively, in ‘Greco’ and ‘Surfing’. The enhanced root induction observed
after IBA and ABA applications could be ascribed to their influence on ethylene biosynthesis, since ethylene treatment increased
rooting percentage in both cultivars. However, high ABA (100 μM) and IBA (12 μl l−1) levels or dark storage reduced the ability of induced roots to continue growth. We attribute our results to plant stress-response
mechanism and ethylene appears to play an important role in the process of root initiation and root growth in Pelargonium cuttings. 相似文献
13.
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
14.
Experiments were conducted to quantify parasitism of Colorado potato beetle,Leptinotarsa decemlineata (Say), by the egg parasitoid,Edovum puttleri Grissell, on 3 different cultivars of eggplant,Solanum melongena L. Levels of parasitism were higher (P<0.05) on ‘Black Pride’ than on other cultivars. The percentage of egg masses that
were parasitized was 1.2-fold higher (P<0.05) on ‘Black Pride’ than on ‘Harris Special’ and ‘White’. The number of eggs per
mass that were parasitized was 1.3- and 1.4- fold greater (P<0.05) on ‘Black Pride’ than on ‘Harris Special’ and ‘White’,
respectively. The percentage of eggs that were parasitized per mass and percentage of emerged adult parasitoids did not differ
(P>0.05) among cultivars; between 2.1- to 2.6- fold more females than males emerged from eggs on all cultivars during the
growing season.Edovum puttleri suppressed the 2nd generation ofL. decemlineata on ‘Black Pride’ and ‘Harris Special’, but did not suppress populations on ‘White’.
相似文献
15.
Xinzhi Ni Sharron S. Quisenberry Blair D. Siegfried Kit W. Lee 《Entomologia Experimentalis et Applicata》1998,89(2):111-118
The effect of cereal leaf surface wax on Diuraphis noxia (Mordvilko), the Russian wheat aphid, probing behavior and nymphoposition was evaluated. Ultrastructure of leaf epicuticular wax from wheat (Triticum aestivum L.) c.v. Arapahoe and Halt was different from barley (Hordeum vulgare L.) c.v. Morex, and oat (Avena sativa L.) c.v. Border. Both wheat cultivars had similar rod-shaped epicuticular wax, while barley and oat plants had flakes. The chemical composition comparison of gas chromatograms also indicated that the extract of the two wheat cultivars had similar pattern of peaks, while the barley and oat leaves had similar peaks. Cereal variety significantly affected aphid probing behavior (P < 0.05), but wax removal using ethyl ether swab did not (P < 0.05). Aphids initiated significantly more probes on Border oat leaves than on Morex barley irrespective of wax removal, although total probing duration per aphid was not significantly different among the four cereals examined. Accumulative salivation duration per aphid on oat leaves with wax was significantly longer than other cereal leaves with wax, while accumulative ingestion duration per aphid on Arapahoe wheat and Morex barley was significantly longer than on oat. Nymphoposition of D. noxia on cereal leaves maintained on the benzimidazole-agar medium showed that aphids produced a greater number of nymphs on Morex barley and less on Border oat leaves, although wax removal did not affect aphid nymphoposition. Removal of leaf epicuticular waxes from the 4 cereal genotypes using ethyl ether swab indicated that the influence of wax on plant resistance to D. noxia probing and reproduction was limited. Morex barley was the most favorable, while Border oat was the least favorable cereal host of D. noxia. 相似文献
16.
Pyrolysis mass spectrometry (PyMS) is a rapid, simple, high-resolution analytical method based on thermal degradation of complex
materials in a vacuum. It is widely applied to the discrimination of closely related microbial strains. Leaf samples from
eight cultivars (‘Apricot Delight’, ‘Cooler Grape’, ‘Cooler Peppermint’, ‘Equator Grape’, ‘Equator Rose’, ‘Equator White’,
‘Equator White Eye’, and ‘Little Bright Eye’) of Catharanthus roseus were subjected to PyMS for spectral fingerprinting. Discriminant analysis (DA) of PyMS data enabled us to assign these cultivars
to discrete clusters. A hierarchical dendrogram based on DA provided a possible relationship among them that was in general
agreement with a previously reported classification of the cultivars based on DNA fingerprints. Furthermore, those belonging
to the same ‘series’ were grouped into a single cluster, which previously could not be achieved through similar approaches
based on Fourier transform infrared spectroscopy or 1H NMR data. Overall results suggest that chemical differences (i.e., in pyrolysate composition) among cultivars, as detected
by mass spectrometry, reflect their genetic variation. 相似文献
17.
H.M. Mamrutha T. Mogili K. Jhansi Lakshmi N. Rama Dylan Kosma M. Udaya Kumar Matthew A. Jenks Karaba N. Nataraja 《Plant Physiology and Biochemistry》2010,48(8):690-696
Mulberry leaves are the sole source of food for silkworms (Bombyx mori), and moisture content of the detached leaves fed to silkworms determines silkworm growth and cocoon yield. Since leaf dehydration in commercial sericulture is a serious problem, development of new methods that minimize post-harvest water loss are greatly needed. In the present study, variability in moisture retention capacity (MRC, measured as leaf relative water content after one to 5 h of air-drying) was examined by screening 290 diverse mulberry accessions and the relationship between MRC and leaf surface (cuticular) wax amount was determined. Leaf MRC varied significantly among accessions, and was found to correlate strongly with leaf wax amount. Scanning electron microscopic analysis indicated that leaves having crystalline surface waxes of increased facet size and density were associated with high MRC accessions. Leaf MRC at 5 h after harvest was not related to other parameters such as specific leaf weight, and stomatal frequency and index. This study suggests that mulberry accessions having elevated leaf surface wax amount and crystal size and density exhibit reduced leaf post-harvest water loss, and could provide the foundation for selective breeding of improved cultivars. 相似文献
18.
19.
The purpose of the study was to examine water stress-induced changes in the ABA and proline contents in roots and leaves of
a potentially more resistant wild accession of Hordeum spontaneum and the modern cultivar Maresi (Hordeum vulgare). Leaves of H. spontaneum had higher contents of constitutive ABA and proline in comparison to those of ‘Maresi’. A moderate water deficit resulted
only in root dehydration, which was higher in ‘Maresi’. Increases of water deficit in roots coincided with an increase of
ABA content in roots, followed by that in leaves. The level of proline increased only in leaves and only in the case of H. spontaneum. Under conditions of severe water stress, the root dehydration levels were similar in the both genotypes, whereas leaf dehydration
was higher in ‘Maresi’. H. spontaneum, as compared to ‘Maresi’ showed an earlier increase of ABA content in the roots and accumulated more ABA in the leaves. Free
proline levels in the roots increased in both genotypes but H. spontaneum exhibited a 2-fold higher proline accumulation than ‘Maresi’. In H. spontaneum the accumulation of proline in the leaves occurred noticeably earlier and to a higher extent than in ‘Maresi’. A possible
connection of these modifications with water stress resistance of the investigated genotypes is discussed in this paper. 相似文献
20.
Summary This study is mainly concerned with some parameters contributing to growth as indicators of difference in drought resistance
and salt tolerance of wheat and barley cultivars. Parameters made use of are: transpiration efficiency (‘dry matter/transpiration’
ratio), ‘leaf/root’ ratio, chlorophyll content, chlorophyll stability to heat and anatomical modifications. The results revealed
that transpiration efficiency is much higher in mexican ‘super-x’ wheat than in the egyptian ‘Giza-155’ cultivar under reduced
soil water matric- or osmotic potentials. Chlorophyll content increased in super-x with decreasing soil water potential while
chlorophyll heat stability decreased. The reverse is true in Giza-155 cultivar. Decreased leaf/root ratio in super-x is interpretted
in favour of more beneficial water balance in this cultivar. Development of more sclerenchyma in its stems supports this judgement.
Of barley cultivars tested, Borg El-Arab is favoured for drought resistance and Giza-117 for salt tolerance. re]19751014 相似文献