Helaly M.N.,Mansoura University |
El-Hosieny H.,Horticulture Research Institute Agriculture |
Tobias N.,University of KwaZulu - Natal |
Alsudays I.,Qassim University |
And 2 more authors.
Australian Journal of Crop Science
The present study aimed to develop an in vitro regeneration of plantlets of four commercial pomegranate genotypes (Manfalouty, Tahrir, Badr and Araby) grown in Egypt. Shoot tips were selected and separated from 7-year-old mother plants as explants. The MS media supplemented with different dosage of growth substances were examined under controlled conditions. Gene transformation mediated by Agrobacterium tumefaciens was examined for only two genotypes (Manfalouty and Araby) which recorded highest and lowest regeneration capacity, respectively. The results showed that regeneration of pomegranate was mainly controlled by genotype, whereas the response of the explants was largely affected by the environmental factors. The data also show that the embryonic calli were formed within six weeks in the presence of MS media supplemented with 1 mg L-1 of 2,4-D. Shoots emerged successfully from the embryonic callus in the presence of 6 mg L-1 BA. Addition of 1 mg L-1 IBA to the MS basal medium increased the shoot forming, roots ratio (100%) and plantlet growth in all pomegranate genotypes. The highest recorded regeneration frequency was 79.75% in genotype Manfalouty followed by 70%, 63% and 55% in Tahrir, badr and Araby, respectively. The regenerated putative transgenic plantlet inoculated and co-cultivated with Agrobacterium tumefaciens were able to grow vigorously in the media containing 50 mg l-1 Kanamycin with high degree of gene stability. Fresh weight (FW) of the regenerated plantlets was increased, whereas the concentration of H2O2 was decreased due to the infection with A. tumefaciens in both genotypes. Similarly, the infected plants showed higher specific activities of CAT and SOD compared to control. The PCR analysis showed the integration of the transgene into the infected plant genome corresponding to the relevant sequence of both of the NPT-11 gene and the 35 S promoters. This protocol can be used to produce tolerant to stress pomegranate plantlets and needs further investigation. Source