أسباب تدني نتائج امتحان الكفاءة الجامعية : "دراسة حالة طلبة قسم المحاسبة جامعة العلوم التطبيقية الخاصة"

الملخص EN

This study was conducted to purify of Potato leaf roll virus (PLRV), study its serological properties, importance, and its movement within the plant.

It was found that the more suitable host for virus multiplication was potato plants.

An average of 5.76 mg of purified virus per 100 g of leaves and stems at purity of 1.46 was obtained.

The purified virus had preserved its infectivity and immunogenicity.

An antiserum against the virus was obtained after 4 injections of pure virus, each of 1 ml at 0.8 mg/ml.

The first 3 injections were intramascular with Incomplete Freund’s Adjuvant weekly.

The fourth booster one was in the external ear vein after 2 weeks.

The efficiency of the AS was tested by ELISA test with pure virus and extracts from virus infected plants.

It was found that the absorbance of ELISA reaction at 405 nm is 0.616 at 10-2 dilution for pure virus (at 0.8 mg/ml), and 0.396 for extract from virus infected plants at the same dilution as compared with 0.03 for extract from healthy plants, and 0.009 for extraction buffer.

Results showed that the percent of infected tuber from virus inoculated plants after 10 – 30 days of germination reached to 100% after 4 weeks of the last inoculation, 80% and 87.5% from virus inoculated plants after 40 days of germination collected after 2 and 4 weeks of the last inoculation respectively.

The percent of infected tubers was decreased to (55.55 and 65.0)% , (34.78 and 40.0)% from plants inoculated after 50 and 60 days of germination, collected after 2 and 4 weeks of the last inoculation.