Objectives:This study evaluates the ability of a non-white rot fungus strain, HESHAM-1, to degrade a mixture of low (naphthalene and phenanthrene) and high (chrysene and benzo(a)pyrene) molecular weight polycyclic aromatic hydrocarbons (LMW and HMW PAHs). Methods:Strain HESHAM-1 was isolated from oil polluted soil by enrichment method using phenanthrene as the sole source of carbon and energy. The strain showed the ability to tolerate and degrade a mixture of both low and high molecular weight PAHs. In the presences of LMW-PAHs (naphthalene and phenanthrene) as co-substrate, chrysene and benzo(a)pyrene (HMW-PAHs) were, respectively degraded by the fungus strain HESHAM-1 which was confirmed by GC-MS analyses. Results:The degradation rate was found as 84.82% for naphthalene, 40.09% for phenanthrene, 57.84% for chrysene and 71.06% for benzo(a)pyrene at the end of 10 days. This is the first report describing the biodegradation of a mixture of four PAH compounds by non-white rot fungus strain HESHAM-1 isolated from Egyptian oil-polluted soil. The fungus strain HESHAM-1 was identified by morphological characteristics and molecular genetics technique based on PCR amplification and sequencing of the internal transcribed spacers (ITSs) of the rDNA region and intervening 5.8S rRNA gene. Blast result and phylogenetic analysis of gene sequencing suggested that strain HESHAM-1 was closely related to Fusarium solani with 100% sequence identity. Conclusion:The present study clearly demonstrates that, strain HESHAM-1 could be used to remove the crude oil from the environment.

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The genetic diversity estimates can be useful in important genotypes selection for plant breeders. Eight durum and three bread wheat cultivars were used to study and compare morphological traits with molecular study using SSR technique based genetic diversity estimates. Significant and highly significant differences among wheat genotypes were observed for all traits except flag leaf attitude and outer glume pubescence. Highly significant differences were obtained between durum and bread wheat genotypes for most studied traits. Moderate to low broad-sense heritability estimates were obtained for morphological studied traits. Positive and high significant correlation was found for ear density with foliage color (r= 0.51), waxiness of flag leaf sheath (r= 0.57), waxiness of peduncle (r= 0.60) and peduncle length (r= 0.53), whereas a negative correlation was found between ear density and plant height (r=-0.52, P<0.01). However, waxiness of flag leaf sheath was positively correlated with ear waxiness (r= 0.53, P<0.01), waxiness of peduncle (r= 0.56, P<0.01), and Peduncle length (r= 0.43, P<0.05). The higher polymorphism (90.63%) was found in the B genome than in the A genome (81.97%). Single marker analysis showed that 11 SSR markers were significantly associated with phenotypic traits, including Xgwm111-2B associated with waxiness of peduncle. A significant but low correlation (r = 0.25) was found between the dissimilarity matrix generated from the phenotypic data and that obtained from the SSR markers, suggesting that the characterization based on agromorphological traits and SSR markers will be a useful tool to the breeders for selection of genotypes with appropriate.

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This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.Plant Breed. Biotech. 2014 (September) 2(3):276~288 http://dx.ABSTRACT Drought is one of the most important abiotic factors affecting wheat production and development of tolerant genotypes is limited by the lack of effective selection criteria. A genetic analysis of drought tolerance indices at seedling stage (i.e. root length, shoot length, root/shoot ratio and seedling dry weight) was performed for a seven-parent half diallel cross of bread wheat (Triticum aestivum L.) in Egypt. The parents and their F2 progenies were evaluated in the laboratory under osmotic stress induced by polyethylene glycol (PEG) with five treatments (i.e. 0, 5, 10, 15 and 20% PEG-6000). Grain yield per spike was also evaluated under drought stressed field conditions. The parent P7 had maximum root and shoot lengths under stress conditions, highest root/shoot ratio under 20% PEG and higher grain yield per spike than the other parents suggesting that P7 possessed stress tolerance genes. Grain yield/spike was significantly correlated with root length (r= 0.41, P<0.05) and seedling dry weight (r= 0.46, P<0.05) at 15% PEG. Both additive and non-additive gene effects were involved in the genetic control of all traits. Rather low to moderately narrow-sense heritability was obtained for root length (0.18 and 0.12) and shoot length (0.19 and 0.12) at 15 and 20% PEG, respectively; root/shoot ratio (0.15) and seedling dry weight (0.16) at 15% PEG. Moderate genetic advance was observed for root length (41.24%) and shoot length (29.96%) under stress conditions suggesting that selection could be practiced on both traits for improving drought tolerance in wheat breeding programs.