الفهرس Only 14 pages are availabe for public view
 |  | from | 213 |  |  |
| | | from | 213 | | |
Abstract
Seven genotypes of canola (Brassica napus. L) were obtained from Agriculture Research Center (ARC),Giza and used in this investigation. The seven parents were crossed in all possible combinations without reciprocals, to obtain 21 F1’S (half diallel). All genotypes (Seven parents and 21 F1’S) were evaluated under field and greenhouse conditions to estimate genetic components, heritability (Hayman 1954 a& b), combining ability (Griffing 1956), heterosis under different sowing dates and different salinity levels. Data of survival ability, Phenology traits, plant height (cm), number of primary branches, number of pods/ plant , 1000-seed weight (g), Seed yield /plant (g), Seed yield / feddan (kg), seed oil content (%), erucic acid %- proline, relative water content, osmotic adjustment, shoot and root dry weight and shoot root ratio(%) were recorded under three sowing dates ( 20 September, 20 October and 20 November) and salinity levels (4000, 6000 ppm and control). The results indicated that seed yield/ plant was significantly higher in early sowing date (17.4 g) compared to mid (15.4 g) and late (6.2 g) sowing dates. The erucic acid (%) of all genotypes in the early sowing date was lower (0.23 mg/g) than the late sowing date (0.27 mg/g). Mean seed yield decreased significantly with increasing salinity levels. The crosses P1×P2 and P2×P7 gave the highest yield under 6000 ppm and may be considered as a promising genotypes for salinity tolerance. Heritability values (h2) in narrow sense were low to moderate for all studied traits. The best general combiners of parental lines for the most studied traits were P2 (Serw 4), P5 (Pactol) and P6 (Serw 46) under different sowing dates and different salinity levels. The results of the SDS-PAGE, the overall pattern of seed storage-proteins showed high degree of heterogeneity which was in agreement with genetic analysis and physiological characters for genotypes of canola planted under salinity stress.