Mahmoud AbdAlbaky Askan
General Commission for Scientific Agricultural Research-
Faculty of Agriculture, Damascus University,
The results of treating the seeds of two barley cultivars (Furat1 and Arabi Aswad) with three various doses of gamma rays (5, 10 and 15Kilo Rad) were studied.
The treated seeds were grown during the two seasons (2007/2008, 2008/09) in Abo Jarash farm of Faculty of Agriculture, University of Damascus. The experiment was designed using randomized complete block design (RCBD).
Quantitative and qualitative traits were evaluated and studied in both F1, and F2 generations.
The aim of this study is to evaluate and characterize quantitative and qualitative traits of barley affected by various doses of gamma rays in F2, to determine and calculate the proportion of total and relative changes of barley in F2, to determine the best doses of gamma rays, and to study the relationship among the quantitative traits under study.
The results of the quantitative traits in F1 showed that the average number of total tillers on Arabi Aswad was 9.82, while it was 7.47 on Furat1. The average number of fertile tillers of Arabi Aswad was 6.57 while it was 4.57 on Furat1. The highest average number of fertile tillers under high and medium doses for Arabi Aswad was 7.13, and 6.87 respectively. The least average number under low and high doses for Furat1 was 4.6. Various treatments outperformed the check
but without significant differences. The highest plant height under high and medium doses was 66.8 and 66.4 respectively while under the two doses it was 62.33. The check was significantly superior over various treatments. The highest average main spike length under the treatment (15Kr) and the lowest under (10Kr) for Arabi Aswad was 6.8 and 5.87cm respectively.
The highest average main spike length under (5Kr) for Arabi Aswad was 6.47cm and the plant height under high and medium doses were 73.18 and 72.69 cm respectively, while the average plant height under low dose was 68.60 cm without significant differences between high and medium doses. The check (86.60 cm) significantly outperformed the various doses in terms of plant height.
Average grain number and weight per plant for Furat1 were higher than those of Arabi Aswad. Average grain number per plant for Furat1 was (149.1) significant different from that of Arabi Aswad (77.9).
The highest average grain number per plant under (5Kr) was 121.25 without significant differences when compared to the lowest value under (10 and 15 Kr) (103.5, 109.75 respectively).
The low dose apparently outperformed the check in terms of average grain number per plant (121.25 and 119.5 respectively). While under high and medium doses this was not observed.
Average grain number per plant under (5Kr) was (5.44g) significantly different from that of the dose (15Kr) (4.14g). The dose (5Kr) outperformed the check significantly in terms of grain weight per plant in Furat1, while the doses (10 and 15 Kr) were not significantly different from the check. As for Arabi Aswad, there were no significant differences among the check and the various treatments. Average thousand-kernel weight under (5Kr) was (45.23g), while under (15Kr), it was (40.83g). Where there were no significant differences among various treatments. However, the three treatments outperformed the check significantly in terms of thousand-kernel weight.
The average total changes in Furat1 were higher than those of Furat1 (12.67 and 9.35% respectively).
Qualitative traits observed in F2 plants were evaluated and studied. Number of qualitative changes in Furat1 (9) was higher than that of Arabi Aswad (7). The partial sterility occurred in Furat1 under (15Kr), while in Arabi Aswad under various doses. Complete sterility occurred in both cultivars under various treatments except for Furat1 under (5Kr). The (inclined straw was observed in Furat1 under (10Kr), while in Arabi Aswad under various treatments. Plants of early heading were found in both cultivars studied under all treatments. Plants of late heading were also found in all cases but of Arabi Aswad under (5Kr). Colour mutations were observed in Furat1 under various treatments, while they were not observed in Arabi Aswad. Averaged -height plants were found in Furat1 under (10 and 15Kr), while they were not found in Arabi Aswad. Six-rowed spikes of Furat1 were converted to two-rowed under (5Kr), and also there were spikes of Arabi Aswad. That shifted from two-rowed to six-rowed under (15Kr).
Quantitative traits in F2 were studied. The results showed that the total average tiller number and average fertile tillers for Arabi Aswad were higher than those of Furat1 (9.98, 7.41 for Arabi Aswad and 7.84, 55.11 for Furat1). The highest plant height under (5Kr) was (74.22). While the lowest under (10 and 15Kr) were (69.75 and 69.52 respectively) The check (77.82cm) outperformed the mid and high doses significantly, while there was no significant difference between the check and the lowest treatment. The highest main spike length under (5Kr) in Arabi Aswad was (7.61cm). Average spike length under (5 and 10Kr) was (6.89 and 6.4cm) respectively with significant difference. The low dose outperformed the check significantly, while for mid- and high doses no superiority over the check was observed. The check outperformed various treatments in terms of plant height.
Grain weight and number per plant in Furat1 was higher than that of Arabi Aswad. The highest grain number per plant under (15Kr) was (157.6) while the lowest under (10 and 15Kr) was (138.4, 143,05 respectively) without significant differences. The highest dose insignificantly outperformed the check, while there was no superiority under (5 and 10Kr). The highest average grain weight per plant under (5Kr) was (5.64g) and the lowest under (10 and 15Kr) was (5.05 and 5.59 respectively) without significant differences.
Low and high doses were insignificantly superior to the check, while the medium dose was not. Thousand-kernel weight under (5 and 10Kr) was (39.89 and 37.26 respectively) while under (15Kr) it was (35.33). The lowest dose (5Kr) outperformed the check significantly, while the treatment (10Kr) was not significantly superior.
The results of correlation coefficient among studied traits for Furat1 in F1 And F2 revealed significant correlation between stem length and plant height (0.98 and 0.99 respectively), spike length and grain number (0.63 and 0.73 respectively), number and weight of grain per plant (0.88 and 0.89 respectively).
There was a negative insignificant correlation between thousand-kernel weight and total tiller per plant (- 0.04 and -0.42 respectively), stem length (-0.56 and -0.15 respectively) and plant height (-0.57 and -0.15 respectively).
The results of correlation coefficient among studied traits in Arabi Aswad in F1 and F2 revealed the existence of a strong significant correlation between number of total tiller and fertile tiller (0.79 and 0.95 respectively), length of stem and main spike (0.75 and 0.83 respectively), stem length and plant height (0.99), grain number and weight (0.88 and 0.79 respectively). There was a negative insignificant correlation between grain number per plant and thousand-kernel weight (-0.32 and -0.08 respectively).