三株促生菌及其混合微生物菌剂对莴笋生长和品质的影响

Effects of three growth promoting bacteria and their mixed microbial agents on growth and quality of lettuce

为验证从莴笋根际分离筛选出的菌株GNB6、MGBC3、MGBD1及其混合菌剂对莴笋生长与品质的影响,进而确定不同菌株及混合菌剂的最佳用量,为研制莴笋专用促生菌剂提供依据,文章采用盆栽法,设置不同用量固氮菌A(2、4、6 mL·株^(-1))、溶磷菌B(2、4、6 mL·株^(-1))、分泌IAA菌C(2、4、6 mL·株^(-1))、混合微生物菌剂D(2、4、6 mL·株^(-1)),及清水对照(CK)共计13个处理。结果表明:相同施肥条件下,添加适宜用量的单一和混合微生物菌剂能显著促进莴笋生长、提高莴笋的营养品质,并且可有效促进莴笋叶片花青素的积累,同时显著降低莴笋茎中亚硝酸盐的含量,其中,D3处理表现最好,较CK处理茎粗和单株鲜重分别增加24.71%和55.67%,茎和叶可溶性蛋白含量分别增加83.49%和139.46%,茎和叶可溶性糖含量增加51.28%和29.19%,茎和叶VC含量增加88.89%和13.57%,茎中亚硝酸盐含量降低了1.47%,叶片花青素含量提高53.63%。通过主成分分析可知,各处理组综合得分由高到低为:D3>B1>C2>B2>D2>A2>D1>C3>A1>A3>B3>C1>CK。综合分析发现,每种菌剂促生效果最适宜用量分别是A2(4 mL·株^(-1))、B1(2 mL·株^(-1))、C2(4 mL·株^(-1))、D3(6 mL·株^(-1)),其中混合微生物菌剂D3(6 mL·株^(-1))对促进莴笋生长和改善品质的效果最佳。

To verify the effects of strains GNB6,MGBC3,MGBD1 and their mixture on the growth and quality of lettuce,and to determine the optimal dosage of different strains and their mixture,so as to provide basis for the development of special growth promoting bacteria for lettuce,a total of 13 treatments were set up in this study,including nitrogen fixing bacteria A(2 mL per plant,4 mL per plant,6 mL per plant),phosphate solubilizing bacteria B(2 mL per plant,4mL per plant,6 mL per plant),IAA secreting bacteria C(2 mL per plant,4 mL per plant,6 mL per plant),mixed microbial agent D(2 mL per plant,4 mL per plant,6 mL per plant),and water control(CK).The results showed that:under the same fertilization conditions,adding the appropriate amount of single and mixed microbial agents could significantly promote the growth of lettuce,improve the nutritional quality of lettuce,effectively promote the accumulation of anthocyanins in lettuce leaves,and significantly reduce the content of nitrite in lettuce stems.Among them,D3 treatment was the best,with the stem diameter and single plant weight increased by 24.71%and 55.67%respectively compared with CK.The soluble protein of stem and leaf increased by 83.49%and 139.46%,soluble sugar of stem and leaf increased by 51.28%and 29.19%,VC content of stem and leaf increased by 88.89%and 13.57%,nitrate content of stem decreased by 1.47%,anthocyanin content of leaf increased by 53.63%.According to the principal component analysis,the comprehensive scores of each treatment group from high to low were:D3>B1>C2>B2>D2>A2>D1>C3>A1>A3>B3>C1>CK.Comprehensive analysis showed that the most suitable dosage of each microbial agent was A2(4 mL per plant),B1(2 mL per plant),C2(4 mL per plant),D3(6 mL per plant),and the mixed microbial agent D3(6 mL per plant)had the best effect on promoting the growth and improving the quality of lettuce.