Journal of Ecosystem & Ecography
Open Access

Abstract

Sweet potato feathery mottle virus (SPFMV) isolated from sweet potato plants was purified using two methods different in the procedure of extraction and precipitation. Phosphate buffer and polyethylene glycol (PEG) in the first and borate buffer and differential centrifugation in the second were used as extraction buffers and precipitation means, in the order given. The first method yielded about 2.84 mg virus/100 g fresh weight of sweet potato leaves while the second procedure gave a corresponding value of 1.63 mg virus/100 g fresh weight. The Ultraviolet absorption spectra of the purified virus preparations were typical for nucleoproteins. A polyclonal antiserum against the virus was produced by two different protocols of injection (four weekly intramuscular injections versus one intravenous followed by three intramuscular injections) and antisera titre was determined by indirect ELISA. The titre with the first protocol reached up to 1:64000 while with the second one, it was only 1:8000. The antisera raised could detect SPFMV in some naturally infected sweet potato plants using indirect ELISA with high efficiency. Adding cellulase or macerozyme to the extraction buffer enhanced the sensitivity of the test. The highest absorbance values were obtained when SPFMV infected samples were extracted in carbonate buffer and treated with macerozyme followed by cellulase.

Biography

Sweet potato feathery mottle virus (SPFMV) isolated from sweet potato plants was purified using two methods different in the procedure of extraction and precipitation. Phosphate buffer and polyethylene glycol (PEG) in the first and borate buffer and differential centrifugation in the second were used as extraction buffers and precipitation means, in the order given. The first method yielded about 2.84 mg virus/100 g fresh weight of sweet potato leaves while the second procedure gave a corresponding value of 1.63 mg virus/100 g fresh weight. The Ultraviolet absorption spectra of the purified virus preparations were typical for nucleoproteins. A polyclonal antiserum against the virus was produced by two different protocols of injection (four weekly intramuscular injections versus one intravenous followed by three intramuscular injections) and antisera titre was determined by indirect ELISA. The titre with the first protocol reached up to 1:64000 while with the second one, it was only 1:8000. The antisera raised could detect SPFMV in some naturally infected sweet potato plants using indirect ELISA with high efficiency. Adding cellulase or macerozyme to the extraction buffer enhanced the sensitivity of the test. The highest absorbance values were obtained when SPFMV infected samples were extracted in carbonate buffer and treated with macerozyme followed by cellulase.