不同土壤盐度对胡萝卜品质的影响

采用土壤盆栽试验,设置6个盐度水平（0、500、1000、1500、2000、2500 mg/kg）,研究胡萝卜种植过程中盐度对其叶绿素、维生素C、可溶性糖、可溶性蛋白质及硝酸盐含量的影响。结果表明,种植胡萝卜的土壤盐度控制在500 mg/kg,可以提高胡萝卜的品质,减少盐分对土壤的损伤。具体表现为,500 mg/kg盐度处理对胡萝卜叶绿素含量无显著影响,而高盐度使胡萝卜叶绿素总含量降低;500～1000 mg/kg盐度可增加胡萝卜维生素C和可溶性蛋白质含量;可溶性总糖含量以500 mg/kg处理的降低幅度最小,500～2000 mg/kg处理使胡萝卜硝酸盐含量呈降低趋势,但高盐度（2500 mg/kg）则会增加其硝酸盐含量。     

The Effects of Soil Salinity and Meloidogyne javanica on Tomato

A non-sodic, non-saline sandy loam soil was salinized to anion-cation ratios similar to those naturally occurring in Iraq and California. The interactions of saline soils (conductivities 4, 8, 12 and 16 mmhos/cm) with a moderately salt-tolerant plant (Lycopersicon esculentum ''Marimond'') and a plant parasitic nematode (Meloidogyne javanica) were investigated. Plant parasitic nematodes were shown to be an important modifying influence within the plant environment, either accentuating or ameliorating salinity stress effects.     

Effects of Soil Salinity and Growth Regulators on Germination and Seedling Metabolism of Wheat

Germination studies were carried out with the wheat varieties NP823, Karchia, Sonora 63, Sonora 64, Mayo 64 and Lerma Rojo in artificially salinized soil maintained at EC_e 2, 8, 12 and 16 mmhos/cm at 25°C. Early seedling growth and metabolism of variety NP 823 was studied in salt solutions alone and with addition of the growth regulators GA₃ and Cycocel (2-chloroethyl trimethylammonium chloride). Soil salinity both depressed and delayed the germination. Among the varieties tested NP 823 and Karchia were relatively less susceptible to salt injury while Lerma Rojo exhibited a maximum susceptibility. Salt supply also brought about a reduction in the early seedling growth, the release of reducing sugar and the amylase activity. The adverse effect on amylase activity was not mediated through the synthesis of enzyme protein but by an inhibition of the enzyme activity. Exogenous supply of GA₃ counteracted the adverse effect of salt on amylase activity and the release of reducing sugar but not on the early seedling growth.     

温度,盐度,碱度对池沼公鱼胚胎发育的影响

池沼公鱼(Hypomesus olidus Pallas)是亚冷水小型经济鱼类,栖居于淡水、河口咸淡水中。近年来国内池沼公鱼移植广泛展开,为探讨池沼公鱼对不同生态条件的生存适应能力和     

Effects of Salinity on Some Citrus Scion-Rootstock Combinations

Chloride and sodium concentrations, water relations and gasexchange parameters were measured on leaves of Clementine (CitrusClementine Hort. ex. Tan) and Navel orange [C. sinensis (L.)Osb] scions grafted on Cleopatra mandarin (C. reticulata Blanco)and Troyer citrange (C. sinensis x Poncirus trifoliata) rootstocksgrown at increasing levels of NaCl in the external medium. Otherparameters affected by salinity such as growth and defoliationwere also recorded. Scions on Cleopatra mandarin accumulated less Cl^- in their leavesthan did scions on Troyer citrange. Also, leaf Cl^- levels inClementine scions were lower than in Navel orange when bothwere grafted on the same rootstock. However, sodium concentrationwas lower in scions on Troyer citrange than in Cleopatra mandarin. Leaf water potential, stomatal conductance, photosynthesis andgrowth were reduced more in grafted plants of salt-treated Navelorange than those of salt-treated Clementine. However, choiceof rootstock had little effect on salt-induced changes in theseparameters. For each scion, reduction in leaf stomatal conductancewas closely correlated with decrease in leaf water potential.Also, a significant correlation between photosynthesis and stomatalconductance was found. The results indicate that reductions in gas exchange parametersand growth at increasing salinity levels depended more on thescion type than on Cl^- or Na⁺ concentration in leaves. Otherwise,leaf injury and defoliation were closely correlated with leafCl^- concentration.Copyright 1995, 1999 Academic Press Citrus, photosynthesis, salinity, water relations     

Moderate Soil Salinity Alleviates the Impacts of Drought on Growth and Water Status of Plants

Russian Journal of Plant Physiology - Drought and soil salinity are the main environmental stress factors affecting plant growth and development. A certain appropriate concentration of NaCl in the...     

Effects of Salinity on the Growth Rate and Survival of Juvenile Littorina saxatilis Gastropods from Habitats with Different Salinity Regimes

The effects of salinity on the growth rate and survival of juvenile Littorina saxatilis gastropods reared in the laboratory from the young of progenic females collected in estuarine, intermediate, and marine habitats were studied. The optimum growth conditions of juveniles were dependent on the salinity regime in their original habitat. The progeny of females from the marine site showed maximum survival at a salinity of 23, the value corresponding to the normal salinity in their native habitat during the breeding period, while at 14, the growth of juveniles from this population was strongly suppressed. Juveniles originating from the estuarine habitat were able to maintain equally high growth rates at 23 and 14; however, at 14, they grew significantly faster than juveniles from the marine site. The progeny of females from the intermediate habitat showed intermediate growth rates at 14. Fluctuating salinity (23–8–23) had an adverse effect on the growth of juvenile Littorina, irrespective of the parental habitat. The differences in survival, size, and growth rates of the progeny of L. saxatilis in habitats with different salinity regimes are discussed in relation to their potential adaptive significance to life in estuaries.     

盐度对裸项栉鰕虎鱼繁殖和生长的影响

目的探索裸项栉鰕虎鱼繁殖和育苗的适宜盐度。方法比较不同盐度梯度条件下裸项栉鰕虎鱼的产卵率、孵化率和生长存活情况。结果裸项栉鰕虎鱼性腺成熟、产卵和孵化的适宜盐度为10‰-20‰,过低或过高盐度该鱼产卵量少,孵化率极低;适宜的盐度有利于裸项栉鰕虎鱼的生长。结论裸项栉鰕虎鱼适盐范围广,适宜的繁殖、生长盐度较低。     

Host-specific Fusarium oxysporum Causes Wilt of Jojoba

Jojoba [Simmondsia chinensis (Link) Schneider] plantations in Israel originated from vegetative propagation, planted during 1991–92, have shown symptoms of wilting and subsequent death. Verticillium dahliae was only rarely isolated from these plants and artificial inoculation showed only mild disease symptoms. Fusarium oxysporum caused severe chlorosis, desiccation, defoliation and wilt in leaves of jojoba plants, resulting in plant death. Recovery of the fungus from artificially inoculated stem cuttings and seedlings showed for the first time that F. oxysporum was the primary pathogen. Inoculated cuttings exhibited wilt within 3 weeks, while in seedlings wilt occurred 10–24 weeks after inoculation. Seedlings and cuttings of jojoba which were inoculated with other Fusarium isolates originating from different crops (F. oxysporum f. sp. vasinfectum from cotton, F. oxysporum f. sp. dianthi from carnation, F. oxysporum f. sp. lycopersici from tomato and F. oxysporum f. sp. basilicum from basil) did not develop symptoms. Moreover, cotton, tomato, melon and cucumber seedlings inoculated with several virulent F. oxysporum isolates from jojoba did not show any symptoms of wilt or defoliation. These results indicate a high degree of specificity of the Fusarium isolates from jojoba; therefore, it is suggested that this isolate be defined as F. oxysporum f. sp. simmondsia.     

Combined Effects of Seawater Temperature and Salinity on Development of the Larvae of the Rhizocephalan Peltogaster reticulatus (Crustacea: Cirripedia)

The effects of seawater temperature (12, 16, 20, 22, and 25°C) and salinity (of 8 to 34) in different combinations on the larvae of the rhizocephalan Peltogaster reticulatus (Crustacea: Cirripedia), a parasite of the hermit crab Pagurus proximus, were examined. The development of P. reticulatus is comprised of five naupliar stages and one cypris stage. Nauplii have a specific structure, the flotation collar encircling the dorsal side of the larval body. Larvae lack the pigmented nauplius eye, and they show no positive phototaxis. Successful naupliar development occurred in temperature and salinity ranges of 16–25°C and 20 to 34, respectively; but all nauplii died at 12°C and 16. The duration of each naupliar stage increased under lowering of the seawater temperature. At 22–25°C and 26–28, the entire development cycle was completed in 72–80 h; and at 16°C and 20 it lasted 153 h. The cypris larvae showed a greater resistance to decreased salinity in comparison with the nauplii. At temperatures of 16–25°C and salinities of 14 to 34, the lifespan of cyprids was 6 to 12 days, and it decreased at increasing temperature.     

Interaction of Rotylenchulus reniformis,Soil Salinity,and Cotton

Rotylenchulus reni]ormis occurred equally in relatively non-saline (4.0 mmhos/cm) and highly-saline (16.5 mmhos/cm) soils in sampling transects across zones of depressed plant growth in six Texas cotton fields.Results from greenhouse pot experiments indicated progressive positive interaction of salinity and R. reni[ormis pathogenicity in the range 6-18 mmhos/cm.     

Influence of Plant Growth Promoting Rhizobacterial Inoculation on Wheat Productivity Under Soil Salinity Stress

Soil salinity affects the growth and yield of crops. The stress of soil salinity on plants can be mitigated by inoculation of plant growth promoting bacteria (PGPR). The influence of PGPR inoculation on wheat (Triticum aestivum L.) crop productivity under salinity stress has not been properly addressed so far. Therefore, the present study was conducted to investigate the effects of various PGPR strains (W14, W10 and 6K; alone and combined) at several growth attributes of wheat plant under different soil salinity gradients (3, 6 and 9 dS m-1). The growth attributes of wheat (height, roots, shoots, spikes, grains quality, biological and economical yield, nutrients nitrogen, phosphorus and potassium in grains) were highly affected by salinity and decreased with increasing salinity level. The PGPR inoculation substantially promoted growth attributes of wheat and prominent results were observed in W14 × W10 × 6K treatment at all salinity levels. The results suggest that inoculation of PGPR is a potential strategy to mitigate salinity stress for improving wheat growth and yield.     

Effects of Salinity on Primary Processes of Photosynthesis in the Red Alga Porphyra perforata

The effects of salinity on the primary processes of photosynthesis were studied in the red alga Porphyra perforata. The results show that there are at least three sites in the photosynthetic apparatus of this alga that were affected by increased salinity. The first site, photoactivation and dark-inactivation of electron flow on the reducing side of photosystem I, was completely inhibited at high salinity. The second site, electron flow on the oxidizing side (water side) of photosystem II, was inhibited as was the re-oxidation of Q in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea. The third site affected by high salinity was the transfer of light energy probably from pigment system II to I. High salinity reduced the amount of light energy that reached the reaction centers of photosystem II.

These effects are discussed in relation to the mechanisms available to this plant to avoid photoinhibition when it is exposed to stresses such as high light and high salinity which are conditions that are commonly found in the intertidal habitat.

     

Anion-Mediated Salinity Affecting Methane Production in a Flooded Alluvial Soil

In a laboratory incubation study, effects of amendment with sodium salts of SO₄ ^2?, Cl^? and HCO₃ ^? either singly or as a mixture on CH₄ production in a nonsaline alluvial soil under flooded condition were investigated. Methane production was considerable in the unamended alluvial soil, but was significantly inhibited following amendment with salts of different anions to raise the pore water EC to 8 dS·m^?1. SO₄ ^2? was the most inhibitory to CH₄ production and the degree of inhibition followed the order SO₄ ^2? > salt mixture > HCO₃ ^? > Cl^?. Salt amendment did not adversely affect soil microbial activities as expressed in terms of soil redox potential (Eh) and soil pH. However, readily mineralizable carbon content, an indicator of substrate availability for methanogenic bacteria, differed significantly among the treatments. Most probable number estimates indicated that acetotrophic methanogenic bacterial population was lowest in Cl^?-amended soils followed by SO₄ ^2?-amendment with little or no changes in HCO₃ ^?-amended soils. The data suggested that the inhibition in methanogenesis in saline soils rich in sulphate as in coastal saline soils could be due to competitive inhibition of methanogens, while in inland soils, Cl^? content could be a deciding factor.     

Auxin and Sodium Nitroprusside Effects on Wheat Antioxidants in Salinity

The effect of indole butyric acid (IBA) as auxin hormone and sodium nitroprusside (SNP) on total antioxidant, carotenoid, total phenolic compounds, catalase activity and shoot dry weight in wheat (Triticum aestivum L. cv. Chamran) under 50 and 100 mM NaCl as salt stress were studied. These two experiments were done separately and in a completely randomized design, in three replications. Indole butyric acid in three levels and sodium nitroprusside in one level were used as spray on the plant to compare their effects. According to the results, the amount of carotenoid, total phenolic compounds, antioxidants and catalase activity have increased but shoot dry weight have decreased by either salinity alone and/or combined with IBA and SNP in our experiments, comparison to the control but with different level. None of the carotenoid, total phenolic compounds, antioxidants, catalase activity and shoot dry weight showed significant changes when indole butyric acid or sodium nitroprusside treatment were induced alone that shows their nontoxicity for seedlings. In connection with indole butyric acid or sodium nitroprusside treatment, these compounds appears to alleviate the stress conditions by showing significant decreasing of carotenoid, total phenolic compounds, antioxidants and catalase activity and significant increasing of shoot dry weight. Our results showed that IBA and SNP had the same effects in salt stress, so in salt stress conditions it is recommended to use IBA for crop and non-crop plants and SNP for only not edible plants.     

土壤盐度对加拿利海枣幼苗生长与生理指标的影响

将加拿利海枣(Phoenix canariensis Hort. ex Chab.)幼苗培养在不同盐度(1.2~14.5)的土壤中,探讨土壤含盐量对其生长及生理指标的影响。结果表明:随基质盐度的提高,幼苗新生叶片数降低且叶片死亡数增加。随基质盐度的提高,叶绿素含量增加,叶绿素a/b在低盐度时增加而当盐度超过5.1时下降。土壤盐度在1.2~5.1时,MDA含量约为4.30 μmol g^-1,以后随土壤盐度的升高而升高。SOD活性在低盐时升高,土壤盐度超过10.8时,SOD活性迅速下降。盐胁迫下叶片Na⁺和Cl^-含量升高,K⁺、Ca²⁺、Mg²⁺含量及K⁺/Na⁺下降。盐胁迫导致加拿利海枣生长下降的主要原因是叶片有效光合面积减少,离子平衡破坏。这些表明加拿利海枣具有很高的耐盐能力,其幼苗在土壤盐度5.1时生长正常,当土壤盐度为10.8时才开始出现受害症状,适宜在滨海地区推广应用。     

Impact of Soil Salinity on Barley Allelopathic Potential and Main Secondary Metabolites Gramine and Hordenine

Journal of Plant Growth Regulation - Crop allelopathy is a useful tool in integrated weed suppression. Although the abiotic stresses affect the produced secondary metabolites, the impact of soil...