تحليل التغيرات الوراثية في الذرة الصفراء

Abstract EN

A line x tester cross comprising eleven inbred lines, DK, OH40, ZP-607, used as testers (female parents), ZM478, G105, ZM51, Pakistanian, ZM49R, Inbreed2, Inbreed12 and G54, used as lines (male parents), was studied for six traits (plant height, ear length, ear diameter, number of rows per ear, 300 grain weight and grain yield per plant), to determine the nature of gene action in parents and hybrid population and estimation of heterobeltiosis.

The results revealed that mean square for all genotypes and each of parents, hybrids and parents vs hybrids was highly significant for all traits except plant height in case of parents and number of ears per row in case of parents vs hybrids (significant at 5% level) and plant height in case of parents vs hybrids (not significant), that is an indication of the diversity between parents (lines and testers) which cause significant differences between single crosses among them.

Also it was shown that mean square due to each of lines and testers was highly significant for all traits indicated the presence of additive gene effects controlling these characters, and that due to the interaction of line x tester was significant at 5% level for ear diameter and at 1% for other traits meaning the presence of dominance dene effects controlling them.

The ratio of general combining ability components to the specific combining ability compo-nents was less than one for all traits indicated that dominance gene effects were more prominent for all studied traits.

The line DK and tester G54 were the best general combiner for larger number of traits including grain yield per plant, and the crosses (DK x INBRED12) , (ZP-607 x G54) and (ZP-607 x Inbreed12) showing significant specific combining ability effects for larger number of traits and could be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigor.

The range of narrow sense heritability was from 22.61% to 44.72%, respectively, 300 grain weight and number of rows per ear.

The highest values of additive and dominance variance for grain yield were (489.019 and 837.605) respectively while the highest degree of 300 gram seed weight was 2.239 such the highest expected genetic advanced genetic for grain yield was 11.689%.