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- MakaleYalnız künye2010Responses of some wheat genotypes and their F2 progenies to salinity and heat stress
Yildirim, Mehmet; Bahar, Bilge
Both heat and salinity cause yield decrease in wheat. Grain yield in wheat has increased as a result of breeding efforts for different stress conditions. However, there are still substantial opportunities to improve grain yield by using conventional breeding under stress conditions, like heat and salt stress. The objective of this study was to investigate heat and salt effects on yield and some agronomic traits of four wheat genotypes and their six half F2 diallel cross progenies grown in pots. Significant differences were found among the genotypes for grain yield under both heat stress and non-stress condition. There was a mean reduction in yield of 12.6% due to salt stress. The reduction in biomass was higher than grain yield under salt stress while it was lower at heat stress. Grain yield was positively correlated with spike weight, harvest index, grain numbers per plant and biological yield under non stress (NS), heat stress (HS) and salt stress (SS) conditions. Cultivars Seri 82 and Chil's had high yield among parents under both NS and SS. Chil's and its hybrids showed low reduction in yield due to SS; thus, exhibiting salt tolerance. Also, Chil's was found to be good combiner with high General Combining Ability (GCA) effects for grain yield under SS conditions. 84 CZT04 was the most susceptible cultivar under SS. Significant GCA effects of Genç 99 and 84CZT04 provided positive contribution to grain yield under HS. It was impossible to select both heat and salt tolerant genotype with high yield capacity from the used genotypes. However, heat or salt tolerant genotypes can be improved by selection breeding due to genetic variation among genotypes.
- MakaleYalnız künye2010Optimum design of planar beams based on sensitivity analysis
Uysal, H.; Asci Demiröz, N.; Uzman, U.
In this study, the size optimization problem of a beam, in which the beam heights are determined along the beam axis, is considered as a shape optimization problem of a plate in plane elasticity. To achieve the shape optimization, different principles such as structural analysis, sensitivity analysis and mathematical programming are interrelated. The ANSYS that is a reliable finite element package programme is used only for the static analysis. The objective of this optimization problem is to minimize the volume of the beam under the constraints that the maximum value of the von Mises stress in each node do not exceed a predefined value and the beam axis is to remain straight. Design variables are the vertical coordinates of the corner nodal points of design elements. The design sensitivities are calculated through the finite, difference method and linear programming technique is used for obtaining the final shape of a beam. Several examples are solved under different loadings and boundary conditions. The obtained optimum beam volumes and the design variables are given in tables and the optimum beam shapes are plotted. One of the results given is compared with the literature.
- MakaleYalnız künye2010Heat and drought resistances criteria in spring bread wheat: Drought resistance parameters
Bahar, Bilge; Yildirim, Mehmet
Some spring bread wheat genotypes were evaluated for drought resistance using drought tolerance efficiency (DTE) and drought susceptibility index (DSI) under rainfed conditions in this study. Field trials were conducted in the Research Area of Field Crops Department, Agricultural Faculty, Cukurova University during 2002 - 2003 with high rainfall and 2003 - 2004 with low rainfall growth seasons. High variations were observed for drought resistance parameters both DTE and DSI in this study. While DTE values ranged from 65 - 98%, DSI values changed 0.077 - 1.761. The genotypes with high DTE and low DSI were evaluated as drought resistant; meanwhile, genotypes with low DTE and high DSI were considered as drought susceptible. Thus, genotypes Croc 1/Aegilops squarrosa, Genc 99, Weawer/WL 3926, Oasis/Kauz//*4 Bcn, and Punjab 96 with the lowest DSI and the highest DTE values were accepted drought resistant genotypes which may be used as the genetic sources for drought resistance.
- MakaleYalnız künye2010Wall traverse with GPSSIT and 3D positioning of urban details
Corumluoglu, Ozsen
In an urban environment, sometimes surveying becomes a very hard task, especially measuring some certain points or details on the ground that are surrounded by obstacles such as trees, fences or buildings. On the other hand, in such areas, survey points installed as references on the ground can easily be lost because of city activities. Wall traverse supported by GPSSIT (GPS Sanal Istasyon Teknigi - GPS Virtual Point Technique) and relying on freely chosen Sanal Istasyon Noktalari (SINs) or - virtual points (VIPs) without worrying about installing any control point on the ground provide a reliable resolution. In this study, establishment of wall traverse points by the support of GPSSIT and TS (GPSSIT and total station) and a detail measurement technique with 3D coordinates using these wall points were introduced and applied in a sample area. As a conclusion, standard deviations were found as mp = ± 4.53 cm and mH = ± 3.85 cm in position and height respectively for details.
- MakaleYalnız künye2009Yields and qualities of some red clover (Trifolium pratense L.) genotypes in crop improvement systems as livestock feed
Tavlas, Ayten; Yolcu, Halil; Tan, Mustafa
The objective of this study was to compare twenty-five genotypes of red clover (Trifolium pratense L.) in terms of yield (in 2000 - 2004) and quality performance (in 2000 - 2001) for animal feeding. The genotypes were evaluated for dry matter yield (DMY), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), digestible dry matter (DDM), dry matter intake (DMI), relative feed value (RFV), total digestible nutrients (TDN), net energy-lactation (NEl), net energy-maintenance (NEm) and net energy-gain (NEg) content. There were significant differences in DMY (P < 0.01), CP, ADF, NDF, DDM, DMI, RFV (P < 0.05), TDN, NEl, NEm and NEg (P < 0.01) amongst the genotypes. The Rajah cultivar had the highest DMY (13629 kg ha-1) amongst the genotypes according to five year results. While the highest CP (15.94%), NDF (50.59%), DDM (68.68%), TDN (66.50%), NEl (0.70 Mcal/1b), NEm (0.76 Mcal/1b) and NEg (0.44 Mcal/1b) were determined in the L-818 line, the lowest ADF (25.96%) was also found in the L-818 line. The highest DMI (3.16%) was observed in the Hamua cultivar. The highest RFV was determined in the Tohum Islah ecotype (156), the Hamua (155), the Orbit (154) cultivars and the L-812 (154) line. Our results showed that there were large variations in terms of yield and quality performances amongst the red clover genotypes for animal feeding. The Rajah, L-832 (selected from wild forms) and Pawera had the highest yields amongst the genotypes. The L-818, L-812 lines (selected from wild forms), Tohum Islah ecotype, Lucrun and Redwent cultivars were superior in terms of forage quality properties (low in ADF and NDF and high CP, DDM, DMI, RFV, TDN, NEl, NEm, NEg) than the other red clover genotypes.