Application Of Mutagenesis In Vitro And Tissue Culture In Germplasm Innovation Of Jerusalem Artichoke

Regarding the trend of fossil energy exhaustion and the demand of improving environment, people start to develop and utilize energy plant to relieve the shortage of energy. Energy plants are plant species that can produce more organic components serving as substitute for ingredients made from petroleum. Jerusalem artichoke (Helianthus tuberosus L.) is a perennial herb plant belonging to the family of composite. It's tubers have high content of inulin that can be converted to fuel ethanol. Jerusalem artichoke can be planted in arid and semiarid area in most part of the world based on its extensive adaptability, including tolerance to salt drought, and cold temperature. Jerusalem artichoke is widely considered as one of energy plants with great potential.Based on the jerusalem artichoke germplasm resource collected by Shanghai Agrobiological Gene Center, the study explores application of mutagenesis in vitro and biotechnology in genetic improvement of jerusalem artichoke. That will provide evidence for further study and germplasm innovation. The main results were as follows:Total sugar contents in jerusalem artichoke tubers were determined by phenol-sulfuric acid method. Seven landraces of jerusalem artichoke were named Shjy-1, Shjy-2, Zjjy-1, Dljy-1, Dljy-2, Dljy-3 and Qhjy-1. Theirs total sugar contents were 13.9%,11.8%,13.1%,14.2%,17.1%,15.3% and 16.7% in proportion to fresh weight, respectively.Regeneration system based on tissue cultured in Vitro was established using nodes with lateral buds. Effective multiplication method was set up by adjusting the concentration of BA and NAA in MS medium, The results showed that MS medium with only BA is better than with BA and NAA. The best concentration of inducing larger quantity of buds was 2mg/L BA that induced the largest quantity of buds with an average number of 3.88 buds per node. Different concentration of IAA, NAA affected rootingwith0.5mg/L IAA giving the best growth of roots. In this case, each seedling had about 5.5 roots after seven days. After 30 days, the plantlets were transplanted to greenhouse.Induction of microtubers during tissue culture in vitro was researched. The inducing factors included the concentration of sucrose, 6-BA, NAA and temperature of the environment where the nodes with lateral buds were cultured at darkness. The results showed that sucrose may play an important role for the induction of microtubers while BA increases microtubers. The combination of 120g/L sucrose and 1mg/L BA was the best for inducing microtubers.Induction of mutations of jerusalem artichoke tubers by ⁶⁰Coγirradiation. Half lethal dose was about 20Gy for Jerusalem artichoke. Seven varieties were treated by 20Gy irradiation and planted in the field for observation the change in plants in M₀ generation. The results showed that there were many phenotypic changes, including shorter plant height, the nodulation of root, divided leaves and obleat stems. The tuber production was lower than that of control group.Detecting mutation by SRAP molecule marker .DNA samples were extracted and purified from Jerusalem artichoke leaves. Total 34 pairs of SRAP markers with clear production bands were used to detect the mutants after modification the SRAP amplification system from protocol of sugarcane.