Summary
Line × Tester experiment was carried out at the Experimental Farm of Rice Research and Training Center (RRTC), Sakha, Kafrelsheikh, Egypt during three growing seasons to evaluate the performance of 21 F1 hybrids along with their parents. Three cytoplasmic male sterile lines, two wild abortive (Wild Abortive); IR69625A, IR70368A and one (Kalinga) K17A as female were tested with seven cultivars/lines as testers. The analysis of variance detected that, highly significant variations among genotypes (parental lines with their crosses) for all traits in both seasons and in their combined analysis. Two hybrid combinations; IR69625A×Giza178 and IR69625A×Giza179 were recorded the best values for grain yield under both seasons and their combined. General combining ability (GCA) and specific combining ability (SCA) effects of genotypes for the studied traits were estimated. The results indicated that, K17A (female) and Giza 179 (male) were the best combiner for early heading date and could be useful to breed early maturing rice cultivars. The CMS line IR69625A and Giza178, Giza179 gave highly significant and positive GCA value and so appeared to be good parental lines combiner in hybrid combinations for high grain yield/plant. The positive values of GCA mean increased for grain yield/plant, which could be useful in breeding programs for high yield potential rice cultivars. The hybrid combination IR69625A×Giza179 showed highly significant and positive SCA estimates under both seasons and their combined. In conclusion, it is clear that this hybrid seemed promising hybrid for earliness and high grain yield under Egyptian conditions.
Abstract. This experiment was carried out at the Farm of Rice Research and Training Center, Sakha, Kafrelsheikh, Egypt during three rice grown seasons from 2014-2016. Three cytoplasmic male sterile lines, two wild abortive type (WA); IR69625A, IR70368A and one (K-type) K17A as females were tested with seven rice genotypes Giza 178, Giza 179, Giza 181,Giza 182, Sakha 105, GZ 6296-12-1-2-1-1 and HR195R as testers using line x tester model of hybridization. The parental lines and their resulting (21F 1 crosses) were evaluated in Randomized Complete Block Design (RCBD) experiment having three replications during 2015 and 2016 growing seasons and surrounded by susceptible rice varieties i.e. Giza 171, Giza 177 and Giza 159 as natural infection to brown spot (Helminthosporium oryzae). Three brown spot acceptability traits; disease severity (%), infected leaves (%) and infected grains/panicle (%) were observed during this investigation. The combined data was calculated over both seasons to test the interaction of the different genetic components. According to the results, the male parents Giza178, Giza179, HR195, Giza 181 and Giza 182 could be utilized either for producing new hybrid combinations or for developing new parental lines in brown spot resistance program. The female line K17A was found to have a good combiner to brown spot resistance. Evaluation of hybrids for heterosis breeding based on mean performance, better-parent (BP %) and mid-parent heterosis (MP %) indicated that, out of 21F 1 hybrid rice combinations, one hybrid K17A x Giza182 found significantly desirable values for most brown spot traits and can be utilized as commercial hybrids resistant to brown spot disease.
The drying characteristics of Thompson seedless grape (vitis vinifera L.) were investigated using laboratory scale infra-red dryer at four levels of intensity of infra-red radiation (0.861, 0.973, 1.039 and 1.161 kW/m 2 ). The drier was also equipped with three axial flow fans to supply air with at three different temperatures (40, 50 and 60 o C) and constant velocity of 2 m/s over the samples to carry the evaporated moisture. The results showed that the moisture content of dried grapes was decreased from (287.15 ±1, %d.b.) to (19.83 -12.37, % db). It has been found that, both air temperature and infra-red radiation intensity affects rate of drying. Two drying models: Lewis model and Henderson and Pabis's model were examined. The models were compared using the statistical coefficients such as (R), (SE), (χ 2 ), (MBE) and (RMSE). Lewis's model was the best model for describing the drying curves of Thompson seedless grapes. A diffusion model was used to describe the moisture transfer and the effective diffusivity at each drying temperature and radiation intensity. The effective diffusivity ranged from (2.2393x10 -9 ) to (2.3033x10 −10 m 2 /s) and was significantly affected by radiation intensity. The average value of activation energy was (3.2051 kW/kg). The seedless Thompson grape dried at radiation intensity of (0.973 kW/m 2 ) and air temperature of (60 °C) recorded the highest quality of the dried samples in terms of, total soluble solid, total sugar, reducing sugars and remained Residual sulphur (SO2).
The investigation was conducted at the experimental farm of the Rice Research and Training Centre, Kafr el Sheikh, Egypt, during the summer seasons from 2017 to 2019 using the experimental material consisting two populations with their two parents (P1, P2, F1 and F2) to study the variability in the F2 population of four crosses: IR 78,936-B-B-B-B (water deficit tolerant) x Giza 177 (water deficit sensitive), FL-496 (moderately water deficit tolerant) x Giza 177, IR 78,936-B-B-B-B (water deficit tolerant) x Giza 178 (moderately water deficit tolerant), FL-496 × Giza 178 under normal (NWS) and deficit water supply (DWS). The experiment was conducted in a randomized complete block design with three replications. The results indicated that the phenotypic values of the measured characters were significantly different between the two parents of all the studied crosses under the two water supply conditions. The means of all the studied characters under DWS were lower than the means under NWS, but the yields and the yield components under DWS varied greatly among the parents due to stress. The averages of the measured traits of the F1 plants and the F2 populations in all crosses were near the averages of those of the parents. The results showed no consistent reduction in heritability under DWS compared to NWS. High heritability in a broad sense coupled with high genetic advance (GA) was observed for grain yield in Cross 1 under the two studied conditions offering good scope for selection.
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