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1.
After aluminum toxicity, manganese (Mn) toxicity is probably the second most important growth limiting factor in acid soils.
The purpose of this study was to determine the feasibility of using chlorophyll content and leaf elongation rate (LER) for
regrowth of Mn stressed seedlings as a rapid seedling based screening bioassay for Mn tolerance in segregating populations
of wheat (Triticum aestivum L.). In one experiment, chlorophyll was determined for the cultivars Norquay (Mn-tolerant) and Columbus (Mn-sensitive) subjected
to twelve Mn levels (2 to 2000 μM) in nutrient solutions. As Mn concentration increased, chlorophyll ‘a’ and ‘b’ contents of the Mn-tolerant cultivar decreased
up to 9%, while in the Mn-sensitive cultivar it was reduced by as much as 43%. The chlorophyll ‘a/b’ ratio did not differ
among Mn concentrations for either cultivar. In a second experiment, chlorophyll content and LER for regrowth of Mn stressed
seedlings (1000 μM) was determined for Columbus and Katepwa (Mn-sensitive), Oslo (Mn-intermediate), and Norquay and Laura (Mn-tolerant). Manganese
tolerance as assayed by chlorophyll ‘a’ and ‘b’ and LER was significantly correlated with Mn tolerance as assayed by the relative
root weight methodology (RRW). Thus, chlorophyll content of Mn-stressed seedlings and LER of seedling regrowth appear to be
suitable techniques for screening unreplicated selections of segregating populations for tolerance to Mn. 相似文献
2.
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
3.
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
4.
Effect of drought on chlorophyll content and antioxidant enzyme activities in leaves of three wheat cultivars varying in productivity 总被引:1,自引:0,他引:1
M. K. Nikolaeva S. N. Maevskaya A. G. Shugaev N. G. Bukhov 《Russian Journal of Plant Physiology》2010,57(1):87-95
Seedlings of three wheat varieties (Triticum aestivum L.)—highly productive cv. Ballada, moderately productive cv. Belchanka, and low productive cv. Beltskaya—were exposed to
progressive soil drought (cessation of watering for 3, 5, and 7 days) and then analyzed for chlorophyll content and activities
of ferredoxin-NADP+ oxidoreductase (FNR) and antioxidant enzymes, namely, glutathione reductase (GR) and ascorbate peroxidase (AscP). In addition,
the proline content, and the extent of lipid peroxidation were examined. In the first period of water limitation, the water
loss from leaves was slight for all wheat cultivars, which is characteristic of drought-resistant varieties. After 7-day drought
the leaf water content decreased by 5.2–6.8%. The total chlorophyll content expressed per unit dry weight increased insignificantly
during the first two periods of drought but decreased by 13–15% later on. This decrease was not accompanied by changes in
chlorophyll a/b ratio. The plant dehydration did not induce significant changes in FNR activity. Activities of GR and AscP in leaves of wheat
cultivars Ballada and Belchanka increased on the 3rd and 5th days of drought. Owing to the coordinated increase in GR and
AscP activities, the lipid peroxidation rate remained at nearly the control level observed in water-sufficient plants. When
the dehydration period was prolonged to 7 days, activities of GR and AscP in wheat cultivars reduced in parallel with the
increase in malonic dialdehyde (MDA) content, indicating that the antioxidant enzyme defense system was weakened and lipid
peroxidation enhanced. Unlike Ballada and Belchanka, the wheat cv. Beltskaya did not exhibit the increase in GR and AscP activities
during progressive soil drought. The increase in MDA content by 16% in this cultivar was only observed after a 7-day drought
period. The proline content in leaves of all wheat cultivars increased substantially during drought treatment. Thus, in wheat
cultivars examined, different responses of the defense systems were mobilized to implement plant protection against water
stress. The activities of antioxidant enzyme defense system depended on wheat cultivar, duration of drought, and the stage
of leaf development. 相似文献
5.
Response of twenty eight cultivars of durum wheat (Triticum turgidum var. durum) to immature embryo culture, callus production and in vitro salt tolerance was evaluated. For assessment of cultivars to salt tolerance, growing morphogenic calli were exposed to different
concentrations of NaCl (0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8 and 2.1% w/v) added to the culture medium during two subsequent subcultures
(4 weeks each). Comparison of cultivars for callus induction from immature embryo was based on callus induction frequency
and fresh weight growth of callus (FWG). While, for salt tolerance, the relative fresh weight growth (RFWG) and necrosis percent
of callus were used. There were significant differences among cultivars for potential of regeneration from immature embryo,
and ‘Shahivandi’ a native durum wheat cultivar originating from western Iran was superior among the cultivars tested. The
FWG distinguished cultivars more than callus induction frequency did for callus induction evaluation. Hence, a range of FWG
from 1.23 to 14.65 g was observed in ‘Mexical-75’ and ‘Omrabi-5’ cultivars, respectively. Growing calli derived from cultivars
‘PI 40100’ and ‘Dipper-6’ showed superiority for tolerating salinity under in vitro conditions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
干旱胁迫对小麦幼苗根系生长和叶片光合作用的影响 总被引:25,自引:1,他引:24
采用水培试验方法,以2个耐旱性不同的小麦品种(敏感型望水白和耐旱型洛旱7号)为材料,研究了干旱胁迫对小麦幼苗根系形态、生理特性以及叶片光合作用的影响,以期揭示小麦幼苗对干旱胁迫的适应机制.结果表明: 干旱胁迫下,2个小麦品种幼苗的根系活力显著增大,而根数和根系表面积受到抑制;干旱胁迫降低了望水白的叶片相对含水量,提高了束缚水/自由水,而对洛旱7号无显著影响;干旱胁迫降低了2个小麦品种叶片的叶绿素含量、净光合速率、蒸腾速率、气孔导度和胞间CO2浓度,但随胁迫时间的延长,洛旱7号的叶绿素含量和净光合速率与对照差异不显著;干旱胁迫降低了2个小麦品种幼苗的单株叶面积,以及望水白的根系、地上部和植株生物量,而对洛旱7号无显著影响.水分胁迫下,耐旱型品种可以通过提高根系活力、保持较高的根系生长量来补偿根系吸收面积的下降,保持较高的根系吸水能力,进而维持较高的光合面积和光合速率,缓解干旱对生长的抑制. 相似文献
7.
Co-existence of salt and drought tolerance in Triticeae 总被引:1,自引:0,他引:1
Cell membrane stability (CMS) technique was used to screen for drought tolerance, salt tolerant accessions of three Aegilops species, Ae. tauschii, Ae. cylindrica, Ae. geniculata and two hexaploid wheat (Tricitum aestivum L.) cultivars comprising salt tolerant LU-26 and drought tolerant Chakwal-86. The objectives were to see how valid it is for a salt tolerant plant to be drought tolerant as well and to identify the character(s) that may contribute to drought tolerance. Three moisture levels equal to 100, 50 and 25% saturation capacity of the soil were used for plant cultivation. Injury percentage (IP) based on in-vitro desiccation induced by polyethylene glycol (PEG) in leaf tissue was measured through the conductivity of the electrolyte leakage. Injury percentage decreased in all the test material with decrease in soil moisture contents. Ae. cylindrica exhibited minimum injury at 100% soil moisture level followed by Ae. tauschii and Ae. geniculata while drought tolerant wheat cultivars exhibited the maximum. The wheat cultivar Chakwal-86 has been developed for dry areas, with low soil moisture levels, and high water potential enhances the injury percentage. Aegilops cylindrica is a salt tolerant species and can thus tolerate water deficit conditions created due to low osmotic potential. Potassium appeared to play an important role in drought tolerance which was evident from high K+ contents and low K+ leakage from Aegilops cylindrica and drought tolerant wheat cultivar Chakwal-86. It was inferred from the study that salt tolerant species might prove drought tolerant in the areas where water deficit prevails due to the ability to create low intracellular osmotic potentials. 相似文献
8.
Photosynthetic gas exchange, vegetative growth, water relations and fluorescence parameters as well as leaf anatomical characteristics
were investigated on young plants of two Olea europaea L. cultivars (Chemlali and Zalmati), submitted to contrasting water availability regimes. Two-year-old olive trees, grown
in pots in greenhouse, were not watered for 2 months. Relative growth rate (RGR), leaf water potential (ΨLW) and the leaf relative water content (LWC) of the two cultivars decreased with increasing water stress. Zalmati showed higher
values of RGR and LWC and lower decreased values of ΨLW than Chemlali, in response to water deficit, particularly during severe drought stress. Water stress also caused a marked
decline on photosynthetic capacity and chlorophyll fluorescence. The net photosynthetic rate, stomatal conductance, transpiration
rate, the maximal photochemical efficiency of PSII (F
v/F
m) and the intrinsic efficiency of open PSII reaction centres (F′
v/F′
m) decreased as drought stress developed. In addition, drought conditions, reduced leaf chlorophyll and carotenoids contents
especially at severe water stress. However, Zalmati plants were the less affected when compared with Chemlali. In both cultivars,
stomatal control was the major factor affecting photosynthesis under moderate drought stress. At severe drought-stress levels,
the non-stomatal component of photosynthesis is inhibited and inactivation of the photosystem II occurs. Leaf anatomical parameters
show that drought stress resulted in an increase of the upper epidermis and palisade mesophyll thickness as well as an increase
of the stomata and trichomes density. These changes were more characteristic in cv. ‘Zalmati’. Zalmati leaves also revealed
lower specific leaf area and had higher density of foliar tissue. From the behaviour of Zalmati plants, with a smaller reduction
in relative growth rate, net assimilation rate and chlorophyll fluorescence parameters, and with a thicker palisade parenchyma,
and a higher stomatal and trichome density, we consider this cultivar more drought-tolerant than cv. Chemlali and therefore,
very promising for cultivation in arid areas. 相似文献
9.
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
10.
Koon-Hui Wang Adelheid R. Kuehnle Brent S. Sipes 《In vitro cellular & developmental biology. Plant》1997,33(3):205-208
Summary A reliable method to screen Anthurium for burrowing nematode resistance and tolerance in vitro was developed using 17 genetically distinct Anthurium cultivars. Based on nonparametric data analysis, tolerance and resistance were found to be independent traits to be evaluated
separately. An effective parameter for tolerance evaluation was ranking of relative leaf retention, whereas an effective parameter
for resistance evaluation was the ranking of nematode reproduction, log(Rf+1). A comparison of the ranking of leaf retention
with ranking of nematode reproduction clustered the cultivar responses to burrowing nematode infection into four groups: intolerant
and resistant, moderately tolerant but susceptible, intolerant and susceptible, and tolerant and susceptible. ‘Ozaki’ was
identified as an intolerant reference, ‘Nitta’ as a susceptible reference. ‘Blushing Bride’ was the most tolerant cultivar
among those screened, but it may not be an ideal tolerant reference due to its low vigor. Future screening for burrowing nematode-tolerant
and-resistant cultivars in Anthurium should include ‘Ozaki’ and ‘Nitta’ as internal controls. Evaluation of resistance should be based on a resistance index obtained
by log(Rf of hybrid tested +1) divided by log(Rf of ‘Nitta’ +1); tolerance should be based on ranking of relative leaf retention. 相似文献
11.
Zhen-Yu Wang Feng-Min Li You-Cai Xiong Bing-Cheng Xu 《Journal of Plant Growth Regulation》2008,27(4):309-319
The soil-water threshold range of chemical signals and reactive oxygen species (ROS) homeostasis could have a profound impact
on drought tolerance in wheat. A pot experiment was used to investigate the homeostasis between ROS and antioxidant defense
at five harvest dates, and its role in the correlation between soil-water threshold range of chemical signals and drought
tolerance in three wheat (Triticum aestivum) cultivars during progressive soil drying. The cultivars were bred at different periods, cv. BM1 (old), cv. Xiaoyan6 (recent),
and cv. Shan229 (modern). They were treated with progressive soil drying. Shoot biomass was affected by drought imposed by
two water treatments (90% and 55% field water capacity). The modern wheat cultivar had a lower ROS content and higher ROS-scavenging
antioxidant capacity with greater soil drying (68–25% soil water content) compared with the older cultivar. The modern cultivar
also had excellent adaptation to drought, with a longer survival of 22.7 days and less reduction in shoot biomass of 20.9%
due to early chemical signals and better balance between ROS production and antioxidants. The older cultivar had survival
of 15.3 days and 37.3% reduction of shoot biomass. A wider soil-water threshold range of chemical signals was positively correlated
with improved drought tolerance and better ROS homeostasis. These results suggest that ROS homeostasis acts as a regulator
in relationships between the soil-water threshold range of chemical signals and drought tolerance. 相似文献
12.
Modeling and mapping QTL for senescence-related traits in winter wheat under high temperature 总被引:3,自引:0,他引:3
Kolluru Vijayalakshmi Allan K. Fritz Gary M. Paulsen Guihua Bai Satchidanand Pandravada Bikram S. Gill 《Molecular breeding : new strategies in plant improvement》2010,26(2):163-175
Senescence is a genetically programmed and environmentally influenced process resulting in the destruction of chlorophyll
and remobilization of nutrients to younger or reproductive parts of plants. Delayed senescence, or stay-green, contributes
to a long grain-filling period and stable yield under stress. To model senescence and identify quantitative trait loci (QTL)
for the trait, a population of recombinant inbred lines (RIL) from a cross between winter wheat cultivars, ‘Ventnor’ and ‘Karl
92’ was evaluated for heat tolerance under optimum temperature of 20/15°C (day/night) and continuous heat stress of 30/25°C
from 10 days after anthesis (DAA) until maturity. Ventnor is a heat-tolerant cultivar and Karl 92 is a relatively heat-susceptible
cultivar. Green leaf area was measured and used to model percent greenness retained over the reproductive period. Chlorophyll
content and chlorophyll fluorescence were recorded on flag leaves. Senescence was converted to a quantitative trait using
the model. Based on the modeled parameters, the RILs were categorized into three groups. When senescence-related traits were
evaluated, nine QTL for heat tolerance were found on chromosome 2A, two each on chromosomes 6A and 6B and one each on chromosome
3A, 3B, and 7A. Both parents contributed favorable alleles for most of the senescence-related traits. Microsatellite markers
Xgwm356 and Xgwm5 prominently linked to the senescence-related traits may be useful in marker-assisted breeding. These and the linked AFLP
(amplified fragment length polymorphism) markers XCGT.TGCG-349, XCGT.GTG-343, and XCGT.CTCG-406, if converted to STS (sequence tagged sites), can be used for further molecular dissection of the QTL for post-anthesis heat
tolerance. 相似文献
13.
Root Respiration,Photosynthesis and Grain Yield of Two Spring Wheat in Response to Soil Drying 总被引:3,自引:0,他引:3
The effects of soil water regime and wheat cultivar, differing in drought tolerance with respect to root respiration and grain
yield, were investigated in a greenhouse experiment. Two spring wheat (Triticum aestivum) cultivars, a drought sensitive (Longchun 8139-2) and drought tolerant (Dingxi 24) were grown in PVC tubes (120 cm in length and 10 cm in diameter) under an automatic rain-shelter. Plants were subjected
to three soil moisture regimes: (1) well-watered control (85% field water capacity, FWC); (2) moderate drought stress (50%
FWC) and (3) severe drought stress (30% FWC). The aim was to study the influence of root respiration on grain yield under
soil drying conditions. In the experiment, severe drought stress significantly (p < 0.05) reduced shoot and root biomass, photosynthesis and root respiration rate for both cultivars, but the extent of the
decreases was greater for Dingxi 24 compared to that for Longchun 8139-2. Compared with Dingxi 24, 0.04 and 0.07 mg glucose m−2 s−1 of additional energy, equivalent to 0.78 and 1.43 J m−2 s−1, was used for water absorption by Longchun 8139-2 under moderate and severe drought stress, respectively. Although the grain yield of both cultivars decreased with declining
soil moisture, loss was greater in Longchun 8139-2 than in Dingxi 24, especially under severe drought stress. The drought tolerance cultivar (Dingxi 24), had a higher biomass and metabolic activity under severe drought stress compared to the sensitive cultivar (Longchun 8139-2), which resulted in further limitation of grain yield. Results show that root respiration, carbohydrates allocation (root:shoot
ratio) and grain yield were closely related to soil water status and wheat cultivar. Reductions in root respiration and root
biomass under severe soil drying can improve drought tolerant wheat growth and physiological activity during soil drying and
improve grain yield, and hence should be advantageous over a drought sensitive cultivar in arid regions. 相似文献
14.
M. Ashraf 《Plant and Soil》1989,119(2):205-210
The physiological basis of salt tolerance of two cultivars of blackgram, cv Candhari Mash (relatively salt tolerant) and cv
Mash 654 (salt sensitive), was assessed in salinized sand culture at the flowering stage. Increasing NaCl concentration in
the rooting medium significantly reduced the chlorophyll a, chlorophyll b, and total chlorophyll, leaf water potential (Ψw), leaf solute potential (Ψs), and leaf turgor potential (Ψp) in both the cultivars. Leaf protein and proline content was increased as a result of increasing salt concentration in both
cultivars. High salt concentrations had no significant effect on the seed protein content of both cultivars. At high salinities,
cv Candhari Mash had significantly greater chlorophyll a, chlorophyll b and total chlorophyll, leaf water potential, solute
potential, and turgor potential than cv Mash 654, but the latter had greater leaf proline content than cv Candhari Mash. Cultivars
did not differ significantly for both leaf and seed protein contents.
The relatively salt tolerant cv Candhari Mash maintained high leaf water potential and turgor potential to resist salt injury.
Leaf proline content had negative correlation with salt tolerance in blackgram. 相似文献
15.
Soil water deficits reduce rice (Oryza sativa L.) productivity under upland field conditions. In this study, we constructed screening facilities to evaluate the performance
of rice cultivars under drought conditions and to assess the roles of deep roots. Two experiments were conducted with six
rice cultivars, including drought-tolerant and drought-susceptible cultivars, grown in two root environments: a root-restricted
treatment that restricted rooting depth with water-permeable sheets, and a raised bed that reduced water availability in the
surface soil by inserting a gravel layer between the topsoil and subsoil layers to interrupt capillary transport of water.
In the root-restricted treatment, in which root growth was restricted to the surface 25-cm layer, leaf water potential decreased
faster in cultivars with a large canopy during drought stress, and there was little difference in panicle weight among cultivars.
With a normal (unrestricted) root environment, the deepest-rooting cultivar (‘IRAT109’) maintained higher leaf water potential
during drought, although panicle weight under drought stress was affected by yield potential as well as by deep rooting. Under
the intermittent drought stress in the raised bed, deep-rooting cultivars accumulated more nitrogen and produced more biomass,
and the difference in panicle weight between deep-rooting drought-tolerant and shallow-rooting drought-susceptible cultivars
was magnified by the raised bed compared with the yield differences under drought in a normal root environment. These results
demonstrate that the drought screening facilities we developed can help to identify superior cultivars under upland field
conditions without time-consuming measurement of deep root systems. 相似文献
16.
Andrea R. Gutsche Tiffany M. Heng-Moss Leon G. Higley Gautam Sarath Dolores W. Mornhinweg 《Arthropod-Plant Interactions》2009,3(4):233-240
Knowledge of the physiological responses of barley, Hordeum vulgare L., to the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae) is critical to understanding the defense response of barley to aphid injury and identifying
resistance mechanisms. This study documented the impact of D. noxia feeding on resistant (‘Sidney’) and susceptible (‘Otis’) barley through chlorophyll fluorescence measurements, chlorophyll
content, and carbon assimilation (A–Ci) curves recorded at 1, 3, 6, 10, and 13 days after aphid introduction. All chlorophyll fluorescence parameters evaluated
were similar between aphid-infested and control plants for both cultivars. A–Ci curves showed that D. noxia feeding negatively impacts the photosynthetic capacity in both cultivars, but this effect was greater in the susceptible
plants. From the A–Ci curves, it is apparent that compensation occurs in resistant barley by day 10, but by the conclusion of the experiment, aphid
populations reached levels that overwhelmed the resistant barley seedlings. Differences observed in carbon assimilation curves
between control and infested plants show that D. noxia feeding impacts the dark reaction, specifically rubisco activity and RuBP regeneration. It is likely that declines in the
photochemical efficiency and chlorophyll content of the plants may be a secondary effect and not the primary trigger of declines
in host plant function. 相似文献
17.
In Mediterranean regions drought is the major factor limiting spring barley and durum wheat grain yields. This study aimed to compare spring barley and durum wheat root and shoot responses to drought and quantify relationships between root traits and water uptake under terminal drought.One spring barley(Hordeum vulgare L. cv. Rum) and two durum wheat Mediterranean cultivars(Triticum turgidum L. var durum cvs Hourani and Karim) were examined in soil‐column experiments under well watered and drought conditions. Root system architecture traits, water uptake, and plant growth were measured. Barley aerial biomass and grain yields were higher than for durum wheat cultivars in well watered conditions. Drought decreased grain yield more for barley(47%) than durum wheat(30%, Hourani). Root‐to‐shoot dry matter ratio increased for durum wheat under drought but not for barley, and root weight increased for wheat in response todrought but decreased for barley. The critical root length density(RLD) and root volume density(RVD) for 90% available water capture for wheat were similar to(cv. Hourani) or lower than(cv. Karim) for barley depending on wheat cultivar. For both species, RVD accounted for a slightly higher proportion of phenotypic variation in water uptake under drought than RLD. 相似文献
18.
During vegetative period 2004–2005 powdery mildew (Erysiphe graminis DC. f. sp. hordei Em. Marchal) field resistance of spring barley cultivars was investigated at the Lithuanian Institute of Agriculture. The
spring barley genotypes tested were Lithuania-registered cultivars, cultivars from genetic resources collection, and the new
cultivars used for initial breeding. In total, 23 resistance genes were present in the 84 cultivars studied. Among mono-genes
only mlo and 1-B-53 showed very high resistance. Slight powdery mildew necroses (up to 3 scores) formed on cultivars possessing these genes.
The maximal powdery mildew (PM) severity reached a score of 8.5 and the area under disease progress curve (AUDPC) a value
of 1216.8. The cultivars ‘Primus’, ‘Astoria’, ‘Power’, ‘Harrington’ and ‘Scarlett’ were the most resistant among the non mlo cultivars. Severity of PM on ‘Primus’ reached a score of 3.5 (3.0 of PM necrosis) in average, the other cultivars were diseased
from 4.5 (3.0) to 5.0 (2.0). The AUDPC values for these cultivars except ‘Scarlett’ were the lowest (85.0–145.3) among the
other cultivars. The highest contrast in development of the other leaf diseases was between highly resistant and susceptible
to PM cultivar groups. The fast development of PM depressed development of the other diseases 4.7 times. 相似文献
19.
Gas exchange,chlorophyll fluorescence,and osmotic adjustment in two mango cultivars under drought stress 总被引:1,自引:0,他引:1
The responses of photosynthetic gas exchange, chlorophyll fluorescence, content of pigments, main osmolytes, and malondialdehyde
(MDA) to water-withholding for 15 days and re-hydration in seedlings of two mango cultivars (Mangifera indica L. var. “Choke Anand’ and var. “Khieo Sawoei”) under 50% sunlight and full sunlight were investigated. For both cultivars, the water-witholding resulted
in progressively decreases in leaf relative water content, net photosynthesis (P
n), stomatal conductance (g
s), and increases in the conversion of xanthophyll cycle pigments estimated by an index of leaf spectral reflectance (ΔPRI),
carotenoid to chlorophyll ratio, non-photochemical quenching (NPQ), the contents of malondialdehyde (MDA) and compatible solutes
(total soluble sugar and proline). The effect of the water stress was more pronounced in full sunlight than 50% sunlight.
The maximum photochemistry efficiency measured at dawn was fairly constant during the period of the treatment for both cultivars
under both light regimes. The water stress caused less pronounced inhibition of photosynthesis in “Choke Anand” than in “Khieo
Sawoei” cultivar under both light regimes. After re-hydration, the recovery was relatively quicker in “Choke Anand” than in
“Khieo Sawoei” cultivar. Both cultivars in both 50% and full sunlight showed complete recovery in photochemistry after 5 days
of re-watering but photosynthesis did not show a complete recovery as indicated by gas exchange rates. As the results of lower
NPQ, ΔPRI and osmotic adjustment in the cultivar “Khieo Sawoei” compared to the cultivar “Choke Anand”, the former cultivar
was less tolerant to drought than the latter. Our study further showed that partial shading (e.g., 50% of sunlight) significantly
alleviated the harmful effect of drought stress on mango cultivars but in fact stomata of seedlings grown in partial shade
was more responsive to water deficit than in full light. 相似文献
20.
不同菊花品种根系、地上部和叶片相关指标分析及抗逆性评价 总被引:1,自引:0,他引:1
采用盆栽法对6个菊花(Chrysanthemum morifolium Ramat.)品种幼苗的根系和地上部相关指标及叶片光合和气体交换参数进行了比较和相关性分析;并基于叶片相对含水量、相对电导率、丙二醛含量和可溶性糖含量4个生理生化指标,采用隶属函数法对不同菊花品种幼苗的抗旱性和耐热性进行了评价.结果表明:不同菊花品种间幼苗的根系和地上部相关指标及叶片光合和气体交换参数存在一定差异.相关性分析结果表明:根系的大多数相关指标与株高呈显著(P<0.05)或极显著(P<0.01)正相关,但与茎粗和单株叶数却没有显著相关性;并且,单株的根体积、根鲜质量和干质量与单株地上部鲜质量呈极显著正相关(相关系数分别为0.598、0.642和0.599),与单株地上部干质量呈极显著或显著正相关(相关系数分别为0.736、0.606和0.553).主根长与净光合速率和蒸腾速率,平均根长与水分利用效率及单株根鲜质量与蒸腾速率呈显著正相关(相关系数分别为0.475、0.517、0.570和0.477);单株根干质量与蒸腾速率及根系活力与净光合速率和水分利用效率呈极显著正相关(相关系数分别为0.641、0.877和0.814).抗逆性评价结果表明:品种'南农红霞'('Nannong Hongxia')、'大白托桂'('Qx073')和'天使'('Angelina')的平均隶属函数值分别为0.93、0.93和0.72,据此判断这3个菊花品种的抗旱性最强;品种'馒头菊'('Cayman')和'南农红霞'的平均隶属函数值分别为0.82和0.70,据此判断这2个菊花品种的耐热性最强.综上所述,不同菊花品种幼苗的根系相关指标差异明显,并且根系生长状况能够影响地上部的生长和发育,品种'南农红霞'的抗旱性和耐热性均很强,具有较高的抗性育种价值. 相似文献