A diversity of traits contributes to salinity tolerance of wild Galapagos tomatoes seedlings

Abstract

22Traits of modern crops have been heavily selected in agriculture, causing the commercial 23 lines to be more susceptible to harsh conditions, which their wild relatives are naturally better 24 able to withstand. Understanding the developed mechanisms of tolerance present in wild 25 relatives can enhance crop performance under stress. In this study, salinity tolerance traits of 26 two species of wild tomato endemic to the Galapagos Islands, Solanum 27 cheesmaniae and Solanum galapagense, were investigated. Since these tomatoes grow well 28 despite being constantly splashed with seawater, they could be a valuable genetic resource for 29 improving salinity tolerance in commercial tomatoes. To explore their potential, over 20 30 traits reflecting plant growth, physiology and ion content were recorded in 67 accessions of S. 31 cheesmaniae and S. galapagense and two commercial tomato lines of Solanum lycopersicum. 32 Salt treatments of 200 mM NaCl were applied for ten days, using supported hydroponics. 33Great natural variation was evident in the responses of the Galapagos tomatoes to salt stress 34 and they also displayed greater tolerance to salt stress than the commercial lines tested, based 35 on multivariate trait analyses. Although Galapagos tomatoes in general exhibited better 36 tolerance to salt stress than the commercial lines tested, the accessions LA0317, LA1449 and 37 LA1403 showed particularly high salinity tolerance based on growth maintenance under 38 stress. Thus, Galapagos tomatoes should be further explored using forward genetic studies to 39 identify and investigate the genes underlying their high tolerance and be used as a resource 40 for increasing salinity tolerance of commercial tomatoes. The generated data, along with 41 useful analysis tools, have been packaged and made publicly available via an interactive 42 online application (https://github.com/mmjulkowska/La_isla_de_tomato) to facilitate trait 43 selection and the use of Galapagos tomatoes for the development of salt tolerant commercial 44 tomatoes. 45 46 3 Keywords: 47 salinity tolerance, salt stress, wild relatives, tomato, S. cheesmaniae, S. galapagense, seedling 48 screen, hydroponics, phenotyping, Galapagos tomatoes. 49 2016). Salt stress affects the growth and development of plants, thus significantly reducing 52 their yield and productivity (Arzani and Ashraf, 2016). Global cultivated lands cover ~1.5 53 billion hectares, and an estimated 32 million hectares are damaged by salinity. Irrigated 54 lands, having the highest productivity, comprise just 230 million hectares, of which an 55 estimated 20% have yields significantly reduced by high soil salinity (Munns, 2005). Water 56availability for agriculture is another major concern, not only in desert regions but at a global 57 level, as freshwater supplies are depleting (Famiglietti, 2014). Salt-affected areas worldwide 58 are predicted to continue expanding at a rate of ~10% per year due to low precipitation, high 59 surface evaporation, erosion of rocks, irrigation with sal...

Physiological changes and growth of soursop plants under irrigation with saline water and H2O2 in post-grafting phase

“…This region usually presents high temperatures, low rainfall, irregular rainfall distribution, and intense evaporation in most months of the year, making irrigation an indispensable practice to ensure satisfactory agricultural production (Lima et al, 2018). However, the low water availability associated with the high concentrations of salts in the water used for irrigation is one of the leading agricultural challenges in the modern world (Pailles et al, 2020).…”