Genetic variability in Chilean pepino (Solanum muricatum Aiton) fruit

Solanum muricatum Aiton is an herbaceous perennial fruit species native to the Andean region of Colombia, Ecuador, and Peru. In Chile, it was probably introduced in pre-Columbian times as a domesticated species and is presently grown in the coastal areas of the north-central regions of Coquimbo and Valparaíso. The species has been bred, but little information is available on its genetic variability in Chile. To characterize the genetic variability in this species, fruits were collected from 14 different ecotypes and seeds were sown to generate approximately 60 segregants from each accession. Segregants were planted at two different locations to characterize their fruits and fruiting habits. Fruit weight ranged from 30 to 485 g, while length was 3.5 to 16.7 cm, equatorial diameter 3.4 to 9.5 cm, pulp firmness 1.7 to 10 N, and soluble solids content 6.3 to 13.5° Brix. Fruit shape ranged from flat to oblong. When analyzing the estimated variance components with a mixed linear model, most of the variability between different ecotypes was in fruit shape, length, and weight, which resulted in a genetic contribution of 34.6%, 29.3%, and 18.1% of the total variability of these traits, respectively. Genetic variability was also found for pulp firmness and soluble solids content. Therefore, enough variability is available in seed-propagated pepinos from Chilean ecotypes to allow genetic improvement of these fruit quality traits. There was also variability from genotype x environment interactions; therefore, selections must be performed for specific environments or stable selections must be found

Genetic variability in Chilean pepino fruit (Solanum muricatum Aiton)

Solanum muricatum Aiton is an herbaceous perennial fruit species native to the Andean region of Colombia, Ecuador, and Peru. In Chile, it was probably introduced in pre-Columbian times as a domesticated species and is presently grown in the coastal areas of the north-central regions of Coquimbo and Valparaíso. The species has been bred, but little information is available on its genetic variability in Chile. To characterize the genetic variability in this species, fruits were collected from 14 different ecotypes and seeds were sown to generate approximately 60 segregants from each accession. Segregants were planted at two different locations to characterize their fruits and fruiting habits. Fruit weight ranged from 30 to 485 g, while length was 3.5 to 16.7 cm, equatorial diameter 3.4 to 9.5 cm, pulp firmness 1.7 to 10 N, and soluble solids content 6.3 to 13.5° Brix. Fruit shape ranged from flat to oblong. When analyzing the estimated variance components with a mixed linear model, most of the variability between different ecotypes was in fruit shape, length, and weight, which resulted in a genetic contribution of 34.6%, 29.3%, and 18.1% of the total variability of these traits, respectively. Genetic variability was also found for pulp firmness and soluble solids content. Therefore, enough variability is available in seed-propagated pepinos from Chilean ecotypes to allow genetic improvement of these fruit quality traits. There was also variability from genotype x environment interactions; therefore, selections must be performed for specific environments or stable selections must be found.Fil: Muñoz, Carlos. Universidad de Chile; ChileFil: Pertuzé, Ricardo. Universidad de Chile; ChileFil: Balzarini, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Bruno, Cecilia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Salvatierra, Angelica. Instituto de Investigaciones Agropecuarias. La Serena; Chil

Salt stress differently affects growth, water status and antioxidantenzyme activities in Solanum lycopersicum and its wild-relative Solanum chilenseDUN.

The effect of saline stress (NaCl, 40, 80 and 160 mmol L-1 of NaCl) on growth, plant water status and leaf antioxidant enzyme activities was investigated in a commercial cultivar of cherry tomato (Solanum lycopersicum var. cerasiforme L.) and in a wild-related species collected in a salt-affected area of North Chile (Solanum chilense Dun.). Salt stress was applied in a nutrient solution at the vegetative stage during 40 days. The highest NaCl concentration reduced shoot relative growth, fresh and dry weight and leaf area in the cultivated S. lycopersicum but had less impact on S. chilense. Both species were able to efficiently perform osmotic adjustment but S. chilense also exhibited an increase in leaf succulence. The oxidative stress estimated through malondialdehyde quantification was always higher in the cultivated S. lycopersicum, both in the absence and in the presence of salt. Total superoxide dismutase activity (EC 1.15.1.1) increased in response to the highest dose of NaCl in S. chilense but remained constant in S. lycopersicum. Salinity induced an increase in ascorbate peroxidase (EC 1.11.1.11) in S. chilense but reduced it in S. lycopersicum. It is concluded that S. chilense displays efficient strategies to cope with high NaCl doses and that management of the oxidative status is a key mechanism allowing this species to tolerate salinity

Seed morphology and anatomy of Rubus geoides Sm.

Rubus geoides Sm. is a wild raspberry native in Patagonia. Its domestication can broaden the genetic base of the cultivated raspberry, prevent over exploitation of wild populations, and diversify fruit production in areas where few fruit species can be cultivated, like the Chilean Patagonia. One important step in the domestication of plant species is the unveiling of the reproductive biology of the species, particularly seed germination. The goal of this work was to study seed morphology and anatomy of R. geoides in order to identify possible factors that may affect germination and species identification based on seed morphology, since seed shape, surface sculpturing and raphe characteristics are discriminating factors for species identification within Rubus. Morphoanatomical studies were performed using both scanning electron microscopy (SEM) and light microscopy. Rubus geoides seeds turned out to be similar to those of R. idaeus. Seeds were pale brown, with a semi globular shape, sharpened at the apical region and oval toward the opposite end. Seed size was variable, showing an average 1.9 mm width, 2.6 mm length, and 1.3 mm thickness. Small rounded depressions and ridges sculptured seed surface. The endocarp was hard and rough, and consist of several layers of sclerenchymatous lignified cells with 139 mu m averaged thickness, which suggest that to enhanced germination seed may require its weakening or eventual elimination, as is done in other Rubus species. The embryo varied with seed size between 1.6 and 2.0 mm. Energy Dispersive X-Ray Spectroscopy allowed for the identification of the endosperm cells

Challenges for agroecology development for the building of sustainable agri-food systems

Environmental and social crises in agriculture have led to growing recognition that more ecologically sustainable and socially just food and agricultural systems are needed. This thematic number of the International Journal of Agriculture and Natural Resources gathers the papers submitted to the workshop “Challenges for agroecology development for the building of sustainable agri-food systems,” an OECD Co-operative Research Programme-sponsored conference. The aim of the workshop was to promote the transition from conventional agriculture towards agroecology as a science, practice and social movement through sharing the experiences of different OECD countries: Australia, Canada, Chile, Colombia, Hungary, Italy, Netherlands, Norway, Spain, Sweden and the United States. The main topics discussed at the workshop included i) agroecology development in OECD countries: local experiences and international collaboration; ii) agroecology as a social movement and related public policies; iii) agroecology education to promote sustainable agri-food systems; and iv) science, innovation and technologies in agroecological systems. While not a comprehensive assessment of the state of agroecology in OECD countries, this thematic number integrates diverse perspectives on some main research and policy advances and uncovers some existing gaps in agroecology practice as an approach for transitioning towards ecologically sustainable and socially just agricultural systems