Isolation and Identification of Fungi Caused Data Palms Inflorescence Rot Disease in Some Area of Diyala- Iraq and Control of Disease by Sodium Chloride Salt

This work was carried out in Diyala Province, North of Baghdad, Iraq during 2016-2017 to isolation and identification the fungi caused Inflorescence rot on data palm and try to combat the disease by using sodium chloride salt. 32 infected samples were collected from 8 varieties of data palm which has been isolated 60 isolates of fungi belong to 6 genus and species of fungi which were Mauginiella scattae, Fusarum proliferum, Penicillum chrysogenum, Rhizopus spp., Mucor spp. and Aspergillus niger, the number of isolates for each one were (20,12,10,6,6,6) respectively. M. scattae showed highest percentage of frequency and occurrence that (33.33, 65.63) %, while F. proliferum recorded the lowest percentage of frequency and occurrence which were (6.66 , 18.75)%. Treatment with the sodium chloride salt gave significant reduction in Inflorescence rot on all data palm varieties. Disease incidence and percentage of Infection, which were 0% in all data palm varieties excepting khistawi variety which recorded (22.22, 33.33)% respectively for while control treatment recorded (100, 100)% respectively for Disease incidence and percentage of Infection. This confirms the possibility of using sodium chloride salt as a substitute for chemical fungicides.


INTRODUCTION
In Iraq the main problems of data palm (Phoenix dactylifera L.) are exposed to many diseases and pests that effect on fruit production but nature and severity The problems vary by cultivar, location, weather, and cultural practices, These diseases caused by different type of pathogens like fungi , insect , nematode. (Zaid et al. 2002;Al-Jboory 2007).
Inflorescence rot is one of these disease which transmission during the infection season occurs through the contamination of male inflorescences during the pollination period and the first symptoms occur at the external surface of unopened spathes especially if emerges early in the spring season with typical brownish or rusty color lesion, Infected inflorescences remaining on palms from the previous season or infected leaf bases may serve to spread the disease (Abdullah et al. 2005).
The first recorded of it in Iraq in 1949 by Hanford this disease caused by Mauginiella scattae fungus (Al- Ani et al. 1971). Some studies recorded another fungi along with Mauginiella scattae such as Thielaviopsis paradoxa and Fusarium moniliforme (Dherbi 1983) , in some area of Thi-Qar in Iraq The main reason of this disease was Mauginiella scattae and another fungi which were Fusarium spp., Aspergillus spp., Penicillium spp., Acremonium spp., and Mucor spp. (Al Ghilan 2012), In Hameed (2012) study found that the causal organism of data palm inflorescence rot disease in southern part of Iraq is Fusarium proliferatum .
For development of novel, more effective, safe and environmental friendly antifungal agents as an alternative to the chemical fungicides used for combating a variety of crop diseases is currently an environmental challenge. In Diyala -Iraq there were few and old studies That looked at this disease and its pathogenical causes there for the current study aimed to isolation and identification of fungi which caused inflorescence rot disease on data palms Phoenix dactylifera L. and using Sodium Chloride salt to fight disease on the trees.

Sample collections
Several visits to some palm date orchards in Al-Migdadiyah in Diyala, Iraq In the flowering season of the data palm in 2016-17, were carried out to collect samples. A total of 32 samples were collected from 8 varieties of data palm that infected with inflorescence rot disease, each sample was placed in plastic bags and data were recorded in terms of the variety and number of infected palm, then the samples were stored in a laboratory refrigerator at 5-7°C until the isolation.

Isolation of the pathogen
Small pieces from each infected inflorescence (2 cm long) were surface-sterilized with 10% sodium hypochloride for 5 min, then wash with sterilized distilled water and dried on filter paper than3 pieces were placed onto plates containing potato dextrose agar (PDA) Added to it chloramphenicol 200mg/L and each sample with 3 replicates. All plates were incubated at 25 ± 1°C until the fungus started growth. A hyphal tip for each isolate was excised on to a PDA plate to establish its colony. Single spore technique was used to ensure the purity of cultures. Isolated fungi were identified based on the morphological characters in culture. The identification was based on (Ellis 1971;Alexoplulos et al. 1996; Barnett and Hunter 1998). Percentage of appearance for each isolated fungi are calculated according to the following formula (Krebs 1978): The Percentage of occurrence (%) = N. of sample which has the same genera or species /N. of total samples of genera or species. Percentage of frequency calculated according to formula (Krebs 1978) The Percentage of frequency (%) = No. of isolate for fungus / No. of total isolates for all fungi Treatment with Sodium Chloride salt The infected data palm trees were treated with Sodium Chloride ascoarse salt at 1 Kg / tree, the salt was sprayed on the sites of infection in the trees and the control treatment was left without salt spray. The spraying was carried out in two stages the first of January2016 and the second in March 2017. After the completion of the exit and cracking all the spathes on all the palm the Disease incidence and Infection percent was scored according to the formulas: Disease incidence = (No. of infected date palms / No. of total date palms) x 100 % Infection= (No. of Infected spathes / No. of total spathes ) x 100

Statistical Analysis
For statistical analysis SPSS version 17.0 was used, The comparison between the averages using Less Significant Difference test (LSD) Least Significant Deference at the level of probability of 0.05.
The results of isolating the fungi showed a difference in the causes of inflorescence rot disease this agree with Al-Ghilan (2012) study which showed more than one cause of inflorescence rot and which were Mauginiella scattae, Fusarium spp., Aspergillus spp., Penicillium spp. Acremonium spp. and Mucor spp. some studies showed that only Mauginiella scattae fungi caused this disease (Hameed 2005 The results in (Table 2) Showed the possibility of using salt effectively to reduce inflorescence rot disease on all data palm The exact mechanisms of how NaCl amendments suppress disease are still unclear, but two areas where it could affect disease are those that have direct effects against the pathogen and those that have effects on the resistance of the plant (Fixen 1993). Sodium chloride may have caused a fungistatic effect in these soils and prevented the onset of pathogenesis. They suggested NaCl could reduce competitive saprophytic ability of the pathogen while increasing antagonistic microbes (Amir et al. 1996).