Phenotypic diversity in wild barley (Hordeum vulgare L. ssp. spontaneum (C. Koch) Thell.) accessions collected in Jordan

Abstract

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.

Assessment of genetic diversity among Jordanian wild barley (Hordeum spontaneum) genotypes revealed by SSR markers

“…These included 103 H. spontaneum accessions originated from Jordan, 27 improved cultivars which are known to perform well under drought conditions, and two check cultivars (Shakhatreh 2006;Shakhatreh et al 2010). All the genetic materials used in this study were obtained from ICARDA gene bank and barley breeding program, except the check cultivars, which were from The National Center for Agricultural Research and Extension (NCARE) in Jordan.…”

“…2). These distinct groups reflect the distinct agro-ecologies from where these populations originated, which might be a result of region-specific natural selection (Volis et al 2002;Shakhatreh et al 2010). Therefore, the separation of H. spontaneum populations seems logical, since they grouped according to their ecological geographical pattern (Fig.…”

“…H. spontaneum is a valuable source of new genes for breeding. These include, grain protein content (Jaradat 1991), resistance to powdery mildew (Dreiseitl and Dinoor 2004), earliness (Korff et al 2004;Li et al 2005), biomass (Lu et al 1999), plant height under drought (Baum et al 2003), drought tolerance (Baum et al 2003;Korff et al 2004;Hübner et al 2009;Shakhatreh et al 2010;Lakew et al 2013), cold tolerance Crosatti et al 1996), deep-seeding tolerance and fast emergence of seedlings from deep seeded conditions (Takahashi et al 2001).…”

“…''Only Jordan and Syria have high genetic diversity of wild barley similar to Israel''. As for morphological traits, plant height, biomass yield, earliness, peduncle length, peduncle extrusion and awn length are among the important morphological traits to increase abiotic stress tolerance (Ellis et al 2000 andBaum et al 2003;Shakhatreh et al 2010). …”

Leaf proteome alterations in the context of physiological and morphological responses to drought and heat stress in barley (Hordeum vulgare L.)

“…This germplasm is also interesting in order to study the genetic basis of adaptation to stress in genetically diverse genotypes. Stress adaptation in barley has been attributed to the plasticity of morphological traits such as biomass production, plant growth, tiller number, and peduncle extrusion (von Korff et al , 2008; Shakhatreh et al , 2010). Growth-related responses to stress are typical of stress avoidance strategies which allow the plant to maintain a homeostasis despite changes in the environments.…”