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Accueil du site → Doctorat → Espagne → 1997 → Adaptación y llenado del grano de cebadas de dos y seis carreras en secanos del noreste de España

Universitat de Lleida (1997)

Adaptación y llenado del grano de cebadas de dos y seis carreras en secanos del noreste de España

Muñoz Odina, Mª Pilar

Titre : Adaptación y llenado del grano de cebadas de dos y seis carreras en secanos del noreste de España

Auteur : Muñoz Odina, Mª Pilar

Université de soutenance : Universitat de Lleida

Grade : Doctoral thesis 1997

Résumé
Barley is an early maturing crop with high yield potential and a wide range of adaptation. It is produced in both irrigated and dryland environments througout the world. It can be grown sucessfully where other cereals are poorly adapted, including high latitude and high elevation regions and even bordering deserts. Barley breeding has allowed for an increased productivity in Spain in the last 50 years, particularly for the more favorable areas. Ten two-rowed and ten six-rowed barley genotypes were sown in multilocation trials at four sites (three sites closed to Lleida and another close to Zaragoza) and for four years (1990, 1991, 1992 and 1993). Differential adaptation of two- and six-rowed barley to rainfed Mediterranean conditions of the North East of Spain was studied. Characterization of grain filling and nitrogen content under these conditions were also evaluated. Plant breeding has brought about a genetic gain for grain yield for both two and six-rowed barleys. Average grain yields of recent releases were higher than those of old varieties. However, the most recent varieties are less specifically adapted to the drier environments, whereas the new ones are specifically adapted to better environmental conditions. This has translated into an indirect genetic downshift for water used efficiency. Old varieties seem to have a higher WUE than new ones, as revealed by 13C/12C stable isotope discrimination ratios. Grain filling characterization revealed a tight genetic control for rate of grain filling, whereas grain filling duration was more environmental dependent. New six-rowed varieties have a higher grain filling rate. Both lateral and central grains of six-rowed varieties seem to fill in a similar fashion. The lateral to central grain weight ratio was relatively independent of the environment. The role of the last internode as a depository of nitrogen to be translocated to the spike at post-anthesis was clearly shown. New varieties tended to have higher nitrogen concentration in the grains that old landraces

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