Effect of GA_(3) Concentration and Soaking Time on Seed Germination Characteristics of Blueberry

This study aims to explore the effect of GA_(3) concentration and soaking time on seed germination characteristics of blueberry.To be specific,big(B),medium-sized(M),and small(S)blueberry seeds were soaked in 0,100,200,and 300 mg/L GA_(3) solution for 18 h and 200 mg/L GA_(3) solution for 0,24,and 48 h,respectively.The results showed that 300 mg/L GA_(3) had significant effect on the germination of B and M seeds(P<0.01)and enabled the germination 4~5 d and 7~8 d earlier,respectively.Soaking with 200 mg/L GA_(3) for 24 h was conducive to the germination of B and M seeds(P<0.05).However,GA_(3) concentration and soaking time had no obviously promoting effect on the germination of S seeds.The interactions between GA_(3) concentration and seed size and between soaking time and seed size were significant(P<0.01).

Effects of Salt Stress on Seed Germination and Seedling Growth in Raphanus sativus L.

[Objective] This study aimed to investigate the effects of salt stress on seed germination and seedling growth in radish（Raphanus sativus L.）.[Method] First,effects of soaking seeds with clear water and different concentrations of saline solution were compared; then,different concentrations of salt solution （0.2％-1.0％） was used to treat radish during the whole germination period.[Result] soaking seeds with clear water can improve the germination indicators of radish seeds exposed to high salt stress; low salt concentration（0.2％,0.4％） had little effect on the growth indicators of radish seedlings,and 0.2％ salt concentration can even promote the growth of radish seedlings,however,the high salinity had a bad inhibition on seedling growth,the higher the salt concentration,the stronger the inhibition.[Conclusion] According to the comprehensive comparison,the order of the six varieties in salt-tolerance was as follows：Xinxiayuanbai＞W1029,Xiayuanbai ＞ Nanyangbailizhi,Chunyidianhong＞ Sijihong 3.

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Brassica napus L.

To investigate the effects of the heavy metal cadmium （Cd） on seed ger- mination and seedling growth of Brassica napus L., 25 B. napus lines with different genetic background were treated with four concentrations （0, 1, 5 and 10 mg/L） of Cd, and then, their germination potential, germination rate, seedling length, main root length, seedling fresh weight, and seedling dry weight were measured. The re- sults showed that the response of the B. napus lines to Cd stress was different. With the increase of Cd concentration, the relative germination potential and relative seedling rate increased first and then decreased, and reached the maximum levels when the Cd concentration was 5 rag/L. The inhibitory effects of Cd stress on seedling growth indices in a decreasing order were root length〉seedling length〉 seedling fresh weight〉seedling water content. There were extremely significant differ- ences in the relative root length, relative seedling length, relative seedling fresh weight and relative seedling water content among the B. napus lines treated by dif- ferent concentrations of Cd, while there were no significant differences in the rela- tive germination potential and relative seedling rate among the lines, except that the relative seedling rate was significantly different among the lines treated by 5 mg/L Cd. The results suggested that seedling growth was more sensitive than seed ger- mination to heavy metal stress.

Allelopathic effects of extracts from Solidago canadensis L. against seed germination and seedling growth of some plants

To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry （Morus alba）; morning glory （Pharbitis nil）, wheat （Triticum aestivum） and rape （Brassiea campestris）. Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts （especially from leaves） imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts of S. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition ofS. canadensis over other plants, and make it invasive in new habitats.

Interaction between seed size and NaCl on germination and early seedling growth of some Turkish cultivars of chickpea(Cicer arietinum L.)

Chickpea is an important food legume crop of Turkey and is largely grown for human consumption on low moisture or salt-affected soils. The objective of the study was to find the effects of NaCl stress at electrical conductivities of 4.5, 8.6, 12.7 and 16.3 dS/m and seed sizes （7, 8 and 9 mm） on germination and early seedling growth of three popular chickpea cultivars （AKN-97, Gokce and Uzunlu-99）. Mean frequency of germination, germination time, germination index, root length, shoot length and seedling fresh weight showed seed size-dependent responses ofcultivars to salt stress. In general, small seeds germinated and grew more rapidly compared to medium and large seeds of the same cultivars against all levels of salt stress, with the best results in cultivar Uzunlu-99. No effect of NaCl treatments was observed on frequency of germination; however, a drastic decrease in early seedling growth was recorded at increased NaC1 concentrations. Regression analysis results showed a significantly positive relationship （P〈0.01） between seed size and mean germination time, whereas a significantly negative relationship was recorded between seed size and germination index, root length, shoot length. Moreover, linear regression values apparently confirmed that increased seed size in each cultivar affected decreased germination index, root and shoot lengths with enhanced mean germination time. Thus, it was concluded that the use of small seeds could considerably reduce the production costs of chickpea in salt-affected soils.

Influence of Temperature and Salinity on Germination of Eelgrass (Zostera marina L.) Seeds

Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.

Brassinosteroid and gibberellin coordinate rice seed germination and embryo growth by regulating glutelin mobilization

Seed germination is the beginning of a new lifecycle,and involves many complex physiological and biochemical reactions including seed reserve mobilization in the endosperm and nutrient transport and reuse in the embryo.Although glutelin is a dominant storage protein in rice,its contribution to seed germination and its regulatory mechanisms are mostly unknown.Gibberellin (GA) and brassinosteroid (BR),two major growth-promoting phytohormones,also play positive roles in controlling seed germination.However,how GA and BR interact and coordinate seed germination and facilitate glutelin mobilization remains unclear.In the present study,biochemical and physiological analyses of seed germination indicated that both GA and BR promote seed germination and post-germination growth.Exogenous application of GA restored germination defects caused by BR deficiency or insensitivity.Proteomic and q RT-PCR results showed that the expression of several glutelin proteins and their encoding genes was induced by BR and GA in the embryo.Expression assays suggested that the increased accumulation of glutelin protein in the embryo was due to the accelerated degradation of glutelin by a cysteine proteinase (REP-1) in the endosperm.The breakdown of glutelin in the endosperm showed a strict positive correspondence with the length of the shoot.The GluA2 mutation led to reduced degradation rate of glutelin and defects in seed germination,and the promotion effect of GA on seed germination was weakened in the glua2mutant.In vitro culture assay of rice embryos showed that glutelin mobilization functioned downstream of the GA and BR pathways to promote shoot elongation.These findings suggest a mechanism that mediates crosstalk between BR and GA in co-regulating rice seed germination and embryo growth.

Response of Vicia angustifolia L.Seed Germination and Growth to Drought Stress

Seeds germination and seedling stages were studied on the legume seeds of Vicia angustifolia L. to reveal the effects of drought stress on germination char- acteristics and water absorption characteristics. The results showed that the rate of seed water uptake,germination percentage,germination index,vigor index,seedling height,root length and plant water content decreased with the increase of concen- tration of PEG stress. However,seedling and root dry weight and root/shoot ratio ini- tially increased followed by a decrease. The lowest osmotic potential threshold was -0.42 MPa.

Effects of GA3 and NAA on Fatty Acid Degradation in Germination and Seedling Growth of Cassia obtusifolia L. Seed

[Objectives]To understand the content changes of fatty acid compositions and seedling growths during seed germinations of Cassia obtusifolia L.[Methods]The fatty acid compositions of germinations and seedling growths of C.obtusifolia seeds treated with different concentrations of gibberellin(GA3)and naphthalene acetic acid(NAA)were analyzed using gas chromatograph-mass spectrometer(GC-MS),and the germination rates,root lengths,plant heights and fresh weights of their seedlings were analyzed.[Results]The contents of eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid of C.obtusifolia seeds treated with different concentrations of GA3 and NAA decreased with germination time.There were significant differences between the ratios of germinations of C.obtusifolia seeds treated with different concentrations of GA3 and NAA.GA3 and NAA of different ratio treatments could promote seedling heights and fresh weights of C.obtusifolia,but increases of seedling heights and fresh weights were different.Eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid were remarkably negative correlation with seedling heights and fresh weights.[Conclusions]The fatty acid components of C.obtusifolia seed germination and growth of their seedlings were affected.It indicated that GA3 and NAA treatments can affect fatty acid metabolism,the germination rates,root lengths,plant heights and fresh weights of C.obtusifolia.It is intended to provide a theoretical basis and technological reference for standardized cultivated techniques of C.obtusifolia.

Allelopathic Effects of Cedrus deodara Needle Extracts on Seed Germination and Early Growth of Three Turfgrasses

[Objectives]This study was conducted to provide reference for plant landscaping,optimization of planting structure and rational allocation of species in Cedrus deodara gardens.[Methods]With three common garden plants in northern China,Trifolium repens L.,Poa pratensis L.and Trifolium pratense L.,as receptors,the effects of four concentrations(0.025,0.05,0.075 and 0.10 g/ml)of C.deodara needle extract on seed germination and early seedling growth of the three turfgrasses were studied by the Petri dish filter paper method,using a clear water treatment(0 g/ml)as control check(CK).Data were subjected to analysis of variance(ANOVA)and multiple comparisons(Duncan)using SPSS16.0.[Results]Different concentrations of C.deodara needle extract had significant inhibitory effects on seed germination,radicle and seedling height growth of T.repens,T.pratense and P.pratensis(P<0.05),and the inhibitory effects increased with the increase of concentration.When the concentration reached 0.075 g/ml,seed germination and seedling growth of T.repens stopped,and radicle and seedling growth of T.pratense and P.pratensis also stopped.When the concentration was equal to 0.10 g/ml,germination of T.pratense and P.pratensis seeds was inhibited,and the absolute values of allelopathic index was the largest,that is,the inhibitory effects were the largest.And with the increase of concentration,the absolute value of synthetical allelopathic index also increased.The extract of C.deodara needles contained main allelochemicals leading to the scarcity of understory vegetation.[Conclusions]This study provides a theoretical basis for reasonable garden plant configuration during C.deodara greening and garden landscaping.

Environmental Factors Influencing Seed Germination Characteristics of Vicious Weed Green Foxtail

[ Objective] The paper was to optimize the optimal conditions for seed germination and seedling emergence of green foxtail [ Setar/a viridis （ L. ） Beauv. ], so as to solve the problem of serious damage caused by green foxtail. [Method] Using the orthogenal test and the LSD method of software SPSS 18.0, with the number of emerged seedlings of green foxtail as the evaluation index, the influencing factors such as pretreatment of green foxtail, earth covering depth, soil temperature and soil moisture content were compared in the test. [Result] These four experimental factors had great impact on seed germination characteristics of green foxtail. The optimal scheme for seedling emergence of green foxtail was as follows： pretreatment of green foxtail for 3 d, earth covering depth 0.5 cm, soil temperature 32 ℃, soil moisture content 15%. The optimum condition was consistent with the actual situation of serious damage of green foxtail （ suffering moderate and heavy rainfall after sowing and before seedling of millet ）. Avoiding sowing millet before moderate and heavy rainfall could effectively control serious damage of green fox＇tail. [ Conclusion] The study provided theoretical support for effective control against the vicious weed green foxtail.

Effects of Water Extract of Erigeron canadensis L. on Seed Germination of Plants

[Objective] The paper was to explore the effect of water extract of Erigeron canadensis L. on seed germination of plants. [Method] Using constant temperature culture method, the effects of water extracts of roots, stems and leaves of E. canadensis on seed germination of 14 species of test plants （crops and weeds） were studied. [Result] Water extracts of roots, stems and leaves of E. canadensis had obvious inhibition effect on seed germination of test plants. The water extract of leaves had the strongest inhibition effect, which could completely inhibit the seed germination of Crepis tectorum L., Amaranthus tricolor L. and Chrysanthemum coronarium L. under the lower concentrations of 0.050 and 0.075 g/ml, and completely inhibit seed germination of all the plants under the concentration of 0.400 g/ml except Zea maize L. and Allium fistulosum L.; followed by water extract of stems, and the water extract of roots had the lowest the inhibition effect, except for completely restraining seed germination of Lycopersicum esculentum L. under the concentration of 0.300 g/ml, it still could not completely restrain seed germination of the other plants under the highest concentration of 0.500 g/ml. The inhibition effect of water extract of E. canadensis on seed germination of plants had obvious selectivity, which had more obvious effect on dicotyledonous plants than monocotyledonous plants. [Conclusion] The study provided reference for screening and utilization of allelochemicals of E. canadensis and research on its allelopathy mechanism.

Artificial seed germination and seedling production of Zostera marina L.by salinity manipulation

Vast declines in Zostera marina seagrass beds demand effective methods of rehabilitation. In this study, we developed a practical method by reducing salinity to induce seed germination followed with recovering salinity to facilitate seedling production of Z. marina. The results showed that Z. marina seeds collected from natural seawater（salinity 30） were induced to germinate at reduced salinities. Percent germination（GR） was higher and mean-time-to-germinate（MTG） was shorter at lower salinities. The highest GR and shortest MTG occurred at salinity 0（deionized freshwater）. After germination in freshwater, seeds could develop into seedlings at salinities5–30 and continue the growth. Viability or development of germinated seeds was not significantly different during the 40 d of post-germination incubation at salinities 5–15 after 1–20 d of germination in freshwater. However,during the process of translating germinated seeds from salinity 0 and 5 to salinity 30, reducing the gradients of post-germination acclimation facilitated more seeds forming seedlings in less time. On average, after 60 d of static incubation, including 20 d in freshwater for germination followed with immediate shift to salinity 5 and increasing to salinity 30 at increment of 5 every two days until cultivation at constant salinity 30, 33% of Z. marina seeds produced healthy seedlings. The results indicate that the salinity-manipulation based method of artificial germination and seedling production is practical and effective in supporting rehabilitation of Z. marina bed.

Effects of Different Treatments on Seed Germination of Bupleurum chinensis

In order to solve the problem of low emergence rate of Bupleurum chinense seeds, and screen out the best germination conditions, the seeds of Bupleurum chinense L. were treated with different soaking time, germination temperature and exogenous regulating substances to improve the germination rate. The results showed that the germination rate of fresh water at 12 h was significantly higher than that at 8 h and 36 h; The germination rate of seeds treated with constant temperature 15℃ and variable temperature 25 ℃/15 ℃ （day/night） was significantly higher than that of other temperature treatments. Seed soaking time and culture temperature also influenced seed germination start day and peak day. Different concentrations of regulatory substances could promote seeds germination. The germination rate of seeds induced by 0.50 mg/L 6-BA was the highest, the start day and peak day were 4 days and 5 days earlier than control check （CK） respectively.

Effects of Priming in Combination with Fungicides on Germination and Infestation of Lettuce (Lactuca sativa L.)

Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.

Maximizing seed germination in two Acacia species

Revegetation of disturbed land, particularly in arid environment, is often hindered by low seedling establishment. Information on seed biology and germination cues of valuable species is lacking. We investigated seed germination of two Acacia species （Acacia tortilis （Forsk.） Hayne and Acacia oerfota （Forssk） schwein/）, required for nitrogen fixation and rehabilitation of arid and semi-arid areas.（four pregermination seed treatments were applied in order to find the best treatment in germinating acacia species. The medium was L2 and three replicates were used. Seeds pretreated with sand paper and also with H2SO4 and then H2O2 had the highest germination percentage in both species. The lowest germination percentage resulted from soaking seeds in water for 48 h followed by soaking in H2SO4 for A. oerfota and from soaking in water for 24 h for A. tortilis. Because the use of sand paper is difficult and time consuming, we recommend pretreatment ofA. tortilis and A. oerfota seeds with H2SO4 and H2O2 before planting. Our study results are significant for conservation agencies with an interest in optimizing germination in arid zones for rehabilitation and reforestation.

<i>In Vitro</i>Germination and Plantlet Establishment of Wild Chamomile of Morocco <i>Cladanthus mixtus</i>(L.) Oberpr. and Vogt

In vitro seeds germination and plantlets establishment of Cladanthus mixtus (L.) Oberpr. and Vogt were studied in this report. A reliable protocol was developed for in vitro seed germination, multiplication and plantlet regeneration of Cladanthus mixtus. The seeds were sterilized and cultured in different media. Among the two basal media evaluated for symbiotic seed germination, gelled distilled water was found to be the best with a high percentage of seeds germination (100%) after 33 hours of culture. Seedlings were further transferred to different types of media. Result observed after 4 weeks showed that MS medium promotes the highest growth with an average of 2.75 ± 0.12 cm shoot length and 2.60 ± 0.29 shoots per explants, and the mean number of roots achieved 3.33 ± 0.17 root per explants with a length of 2.42 ± 0.16 cm. This study showed that macroelements of MS (1962) medium is essential for in vitro shoot multiplication, growth and rooting of shoots of Cladanthus mixtus L.

Protein Bodies in Cotyledon Cells Exhibit Differential Patterns of Legumin-Like Proteins Mobilization during Seedling Germinating States

Olive (Olea europaea L.) tree is one of the most extensive and important agricultural crop in Mediterranean countries due to its beneficial health and nutritional properties and its high economic value. Currently, olive tree constitutes the sixth most important cultivated plant in the world, spreading from the Mediterranean region of origin to new production areas such as Australia, South and North America and South Africa. However, the mobilization processes of storage materials i.e. reserve proteins during seed germination, which are largely involved in essential physiological process including plant growth and development, remain poorly understood. Morphometric and immunohistochemistry analyses of protein bodies contained in olive seed storage tissues, cotyledon and endosperm, were performed by using different microscopy techniques, including light (bright-field and fluorescence) microscopy and transmission electron microscopy. Furthermore, we used legumin-like proteins (11S-type globulins) as a molecular marker to study the mobilization of reserve proteins from PBs of cotyledons at germinating seedling stages by using immunofluorescence assays. Results demonstrated that cotyledon and endosperm are characterized by distinct PBs populations containing legumin-like proteins, distinctly discriminated by the number of PBs per cell and tissue, size, immunofluorescence and histochemical staining. These features reflect differential PBs biogenesis during development and maturation processes in olive seed tissues endosperm and cotyledon, in relation to proteins (polypeptides) final composition, SSPs processing and/or packaging during seed maturation. Three different mobilization patterns of legumin-like proteins were identified for the first time in cotyledon PBs during seedling germinating process. Mature proteins composition and/or processing, cell types and enzyme composition and/or differential activation have been discussed as key features determining how proteins mobilize from PBs for further degradation in the cotyledon.

外源褪黑素对NaCl胁迫下向日葵种子萌发的影响

盐胁迫是影响作物产量和质量的非生物胁迫之一,褪黑素能有效提高植物应对盐胁迫的水平。本文以矮生向日葵为研究对象,以筛选出的0.25mol/LNaCl为胁迫浓度,通过测定种子萌发指标、膜脂过氧化程度、渗透调节物质含量和抗氧化酶活性等,研究外源褪黑素对盐胁迫下向日葵种子萌发的生理调控机制。结果表明:随着褪黑素浓度的增加,种子的发芽势、发芽率、发芽指数、可溶性蛋白质含量均呈先升后降趋势,其中25μmol/L的效果最佳。脯氨酸含量较对照不断增长,以100μmol/L的效果最佳。MDA含量较对照减少,以25μmol/L的抑制作用最为显著。不同浓度外源褪黑素对种子SOD、POD和CAT活力均有明显的增加,以25μmol/L的效果最为显著。综上所述,25μmol/L褪黑素可以作为向日葵种子萌发期对抗NaCl胁迫的有效预处理措施,本研究为褪黑素的利用和向日葵栽培调控提供依据。

纳米级Fe_(3)O_(4)分散液浸种对NaCl胁迫下番茄种子萌发及幼苗保护酶系统的影响

为揭示纳米级Fe_(3)O_(4)(Fe_(3)O_(4)NPs)调控作物耐盐的效应和机理,采用共沉淀法成功合成10 nm粒径的Fe_(3)O_(4)NPs,并通过了表征分析和鉴定;进一步研究其0、1、10、50、100、200、300、400 mg·L^(-1)分散液浸种处理对NaCl胁迫下番茄种子萌发、幼苗生长及其抗氧化的影响。结果表明:盐胁迫下1 mg·L^(-1) Fe_(3)O_(4)NPs浸种明显降低番茄种子发芽、幼苗胚根和下胚轴生长,随着浸种浓度上升,其发芽逐步得到改善;100 mmol·L^(-1)NaCl胁迫下,200 mg·L^(-1)Fe_(3)O_(4)NPs浸种的种子发芽势和下胚轴长达到峰值,显著高于仅盐处理的对照。100 mmol·L^(-1) NaCl胁迫明显降低番茄种子成苗率、幼苗鲜物质量和含水量,1 mg·L^(-1)Fe_(3)O_(4)NPs浸种,导致其进一步降低,随着Fe_(3)O_(4)NPs浸种浓度上升,其数值逐渐上升,200 mg·L^(-1)Fe_(3)O_(4)NPs浸种的幼苗鲜物质量和含水量达到峰值,显著高于仅盐处理的对照。盐胁迫下,1 mg·L^(-1)Fe_(3)O_(4)NPs浸种的幼苗超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著上升,而过氧化氢酶(CAT)活性下降,随着Fe_(3)O_(4)NPs浸种浓度上升,SOD和POD酶活逐渐下降再逐渐回升,CAT酶活逐渐上升再回落,100~200 mg·L^(-1) Fe_(3)O_(4)NPs浸种的幼苗SOD和POD酶活、丙二醛(MDA)、脯氨酸(Pro)含量、超氧阴离子自由基(2O×-)和过氧化氢(H2O_(2))含量均最低,而其CAT酶活最高。相关性分析表明,幼苗鲜物质量、成苗率与SOD和POD活性以及MDA和活性氧含量均呈极显著负相关。综上所述,在盐胁迫下Fe_(3)O_(4)NPs浸种处理的番茄种子萌发和成苗依赖于Fe_(3)O_(4)NPs不同浓度的调控特征,即1 mg·L^(-1) Fe_(3)O_(4)NPs浸种处理展示了进一步抑制的典型特征,其氧化胁迫加剧;而200 mg·L^(-1) Fe_(3)O_(4)NPs浸种处理表现为促进萌发、成苗和壮苗的显著作用,与其抗氧化得到明显改善直接相关。