Comparative transcriptomic analysis provides a new insight into graft incompatibility in Citrus grandis cv. Hongmian miyou

In our previous study, we found that trifoliate orange is widely used as a rootstock in Guanxi miyou (C. grandis) grafting, whereas Hongmian miyou is incompatible with available trifoliate orange, which leads to huge economic losses. Hongmian miyou was discovered in China as a bud mutation of Guanxi miyou with carotenoid accumulation in spongy layer. Here, we used Hongmian miyou grafted onto trifoliate orange as incompatible combination, Guanxi miyou grafted onto trifoliate orange and Hongmian miyou grafted onto Xiangcheng (C. junos) as compatible combinations. The purposes of this study were to understand the physiology, biochemistry and molecular mechanisms of etiolation process and to explore the possible mechanism of graft incompatibility in Citrus.