DETECTION OF THE FUNGUS ASPERGILLUS AND ITS TOXINS ASSOCIATED WITH COTTON SEEDS AND CAKES AND EVALUATION OF THEIR EFFECTS ON SEED GERMINATION.

S. JUBER, KAMIL; A. AL-RUBAIEE, HAMEEDA

	DETECTION OF THE FUNGUS ASPERGILLUS AND ITS TOXINS ASSOCIATED WITH COTTON SEEDS AND CAKES AND EVALUATION OF THEIR EFFECTS ON SEED GERMINATION.
The Iraqi Journal of Agricultural Science
Article 1, Volume 39, Issue 4, 2008, Pages 1-14
Authors
KAMIL S. JUBER; HAMEEDA A. AL-RUBAIEE
Abstract
Results of isolation and identification for the associated Asprergillus species with the fibrous and unfiber cotton seeds collected from 25 locations at Baghdad, Ninewa, Wasit, Taameem and Salah Al-din governorates using Agar plate method revealed an association of three Aspergillus species, A. flavus ,A. niger and A. terrus with the fibrous cotton seeds with the high frequency of A. niger in the seed samples, the high percentage for it reached 85%, while the unfibrous cotton seeds contain also the same above three species with high frequency of A. niger, at rate 70%. Only A. flavus was isolated from cotton cakes at rate 1200 colony/g from squeezing cakes and 200 colony/g by the chemical extraction. The test of six isolates of A. flavus on the stored cotton seeds for 2, 4 and 6 months significantly caused negative effect reduced the percentage of seed germination, moisture content, germination vigority and number of abnormal seedlings. The percentage of seed germination in the treatments of the six isolates ranged 62.3-83.5, 58.0-83.0 and 54.8-75.8% after 2,4 and 6 months of inoculation respectively, while it was in the control treatment 89.0,88.0 and 86.0% respectively for the same above periods. The percentage of germination vigority ranged 19.0-24.0, 18.2-24.0 and 17.2-20.8 respectively for the same above period while it was in the control treatments 28.6, 26.3 and 25.0 respectively. The percentage of abnormal seedlings where 12.3-24.5, 14.0-28.0 and 18.4-30.8 while it was in the control treatments 10.8,11.3 and 13.3, and the moisture content for the seeds 7.9-9.7, 9.2-10.2 and 11.6-14.0 while it was in the control treatments 7.9, 9.7 and 10.1 for the three periods respectively. Besides the results showed the contamination of cotton seeds and cakes produced by squeezing or by chemical extraction by the aflatoxin B1, with the highest concentration of the toxin was found in contaminated cotton seed cakes produced by squeezing extraction which was 120ppb. The results showed that isolates of A. flavus associated with cotton seed samples were able to produce aflatoxin B1 when they were examined by TLC and photobrightness methods.

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