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1.
Blanche Benzian 《Plant and Soil》1972,36(1-3):243-245
Summary Cumulative dressings of potassium metaphosphate tested on seedlings and transplants ofPicea sitchensis gave promising results from 1964 to 19661 at two nurseries — a sandy podsol and a sandy loam with better nutrient retention. The four experiments, which also included
superphosphate alone, KC1/superphosphate, with and without topdressings of KNO3, and potassium dihydrogen phosphate, were continued until 1969. On the podsol, potassium metaphosphate maintained its superiority
for seedlings and also left larger residues in the surface soil. It had no special merit on the sandy loam or for transplants
on either soil. 相似文献
2.
Summary In a heathland nursery on an acid sandy podsol and in a nursery on moderately acid agricultural land, four PK fertilizers were compared with superphosphate alone, using seedlings and transplants of Sitka sprucePicea sitchensis and Norway sprucePicea abies as test crops. The four fertilizers were: 1) a compound prepared from KCl and superphosphate (KCl/superphosphate), 2) the same compound supplemented by three summer topdressings of potassium nitrate, 3) potassium dihydrogen phosphate, 4) potassium metaphosphate. Except for potassium nitrate all fertilizers were applied in the spring before sowing or transplanting.Mid-season analyses (confined to Sitka spruce seedlings) showed that the effectiveness of different fertilizers depended on the rainfall pattern during growth. Phosphorus and potassium were leached less and nutrients used more efficiently with potassium metaphosphate than with KCl/superphosphate. Potassium nitrate applied on three occasions during the summer to plots with KCl/superphosphate maintained the best growth and largest K-concentrations in the seedlings. Differences between fertilizers were small for transplants at the heathland nursery and for all crops at the nursery on an agricultural-type soil. Losses of P and K by leaching on the sandy podsol both decreased in the order KCl/superphosphate > or=potassium dihydrogen phosphate > potassium metaphosphate. 相似文献
3.
4.
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
5.
Khaled Sebei Ahmed Debez Wahid Herchi Sadok Boukhchina Habib Kallel 《Journal of Plant Biology》2007,50(4):447-454
Because of its high contents of protein, α-linolenic-rich oil, lignans, and fiber, demand is increasing for flax(Linum usitatissi-mum L.) and flax seed oil as a food source. In this comparative survey, we examined germination and the mobilization of seed
storage products (lipids and soluble proteins) of 3-d-old seedlings from two flax cultivars (N 51 and H 52) challenged with
moderate salinity (up to 200 mM NaCl). At the highest salt concentration, germination appeared to be cultivar-dependent, with
that of ‘N 51’ being less impaired and delayed than in ’H 52’. Sodium chloride inhibited germination via osmotic and toxic
effects, so that seed viability was altered, especially in ‘H 52’. At 200 mM NaCl, lipid mobilization was delayed in the earliest
germination phases. This response was associated with increased proportions of linolenic acid contents in both cultivars and
more linolenic acid-rich molecular species of TAGs. Irrespective of the salt level, soluble protein contents in both cultivars
decreased over time, although a salt-related precocity of protein degradation occurred at 200 mM NaCl. 相似文献
6.
M. T. McHenry B. R. Wilson J. M. Lemon D. E. Donnelly I. G. Growns 《Plant and Soil》2006,285(1-2):245-255
Dense White Cypress Pine (Callitris glaucophylla J. Thompson and L.A.S. Johnson) regrowth occurs frequently across previously cleared landscapes in New South Wales (NSW), and is thought to adversely affect agricultural production and to cause land degradation. The NSW Native Vegetation Act (2003) requires that management of native vegetation including pre-1990 regrowth must ‘improve or maintain’ site condition, yet there is currently limited information regarding techniques for the optimum management of C. glaucophylla in this regard. We conducted a preliminary study to examine floristic composition, soil condition (to 50 cm) and carbon storage under ‘Dense’ (dense regrowth), ‘Thinned’ (dense regrowth thinned 2000/2001) and ‘Un-colonised’ (pasture not yet recolonised by C.␣glaucophylla) plots on private lands in NSW. Reduced tree density from thinning resulted in increased biomass of the remaining individual trees. Un-colonised plots had significantly more groundcover than thinned plots, which had significantly more groundcover than dense plots. Differences in plant diversity however, were explained by site factors rather than land use. Soils in the dense plots were the most acid but soil pH was significantly higher in thinned plots and pH was highest in soil of the un-colonised plots. Mean values for carbon, nitrogen, sulphur and extractable phosphorus varied among sites, although each were significantly more abundant in the mineral soil of dense and thinned plots compared with un-colonised plots, suggesting that thinning had had a minimal effect on the soil parameters assessed. Accounting for all site components, site carbon storage was significantly higher in dense and thinned plots compared with un-colonised plots due to elevated levels of soil and litter carbon as well as the presence of trees. The results indicate that thinning dense C. glaucophylla can maintain and (by some measures) improve site condition. However, given the variability in some of the parameters assessed, further study across a wider range of soil types and rainfall gradients is proposed. 相似文献
7.
Patrick H. Brown Steven A. Weinbaum Geno A. Picchioni 《Trees - Structure and Function》1995,9(3):158-164
The influence of alternate bearing on nutrient utilization and total tree nutrient content was investigated in mature pistachio
(Pistacia vera L. cv Kerman trees). Removal of N, P and Zn in fruit and abscised leaves of cropping (‘on’) trees averaged 5, 6, and 2 times,
respectively, the removal in abscised leaflets of the non-fruiting, ‘off’ year trees. One hundred and thirty-five kg N, 131
kg K, 86 kg Ca, 39 kg Mg and 18 kg P per hectare were removed in fruits and abscised leaves in ‘on’ year trees. Tree nutrient
contents and, presumably, the size of nutrient storage pools in dormant trees varied between ‘on’ and ‘off’ years. There was
22% and 14% more N and P, respectively, in dormant trees following ‘off’ than ‘on’ years. The greater N and P accumulation
in ‘off’ year trees is depleted in support of the large fruit demand for N and P during ‘on’ years. In contrast to N and P,
there was greater K and Ca accumulation in perennial tree parts during ‘on’ years than during ‘off’ years. The greater K accumulation
in perennial tree parts and approximately 30% greater removal of K in annual organs during ‘on’ than ‘off’ years suggests
that K uptake could be 4 times higher in ‘on’ year trees than in (non-cropping), ‘off’ year trees. 相似文献
8.
A parentage study of closely related Ukrainian wine grape varieties using microsatellite markers 总被引:1,自引:0,他引:1
S. Goryslavets V. Risovanna R. Bacilieri J. -F. Hausman M. Heuertz 《Cytology and Genetics》2010,44(2):95-102
Four bred grapevine varieties released for commercial cultivation in Ukraine, namely ‘Antey Magarachskii’, ‘Rubinovyi Magaracha’,
‘Granatovyi Magaracha’ and ‘Rubin Golodrigi’, and their putative parental forms were genotyped using six microsatellite loci.
Genotypes were compared with breeding records to verify genetic relationships among varieties. Results of the analysis confirmed
four of six parent-offspring relationships. Results of the analysis allow to assume that genotype ‘Seyve Villard 20347’ is
the direct parent of ‘Antey Magarachskii’ instead of its grandparent. The first-studied accession believed to be that of ‘Granatovyi
Magaracha’ was identified as impurity. In order to verify the parentage of ‘Granatovyi Magaracha’, rest accessions of that
variety and its putative parent ‘Antey Magarachskii’ were additionally genotyped at 13 nuclear loci and at three chloroplast
loci. The parent-offspring relationship was confirmed, as all ‘Granatovyi Magaracha’ accessions had a common allele with the
parent variety ‘Antey Magarachskii’ at each locus and the same chlorotype A. Different ‘Granatovyi Magaracha’ accessions could
have been obtained via vegetative propagation of two seedlings which arose from one crossing. 相似文献
9.
Christophe Malaterre 《Origins of life and evolution of the biosphere》2010,40(2):169-177
The plurality of definitions of life is often perceived as an unsatisfying situation stemming from still incomplete knowledge
about ‘what it is to live’ as well as from the existence of a variety of methods for reaching a definition. For many, such
plurality is to be remedied and the search for a unique and fully satisfactory definition of life pursued. In this contribution
on the contrary, it is argued that the existence of such a variety of definitions of life undermines the very feasibility
of ever reaching a unique unambiguous definition. It is argued that focusing on the definitions of specific types of ‘living
systems’—somehow in the same way that one can define specific types of ‘flying systems’—could be more fruitful from a heuristic
point of view than looking for ‘the’ right definition of life, and probably more accurate in terms of carving Nature at its
joints. 相似文献
10.
In responding to three reviews of Evolution in Four Dimensions (Jablonka and Lamb, 2005, MIT Press), we briefly consider the historical background to the present genecentred view of evolution,
especially the way in which Weismann’s theories have influenced it, and discuss the origins of the notion of epigenetic inheritance.
We reaffirm our belief that all types of hereditary information—genetic, epigenetic, behavioural and cultural—have contributed
to evolutionary change, and outline recent evidence, mainly from epigenetic studies, that suggests that non-DNA heritable
variations are not rare and can be quite stable. We describe ways in which such variations may have influenced evolution.
The approach we take leads to broader definitions of terms such as ‘units of heredity’, ‘units of evolution’, and ‘units of
selection’, and we maintain that ‘information’ can be a useful concept if it is defined in terms of its effects on the receiver.
Although we agree that evolutionary theory is not undergoing a Kuhnian revolution, the incorporation of new data and ideas
about hereditary variation, and about the role of development in generating it, is leading to a version of Darwinism that
is very different from the gene-centred one that dominated evolutionary thinking in the second half of the twentieth century. 相似文献
11.
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
12.
13.
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
14.
Summary Differences in the productivity of establishedP. radiata plantations on pasture and forest soils were found to be reproducible withP. radiata seedlings in a glasshouse environment. The growth of seedlings on pasture soil exceeded that of seedlings on native forest
soil (the ‘primary pasture effect’). After a history of pine on both native and pasture soils a residual effect of pasture
on seedling growth was evident (the ‘secondary pasture effect’). However, the effect of a history of pine plantation (the
‘pine effect’) was to decrease the productivity of both native and pasture soil as assessed by seedling growth. These effects
were not related to changes due to land management in mycorrhizal infection or in soil structure. The analysis of seedling
growth leads to the conclusion that soil fertility, particularly the availability of nitrogen and phosphorus, has changed. 相似文献
15.
David Penny Marc P. Hoeppner Anthony M. Poole Daniel C. Jeffares 《Journal of molecular evolution》2009,69(5):527-540
We review the introns-first hypothesis a decade after it was first proposed. It is that exons emerged from non-coding regions
interspersed between RNA genes in an early RNA world, and is a subcomponent of a more general ‘RNA-continuity’ hypothesis.
The latter is that some RNA-based systems, especially in RNA processing, are ‘relics’ that can be traced back either to the
RNA world that preceded both DNA and encoded protein synthesis or to the later ribonucleoprotein (RNP) world (before DNA took
over the main coding role). RNA-continuity is based on independent evidence—in particular, the relative inefficiency of RNA
catalysis compared with protein catalysis—and leads to a wide range of predictions, ranging from the origin of the ribosome,
the spliceosome, small nucleolar RNAs, RNases P and MRP, and mRNA, and it is consistent with the wide involvement of RNA-processing
and regulation of RNA in modern eukaryotes. While there may still be cause to withhold judgement on intron origins, there
is strong evidence against introns being uncommon in the last eukaryotic common ancestor (LECA), and expanding only within
extant eukaryotic groups—the ‘very-late’ intron invasion model. Similarly, it is clear that there are selective forces on
numbers and positions of introns; their existence may not always be neutral. There is still a range of viable alternatives,
including introns first, early, and ‘latish’ (i.e. well established in LECA), and regardless of which is ultimately correct,
it pays to separate out various questions and to focus on testing the predictions of sub-theories. 相似文献
16.
There is increasing evidence that temperature, in addition to photoperiod, may be an important factor regulating bud dormancy.
The impact of temperature during growth cessation, dormancy development, and subsequent cold acclimation was examined in four
hybrid poplar clones with contrasting acclimation patterns: ‘Okanese’—EARLY, ‘Walker’—INT1, ‘Katepwa’—INT2, and ‘Prairie Sky’—LATE.
Four day–night temperature treatments (13.5/8.5, 18.5/13.5, 23.5/8.5, and 18.5/3.5°C) were applied during a 60-day induction
period to reflect current and predicted future annual variation in autumn temperature for Saskatoon, SK. Warm night temperature
(18.5/13.5°C) strongly accelerated growth cessation, dormancy development, and cold acclimation in all four clones. Day temperature
had the opposite effect of night temperature. Day and night temperatures appeared to act antagonistically against each other
during growth cessation and subsequent dormancy development and cold acclimation. Growth cessation, dormancy development,
and cold acclimation in EARLY and LATE were less affected by induction temperature than INT1 and INT2 suggesting that genotypic
variations exist in response to temperature. Separating specific phenological stages and the impact by temperature on each
clone revealed the complexity of fall phenological changes and their interaction with temperature. Most importantly, future
changes in temperature may affect time to growth cessation, subsequently altering the depth of dormancy and cold hardiness
in hybrid poplar. 相似文献
17.
D. Gonsalves C. Gonsalves J. Carr S. Tripathi T. Matsumoto J. Suzuki S. Ferreira K. Pitz 《Tropical plant biology》2012,5(2):153-160
In 1992, papaya ringspot virus (PRSV) was discovered in the Puna district of Hawaii island where 95% of the state of Hawaii’s papaya was being grown. By 1998 production in Puna had decreased 50% from 1992 levels. A PRSV-resistant transgenic papaya ‘Rainbow’ containing the coat protein gene of PRSV was released commercially in Hawaii in 1998, and saved the papaya industry from further devastation. In the ensuing years since the release of the transgenic papaya, a number of farmers grew hermaphrodite nontransgenic ‘Kapoho’ papaya in close proximity to plantings of hermaphrodite transgenic ‘Rainbow’ papaya. These plantings provided a unique opportunity to assay for transgenic-pollen drift under commercial conditions. Between 2004 and 2010, assays for the GUS (beta-glucuronidase) transgene in embryos were done to study transgenic-pollen drift in commercial ‘Kapoho’ plantings and in replicated field plots. Very low pollen drift (0.8%) was detected in fruit of ‘Kapoho’ trees in the border row of one plantation when 90 embryos were assayed per fruit, while no pollen drift was detected in four other commercial plantings in which eight embryos were tested per fruit. Pollen drift averaged 1.3% of tested embryos in field plots where individual hermaphrodite ‘Kapoho’ trees were adjacent to two or four ‘Rainbow’ trees. In contrast, 67.4% of tested embryos were GUS positive in similarly located female ‘Kapoho’ trees. The very low transgene flow to close-by ‘Kapoho’ plantings is likely due to the fact that hermaphrodite trees are used commercially in Hawaii and that these trees are largely self-pollinated before the stigma is exposed to external pollen. 相似文献
18.
The objective of this study was to estimate the hydraulic conductivity of sandy soil under different plant cover at the locality
Mláky II at Sekule (southwest Slovakia). Two sites were demarcated at the locality, with mainly moss species at glade site,
and pine forest at forest site. The estimation of unsaturated hydraulic conductivity was conducted by (a) minidisk infiltrometer
and (b) the analysis of a dye tracer total resident concentration. The latter approach assumed the applicability of the stochastic—convective
flow theory in the sandy soil. In the dye tracer experiment, two plots (1 × 1 m each) were established in both sites, and
100 mm of dye tracer (Brilliant Blue FCF) solution was applied on the soil surface. Similar results were obtained in both
plots, with more than 70 % area of horizons stained in the depth of 30–50 cm. In some cases, the predicted and measured hydraulic
conductivity were found within an order of magnitude, thus revealing similar impact of different plant cover on hydraulic
properties of sandy soil studied. In contrast to sandy soils used for agriculture, the influence of the plant/surface humus
and topsoil interface extended in the form of a highly heterogeneous matrix flow to the depth of 50–60 cm, where it was dampened
by horizontal layering. 相似文献
19.
C. Douglas Boyette Mark A. Jackson Charles T. Bryson Robert E. Hoagland William J. ConnickJr. Donald J. Daigle 《BioControl》2007,52(3):413-426
The weed Sesbania exaltata (Raf.) Rydb. ex A.W. Hill (hemp sesbania) was effectively controlled in soybean [Glycine max (L.) Merr.] field test plots over a 2-year testing period (1995–1996) with microsclerotia of the bioherbicidal fungus, Colletotrichum truncatum, formulated in wheat gluten-kaolin granules called ‘Pesta’. Weed control averaged 84% and 88%, respectively, in plots treated
pre-plant incorporated (PPI) at ‘Pesta’ rates of 168 or 336 kg ha−1, and 71% and 78%, respectively, in plots treated pre-emergence (PE) at ‘Pesta’ rates of 168 or 336 kg ha−1 over the testing period. Post-emergence (POE) control averaged 30% and 50%, respectively, for the 168 and 336 kg ha−1 treatments, and was significantly less effective than either PE or PPI treatments. Although pathogenesis and mortality occurred
in hemp sesbania tissues, satisfactory weed control was not achieved in plots treated at rates of 17 or 84 kg ha−1 with any of the application methods. Soybean yields were significantly greater in test plots treated PPI or PE, as compared
to yields from test plots treated either POE, with inert ‘Pesta’ granules, or from untreated controls. Microsclerotia formulated
in ‘Pesta’ granules exhibited excellent shelf-life, retaining high viability after storage for 10 years at 4 °C. These results
suggest that microsclerotia of C. truncatum formulated in ‘Pesta’ granules offers an effective method for controlling this important weed and preserving the activity
of this bioherbicide. 相似文献
20.
To characterize the stimulatory effects of low-dose gamma radiation on early plant growth, we investigated alterations in
the photosynthesis and antioxidant capacity of red pepper (Capsicum annuum L.) seedlings produced from gamma-irradiated seeds. For two cultivars (Yeomyung and Joheung), three irradiation groups (2,
4, and 8 Gy, but not 16 Gy) showed enhanced development, although Fv/Fm, the maximum photochemical efficiency of Photosystem
II (PSII), did not differ significantly among any of the four groups. In contrast, values for 1/Fo — 1/Fm, i.e., a measure
of functional PSII content, decreased in the irradiated groups of ‘Yeomyung’ but increased in those of ‘Joheung’. Pigment
analyses and enzyme activity assays revealed that irradiation altered the compositions of photosynthetic pigments (chlorophylls
and carotenoids) as well as the activities of antioxidant enzymes (superoxide dismutase and glutathione reductase). However,
these shifts were not directly related to the increase in early growth, although they were cultivar-and developmental stage-dependent
In addition, the effects of irradiation on the enzymatic activities measured here were at opposition between the two cultivars. 相似文献