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.

Low heritability estimates in marginal or stress environments have often been used as one of the main justification for conducting selection work in environments with optimum or near‐optimum conditions for plant growth and grain yield. In this study, we have examined the relationships between grain yield and broad‐sense heritability in four groups of recombinant inbred lines (RILs) obtained from four barley crosses derived from parents differing in adaptation to stress. The RILs and the parents were grown in 13 combinations of years and locations (environments) in Syria and Jordan. Grain yields ranged from about 30 kg ha−1 to nearly 4000 kg ha−1 and genotype × environment interactions explained about half of the total variance for environmentally standardised data. Broad‐sense heritability in the individual year–location combinations varied from 0 to 0.68 and both the simple correlation and the rank correlation coefficients between grain yield and heritability were not significant. Genotype × years within individual locations, which measures the repeatability of a location in discriminating between genotypes, was also independent from the yield level, confirming that low‐yielding locations can be reliable selection environments. Also, there was no relationship between the type of cross and the magnitude of heritability in the various environments, but, as expected, the magnitude of heritability was significantly associated with the genetic distance between the parents. It is concluded that, holding all other factors affecting response to selection constant, concerns about the magnitude of heritability at low‐yielding locations are not justified and should not prevent them from being used as selection sites.

Changes in allele type, allele frequency and genetic diversity because of selection by individual farmers and breeders were assessed using simple sequence repeats (SSRs) during one cycle of selection in a decentralized participatory barley breeding programme. Selection by both breeders and farmers resulted in the loss of a number of alleles in the majority of the locations, with more alleles lost in the heterogeneous breeding materials than in the fixed genotypes, indicating selection against undesirable traits uncovered in the heterogeneous breeding materials that are presumably linked to SSR alleles. After selection, significant allelic frequency changes were observed at several loci in both the germplasm groups. As the selection was conducted independently in each location, an allele had a chance of being selected in more than one location, and therefore considering the whole study area the allelic composition and diversity of the original genetic materials was maintained after the selection. The study showed the importance of decentralized participatory plant breeding in maintaining genetic diversity that helps stabilize and sustain production in unpredictable production conditions.

As a result of the decreasing availability of high-quality irrigation water, the salinity tolerance of cut flowers is of increasing importance. The influence of salinity on the growth and quality of Chrysanthemum, Chrysanthemum morifolium L. grown in two different media under four salinity levels was evaluated. C. morifolium plants were grown in plastic pots containing either zeolitic tuff or soil as potting media. Seedlings of C. morifolium were subjected to four NaCl/CaCl2 salinity levels (2, 4, 6, and 8 dS.m-1). The effect of increasing salinity level on growth, flowering characteristics, time to flower, length and diameter of flowering shoots, and the diameter of the terminal flower on each stem were evaluated. On termination of the experiment, plant height, two perpendicular canopy widths, and fresh and dry weights of shoots were measured. Results indicated that most of all measured characteristics were reduced in response to increasing salinity levels. Increasing salinity levels caused significant reductions in plant height, fresh and dry yield, and relative water content. Moreover, salinity reduced flower quality (color, size, stem thickness, and length) and yield. Also, some physiological changes occur in stomatal conductance, leaf relative water content, and chlorophyll content. C. morifolium plants showed a good salinity resistance by irrigating plants with saline water up to 4 dS.m-1. Significant differences in C. morifolium plant responses were also detected between soil and zeolitic tuff media for most tested characteristics, in which using zeolitic tuff as rowing media was better to cope with higher salinity levels than plants grown in soil. In conclusion, it is recommended to use zeolitic tuff instead of soil when water salinity is a problem in irrigation water.

The relationship among six Jordanian almond landraces was studied using morphological traits and RAPD analyses. Across six almond landraces studied, nut shape, kernel size, nut length, nut size, and shell length That showed a high level of variation (CV>30%), while kernel length, shell width, internodes length, and nut width showed comparatively low values (CV<20%). Principal component analysis showed that the first five components explained all morphological variation among the landraces investigated. Kernel and nut traits were predominant in the first three components contributing to most of the total variation that existed among landraces. Euclidean distance was used to construct clusters from morphological data which allocated individuals into two main groups with a distance ranging from 5.5 to 10.14. Hajari, Hami Hallo, and Mukhmaly with small fruit sizes composed one main cluster, while the other three landraces (Oga, Fark, and Abu Dabos) with large fruit sizes composed the other main cluster. Out of 62 pre-screened RAPD primers, 12 with reproducible bands and maximum polymorphism were selected for diversity analysis. Seventy-one bands were scored with 28 of them being the polymorphic. Average value of polymorphism/primer ranged from 20% to 74.2%. Nei's genetic distance coefficient ranged from 0.5 to 0.85 with an average of 0.70. Molecular analysis revealed inconsistent separation among the landraces compared with that based on morphological traits. Although landraces found during the screening in the Ajloun area are limited in number, but considerable variation was observed both at morphological and DNA levels indicating that Jordanian almond landraces are rich and valuable genetic materials for almond improvement.

In this study, we reviewed the climate changing and the impact on crop production, and evolutionary breeding as adaptation key to crop resilience. The increasing climate change impact on the agriculture system has renewed interest to the broadest possible germplasm base for a resilient and sustainable food system. Heterogeneous populations developed through evolutionary plant breeding could be the ideal solution to reduce the effects of environment variability on cereal crop planted under low-input conditions.The study assessed the genetic basis of adaptation of a barley population which evolved in different rainfed locations and years in Jordan without any human selection as suggests model of plant breeding strategy to improve food security, nutrition, income and resilience of smallholder farmers in the dryland regions in the climate change scenarios. The study suggests that the breeder can shift the undesirable traits in evolutionary populations by practicing individual selection for specific adaptations, or individual selection from populations showing wide adaptations and high stability. On the other hand, the breeder can overcome the undesirable traits by keeping the highest variations within the population by seed sieving to remove small seed and plant mowing for tallest head.

Climate change, human population growth, human health and food security, safety, and sovereignty all demand that the role of biodiversity in plant breeding be revisited. From a biological standpoint, it is possible that populations of diverse plants developed by evolutionary plant breeding will be able to handle the majority of these major issues. Water stress and soil nutrient deficiency may have a negative impact on wheat (Triticum spp.) and barley (Hordeum vulgare) yields and qualities. Drought-tolerant wheat cultivars with high yield and quality potential and improved grain protein content must be developed if food security is to be maintained. Wheat and barley (Triticum spp. and Hordeum vulgare, respectively) are the focus of this research, which aims to examine the stability of evolutionary populations (EPs) in the face of stressful and changeable settings. It's also important to look at how evolved populations stack up against improved varieties in terms of yield and its components. There has not been much progress in making wheat and barley more resistant to drought, especially in Jordan, where the problem is felt the most.