Biomass accumulation and partitioning of newly developed Green Super Rice (GSR) cultivars under drought stress during the reproductive stage

•Rice introgression breeding for drought tolerance was confirmed as an effective approach.•Identified two key strategies of Green Super Rice (GSR) to cope with drought stress for high yield.•GSR cultivars could have a yield advantage of 31–36% across environments against drought check.•Easy biomass measurements can be used to study the mechanism of stress tolerance of rice cultivar.