International audienc

Traits of modern crops have been heavily selected in agriculture, leaving commercial lines often more susceptible to harsh conditions compared with their wild relatives. Understanding the mechanisms of stress tolerance in wild relatives can enhance crop performance under stress conditions such as high salinity. In this study, we investigated salinity tolerance of two species of wild tomato endemic to the Galapagos Islands, Solanum cheesmaniae and Solanum galapagense. Since these tomatoes grow well despite being constantly splashed with seawater, they represent a valuable genetic resource for improving salinity tolerance in commercial tomatoes. To explore their potential, we recorded over 20 traits reflecting plant growth, physiology, and ion content in 67 accessions and two commercial tomato lines of Solanum lycopersicum. Salt treatments were applied for 10 d using supported hydroponics. The Galapagos tomatoes displayed greater tolerance to salt stress than the commercial lines and showed substantial natural variation in their responses. The accessions LA0317, LA1449, and LA1403 showed particularly high salinity tolerance based on growth under salinity stress. Therefore, Galapagos tomatoes should be further explored to identify the genes underlying their high tolerance and be used as a resource for increasing the salinity tolerance of commercial tomatoes. The generated data, along with useful analysis tools, have been packaged and made publicly available via an interactive online application (https://mmjulkowska.shinyapps.io/La_isla_de_tomato/) to facilitate trait selection and the use of Galapagos tomatoes for the development of salt-tolerant commercial tomatoes.

No abstract

No abstract

Dike intrusions produce faulting at the surface along with seismic swarms and possible eruptions. Understanding the geometry and kinematics of dike-induced fractures can provide relevant information on what controls magma emplacement and the associated hazards. Here, we focus on the Harrat Lunayyir volcanic field (western Saudi Arabia), where in 2009 a dike intrusion formed a NNW-SSE oriented, ten-kilometer-long and up to one-meter deep graben. This widens from ∼2 km in the SSE to ∼5 km in the NNW, showing a well-defined border normal fault to the west but a diffused fracture zone to the east. We conducted a fixed-wing drone survey to create high resolution (∼3.4 cm) ortho-rectified images and DEMs of the western fault and of a portion of the eastern fracture zone to determine the fracture geometry and kinematics. We then integrated these results with field observations and InSAR data from the 2009 intrusion. Both fault zones contain smaller segments (hundreds of meters long) consisting of normal faults and extension fractures, showing two dominant orientation patterns: NNW-SSE (N330 • ± 10 •) and NW-SE (N300 • ± 10 •). The NNW-ESE oriented segments are subparallel to the inferred 2009 dike strike (N340 •), to pre-historical Harrat Lunayyir eruptive fissures (N330 •) and to the overall Red Sea axis (N330 •). This suggests that these segments reflect the present-day off-rift stress field close to the Red Sea shoulder. However, the NW-SE oriented segments are oblique to this pattern and exhibit enechelon structures, suggesting different processes such as: (1) a transfer (or soft-linkage) between dike-parallel fault segments, (2) a topographic control on the fault propagation and (3) a possible reactivation of inherited regional faults. Vertical fault offsets obtained by the drone survey along the western fault vary with the local lithology and these data are not consistent everywhere with the offsets derived from the 2009 InSAR measurements. Field evidence within lava flows also shows the occurrence of previous slipping event(s) on the fault before the 2009 intrusion. Collectively, we suggest that the mismatch between the drone and InSAR datasets is related to the different spatial and temporal resolutions offered by the two techniques.