Comparison Of Different Varieties Of Lotus Roots And Preliminary Study On Fertilizer Reduction

Lotus root is one kind of important aquatic vegetables cultivated in Jiaxing City,Zhejiang Province.However,the ageing of varieties lead to the decrease of yield and quality.Besides,excessive fertilizer is often applied to pursue high yield,and thus results in increased costs and environmental pollution.In the present study,we introduced 7 new cultivars of lotus root(‘New Elian No.5',‘Elian No.6',‘Huaqililan',‘Saizhenzhu',‘Baipaozi' and ‘Hongshanqiao')into Jiaxing City,and took ‘Elian No.5' as the control cultivar.Then we investigated the botanical characteristics,yield,and the root quality,and thus screened varieties suitable for Jiaxing area.Meanwhile,we also screened the optimal amount of fertilizer for ‘Xin Elian No.5' by application of different amounts of fertilizers into the fields.The results were as follows:(1)‘New Elian No.5' had the highest lotus root weight,partial lotus weight and commodity rate among the 7 cultivars.Meanwhile,the weight of main lotus root and thickness of internodes in ‘New Elian No.5' was just after ‘Elian No.6' and ‘Huaqilian',and the main lotus root length and internode length in ‘New Elian No.5' was only second to ‘Hongshanqiao'.Besides,the thickness of stem in ‘Elian No.5' was biggest among the 7 cultivars,suggesting it should be lodging resistant.In addition,the dry matter mass,contents of soluble protein,starch,amylose and amylopectin in ‘New Elian No.5' were the highest among the 7 cultivars.Moreover,the soluble sugar content of ‘New Elian No.5' was 6.81 mg/g,and was only second to ‘Huaqilian'.Thus,we conclude that ‘New Elian No.5' has high nutrient content among the 7 cultivars.(2)We constructed a fast and non-destructive method to measure the content of starch in lotus root by Near infrared spectroscopy with 168 samples.The spectral range is 10000 ? 4000 /cm,the resolution is 8.0 /cm andthe number of scans is 32.In our model,the correlation coefficient(Rc)and mean square errors in calibration set was 0.9513 and 0.487,individually,and the correlation coefficient(Rp)and root mean square error in the prediction set are 0.9469 and 0.395,respectively.So this model can be used for the measurement of starch content in lotus root.(3)The yield of ‘New Elian No.5' was not affected when the fertilization amount per mu was123.5 kg,compared with regular fertilization amount.However,the yield and commodity rate was decreased by 27.1% and 22.7% respectively,compared with regular fertilization amount,when the fertilization amount per mureduced to 110.5 kg.Thus the optimal fertilization amount for ‘New Elian No.5' was 123.5 kg/mu,which was 17.6% less than the conventional fertilization amount.