The study was performed to determine as to whether antioxidant potential (enzymatic and non-enzymatic antioxidants) as well as some other attributes could be used as potential drought resistance markers in two maize lines (B 73 and MO 17). Under water deficit conditions, growth traits, relative water content (RWC), chlorophyll a, total chlorophyll and carotenoids as well as grain yield decreased significantly in both lines compared to those under control conditions. In contrast, water deficit caused a significant increase in the activities of superoxide dismutase (SOD) and catalase (CAT) isozymes as well as levels of glycine betaine (GB), proline and malondialdehyde (MDA), whereas total phenolics, total soluble protein, H 2 O 2 , chlorophyll b, chlorophyll a/b ratio, anthocyanin and peroxidase (POX) isozyme activity remained unaffected in both maize lines. Although water deficit stress induced oxidative stress in both maize lines, the enzymatic and non-enzymatic antioxidants and key organic osmolytes increased significantly in both maize lines. For example, SOD isozyme activities, and GB and proline contents were considerably greater in relatively drought resistant MO 17 than those in relatively drought sensitive B 73. However, in contrast, CAT activity was higher in B 73. Overall, SOD isozyme activities, and GB and proline contents were found to be potential biochemical indicators of drought resistance in the two maize lines used in the present study.

Selection of durum wheat genotypes with wide adaptability across various environments is important before recommending them to reach a high rate of genotype adoption. Multi-environment grain yield trials of 20 durum wheat genotypes were conducted at five locations of Iran (Gachsaran, Gonbad, Moghan, Ilam and Khorram abad) over four years (2009-2013). Combined ANOVA of yield data of the 20 environments revealed highly significant differences among genotypes and environments as well as significant GE interaction indicated differential performance of genotypes over test environments. Results of F Ratio indicated that only five interaction principal components (IPCs) were significant at the 0.01 probability level. Also, the GE interaction is comprised of 29.7% noise and 70.03% signal. According to these distinct numbers of significant axes, fourteen AMMI stability parameters were computed. Finally according to the most of type 1 of AMMI parameters (EV1, AMGE1, SIPC1 and D1), genotypes G8, G17 and G11; based on the type 2 of AMMI parameters and ASV, genotypes G4, G5, G10, G11 and G17; due to type 3 of AMMI parameters and MASV, genotypes G8, G10 and G12 were detected as the most stable genotypes. Considering all of the AMMI stability parameters, genotypes G8, G10, G11, G12 and G17 following to genotypes G7 and G9 were the most stable genotypes. The best recommended genotypes according to the present study are G10 with 3470 kg ha-1 grain yield for Gachsaran and Khorramabad, G12 with 3343 kg ha-1 grain yield for Ilam and G10 and G12 for Moghan and Gonbad regions wich had high mean yield and were most stable for related mega-environments.

No abstract

In the present study, the effects of ultrasound and plant growth regulators on in vitro callogenesis and secondary metabolites production in saffron calli were investigated. Accordingly, the saffron corms surface sterilized, sonicated and cultured on different concentrations of plant growth regulators (0.5, 1, 2 and 4 mg L-1 2,4-D or NAA in combination with 0.5 and 1 mg L-1 Kin or BAP). The percentage of callus induction, callus yield (fresh weight) and embryogenic callus formation were recorded and secondary metabolites of calli were measured by UV/VIS spectrophotometer three months after culture. The results indicated that sonication of the saffron corm explants significantly increased the in vitro callus induction and growth. So, the highest callus induction (100%) and yield (4.68 g) was achieved with sonicated explants cultured on MS medium supplemented with 2 mg L-1 1-naphthaleneacetic acid (NAA) and 0.5 mg L-1 kinetin (Kin). Somatic embryogenesis was significantly influenced by plant growth regulator regimes and the MS medium supplemented with 0.5 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) plus 0.5 mg L-1 6-benzylaminopurine (BAP) and 0.5 mg L-1 NAA plus 0.5 mg L-1 Kin exhibited the highest percentage (75 and 72, respectively) of somatic embryogenesis. Secondary metabolite content of the callus cells was significantly different among the plant growth regulator regimes and the highest production of picrocrocin and safranal were occurred on the medium containing 0.5 mg L-1 2,4-D plus 0.5 mg L-1 BAP and 1 mg L-1 NAA plus 1 mg L-1 BAP.

No abstract