caa a22 4500 475750853 CHVBK 20180406123523.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1023/A:1009856732262 doi (NATIONALLICENCE)springer-10.1023/A:1009856732262 Is there any genetic differentiation among populations of Piptochaetium napostaense (Speg.) Hack (Poaceae) with different grazing histories? [Elektronische Daten] [María Tomás, Alicia Carrera, Mónica Poverene] Native populations of perennial grasses subjected to heavy grazing are typically shorter and more prostrate than ungrazed or lightly defoliated ones. However, it is often difficult to find out whether the morphological modifications are the result of genetic differentiation or phenotypic plasticity. Piptochaetium napostaense (Speg.) Hack. is a native perennial cool-season palatable grass with a dwarf form abundant in the areas subjected to heavy grazing. In this study, we tried to determine whether the populations with different grazing histories are genetically differentiated. We considered three different grazing conditions: enclosure (prevented from grazing during 20years), livestock grazing, and burrow (heavily grazed by cattle and a wild rodent herbivore, the vizcacha). Isozyme analyses were carried out in order to assess the genetic variability of the populations under study. We further studied the progeny of plants with different grazing histories to determine whether the morphological differences are transmitted to the next generation. Seedlings obtained from seeds belonging to enclosure and burrow were grown in the greenhouse and their vegetative and reproductive response under different water and nutrient availability levels were recorded. From the isozymes analyses we found low levels of genetic variation in the populations studied, with an average of 20.5% polymorphic loci, 1.2 alleles per locus and 0.015 mean expected heterozygosity. From the total genetic diversity, only 1.4% was due to differences among population. In addition, either enclosure or burrow populations had the same growth and reproductive response over treatments differing in water and nutrient levels. The morphological differentiation among plants with different grazing histories appears to be the outcome of a phenotypically plastic response of adapted genotypes. Kluwer Academic Publishers, 2000 Argentine nationallicence Ecotypic differentiation nationallicence Genetic variation nationallicence Grasses nationallicence Isozymes nationallicence Phenotypic plasticity nationallicence Tomás María Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut Carrera Alicia Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut Poverene Mónica Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut Plant Ecology Kluwer Academic Publishers 147/2(2000-04-01), 227-235 1385-0237 147:2<227 2000 147 11258 https://doi.org/10.1023/A:1009856732262 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1009856732262 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tomás María Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut NATIONALLICENCE 700 1- Carrera Alicia Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut NATIONALLICENCE 700 1- Poverene Mónica Departamento de Agronomía - CERZOS/CONICET, Universidad Nacional del Sur, 8000-Bahía, Blanca, Argentina aut NATIONALLICENCE 773 0- Plant Ecology Kluwer Academic Publishers 147/2(2000-04-01), 227-235 1385-0237 147:2<227 2000 147 11258 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer