如何在我的情节中使用theme（）函数添加垂直线

Question

大家， 我想生成如下图。我可以靠近，但不能将垂直线作为y轴添加到零点。 enter image description here

这是我的数据和我的代码：

    Variables   MeanDecreaseAccuaracy     MeanDecreaseGini
    band1             33.991                142.946
    band2             32.729                165.892
    band3             32.254                169.372
    band4             36.721                209.631
    band5             36.525                141.047
    band6             40.496                232.536
    band7             39.886                226.782
    band8             4.315                 5.334

我的代码：

p <- ggplot(data = df1, aes(x = df1$MeanDecreaseAccuaracy, y = reorder(factor(df1$Variables),df1$MeanDecreaseAccuaracy)))

p + geom_segment(aes(yend = df1$Variables,xend = 0)) + 
geom_point() + 
theme_minimal() + 
scale_x_continuous(breaks = c(0,10,20,30,40,50)) + 
labs(x = "Mean Decrease in Accuracy",y = "Prdictors variable") + 
theme(axis.line = element_line(colour = "black"),
    axis.text.x = element_text(colour = "black"),
    axis.text.y = element_text(colour = "black"),
    axis.ticks.x = element_line(size = 0.2,colour = "black"),
    axis.ticks.y = element_line(size = 0.2,colour = "black"),
    panel.grid.major = element_blank(),
    panel.grid.minor = element_blank())

注意：df1是我的数据。 这是我的情节。 enter image description here