Germination and emergence variability of alfalfa (Medicago sativa L.) landraces collected in Southern Tunisia oases

Abstract

Alfalfa (Medicago sativa L.) is one of the most important forage crops in the world. It has been originated from the Caucasus region (Michaud et al., 1988). The species presents purple flowers, a tap root, an erect growth habit, coiled pods and no winter dormancy. This plant improves the yield and quality of the following crops by atmospheric nitrogen fixation (Bruulsema and Christie, 1987 AbstractVariability in germination under controlled conditions with and without salt, seeds characteristics and field emergence were evaluated for 20 landraces of Medicago sativa ssp sativa, a forage legume collected from three sites in Tunisia. Highly significant differences were recorded among the landraces (p < 0.001) for all the characters studied except tegument colour. Number of seeds produced per plant ranged between 378 and 460 seeds g -1 . Emergence responses of seeds were different among landraces and sites and their values ranged between 12 to 45%. Salt stress (150 mM) caused substantial reduction in final and rate of germination of all the landraces with an average decline of 62.4 and 69.7%, respectively. Final germination values ranged from 26.5 to 75.75% when supplied distilled water. However, final germination values ranged from 10.75 to 32.5% when the seeds were exposed to saline water (150 mM). Rate of germination ranged from 12.75 to 63.25% and from 6.25 to 21.25% at non-saline and salt stress, respectively. Cluster analysis separated the 20 landraces into four clusters. Three landraces in the first cluster had the lowest germination and the greatest field emergence. One landrace composed the second cluster and showed both high germination and field emergence. Two landraces in the third cluster presented greater germination and low emergence. The other landraces constituted the fourth cluster and had intermediates emergence and germination.Additional key words: arid land; diversity; salt stress; seeds. Resumen Variabilidad en la germinación y en la emergencia de variedades autóctonas de Medicago sativa en diferentes oasis de TúnezSe evaluó la germinación en laboratorio con y sin estrés salino, así como las características de las semillas y la emergencia de 20 poblaciones de la leguminosa forrajera Medicago sativa ssp sativa, procedentes de tres localidades de Túnez. Se observaron diferencias altamente significativas entre las poblaciones (p < 0,001) en todos los caracteres estudiados excepto en el color del tegumento. El número de semillas por gramo varió entre 378 y 460. La emergencia de las semillas fue diferente entre las poblaciones y las localidades (variaron entre el 12 y el 45%). El estrés salino (150 mM) causó una fuerte reducción en todas las poblaciones, tanto en la germinación final como en el porcentaje de germinación, con una reducción media del 62,4 y 69,7%, respectivamente. Los valores de germinación finales variaron entre 26,5 y 75,75% y entre 10,75 y 32,5% con agua destilada y estrés salino, respectivamente. El porcentaje de germinación varió desde el 12,75 al 63,25% y del 6,25 al 21,25% en ...

Comparison of phenotypic trait variation and total protein polymorphism in local and exotic germplasms ofMedicago sativain Iran

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Effects of Salinity and Nutrient Addition on Mangrove Excoecaria agallocha

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Seed emergence of lucerne varieties under different soil conditions

“…Benabderrahim et al (2011) also reported significant differences in seed emergence among 20 lucerne landraces from Tunisia. Nevertheless, the effect of variety could not be separated from the effect of seed lot in our experiment.…”

“…Benabderrahim et al (2011) demonstrated a significant effect of lucerne landrace and geographic origin on germination and field emergence. All Czech lucerne varieties have three national landraces (Hodonínka, Přerovská, Kaštická) in their pedigree, which were naturally differently influenced by sickle lucerne (Medicago falcata L.) considered as a genetic source for im-proving the adaptability of lucerne due to a higher tolerance to low pH (Jelinowska 1964).…”