Study On Germination And Resistance In Biofuel Crops Switchgrass (Panicum Virgatum L.) And Big Bluestem (Androppgon Geradii Vitman)

With the growing problems of energy crisis and energy pollution, plant energy for itssafety, environmental protection, renewable and low-cost, will become the important part offuture energy. The effects of ultrasound treatment on seedling growth in switchgrass and thephysiological and biochemical responses of big bluestem to salt (NaCl) stress wereinvestigated to probe the effects of ultrasound treatment on seedling growth (indicated asplumular and radicular lengths) and the mechanism of plant vegetative growth affected by saltstress.L16(45) orthogonal matrix design was adopted to assign three factors(sonication time(factor A), sonication temperature (factor B) and ultrasound output power (factor C)) and onevacancy with ultrasound treatments in germination of switchgrass seeds. Each factor wasplaced into four levels. A single factor experiment was conducted to investigate thephysiological and biochemical responses of the leaves and roots in big bluestem toNaCl-salinity stress (0g/kg,3g/kg,6g/kg,9g/kg NaCl). The treatment time was30days.The results showed as follows:1) The plumular and radicular lengths of swithchgrass under ultrasound treatment weresignificantly higher than that of control. Different factors influencing the plumular andradicular lengths were orderly as ultrasound output power (factor C)> sonication temperature(factor B)> sonication time (factor A). Observing directly indicated that final optimalultrasonic treatment conditions were: A2B2C2(sonication time15min，sonication temperature35℃，ultrasound output power300W).2）Under NaCl-salinity stress, big bluestem through increase the activity of antioxidantenzymes and the contents of osmolytes to avoid the damage of salinity. The principalcomponents analysis showed that there are several parameters plays a key role in evaluate thebig bluestem`s salt tolerance, and the parameters can be summarized and grouped by the first4principal components. The correlation analysis showed the parameters were positively (78%)and significantly (73%) correlated, and they were all increased by salt stress, and collectivelyserved to protect the plant from salt stress. Additionally, The models we obtained can be usedaccurately to estimate the level of each physiological parameter in roots or leaves based on itscontent in leaves or roots, respectively, at a level of significance of P<0.01. Overall, ultrasound treatment improved seedling growth in switchgrass, and plumularand radicular lengths were significantly higher than that of control. The physiological andbiochemical responses of big bluestem to NaCl-salinity were different.