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A field study was conducted to evaluate the effects of ambient ozone (O-3) on an O-3-sensitive poplar (Populus cathayana) by using ethylenediurea (EDU) as a chemical protectant under two soil water treatments (well-watered (WW) and moderate drought (MD, 50-60% of WW in volumetric soil water content). EDU was applied as foliar spray at 0, 300, 450, and 600 ppm. Photosynthetic parameters, pigment contents, leaf nitrogen, antioxidant capacity, growth, and biomass were measured. The 8 h (9:00-17:0) average ambient O-3 concentration was 71.7 ppb, and AOT40 was 29.2 ppm h during the experimental period (9 June to 21 September), which was high enough to cause plant injury. MD had significantly negative effects on P. cathayana, as indicated by reduced photosynthesis, growth, and biomass, and higher MDA contents. On the other hand, EDU significantly increased photosynthesis rate, chlorophyll a fluorescence, V-cmax and J(max), photosynthetic pigments, total antioxidant capacity, tree growth and biomass accumulation, and reduced lipid peroxidation, but there was no significant interaction between EDU and drought for most parameters, indicating that EDU can efficiently protect Populus cathayana against ambient O-3 and the protection was not affected by soil water contents when soil water reached moderate drought level. Among all doses, EDU at 450 ppm provided maximum protection. Comparison of EDU-treated and non-treated P. cathayana could be used as a biomarker systemin risk assessment of the effects of ambient O3 on forest health. (C) 2016 Published by Elsevier B.V.

Using HS–SPME–GC–MS, characteristics of the volatiles of 50 peaches and nectarines representing different germplasm origins were investigated. Ten of these peaches and nectarines were studied in two successive years. Eighty-four compounds were identified. Volatile composition was relatively consistent, but the amount of total volatiles and certain individual compounds varied between years. Moreover, the composition of volatiles and their contents depended on genotypic background and germplasm origin. Total volatiles in wild peaches and a Chinese local cultivar ‘Wutao’ were much higher than in the other groups. All the peaches and nectarines could be classified into four groups by principal component analysis of the volatiles (excluding C6 compounds): ‘Ruipan 14’ and ‘Babygold 7’ with high contents of lactones, Chinese wild peaches and ‘Wutao’ with high contents of terpenoids and esters, seven cultivars with American or European origins with high content of linalool, and others without characteristic composition of volatiles.

Volatile aroma compounds are one of the important characteristics determining fruit quality. Evaluation of volatiles at the germplasm level is useful for future breeding efforts, aimed at improvement of fruit quality, via effects on fruit aroma. The composition and concentration of volatiles in berries of forty-two grape cultivars belonging to seven genotypic groups were evaluated by headspace solid-phase microextraction with GC–MS. Sixty volatiles were detected, of which C6 compounds were the dominant volatiles in V. amurensis grape, neutral cultivars V. vinifera grapes and hybrid grapes between V. vinifera with V. thunbergii or V. amurensis. Alcohols and carbonyls were relatively low in all Vitis germplasm studied. Terpenoids were abundant in V. vinifera with muscat aroma, while esters were dominant in V. labrusca and its hybrids with V. vinifera or V. amurensis. Via principal component analysis, all the grape germplasm studied could be divided into three groups: (1) V. labrusca and its hybrids with V. vinifera or V. amurensis, (2) V. vinifera with muscat aroma and (3) the others, including V. vinifera without muscat aroma plus V. amurensis, and hybrids between V. vinifera and V. thunbergii or V. amurensis. Seasonal quantitative variations of volatiles were observed, but the qualitative volatile composition of the cultivars was consistent.

During the course of pathogens penetrating the plant cell, besides of chemical secretion, the pathogens may cause mechanical signal by the physical pressure on the plant cell. In the current study, we took the stress as the mechanical signal elicitor to find the effect of plant resistance induced by stress. The results showed that an appropriate stress stimulation can evidently improve the plant resistance. However, disruption the plasma membrane–cell wall adhesion will absolutely eliminate this kind of inducement effect, which suggests that the plant resistance inducement by stress depend on the adhesion of plasma membrane–cell wall. Also we found that stress stimulation may cause synthesis of lignin and increase the activity of phenylalaninc ammonial lyase (PAL) chitinase and β-1,3-glucanase obviously. The results showed that stress stimulation may not only enhance ability of the plant cell resistant to pathogen penetration but also elicit the accumulation of pathogens suppression or antimicrobial chemical substance in the plant cell.

Technological developments in stereo image matching have advanced from traditional area-based to feature-based matching and lately to structural matching. This paper introduces a newly developed matching method utilizing structural matching. An evaluation function based on the joint probability of a possible match is derived. An informed tree search method is applied to find the best match. In order to keep the search time acceptable for photogrammetric applications, a series of strategies have been developed and integrated into the search method. Procedures for extraction of structural descriptions and an algorithm for rotation-invariant correlation are presented. In combining all these tools, the fully automated matching of image features is realized without any a priori information. Several tasks like relative image orientation, image matching of non-metric images and tie point measurement in aerotriangulation, which were fully automated by using the structural matching approach, are presented. The results indicate that structural matching techniques can achieve a very high level of automation in digital photogrammetry.