I Effect Of Poly-(γ-Glutamic Acid) On Tobacco, Pakchoi And Lettuce' Seed Germination And Their Growth

Poly (γ-glutamic acid)(γ-PGA) is a water soluble polyamino acids which have excellent characters such as completely biodegradable, non-toxic to human and environment.γ-PGA and its derivates have potential applications in a broad range of industry and agriculture such as food, cosmetics, medicine and manure. Thus this natural and multifunctional biopolymer is worth researching and developing to a commercial material. In this paper, the effect ofγ-PGA upon the tobacco seeds germination was studied. And we also studied the ability ofγ-PGA that to retained nutrients and enhance plant productivity.The influence ofγ-PGA upon the tobaccos seeds germination was studied. The germination experiment showed that the tobacco seed germination ratio is higher by dipping seed inγ-PGA solution than in water. Different concentrations ofγ-PGA improve seed germination ratio differently while soaking time show little effect on seed germination ratio. Test results showed that dipping tobacco seeds in 0.20g/Lγ-PGA for one day yielded the highest germination ratio.γ-PGA also increased the vitality of tobacco seeds and shortened the time for seed germination. The root length, shoot length, germination factors and simplified dynamic index has been significantly improved compared with the control withoutγ-PGA dipping.And we also studied the ability ofγ-PGA that to retain nutrients and enhance plant productivity. Field trials show thatγ-PGA enhanced pakchoi productivity by more than 20%, especially in bad nutrient condition. Fertilizer dosage was decreased by 25% by addingγ-PGA to fertilizer. The most effective concentration ofγ-PGA was about 0.10—0.30g/L in the field experiment.γ-PGA enhanced lettuce productivity by above 15%, especially in bad nutrient condition. The tobacco seedling water culture and pot experiments showed that theγ-PGA could increase tobacco production, especially in bad nutrient condition. More than 15% increase was yielded by water culture while around 20% increase by pot experiment. The suitable concentration ofγ-PGA was about 0.10—0.30g/L at this experiment.