@article { author = {Atta-Alla, Hamdy and Zaghloul, Mostafa and Waly, Abd El Kawee and Fladung, Matthias and El-Sherif, Fadia}, title = {Activation tagging in aspen using a heat-shock inducible two component Ac/Ds-enhancer element system}, journal = {Catrina: The International Journal of Environmental Sciences}, volume = {4}, number = {3}, pages = {1-7}, year = {2009}, publisher = {Egyptian Society for Environmental Sciences}, issn = {1687-5052}, eissn = {2090-2786}, doi = {}, abstract = {From our earlier work on the genetic transfer of the maize transposable element Ac and its functional analysis in hybrid and pure aspen lines, it was shown that this element is active in transgenic aspen. However, a two element transposon tagging system where the Ds element and the transposase gene are put together in crosses is not feasible in trees due to the in part long vegetative phases. To overcome this barrier, an inducible two element HSP-transposase /ATDs element system is suggested to induce activation tagged variants following two independent transformation steps. The ATDs element is comprised by a 35S enhancer tetramer and outwards facing two CaMV 35S promoter located near both ends of the ATDs element. Following transposition of the ATDs element expression of genes can be elevated which are located adjacent to the new integration site of the element.}, keywords = {Activation tagging,rolC gene,HSP-transposase,ATDs element}, url = {https://cat.journals.ekb.eg/article_18505.html}, eprint = {https://cat.journals.ekb.eg/article_18505_c9e34d362bc9d186646a25690f9aa75b.pdf} } @article { author = {El-Refaey, R. and El-Seidy, E. and Hamada, A. and Arab, S.}, title = {Useful Heterosis Estimates under Different Nitrogen Fertilizer Levels in Half Diallel Crosses of Wheat}, journal = {Catrina: The International Journal of Environmental Sciences}, volume = {4}, number = {3}, pages = {9-21}, year = {2009}, publisher = {Egyptian Society for Environmental Sciences}, issn = {1687-5052}, eissn = {2090-2786}, doi = {}, abstract = {The breeding materials used herein included eight genotypes of wheat i.e., CHAM-6/MayoN's, LAKTA- 1, MELLAL-1, NABEK-4, Gemmeiza 7, Gemmeiza 9, Gemmeiza 10 and Sakha 94. These genotypes were crossed in half diallel mating system in 2003/04 season at the experimental farm of Gemmeiza Agriculture Research Station, Egypt. The parental genotypes and their crosses were evaluated in 2004/05 season under three nitrogen fertilizer levels i.e., 25, 50 and 75 kg N/fad. The reduction in yield and its components under the lowest N level relative to the highest one ranged from 16% to 25%, while the present materials were earlier under the lowest N level relative to the highest one by 13.75% and 4.73% for heading and maturity date, respectively. This would revealed the possibility to minimize the losses of yield and maximize the earliness of the present materials by suitable breeding program under the lowest N level which consider as one of the ways to safe the environment from the pollution. The significant mean squares of genotypes, parents and crosses, where its magnitudes were several times larger than their corresponding mean square of error, indicating the successful of the planned crosses due to the presence of sufficient variability. Parents vs crosses mean squares were found to be highly significant for all studied traits at all nitrogen fertilizer levels and their combined data. The interaction of parents vs crosses. N fertilizer levels was found to be significant for most traits, indicating that average heterosis overall crosses changed from environment to another. The range of mid-parental heterosis was -0.58% to -1.84% under 25 kg N/fad., -0.52% to -2.38% under 50 kg N/fad. and 0.00 to -1.15 under 75 kg N/fad. for earliness attributes. For yield, the range of mid- parental heterosis was 2.76% to 27.71% under 25 kg N/fad., 2.25 % to 23.34% under 50 kg N/fad. and 2.34 % to 32.60 % under 75 kg N/fad. However, in most cases the mid-parental heterosis were due to over-dominance as the potence ratios pointed out. On the other hand, the range of better parental heterosis (useful heterosis) was 2.31 to 26.75% under 25 kg N/fad., 2.72 to 22.86% under 50 kg N/fad. and 2.37 to 25.53 % under 75 kg N/fad. This would indicate that comparable useful heterosis was detected under the lowest level of N (25 kg) which considered as a favorable environment which had low level of pollution in comparison with the other N levels. However, it could be concluded also that the cross- combinations; LAKTA-1 x Sakha 94 and METLLAL-1 x Gemmeiza 10 could be used in breeding programs with low level of N fertilization according to their mean performance and the results of heterosis for most studied traits. The estimates of narrow–sense heritability confirmed the above results.}, keywords = {breeding,diallel mating system,fertilization,genotypes,heritability,Heterosis,nitrogen levels,Wheat}, url = {https://cat.journals.ekb.eg/article_18506.html}, eprint = {https://cat.journals.ekb.eg/article_18506_7b982b7690e417b602e0659ee86fdf6b.pdf} } @article { author = {El-Seidy, E. and El-Refaey, R. and Hamada, A. and Arab, S.}, title = {Estimates of Combining Ability for low Input in Some Wheat Crosses}, journal = {Catrina: The International Journal of Environmental Sciences}, volume = {4}, number = {3}, pages = {23-34}, year = {2009}, publisher = {Egyptian Society for Environmental Sciences}, issn = {1687-5052}, eissn = {2090-2786}, doi = {}, abstract = {The experiment was carried out at the experimental farm of Gemmeiza Agricultural Research Station, Egypt during the two successive seasons, 2003/2004 and 2004/2005. Diallel crosses among eight bread wheat genotypes were used to establish the experimental materials for this investigation. The aim of the present investigation was to determinate the magnitude of both general and specific combining ability and their interactions under three nitrogen fertilizer levels for heading date, plant height, spike length, number of spikes per plant, number of kernels per spike,1000-kernel weight and grain yield per plant. The mean squares associated with general and specific combining abilitiy were highly significant for all studied traits under the three different nitrogen fertilizer levels and their combined data. Results also showed high GCA/SCA variance ratios, which exceeded the unity, suggesting that selection based on phenotype could be effective to improve and develop wheat genotypes concerning these characters under these conditions, where the additive genes were dominant. The mean squares of interaction between nitrogen levels and both general and specific combining ability were significant for all studied traits, except for plant height for general combining ability. Generally, the obtained results showed that CHAM- 6 / Mayon”s”, Gimmeza 9 and Gimmeza 10 wheat genotypes proved to be good combiners for improving grain yield under three nitrogen levels and Gemmeiza 10 for spike length and Sakha 94 for grain yield under low nitrogen level. Some crosses had significant desirable SCA effects for yield, yield components and earliness, and most of these crosses might be of prime important in breeding program for traditional breeding procedures under low nitrogen level for decreasing nitric compound pollution.}, keywords = {diallel crosses,General combining ability,Specific combining ability,nitrogen level,genotypes}, url = {https://cat.journals.ekb.eg/article_18507.html}, eprint = {https://cat.journals.ekb.eg/article_18507_1df1a6ac54cf4ca1b736095bc7c27413.pdf} } @article { author = {El-Refaey, R. and El-Seidy, E. and El-Keredy, M. and Abdel-Hafez, A. and El-Gammaal, A.}, title = {Combining Ability Analysis for Yield and Some Physiological Traits Related to Drought Tolerance in Rice}, journal = {Catrina: The International Journal of Environmental Sciences}, volume = {4}, number = {3}, pages = {35-44}, year = {2009}, publisher = {Egyptian Society for Environmental Sciences}, issn = {1687-5052}, eissn = {2090-2786}, doi = {}, abstract = {The aim of this study was to investigate the differences in several adaptive mechanisms and estimating combining ability for drought tolerance in rice. For this objective, one-set of diallel mating design were made. The selected eight parents; (Sakha 104, Line 1368, Giza 178, Giza 177, IET1444, Sakha 101, Giza 159 and G 46B) and their twenty-eight F1 crosses were grown in a randomized complete blocks design with three replicates. Two adjacent experiments were conducted, the first one was non stress (irrigated every 6-days) and the second one was water stress (irrigated every 9-days). The drought measurements recorded at anthesis stage, in addition, yield and some of its components. Mean squares associated with general and specific combining ability were highly significant for all drought measurements, except total amino acids at normal condition in the combined analysis where the values did not reach the level of significant. High GCA/SCA ratio variance was greater than unity for phenols, total amino acids, total soluble sugars, 1000-kernel weight, no. of grains/panicle and grain yield under both environments as well as their combined analysis, suggesting the importance of additive and additive x additive gene action in the expression of these traits. The parental varieties; Sakha104, IET1444 and Giza159 seems to be good combiners for most drought measurements under both environments as well as their combined analysis. These varieties could be considered as excellent parents in breeding program aimed to release high drought tolerant varieties. The best crosses under both irrigation treatments and the combined analysis were; (Sakha104 x Sakha101), (Sakha104 x G46B), (Giza177 x Sakha101) and (Giza177 x Giza159), where these crosses had highly ^ (Sij) for most drought measurements.}, keywords = {Combining ability,drought,GCA,rice,SCA,Stress,tolerance,yield}, url = {https://cat.journals.ekb.eg/article_18508.html}, eprint = {https://cat.journals.ekb.eg/article_18508_32566a0d7d742a01ecbe513e0d6c2575.pdf} }