Analysis On Purple Sweet Potato Virus-free Technology And Its Physiological And Biochemical Indexes

In this research, apical buds are as plant materials, virus-free plants were acquired by meansof alternating temperature treatment combined with shoot tip culture technique, based onplantlets propagation system. A high-quality Purple Sweet Potato propagation system wasestablished via investigations on disinfection method, plant hormones dosage, heat treatmentconditions. Physiological and biochemical indexes were analyzed to explore the effect ofalternating temperature treatment combined with shoot tip culture on purple sweet potato yield.Results are as followed:1. After screening tests on disinfection, plant hormone6-BA, sucrose concentration andcuttings conditions, MS+6-BA（1.5mg/L）+IAA（0.2mg/L）+Sucrose（30g/L） chosen asthe optimism purple sweet potato propagation medium, an efficient purple sweet potatopropagation system was established.2. MS+6-BA（2.0mg/L）+NAA（0.2mg/L）+Sucrose（30g/L） as inductive shoot tipdifferentiation medium, dark time gradient were0,8,16,24h respectively everyday(40±1)℃,the rest time were recovery cultures under condition of2600lx,(25±1)℃. Result showed thatwith increasing time of dark treatment at (40±1)℃, survival rate was gradually reduced, viruselimination rate was rising. virus elimination rate was the highest when shoot tips were treated24h at (40±1)℃isothermal heat in dark. But survival rate was only46.3%, less virus-free plantswere acquired. Therefore,(40±1)℃,16h/d dark and2600lx,8h/d is the optimism alternatingtemperature treatment condition.3.36shoot-tip regenerated seedlings without SPFMV, SPLV simultaneously were detectedthrough ELISA detection.4. Cultivation experiment were carried out taken ordinary purple sweet potato seedlings forthe control (CK) to detect physiological and biochemical indexes virus-free potted seedlings.Results showed that virus-free treatment has a great influence on the indexes. In the comparisonsof morphological indicators, photosynthesis, sugar content, amylase activity and anthocyanincontents, values of virus-free seedlings were significant higher than CK, which were necessarilylinked. Virus-free treatment impacted differently on several antioxidant enzymes activities.Activities of SOD and POD were significantly greater than CK, whereas CAT activity wassignificantly lower than CK. MDA activity, also lower than CK, was not significantly. Overall,virus-free purple sweet potatoes showed recovery characteristics, strong growth, no virus diseasein growing season and an increasing yielding comparing to CK.