PATRONES DE GERMINACIÓN Y DESARROLLO DE GRAMÍNEAS PRESENTES EN EL DESIERTO CHIHUAHUENSE.

GUTIÉRREZ GUTIÉRREZ, OBED GABRIEL (2020) PATRONES DE GERMINACIÓN Y DESARROLLO DE GRAMÍNEAS PRESENTES EN EL DESIERTO CHIHUAHUENSE. Doctorado thesis, UNIVERSIDAD AUTONOMA DE CHIHUAHUA.

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Resumen

The aim of the present work was to determine the germination and seedling development patterns of wild grasses on the face of climate change for the purpose of restoration or control of invasive species. In a fist evaluation with 22 native and exotic species present at the Chihuahuan desert, germination was measure at a constant temperature of 27 ± 2 °C. Half of those species germinated within the first three days. Germination velocity was from 0.3 to 7.8 seeds d-1. The 50 % of the germination was achieved from the second to the six day. The root:shoot (R:S) ratio ranged from 0.3 to 2.7 at one week old seedlings. On a second experiment with six native and six exotic species, germination response was evaluated under a temperature gradient (14, 18, 22, 26, 30, and 34 °C). Germination response to temperature was lineal, quadratic, and cubic. Two native and one exotic species maintained high germination at 34 C. The R:S ratio was not affected by temperature (P >0.05) for Bouteloua dactyloides. On a third experiment, those 12 species were subjected to four water levels, based on precipitation patterns of the Chihuahuan desert. In general, native and exotic species emerged at all levels, except on the extreme low. Also, R:S ratio increased as the water level decreased. Based on the results, the exotic grass Eragrostis curvula and the natives Bouteloua curtipendula and Leptochloa dubia have the highest adaptation probabilities to climatic change.

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