Efficient propagation of Eleocharis dulcis plantlets in temporary immersion bioreactors(TIBs)

ObjectiveRapid propagation of Eleocharis dulcis plantlets in temporary immersion bioreactors (TIBs) was explored to improve its propagation efficiency , and provide technical support for E. dulcis plantlets factory production.MethodE. dulcis variety Guiti 2 plantlets which obtained through primary inducement culture were taken as explants and propagated using TIBs. Influence of factors such as different subcultures, inoculation densities, different combinations of hormones and different immersion frequency on E. dulcis plantlets propagation were studied. ResultIn TIBs system, multiplication rates of the fourth, fifth and sixth subcultures were high. The sixth subculture had the highest multiplication rate, reaching 31.1 times. The multiplication rates declined after the seventh subculture. When inoculation density was more than 15 clusters per bottle, explant contamination rate reached 16.0%; whereas when the inoculation density was less than 10 clusters per bottle, contamination rate was 0%. When the intermittent immersion frequency was less than 10 min/6 h was beneficial for reducing contamination rate. Less than 15 min/6 h immersion time was beneficial for reducing vitrification seedling rate. With 6-BA 3.0 mg/L+NAA 0.01 mg/L combination of hormones , multiplication rate of the first plantlets was 38.5 times, and the plants were in normal growth. ConclusionIn TIBs system, the fifth subculture with MS+6-BA 3.0 mg/L+NAA 0.01 mg/L+sugar 30.0 g/L as medium, pH value being 6.0, inoculation destiny being ten clus-ter per bottle and immersion frequency being 10 min/6 h can achieve considerable cultivation effect.