The Relationship Between Elements Migration And Rhizosphere Soil Properties With Blossom-end Rot Of Tomato In Coastal Saline-Alkali Land

Blossom-end rot(BRE)of tomato is one of the common physiological diseases in tomato production.BRE can lead to the decrease of crop yield and economic loss.BRE rot is generally considered to be calcium deficiency,however,the mechanism of calcium deficiency in plants is the most complex,and the main reason of this disease is not yet conclusive.The preliminary study on the relationship between the BRE of tomato and the elements of different organs in tomato varieties which were planted in saline soil was carried out in the research.And the relationships between the BRE of tomato and soil physical and chemical properties,enzyme activity and microorganism were also studied.The preliminary researches could provide the scientific basis and new ideas for the study of BRE.The contents of elements(K,Ca,Na,Mg,P and Zn)in different organs(root,stem,leaf and fruit)of five varieties of tomatos(Mengyu,Xiuyu,Moyu,Meiyu and Sufen 11)with blossom-end rot or not were studied in the present experiments.At the same time,those contents of elements in rhizosphere and non-rhizosphere soil were also be determined.The relationship between tomato BRE and the elements was determined.The rhizosphere and non-rhizosphere soil of five varieties of tomatos were selected as experimental materials.Three kinds of enzyme activities(catalase,invertase,phosphatase)and salinity,pH,in the soil were also determined to explore the relationship between soil physical and chemical properties,soil enzyme activities and the BRE of tomatos.The microbial diversity and richness of soil of the rhizosphere and non-rhizosphere soil of three tomato varieties(Mengyu,Xiuyu,Moyu)were measured,and then compared the differences of rhizosphere and nonrhizosphere soil of diseased and heathy tomatos.The results and contents are listed as follows:1.The results showed that there was no significant difference in the contents of the elements(K,Ca,Na,Mg,P and Zn)in the rhizosphere and non-rhizosphere soil of diseased tomato or healthy tomato,so that the effect of soil elements on the growth of tomato was ruled out.2.The distribution of calcium content(mg·g-1)in different organs of healthy tomato was leaf>root>stem.The interaction between Ca and K had no significant correlation with the occurrence of the BRE of tomato.The K/Ca ratio in this experiment did not reflect the significant relationship between the disease and the BRE.There was no significant difference in the contents of Ca in different organs of diseased tomato and healthy tomato,that is,the relationship between the content of Ca in diseased tomato and the occurrence of BRE had no significant.3.The transfer rate of calcium of one variety(Mengyu)which was not suffering from the disease of tomato blossom-end rot between fruit with stem and leaf was highest.It was concluded that the occurrence of blossom-end rot was related to the transfer rate between fruit with stem and leaf.4.In most of the tomato plants,the salt content of the rhizosphere soil was lower than that of the non rhizosphere soil.Pearson correlation coefficients showed that a significantly positive correlation between the salinity and BRE incidence rate.5.Salt had little effect on catalase and invertase activity,but had a significant positive correlation with phosphatase activity.The incidence of BRE was significantly positive correlated with the phosphatase activity.6.In the Soil samples of three kinds of tomato varieties(Meng Yu,Xiu Yu,Mo Yu),Proteobacteria,Acidobacteria,Bacteroidetes,and Chloroflexi were the four most dominant phyla,accounting for>80%of the reads.Proteobacteria of Meng Yu have the highest relative abundance among all of the soil samples.The rich of Proteobacteria maybe was more conducive to the uptake of nitrogen utilization in the plants,thus the tomato(Meng Yu)growth was more heathy.7.The incidence rate of tomato blossom-end rot had a significant negative correlation with the relative abundance of microganisms,and had a significant positive correlation with the Bacteroidetes which is dominant bacterium.Three dominant bacteria Proteobacteria,Acidobacteria,Bacteroidetes had a certain correlation with enzyme activities in the soil.The result suggested that the occurrence of tomato blossom-end rot was related to the transfer rate between fruit with stem and leaf,and the soil salt,phosphatase activity,some microorganism(Bacteroidetes)were also had a significant correlation with the occurrence of blossom-end rot.