الفهرس 
ContentsOnly 14 pages are availabe for public view
 |  | from | 63 |  |  |
| | | from | 63 | | |
Abstract
This study was carried out at the Experimental field of the Medicinal and Aromatic Plants, Fac. Agric., Mansoura Univ. during the two successive winter seasons of 2016/2017 and 2017/2018. This work aimed to investigate the variability in the marigold plant and to start a breeding program to improve this plant. At the same time, an attempt will be made to develop new inbred lines that have a staple and homogenous flower. The obtained results could be summarized as follows : I- Vegetative traits : The study showed that the percentage of heritability for vegetative traits of Calendula plant. Where, plant height has a moderate heritability (50.41%), also number of branches per plant (33.33%). The genetic advance percent of mean for vegetative traits of Calendula plant. Where, plant height has a moderate value (12.44%), and number of branches per plant (15.69%). The highest genotypic coefficient of variation recorded in number of branches/plant (13.15 %), but plant height has (8.51 %). High phenotypic coefficient of variation recorded in number of branches/plant (22.77 %), plant height has (11.98 %). II- Flowering traits : The present study showed that the percentage of heritability for flowering traits of Calendula plant. Where, number of inflorescences per plant has a moderate heritability (54.31%) and other flowering traits has the lowest percentage of heritability, inflorescence diameter (5.80%), disc florets diameter (4.76%), number of petal row (8.11%) and petal length (4.11 %). The genetic advance percent of mean for flowering traits of Calendula plant. Where, number of inflorescences per plant has a highest value (28.08%) and other flowering traits has the lowest value, inflorescence diameter (1.53%), disc florets diameter (1.34%), number of petal row (3.95%) and petal length (83 %). The highest genotypic coefficient of variation recorded in number of inflorescences/plant (18.50 %), while that other flowering trait has the lowest level in this parameter, Inflorescence diameter (3.06 %), disc florets diameter (3.68 %), number of petal row (6.85 %) and Petal length (2.28 %). On the other hand, the highest phenotypic coefficient of variation was recorded in number of inflorescences/plant (25.11 %), Inflorescence diameter (12.72 %), disc florets diameter (16.85 %), number of petal row (24.04 %) and Petal length (11.26 %). III- Chemical constituents : In this investigation, the estimates of heritability for chemical traits represented in Chlorophyll A, Chlorophyll B and Carotenoids. The highest heritability represented in Chlorophyll A, Chlorophyll B (97.06%) and Carotenoids (96%). The highest value of genetic advance percent of mean represented in Chlorophyll A, Chlorophyll B (56.06%) and Carotenoids (162.30%). High genotypic and phenotypic coefficient of variation recorded equally between Chlorophyll A and Chlorophyll B (27.52 %), (27.9 %) but the highest genotypic and phenotypic coefficient of variation recorded in Carotenoids (80.31 %), (81.97 %). CONCLUSION : The estimates of phenotypic coefficient of variance (PCV) was higher as compared to genotypic coefficient variance (GCV), indicating the role of environmental factors for the expression of these characters. However, apart from Chlorophyll A, Chlorophyll B and Carotenoids the difference among genotypic coefficient variance and phenotypic coefficient variance was very less for rest of the characters, indicating the fact that these characters are not much influenced by environmental factors. This also suggests the presence of sufficient genetic variability, which can be exploited by practicing pure line selection. Although the research is not yet complete for any of genotypes discussed. The knowledge obtained thus far is practical significant for plant breeder. For example, it is known that sufficient variation exists in the composition and chemical compounds to allow the development of plants with an enhanced content of a given components, this in turn can lead to improvements in the efficiency of field production.