在温室穴盘栽培条件下,对番茄幼苗接种2种商品用丛枝菌根菌剂BF(mycorrhiza for plants)和VT(mycorrhiza for vegetables),测定幼苗生长发育及光合生理等指标.结果表明:VT和BF均能不同程度地侵染番茄根系,接种35 d后侵染率分别为78.3％、66.4％.接种AMF后幼苗的株高、茎粗、干质量、鲜质量、根系活力、叶绿素含量、净光合速率均大于未接菌对照,且接种VT菌剂的幼苗与未接菌对照相比差异显著.综合分析表明,VT对番茄穴盘幼苗的促生效果较好.

To test the effects of different AMF(arbuscular mycorrhizal fungi)strains mixture inoculum on cucumber seedling growth,seeds of cucumber were covered with 2 different AMF inoculums BF(mycorrhiza for plants)and VT(mycorrhiza for vegetables)from Czech Republic after sawing in the trays in solar greenhouse. Thirty-five days after inoculation the infection rates were 49.30%,37.65%,respectively.The plant height, stem diameter,fresh and dry weight of those seedling inoculated with AMF were higher than that of the control. Compared with the control,VT inoculation could significantly improve the root activity,chlorophyll content and photosynthetic rate of cucumber leaves.Comprehensive analysis showed that VT had better effect in promoting the growth of greenhouse cucumber seedlings.

Mitochondrial uncoupling proteins play important roles in generation of metabolic thermogenesis, response to stress situations, and regulation of energy metabolism. We demonstrated here that the absence of LeUCP in tomato inhibited photosynthesis using virus-induced gene-silencing approach. A significant decrease in the rate of CO 2 assimilation in LeUCP- silencing plants was observed over a range of different light intensities. Absence of LeUCP resulted in lower net photosynthetic rate, light-saturated rate of the CO 2 assimilation ( A sat ), maximum carboxylation rates ( V cmax ) and maximum RuBP regeneration rate ( J max ). Activities of ribulose-1,5-bisphosphate carboxylase/oxygenase Rubisco and stromal fructose-1,6-bisphosphatase and genes expression levels encoded Calvin cycle enzymes of LeUCP gene-silencing plants were inhibited. However, silencing of LeUCP gene had no effect on F v / F m , but decreased photochemical quenching and electron transport rate. Meanwhile, non-photochemical quenching and Je (PSII), the distribution of J e (PCR) and J e (PCO), the content of AsA, NAD, and the ratios of NAD + /NADH, AsA/DHA were significantly reduced with increased reactive oxygen species while GSH and GSSG were unaltered. Taken together, these results strongly suggest that LeUCP gene in tomato leaves is crucial in maintaining the redox poise of the mitochondrial electron transport chain to facilitate photosynthetic metabolism.

The germin-like protein gene Mdip1 was introduced into tomato line Ailsa Craig via Agrobacterium-mediated method. Transgenic lines were confirmed for integration into the tomato genome using PCR, Southern blot hybridization. One to three copies of the transgene were integrated into the tomato nuclear genome. Transcription of Mdip1 in various transgenic lines was determined using real-time PCR. Performance test of resistance analyses to chilling stress with T1 generation transgenic tomato lines showed that the transgenic lines exhibited lighter symptoms of chilling injury and kept higher values of biomass accumulation and chlorophyll content than those of non-transformed plants. The resistance levels were related to expression levels of the transgene compared with wild-type plants, and the contents of AsA and AsA/DHA in both normal and low-temperature conditions were increased, while the H2O2 and MDA content were decreased in the transgenic plants. Meantime, the contents of GSH and GSH/GSSG and GalLDH activity were also increased in the overexpression plants. Based on these results, it can be concluded that Mdip1 may play a pivotal role in increasing tomato tolerance against chilling stress by increasing redox level and lowering H2O2 and lipid peroxidation accumulation.

The widely present symbiotic association between arbuscular mycorrhizal fungi (AMF) and plant roots contributes considerably to improve plant growth, nutrient uptake and stress responses. The present study addressed the potential of AM fungus Funneliformis mosseae in the alleviation of chilling stress for cucumber seedlings. The results showed that the AMF-inoculated cucumber seedlings had significant higher fresh weight and dry weight than non-AMF inoculated control plants under both normal (25/15 degrees C) and low temperature (15/10 degrees C) treatment. Under chilling stress, AMF inoculation significantly improved the content of related secondary metabolites including phenols, flavonoids, lignin, DPPH activity and phenolic compounds compared with the non-AMF control. Furthermore, large increments were observed in a number of enzymatic activities related to secondary metabolism and antioxidant system in AMF-inoculated seedlings under low temperature, such as glucose-6-phosphate dehydrogenase (G6PDH), shikimate dehydrogenase (SKDH), phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), polyphenol oxidase (PPO), guaiacol peroxidase (G-POD), caffeic acid peroxidase.(CA-POD) and chlorogenic acid peroxidase (CGA-POD). As well, the expression of stress-related marker genes was enhanced in AMF-inoculated seedlings in comparison with the non-AMF control. Furthermore, AMF symbiosis decreased hydrogen peroxide (H2O2) content under low temperature. Taken together, these results indicated that the enhanced secondary metabolism and integrated transcriptional regulation might play a crucial role in AMF-mediated alleviation of chilling stress in cucumber. (C) 2013 Elsevier B.V. All rights reserved.

Interaction between Trichoderma harzianum and cucumber Fusarium wilt pathogen was studied in vitro and in vivo. Three tested isolates of T. harzianum exhibited distinct inhibitory effects on Fusarium in dual tests. Isolate TN showed performed more inhibitively than the other tested isolates. Field inoculation of T. harzianum resulted in enhanced content of flavonoids, phenolics and lignin in cucumber plants. Meanwhile, the activities of CAD, PPO, G-POD, CA-POD and CGA-POD were increased by 100%, 54%, 278%, 143% and 52%, respectively. The expression level of resistance-related genes in plants inoculated with T. harzianum was higher than that of the control. The expression levels of all selected genes but CCOMT were higher on 6 dai (days after inoculation) than those on 2 dai. The expression levels of C4H, CAD, CCOMT, G6PDH, PAL andPR-1 in the T. harzianum colonized plants were 5.64, 5.31, 4.28, 15.33, 7.36 and 6.45 times higher than that in control, respectively. Our findings demonstrated the close relationship between secondary metabolism and the T. harzianum-mediated induced resistance towards Fusarium infection in cucumber roots.

To determine the effects of Glomus mosseae(GM) on asparagus seedlings in high-temperature sterilized and non-sterilized matrix(peat:vermiculite=2∶ 1,V/V),the pot experiments with Jersey Knight as material were conducted by inoculating GM to asparagus.The results showed that GM inoculation greatly promoted the growth of asparagus seedlings,formed stronger infection to asparagus roots,and enhanced the absorption to nine mineral nutrients.Meanwhile,GM inoculation in non-sterilized matrix had much more contribution to seedling growth and mineral nutrients absorption.So,non-sterilization was better for culture of asparagus mycorrhizal seedlings.