Abstract:Chickpea is an important food legume crop of Turkey and is largely grown for human consumption on low moisture or salt-affected soils. The objective of the study was to find the effects of NaCl stress at electrical conductivities of 4.5, 8.6, 12.7 and 16.3 dS/m and seed sizes (7, 8 and 9 mm) on germination and early seedling growth of three popular chickpea cultivars (AKN-97, Gokce and Uzunlu-99). Mean frequency of germination, germination time, germination index, root length, shoot length and seedling fresh weight showed seed size-dependent responses of cultivars to salt stress. In general, small seeds germinated and grew more rapidly compared to medium and large seeds of the same cultivars against all levels of salt stress, with the best results in cultivar Uzunlu-99. No effect of NaCl treatments was observed on frequency of germination; however, a drastic decrease in early seedling growth was recorded at increased NaCl concentrations. Regression analysis results showed a significantly positive relationship (P<0.01) between seed size and mean germination time, whereas a significantly negative relationship was recorded between seed size and germination index, root length, shoot length. Moreover, linear regression values apparently confirmed that increased seed size in each cultivar affected decreased germination index, root and shoot lengths with enhanced mean germination time. Thus, it was concluded that the use of small seeds could considerably reduce the production costs of chickpea in salt-affected soils.

We present an in situ beam characterization technique to analyze femtosecond optical beams in a folded version of a 2f-2f setup. This technique makes use of a two-dimensional spatial light modulator (SLM) to holographically redirect radiation between different diffraction orders. This manipulation of light between diffraction orders is carried out locally within the beam. Because SLMs can withstand intensities of up to I ∼ 10(11) W/cm2, this makes them suitable for amplified femtosecond radiation. The flexibility of the SLM was demonstrated by producing a diverse assortment of "soft apertures" that are mechanically difficult or impossible to reproduce. We test our method by holographically knife-edging and tomographically reconstructing both continuous wave and broadband radiation in transverse optical modes.

Fresh seeds of lentil cultivars ‘Pul 11’, ‘Sultan 1’ and ‘Meyveci 2001’ were subjected to hydropriming with an objective to improve germination and seedling vigor under water stress induced by PEG-6000 at the water potentials of 0.0 (distilled water), -0.3 and-0.6 MPa. Results revealed that germination delayed in increasing water stress with variable germination among cultivars. Root, shoot length and germination were higher but mean germination time were lower in the primed seeds. Seeds were able to germinate at all concentrations of PEG but higher germination and improved seedling growth was observed in primed seeds. Cultivars showed variable response to water stress and cv. ‘Pul 11’ with the lightest seed weight gave better performance. Whereas, cv. ‘Sultan 1’ enhanced germination percentage with hydropriming under increased water stress. It was concluded that inhibition of germination due to water stress should be overcome by using primed lentil seeds.

We present intensity-resolved above threshold ionization (ATI) spectra of xenon using an intensity scanning and deconvolution technique. Experimental data were obtained with laser pulses of 58 fs and central wavelength of 800 nm from a chirped-pulse amplifier. Applying a deconvolution algorithm, we obtained spectra that have higher contrast and are in excellent agreement with characteristic 2 and 10 p U cutoff energies contrary to that found for raw data.The retrieved electron ionization probability is consistent with the presence of a second electron from double ionization. This recovered ionization probability is confirmed with a calculation based on the PPT tunneling ionization model [Perelomov, Popov, and Terent'ev, Sov. Phys.JETP 23, 924 (1966)]. Thus, the measurements of photoelectron yields and the proposed deconvolution technique allowed retrieval of more accurate spectroscopic information from the ATI spectra and ionization probability features that are usually concealed by volume averaging.

Safflower is an important oilseed crop and is largely grown for edible oil production in low moisture or saltaffected soils of Turkey. The objective of the study was to find out the quality of seeds with different sized seeds, and the effects of seed size (3, 4 and 5 mm) and NaCl stresses at electrical conductivities of 5, 10, 20 and 30 dS m-1 on the germination and early seedling growth of the safflower cultivar Dinзer. Our results show that heavier one-thousand-seed weight (70.5 g) and higher hull percentage (52.9 %) were obtained from large seeds while the oil content and water uptake of small seeds was higher than that of medium or large seeds. Germination percentage, germination time, root length, shoot length, and seedling fresh and dry weight showed size-dependent responses of the seeds to salt stress. In general, medium-sized (4 mm) seeds germinated more rapidly compared to small and large seeds against all levels of salt stress; however, the highest germination percentage and most vigorous seedling growth was recorded from large seeds after 10 days incubation. The inhibitory effect of NaCl levels was exhibited a drastic effect on seedling growth. Increased NaCl resulted in an increase in the Na+ and Cl- content of the seedlings produced by all seed sizes, while the K+ content was not changed. However, the seedlings from small seeds had the highest Na+ and Cl- content of all measured NaCl levels. It was concluded that large seeds produced vigorous seedling growth due to a lower ion accumulation under NaCl stress. Consequently, large seeds could be used for successful stand establishment in contrast to their slow germination performance if the cultivation of safflower on saline soils is required

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We studied white-light generation in water using spatially- structured beams of femtosecond radiation. By changing the transverse spatial phase of an initial Gaussian beam with a 1D spatial light modulator to that of an Hermite-Gaussian (HGn,m) mode, we were able to generate beams exhibiting phase discontinuities and steeper intensity gradients. When the spatial phase of an initial Gaussian beam (showing no significant white-light generation) was changed to that of a HG01, or HG11 mode, significant amounts of white-light were produced. Because self-focusing is known to play an important role in white-light generation, the self-focusing lengths of the resulting transverse intensity profiles were used to qualitatively explain this production. Distributions of the laser intensity for beams having step-wise spatial phase variations were modeled using the Fresnel-Kirchhoff integral in the Fresnel approximation and found to be in good agreement with experiment.

We investigated molecular alignment wakes of femtosecond laser pulses. Evolution of nonadiabatic molecular alignment in nitrogen gas has been measured via its nonlinear interaction effects with a variably delayed probe pulse. The induced rotational wave packet was mapped as a function of the angular difference between polarization directions of femtosecond pump and probe pulses as well as their relative delay and the plot of the variations of the rotational wave packet, i.e. "quantum carpet", was found to be in good agreement with the calculated angular and temporal dependencies of molecular alignment parameter.