方法1：计算抗性指数用于GWAS分析
GWAS分析一些抗性指标时候，我们一般会做对照与处理，分别调查处理和对照的多种性状数据，然后计算抗性指数：
The response of the genotypes to salt stress was expressed using the stress susceptibility index (SSI) calculated according to Fischer and Maurer39 using the following formula: SSI = (1 − Ys/Yp)/D, where Ys = mean performance of a genotype under stress; Yp = mean performance of the same genotype without stress; D (stress intensity) = 1 − (mean Ys of all genotypes/mean Yp of all genotypes).
方法2：苗期处理，利用死亡率做为抗性指标
参考文献：
https://academic.oup.com/dnaresearch/article/22/2/133/332691#4590366
Fischer R.A. Maurer R. 1978, Drought resistance in spring wheat cultivars. I. Grain yield responses, Crop Pasture Sci., 29, 897–912.
GWAS关联分析课程推荐：https://bdtcd.xetslk.com/s/2KgXQq
