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Iskalni niz: "ključne besede" (Drought stress) .

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Discrimination between abiotic and biotic drought stress in tomatoes using hyperspectral imaging
Barbara Gerič Stare, Gregor Urek, Andrej Vončina, Matej Knapič, Jaka Razinger, Polona Strajnar, Saša Širca, Uroš Žibrat, Nik Susič

Povzetek: Crop plants are subjected to various biotic and abiotic stresses. Both root-knot nematodes (biotic stress) and water deficiency (abiotic stress) lead to similar drought symptoms in the plant canopy. In this work, hyperspectral imaging was used for early detection of nematode infestation and water deficiency (drought) stress in tomato plants. Hyperspectral data in the range from 400 to 2500 nm of plants subjected to different watering regimes and nematode infestation levels were analysed by partial least squares – discriminant analysis (PLS-DA) and partial least squares – support vector machine (PLS-SVM) classification. PLS-SVM classification achieved up to 100% accuracy differentiating between well-watered and water-deficient plants, and between 90 and 100% when identifying nematode-infested plants. Grouping the data according to the time of imaging increased the accuracy of classification. Shortwave infrared spectral regions associated with the OH and CH stretches were most relevant for the identification of nematode infested plants and severity of infestation. This study demonstrates the capability of hyperspectral imaging to identify and discriminate between biotic and abiotic plant stresses.
Ključne besede: nematode, Hyperspectral imaging, Drought stress, Root-knot nematode, Tomato
DiRROS - Objavljeno: 20.07.2018; Ogledov: 1603; Prenosov: 667
.pdf Celotno besedilo (847,87 KB)

Forest resilience to drought varies across biomes
Antonio Gazol, Jesus Julio Camarero, Sergio M. Vicente-Serrano, Raúl Sánchez-Salguero, Emilia Gutiérrez, Martin De Luis, Gabriel Sangüesa-Barreda, Klemen Novak, Vicente Rozas, Pedro A. Tíscar, 2018

Povzetek: Forecasted increase drought frequency and severity may drive worldwide declines in forest productivity. Species-level responses to a drier world are likely to be influenced by their functional traits. Here, we analyse forest resilience to drought using an extensive network of tree-ring width data and satellite imagery. We compiled proxies of forest growth and productivity (TRWi, absolutely dated ring-width indices; NDVI, Normalized Difference Vegetation Index) for 11 tree species and 502 forests in Spain corresponding to Mediterranean, temperate, and continental biomes. Four different components of forest resilience to drought were calculated based on TRWi and NDVI data before, during, and after four major droughts (1986, 1994-1995, 1999, and 2005), and pointed out that TRWi data were more sensitive metrics of forest resilience to drought than NDVI data. Resilience was related to both drought severity and forest composition. Evergreen gymnosperms dominating semi-arid Mediterranean forests showed the lowest resistance to drought, but higher recovery than deciduous angiosperms dominating humid temperate forests. Moreover, semi-arid gymnosperm forests presented a negative temporal trend in the resistance to drought, but this pattern was absent in continental and temperate forests. Although gymnosperms in dry Mediterranean forests showed a faster recovery after drought, their recovery potential could be constrained if droughts become more frequent. Conversely, angiosperms and gymnosperms inhabiting temperate and continental sites might have problems to recover after more intense droughts since they resist drought but are less able to recover afterwards.
Ključne besede: dendroecology, drought stress, forest growth, resilience index, tree-rings
DiRROS - Objavljeno: 20.02.2020; Ogledov: 162; Prenosov: 136
URL Celotno besedilo (0,00 KB)

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