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1.
One of the most important factors limiting agricultural expansion and production is the restricted supply of good quality water. The present study examines the effects of K+ and Ca2+ fertilization on sweet pepper production, blossom-end rot (BER) incidence and fruit quality of pepper plants (Capsicum annuum L.) grown under moderate saline conditions. Pepper plants were grown in a controlled-environment greenhouse under hydroponic conditions with different nutrient solutions obtained by modifying the Hoagland solution. The experiment consisted on four K+ treatments (0.2, 2, 7 and 14 mM) +30 mM NaCl, and four Ca2+ treatments (0.2, 2, 4 and 8 mM) +30 mM NaCl, having in common a control without salt with 7 mM K+/4 mM Ca2+. Salinity decreased total fruit yield and marketable fruit yield by 23% and 37%, respectively. The marketable fruit yield reduction by salt treatment was mainly due to the increase in the number of fruit affected by BER. This typical physiopathy of the pepper fruits occurred between 18 and 25 days after anthesis (DAA), when the highest fruit growth rate was reached. Fruit quality parameters were also affected by salt treatment where the fruit pulp thickness and firmness were decreased, and fructose, glucose and myo-inositol fruit concentrations increased with salinity relative to fruits from control treatment. Under saline conditions an increased supply of K+ reduced the fruit fresh weight, the percentage of BER and the marketable yield although promoted the vegetative growth. However, increasing Ca2+ concentration in the nutrient solution increased the fruit production, and the marketable yield as consequence of decreasing the percentage of fruit affected with BER. Fruit quality parameters also were affected by the K+ and Ca2+ treatments.  相似文献   

2.
The purpose of this study was to investigate the mechanisms underlying alleviation of salt stress by arbuscular mycorrhizal fungi Glomus mosseae. Tomato (Lycopersicon esculentum L. cv. Zhongzha105) plants were cultivated in soil with 0, 50 and 100 mM NaCl. Mycorrhization alleviated salt induced reduction of root colonization, growth, leaf area, chlorophyll content, fruit fresh weight and fruit yield. The concentrations of P and K were higher in AM compared with nonAM plants grown under nonsaline and saline conditions. Na concentration was lower in AM than nonAM plants grown under nonsaline and saline conditions. AMF colonization was accompanied by an enhancement of activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in leaves of both salt-affected and control plants. In addition, inoculation with AMF caused reduction in MDA content in comparison to salinized plants, indicating lower oxidative damage in the colonized plants.  相似文献   

3.
To investigate the feasibility of using salt tolerant rootstock to increase fruit yield and quality of cucumber under NaCl stress, a greenhouse experiment was carried out to determine fruit yield, leaf relative water content, fruit quality, and mineral composition of cucumber plants (Cucumis sativus L. cv. Jinchun No. 2), either self-grafted or grafted onto the commercial salt tolerant rootstock Figleaf Gourd (Cucurbita ficifolia Bouche) and Chaofeng Kangshengwang (Lagenaria siceraria Standl). Plants were grown in a substrate culture (peat:vermiculite:perlite = 1:1:1, v/v) and irrigated with half-strength Hoagland solutions containing 0, 30, or 60 mM NaCl. The results showed that salinity significantly reduced fruit yield of cucumber owing to a decrease both in mean fruit weight and fruit number. Rootstock had no significant effect on leaf relative water content. Plants grafted onto Figleaf Gourd and Chaofeng Kangshengwang had higher fruit number, marketable and total fruit yield than those of self-grafted plants under 0, 30, and 60 mM NaCl, which could be attributed to, at least in part, the higher K+ but lower Na+ and/or Cl contents in the leaves. Salinity improved fruit quality by increasing fruit dry matter, soluble sugar, and titratable acidity contents of all the plants, but had no significant effect on vitamin C content. In comparison to the self-grafted plants, plants grafted onto Figleaf Gourd and Chaofeng Kangshengwang had an overall improved fruit quality under NaCl stress owing to an increase in contents of soluble sugar, titratable acidity, and vitamin C, and a decrease in the percentage of non-marketable fruit and Na+ and/or Cl contents of fruits in comparison to the self-grafted plants, mainly under 60 mM NaCl. Overall, it is suggested that the use of salt tolerant rootstock could provide a useful tool to improve fruit yield and quality of cucumber under NaCl stress.  相似文献   

4.
The effects of NaCl stress on plant growth, gas-exchange, activity of superoxide dismutase (SOD), rate of lipid peroxidation, and accumulation of Na+ ion and sugar were investigated in leaves and fruits of pepper plants (Capsicum annuum L.). Especially, the gene expression of l-galactono-1,4-lactone dehydrogenase (GalLDH), which is the last enzyme of ascorbic acid (AsA) biosynthesis, and the relationships between AsA level and Na+ concentration in plant tissue were investigated with increasing salinity. Plants were treated with three treatments: the control (0 mM NaCl) and two salinity levels (50 and 100 mM NaCl) for 21 days under greenhouse conditions. Plant growth was markedly restricted due to the reduction of photosynthetic rate and the increase of Na+ accumulation in leaves with the increasing intensity of NaCl stress. Salinity had more effect on fruit growth comparing to leaf growth, suggesting that fruits could be more sensitive to salinity than leaves. In comparison with the control, salt stress significantly increased lipid peroxidation (as measured as malondialdehyde content) but decreased SOD activity in both fruits and leaves although the effect was larger in fruits; and the rate of the decrease in SOD activity was greater than that of the increase in lipid peroxidation. The AsA concentration transiently increased first 7 days but it slightly decreased from the initial level in the end of treatment day 21. The change in GalLDH gene expression was similar to AsA concentration. The accumulation of Na+, the reduction of AsA level at severe salinity stress were greater in fruits than in leaves; and AsA level had a negative relationship with Na+ concentration in both leaves and fruits. These results suggest that the difference in salt sensitivity between fruits and leaves in pepper plants can be related to the difference in inhibition of AsA synthesis, which in turn is probably due to the toxicity of extreme accumulation of Na+.  相似文献   

5.
Protected horticultural crops as well as those planted in open fields particularly in the Mediterranean region have to cope with increasing salinization of irrigation water. High salinity of the supply water has detrimental effects on soil fertility and plant nutrition and reduces crop growth and yield. This study was conducted to determine if pre-inoculation of transplants with arbuscular mycorrhizal (AM) fungi alleviates salt effects on growth and yield of tomato (Lycopersicon esculentum Mill. Cv. Marriha) when irrigated with saline water. Tomato seeds were sown in polystyrene trays with 20 cm3 cells and treated with AM fungi (AM) or without (nonAM) Glomus mosseae. Once the seedlings were reached appropriate size, they were transplanted into nonsterile soil in concrete blocks (1.6 m × 3 m × 0.75 m) under greenhouse conditions. The soil electrical conductivity (ECe) was 1.4 dS m−1. Plants were irrigated with nonsaline water (ECw = 0.5 dS m−1) or saline water (ECw = 2.4 dS m−1) until harvest. These treatments resulted with soil EC at harvest 1.7 and 4.4 dS m−1 for nonsaline and saline water treatments, respectively. Root colonization with AM fungi at flowering was lower under saline than nonsaline conditions. Pre-inoculated tomato plants with AM fungi irrigated with both saline and nonsaline water had greater shoot and root dry matter (DM) yield and fruit fresh yield than nonAM plants. The enhancement in fruit fresh yield due to AM fungi inoculation was 29% under nonsaline and 60% under saline water conditions. Shoot contents of P, K, Zn, Cu, and Fe were higher in AM compared with nonAM plants grown under nonsaline and saline water conditions. Shoot Na concentrations were lower in AM than nonAM plants grown under saline water conditions. Results indicate that pre-inoculation of tomato transplants with AM fungi improved yield and can help alleviate deleterious effects of salt stress on crop yield.  相似文献   

6.
Plant production under salinity requires increased capacity for K+ homeostasis. For this purpose, supplementary K2SO4 in the nutrient solution and grafting on a tolerant rootstock were employed in two experiments to test whether grafting, potassium and their interactions can alleviate salinity stress in tomato (Solanum lycopersicum L.). In Exp-ion, plants were cultivated for 122 days to compare different ionic compositions: EC 9 dS m−1 in ECall (by macro-nutrients) and in ECNaCl (by 64.2 mM NaCl), EC 12 dS m−1 in ECK (ECNaCl + 25.8 mM K+). Exp-K+ was established to compare K+ concentrations of 6, 16 and 36 mM at 150 mM NaCl. In both Experiments, ‘ZS-5’, selected as a salt sensitive cultivar, was either self-grafted or grafted onto the cultivar ‘Edkawi’, reported as salt tolerant. Yield and growth, minerals, gas exchange, soluble sugars, and proline were analyzed. Different ionic treatments affected almost all characteristics considered while differences between rootstocks were rarely observed. No pronounced differences were found in shoot growth, yield and gas exchange between ECall and ECNaCl. ECK did not show any salinity alleviative effects but inhibited even growth compared with the other treatments. In Exp-K+, 16 mM K+ increased plant growth, leaf soluble sugars and proline concentrations. 36 mM K+ did not further reduce upper leaf Na+ although leaf K+ concentration increased significantly. The results indicated that the response of tomato plant to NaCl stress was principally attributed to the osmotic component in Exp-ion, excessive K+ showed no mitigating effect on fruit yield and shoot growth. However, 16 mM K+ in the root environment enhanced the salt adaptive capacity of plants stressed at 150 mM NaCl. The use of the tolerant rootstock resulted in no ameliorative effects, owing to its susceptibility to blossom-end rot, failure in enhancing photosynthesis, and ineffectiveness of restraining the long-distance transport of Na+.  相似文献   

7.
The present investigation was conducted during 2006 and 2007 growing seasons in order to study the effects of different salinity levels on the growth and chemical composition of sour orange and Volkamer lemon rootstocks. Besides, this research was also undertaken to elucidate the efficiency of mycorrhizal colonization on controlling the various hazards accompanying salinity stress. One-year-old sour orange and Volkamer lemon rootstocks were kept in a glasshouse and irrigated with control (non-saline), 1500 ppm, 3000 ppm and 4500 ppm of salinity levels. Salinity decreased arbuscular mycorrhizal (AM) colonization. In both the AM and non AM, leaf area, trunk cross-sectional area, total, top, leaf and root dry weights were decreased under salinity. The plants inoculated with the AM fungus had significantly higher growth parameters compared to the non-inoculated plants. Increasing the salinity level tended to increase the concentrations of leaf Na, N, Ca and Cl while P, K, Mg, Fe, Mn, Zn and Cu decreased. On the contrary, inoculating the seedlings with AM tended to increase the levels of P, K, Mg and Zn. Whereas leaf N, Ca and Na of inoculated seedlings was significantly lower than that of un-inoculated ones. Leaf Cl, Fe, Mn and Cu contents did not statistically vary in this concern.  相似文献   

8.
Olive (Olea europaea L.) is the major fruit tree in the Mediterranean region, often grown in locations where plants are exposed to increased salinity. To determine the effect of NaCl on shoot and root growth, dry matter allocation, leaf Na+ and K+ concentration, electrolyte (EL) and K+ leakage (KL), seven olive cultivars of different origins were grown in nutrient solution containing 0, 33, 66, 100 or 166 mM NaCl for three months. The general effect of salinity was linear and quadratic decrease of observed plant growth parameters. Different responses of tested cultivars to applied levels of salinity were found for stem dry weight, shoot length and number of leaves. As salinity increased, growth of ‘Manzanillo’ declined sharply, whereas ‘Frantoio’ was the most tolerant to growth reduction in most of the observed growth parameters. Allometric analysis showed that biomass allocation under salinity stress was similar in all cultivars, but the slope between shoot weight and total plant weight decreased as salinity increased. Since the higher allocation in roots was not found, it seems that salinity only slowed the above ground plant canopy growth. Sodium concentration in leaves of all cultivars increased as salinity increased with the highest increment reached when the salinity of nutrient solution was raised from 100 to 166 mM NaCl. Significant differences among genotypes were found in leaf Na+ and K+ concentration and K+:Na+ ratio, but they were not related to the growth rate. Generally, ‘Frantoio’ and ‘Oblica’ accumulated less Na+ and were able to maintain higher K+:Na+ ratios as compared to other genotypes. Electrolyte leakage and KL linearly increased with increasing salinity and the magnitude of the response depended upon the olive cultivar.  相似文献   

9.
Irrigation with saline water is one of the major problems in citrus crop in arid and semi-arid regions. Because rootstock and fertilization play an important role in citrus salt tolerance, we investigated the influence of the nitrogen fertilization and rootstock on salt tolerance of 2-year-old potted Fino 49 lemon trees. For that, trees grafted on Citrus macrophylla (M) or Sour orange (SO) rootstocks were watered for 12 weeks with complete nutrient solution containing either 0 mM NaCl (control, C), 50 mM NaCl (S), 50 mM NaCl with an additional 10 mM potassium nitrate (S + N), or 50 mM NaCl with a 1% KNO3 (S + Nf) foliar spray application. Trees on M were more vigorous than trees on SO and saline treatments reduced leaf growth similarly in trees on both rootstocks. Trees on SO had a lower leaf Cl and Na+ concentration than those on M. Additional soil nitrogen (S + N) decreased leaf Cl concentration and increased leaf K+ concentration in salinized trees on both rootstocks. However, the salinity-induced reduction leaf growth was similar in S + N and S trees. This was due to osmotic effect, beside leaf Cl and Na+ toxicity, played an important role in the growth response of Fino 49 lemon to the salt stress. Additional foliar nitrogen in the S + Nf treatment also reduced leaf Cl concentration relative to the S treatment but trees from S + Nf treatment had the lowest leaf growth. Net assimilation of CO2 (ACO2ACO2), stomatal conductance (gs) and plant transpiration were reduced similarly in all three salt treatments, regardless rootstock. Salinity reduced leaf water and osmotic potential such that leaf turgor was increased. Thus, the salinity-induced ACO2ACO2 reductions were not due to loss of turgor but rather due to high salt ion accumulation in leaves.  相似文献   

10.
Individual and combined effects of salinity and B toxicity on growth, the major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX) activities, ascorbic acid, proline, and H2O2 accumulation, and stomatal resistance (SR), malondialdehyde (MDA), membrane permeability (MP) and the concentrations of sodium (Na), chloride (Cl) and boron (B) of lettuce were investigated. Boron toxicity and salinity reduced growth of lettuce plants. Under B toxicity, B concentration of the plants was increased, but in the presence of NaCl, the concentration of B was significantly reduced. Sodium and Cl concentrations were increased in B + NaCl and NaCl treatments. Membrane damage was more pronounced in NaCl and B + NaCl treatments. Stomatal resistance of the plants was significantly increased by salinity treatments. The accumulation of proline and ascorbic acid was the highest in the B + NaCl treatment. In general, stress conditions significantly increased H2O2 and antioxidant enzyme (SOD, CAT and APX) activities. The present results indicate that stomatal closure is an important response of lettuce against NaCl and B + NaCl stress. Furthermore NaCl and B + NaCl toxicity-induced oxidative stress in lettuce resulting in lipid peroxidation and membrane damage. Increased antioxidant enzyme activities and also accumulation of ascorbic acid and proline are involved in order to overcome B- and NaCl-induced oxidative stress.  相似文献   

11.
Eight different pepper genotypes inoculated by two different arbuscular mycorrhizal fungi (AMF) [Glomus intraradices (Gi) and Gigaspora margarita (Gm)] in a growth chamber experiment under normal seedling growing conditions were evaluated for seedling traits, colonization and relative mycorrhizal dependency (RMD). In general, inoculated plants had greater dry weights compared to non-inoculated plants. Five cultivars responded positively to inoculation with AM fungi and three responded negatively. A great variation in mycorrhizal colonization dependency was observed among the pepper genotypes, with the N52 genotype showing the highest RMD and the Karaisali genotype the lowest. RMD and dry weights of pepper genotypes were inversely correlated.  相似文献   

12.
The effect of inoculating ‘Maradol’ papaya plants with arbuscular mycorrhizal fungi (AMF) Glomus mosseae (GM) and Entrophospora colombiana (EC) was assessed. The results showed that both mycorrhizae species increased the number of fruits and yield in papaya plants by 41.9 and 105.2% for GM and 22.1 and 44.1% for EC, respectively, with respect to control plants. GM significantly increased plant height. Sugar content, firmness, color (°Hue), and ripening process of mycorrhized plant fruits were similar to those of the control. Weight loss of mycorrhized plant fruits was considerably less than that of the control. Inoculation of papaya with AMF is recommended, particularly with GM since it increases yield, and fruit weight (45.1%), furthermore, it reduced fruit weight loss during ripening.  相似文献   

13.
This study examines the feasibility of using saline irrigation water for commercial pot cultivation of three ornamentals: Calceolaria hybrida, Calendula officinalis and Petunia hybrida. Two saline treatments were assayed: irrigation with low saline tap water (electrical conductivity = 1.16 dS m−1), and irrigation with a high saline solution of NaCl 100 mM + CaSO4 10 mM + MgSO4 2.5 mM (electrical conductivity = 12.5 dS m−1). When the control plants reached marketable size the watering was stopped and the plant response to drought was studied. Petunia and Calceolaria were tolerant to salinity. Petunia saline-treated plants reduced their growth slightly and increased N and chlorophyll contents in the leaves. Calceolaria experienced a strong reduction in growth and a delay in flowering but no toxicity symptoms or mortality was recorded. These species were moderate NaCl accumulators. Calendula was sensitive to salinity: 16% of the plants died and the surviving ones experienced a heavy reduction of growth, a decrease in chlorophyll and a large accumulation of NaCl in the leaves. Saline pre-conditioned plants of Calceolaria and Petunia were tolerant to drought. In these plants, leaf water content and, specifically, leaf relative water content were sustained longer than in non-pre-conditioned plants throughout the drought period. In Calendula, leaf relative water content decreased at the same rate in pre-conditioned and non-pre-conditioned plants. Consequently, salinization did not confer drought resistance upon this species. Possible factors determining the tolerance to drought in saline pre-conditioned plants are discussed.  相似文献   

14.
Pot culture experiments were conducted to assess the extent of growth, photosynthetic capacity, sennoside concentration and yield attributes of Senna plant under the individual as well as combined influence of NaCl and CaCl2. Six treatments, i.e. NaCl (80 and 160 mM), CaCl2 (5 and 10 mM) alone and a combination of NaCl + CaCl2 (80 + 10 and 160 + 10 mM) were given to the growing Senna plants at pre-flowering (45 DAS), flowering (75 DAS) and post-flowering (90 DAS) stages. Significant reductions were observed in pod biomass, leaf area, stomatal conductance, photosynthetic rate and sennoside concentration and yield, with each NaCl treatment. On the contrary, individual CaCl2 treatments had a favourable effect. Under the effect of combination treatments, although these parameters were reduced, the extent of reduction was much less than one caused by NaCl treatments. The combined treatments thus mitigated the adverse effects caused by NaCl.  相似文献   

15.
Citrus, a cold-sensitive plant, often suffers from low temperature, which seriously affects citrus productivity. The objective of the study was to elevate the roles of an arbuscular mycorrhizal fungus, Glomus mosseae, in growth, photosynthesis, root morphology and nutrient uptake of citrus (Citrus tangerine) seedlings under temperature stress conditions. Three-month-old seedlings with or without G. mosseae were grown for 55 days at moderate temperature (25 °C) and low temperature (15 °C). Low temperature severely restrained symbiotic development including mycorrhizal colonization, entry point, vesicle and arbuscule relative to moderate temperature. Mycorrhizal seedlings grown at 25 °C maintained better stem diameter, plant height, leaf area, root and total dry weights, higher photosynthetic rate, transpiration rate and stomatal conductance, higher root volume, and more uptake of P, Ca and Mg relative to corresponding non-mycorrhizal control. However, mycorrhizal inoculation significantly increased only the root length and the Ca content of the seedlings grown at 15 °C. The results indicated that mycorrhizal formation had the beneficial effects on growth, photosynthesis, root morphology and part nutrient uptake of citrus seedlings grown at moderate temperature, but the beneficial roles of arbuscular mycorrhizas were almost lost at low temperature.  相似文献   

16.
Using 102 pepper (Capsicum annuum) genotypes, a greenhouse experiment has been conducted to study genotypic variation in tolerance to 100 mM sodium chloride (NaCl) in nutrient solution. Based on the severity of leaf symptoms caused by the NaCl treatment there was a substantial genotypic variation in salt tolerance. From this screening experiment, six sensitive and six tolerant genotypes were chosen to study dry matter production and root and shoot concentrations of sodium (Na), potassium (K) and calcium (Ca) in a growth chamber experiment in a nutrient solution with and without 150 mM NaCl. The genotypes selected as sensitive were highly damaged and developed severe chlorosis and necrosis under NaCl treatment, while the genotypes selected as tolerant were slightly affected. On average, decreases in shoot dry matter production caused by NaCl were greater in the sensitive than the tolerant genotypes. Application of salt increased shoot Na concentration at greater amount in the sensitive than the tolerant genotypes. Of the tolerant genotypes, the genotype Cac (Capsicum annuum var. cerasiforme) and 1245 F1 had around 2.45% Na in shoot while the sensitive genotypes Kandil and Pazarcik contained, on average, 5.4% Na. All sensitive and tolerant genotypes exhibited more or less similar shoot concentrations of K and Ca. There was very significant and positive correlation between severity of leaf symptoms and shoot Na concentration, but no correlation could be found in the case of K or Ca concentrations with the severity of leaf symptoms. The results indicate existence of substantial genotypic variation in tolerance to NaCl stress in pepper. It seems very likely that exclusion of Na from roots into growth medium plays a critical role in expression of high Na tolerance in pepper.  相似文献   

17.
The importance of root size system has long been recognized as crucial to cope with drought conditions. This investigation was conducted to: (i) evaluate the variability in root size system of hot pepper at maturity; (ii) estimate the effect of root size system on yield under drought conditions; and (iii) effect of water stress on xylem vessel development and total xylem cross-sectional area in roots of hot pepper cultivars. Twelve diverse hot pepper cultivars were grown in wooden boxes with two different water treatments, normal and in 50% water application as water deficit condition. Mean primary root length (PRL) showed a significant positive correlation with final fruit yield at normal as well as stressed condition. Total dry mass of fruit was reduced by 34.7% in drought treatments (DI) compared to full watered treatment (FI). At harvest, water-stressed plants had 21% lower root dry weight mass but higher root:shoot ratio other than FI. PRL, lateral root density, total xylem area per root cross-section showed a significant positive relationship with fruit yield. Also, lateral root density was higher in cultivars with higher xylem density, particularly in tolerant cultivars. Lateral root density (r = 0.847, P < 0.001) and total xylem cross-sectional area in root (r = 0.926, P < 0.001) were tightly related with total biomass production. The importance of root traits contributing to withstand drought in hot pepper is discussed.  相似文献   

18.
Summary

The effect of the arbuscular mycorrhizal (AM) fungus Glomus versiforme on chlorosis due to iron deficiency in trifoliate orange (Poncirus trifoliata L. Raf) was studied under calcium bicarbonate stress in sand culture. Seeds were sown in a mixed substrate [1:1 (v/v), perlite:sand] with or without mycorrhizal inoculum. The test was carried out with four treatments: Hoagland and Arnon nutrient solution with normal, no added iron, or 50% normal iron at two levels of calcium bicarbonate. The results showed that the proportion of the total root length infected by the AM fungus was ≥ 83%, and was depressed under Fe deficiency. No root colonisation was found with no added AM fungus (NM plants).

Colonisation by AM fungus resulted in higher dry weights of both shoots and roots compared to NM treatments, suggesting that the AM fungus accelerated plant growth. The activities of peroxidase and catalase in NM plants were lower than in AM fungus-inoculated plants. The results indicate that AM fungus alleviated calcium bicarbonate stress on the cell membranes of host plants. The results also showed that AM fungus increased chlorophyll concentrations, iron contents, and the Fe:P ratios of whole plants, and decreased 50(10P+K):Fe ratios, which implied that the uptake and translocation of iron was strengthened. Therefore, AM fungus had a positive effect on ameliorating chlorosis due to iron deficiency in P. trifoliata L. Raf.  相似文献   

19.
Information about citrus ethylene-responsive element binding factor (ERF) genes and their functions in fruit ripening or in stress tolerance is still scarce. In the present study, one of ERF genes, CitERF was isolated from fruit of Citrus unshiu with a maximal putative open reading frame encoding 207 amino acids. The deduced protein contains a region rich in acidic amino acids, an AP2/ERF domain and a KRRK nuclear localization signal. It belongs to group B of Class I in the ERF subfamily in which MdERF2 (Malus × domestica ethylene-response factor 2) and PsERF1b (Prunus salicina ethylene-response factor 1b) were involved in the progress of fruit ripening. CitERF mRNA level in fruit peel and pulp increased obviously along with fruit ripening. However, its expression could be reduced significantly by treatments of total shading and fruit-bear-shoot girdling plus defoliation during fruit ripening. As for the response to abiotic stresses, CitERF expression was found to be induced continuously during the treatment of 10% polyethylene glycol. On the other hand, it could be induced to high level at 1 h after the treatment of 4 °C or 250 mM NaCl and then declined continuously. Taken together, the results suggested that CitERF may play an important role in some biological processes during fruit ripening and in improving tolerance to drought, low temperature and salt stress.  相似文献   

20.
We screened the mycorrhizal species for an inoculum protocol would green pepper seedling production and compensate for nutrient deficiency. Three greenhouse studies (on three successive years) were conducted under nursery conditions using five arbuscular mycorrhizal (AM) fungi and their mixture. The AM fungi, Glomus mosseae, G. clarum, G. caledonium, G. intraradices and G. etunicatum propagated on maize roots were used. The AM fungi were inoculated to seed stages and half of the seed stages inoculated plants were re-inoculated at the seedling stages. In Experiment I, plants were harvested once and in Experiments II and III, plants were harvested twice at different developmental stages.  相似文献   

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