Wild barley, Hordeum vulgare L. ssp. spontaneum (C. Koch) Thell., is the progenitor of cultivated barley. Almost unanimously the center of diversity is considered to be in the Fertile Crescent of the Near East, where wild barley grows under a wide range of environmental and climatic conditions. Jordanian wild barley is expected to harbor genes useful for the improvement of cultivated barley, particularly those associated with tolerance to drought. This study evaluated 103 wild barley accessions collected from different areas of Jordan along with 29 cultivated barley genotypes for several morphological and agronomical traits. The Hordeum vulgare ssp. spontaneum C. Koch accessions were grouped into six populations according to the longitude, latitude, altitude, and rainfall zone of the collection site, and the cultivated barley in one population. The evaluation was conducted during the 2004-2005 growing season under field conditions in three locations in Jordan; namely, Khanasri, Ramtha, and Maru with 123.0, 222.9, and 429.2 mm annual rainfall, respectively. We used an unreplicated design with two systematic checks (the cultivars Rum and Mu'ta) each repeated 15 times. The results showed the existence of high variability among the Hordeum vulgare ssp. spontaneum C. Koch accessions for most of the traits, especially for plant height, tiller number, days to heading, days to anthesis, peduncle length, and peduncle extrusion. Plant height, earliness, peduncle length, and peduncle extrusion were found to be adaptive traits under drought conditions and several superior genotypes for each trait were identified. Genetic variation within population was much higher than between populations. Clustering of populations was according to their ecological geographical pattern.

An experiment was conducted at five locations in Jordan (Khanasri, annual rainfall 150 mm; Ramtha, 225 mm; Muwaqar, 150 mm; Rabba, 350 mm; Ghweer, 250 mm) during the 1996/1997 growing season, to evaluate the yield performance and some agronomic traits of 84 barley breeding lines and three long‐term checks (Zanbaka, Arta and Klaxon) for drought tolerance. An α‐lattice design with two replications and six incomplete blocks for each replication was used. Genotype 6 (WI2291/Tadmor) was found to be superior in grain yield, especially compared to the best check (Arta) at the two wettest locations (Rabba and Ghweer). Genotype 21 (Mo.B1337/WI2291/5/Emir/Sb//CM67/3/F8‐HB‐854‐23/121//148‐221/4/CI 08887/CI05761) out‐yielded the best check (Arta) at the driest location (Khanasri), while genotype 61 (Salmas/Arabia Aswad) produced a higher grain yield than the best check (Zanbaka) at Ramtha. The correlations amongst grain yield, biological yield, straw yield, plant height and harvest index were always significant and positive regardless of the location. The correlations amongst days to heading, days to maturity and grain yield were significant at the two driest locations only. This suggests that different phonologies are required to maximize grain yield in wet and dry environments. Also, the relationship between grain yield and the length of grain‐filling period was positive in the wettest location (Rabba), negative in the driest (Khanasri) and not significant at the two intermediate locations. These results emphasize the importance of selection in the target environment and the need to develop early‐maturing genotypes as a way of withstanding drought and high temperatures during the grain‐filling period. A high and negative correlation coefficient was found between the drought susceptibility index and grain yield at the driest site, whereas at the wettest site the correlation coefficient was lower and in some cases positive, indicating the existence of traits that are desirable under drought and undesirable under favourable conditions.

The study assessed farmersÕ and breedersÕ selection efficiencies in one cycle of selection in a participatory barley breeding program. The selectors were compared with each other for objectively measured agronomic traits and for their selection scores. FarmersÕ scores were positively correlated with grain yield in all locations while breedersÕ scores not always. The selection criteria of farmers varied with location; those in low-moisture areas selected for tall plants while those in high rainfall area for short. BreedersÕ gave high scores to tall entries regardless of the selection environment. The results showed that in all locations farmers were at least as efficient as or, in most cases, more efficient than breeders in identifying high yielding genotypes with desirable traits for their specific environment indicating their competence in selection. Breeders appeared to select for their wide geographic mandate area while farmers focused on their specific locality. The finding indicates that decentralized participatory plant breeding is important to increase and stabilize productivity and maintain genetic diversity as each pocket area is occupied by the best and different genotypes.

Wild barley, Hordeum spontaneum is the progenitor of cultivated barley. The center of diversity is in the Fertile Crescent in the Near East, where wild barley grows under a wide range of environmental and climatic conditions. Jordan wild barley is expected to harbor important genes that could be used for the improvement of the cultivated varieties especially in their tolerance to drought. To assess genetic diversity and allelic variation of Jordanian wild barley, 103 wild barley genotypes collected from different parts of Jordan along with 29 cultivated barley genotypes were analyzed for diversity by means of Simple Sequence Repeats (SSR). The spontaneum genotypes were grouped into six populations according to their longitude, latitude, altitude, and rainfall zone of the sites from where they have been collected, and the cultivated in one population. All barley genotypes were analyzed with 11 SSR markers with known sequences and chromosomal locations. The 11 microsatellite markers revealed 237 alleles, with an average of 21.5 alleles per locus. In spontaneum genotypes, 209 alleles were identified with an average of 19 alleles per locus, whereas, cultivated genotypes had 95 alleles with an average of 8.6 alleles per locus. Moreover, 52 alleles were identified in spontaneum (22 %) of the total alleles and 22 alleles in cultivated barley (9 %). The level of genetic diversity was very high; in fact, mean in total gene diversity (Ht) was 0.86 ranging from 0.72 to 0.94. Average gene diversity (H) was 0.79 ranging from 0.74 to 0.82. Genetic variation within population was much higher than among populations at molecular levels: this was also supported by the finding that morphological characters such as awn length, plant height, days to maturity, peduncle length, peduncle extrusion and tillering number, showed higher variation within populations than among populations. Clustering of populations was according to their ecological geographical pattern.

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