Temporal And Spatial Distribution Characteristics Of Mung Bean In Response To Uniconazole And Its Relationship With Aboveground Growth And Yield

This test was conducted in 2016 at National Cereal Engineering Research Center.The drought-resistant mung bean variety Jilv 7 and the non-drought-resistant variety Gonglv 2 were used as test materials with different devices.Uniconazole(30 mg· L-1)was sprayed on the leaves at V3 growth stage,and the samples were collected at V6,R2,R4,R5,and R6 to analyze the effect of uniconazole on photosynthesis,aboveground morphological indicators,and temporal distribution(V6,R2,R4,R5 and R6 phases)and spatial distribution of mung beans roots system(0 ~ 5,5 ~ 10,10 ~ 15,15 ~ 20 and 20 ~ 25 cm soil layers in the horizontal direction;0 ~ 20,20 ~ 40,40 ~ 60,60 ~ 80,80 ~ 100,100 ~ 120,and 120 ~ 140 cm soil layers in the vertical direction),yield and yield factors.The results are as follows:1.From V6 to R6,total root length,total root surface area and total root volume of mung beans showed a unimodal curve distribution,and the maximum value was appeared at R4 or R5.The mung bean root morphology factors reached the peak value earlier than that of horizontal device in the vertical device.In the horizontal direction,the mung bean roots grew to 20 ~ 25 cm soil layer at V6;in the vertical direction,the mung bean roots reached 60 ~ 80 cm soil layer at V6,80 ~ 100 cm soil layer at R2,100 ~ 120 cm soil layer at R4,and 120 ~ 140 cm soil layer at R5.2.Uniconazole increased the net photosynthetic rate in mung bean leaves at V6,R2,R5,and R6,decreased the intercellular carbon dioxide concentration at V6,increased the stomatal conductance at V6 and R5,and increased transpiration rate at R5 and R6 and SPAD value at V6.3.Uniconazole inhibited plant height of mung beans at R2 and R4,increased stem thickness at V6,R2,and R4,and increased dry matter weight of leaves at the R4 stage.4.Uniconazole can reduce the grain number of single pod,increase the weight of 100 seeds,and increase the yield of per plant.5.The dry weight density of mung bean roots in the horizontal 10 ~ 15 cm and vertical 20~ 40 cm soil layers at R5 had a significant positive correlation with the yield of per plant.At the same time,uniconazole can effectively improve the root dry weight density in the horizontal 10~ 15 cm and vertical 20 ~ 40 cm soil layers of mung bean at R5.6.Stem thickness and leaf dry weight of mung bean were both positively correlated with yield;leaf SPAD value in R4 was significantly positively correlated with yield;total root length,total root volume,average root diameter and total root dry weight of mung bean were all positively correlated with stem thickness in R6;total root length,average root diameter and total root dry weight of mung bean were positively correlated with SPAD value in R4.In summary,application of uniconazole can optimize the aboveground morphology of mung bean plants,enhance leaf photosynthesis,adjust the spatial distribution characteristics of plant roots,optimize yield components and increase yield.