This study was included to identify the fungal contamination associated
with callus tissue culture of date palm (Phoenix dactylifera L.) and the attempt
to find the fittest methods to decrease it. The isolation and identification results
of fungi explained the isolation of ten fungal genera. The fungus Asperillus niger
recorded the highest percentage of frequency which was 16.8%, followed by
Penicillium sp.1, while the frequency percentages 10,8,7 and 5% were recorded
in Alternaria alternata ; Epicoccum sp.; Trichoderma harzianum and Nigrospora
sp., respectively. The results proved the high antifungal activity of ethanolic
Henna (Lawsonia inermis) leaves extracts on the radial growth inhibitory
percentage which was 85.15%, with significant difference than Methanolic
extract (53.16%). The extract concentration 1% recorded the highest
percentage of inhibition (81.10%), also the results showed the failure grow of
Epicoccum sp. and Nigrospora sp. on the liquid media (PD Broth) which treated
with ethanolic extract concentrations 0.5 and 1%. The lowest inhibition
percentage (65.15%) of dry growth was recorded in T. harzianum at
concentration 0.5%. The results of fungicides (Benlate; Beltanol and Cryptanol)
survey elucidated the high inhibitory efficiency of Benlate (1gm/L), which led to
inhibite the growth of contaminated fungi on solid and liquid media completely.
The results revealed that the fungicides Benlate (1gm/L) had no effect on the
studied parameters of embryogenic callus of date palm (Berhi and Ashkar cv.).
The results of fresh, dry weight of embryogenic callus and the number of
somatic embryoes had no significant difference than control. Also the treatment
of Benlate led to decrease the percentage of fungal contamination which was
100% and reached 16.6% in Benlate, while the treatment of ethanolic Hennaleaves extract (0.5 and 1%) had a negative effect on the growth of callus (Berhi
and Ashkar cv.). The fresh and dry weight of embryiogenic callus reduced
significantly in the concentrations 0.5 and 1% in contrast with control
treatment results. The number of somatic embryoes was 4.16 in control,
reduced significantly and reached 0.66 embryoes in conc. 0.5 and 1% of
ethanolic extract.
Key words: Date Palm, Henna, tissue culture, Phoenix dactylifera , fungal contamination |