Lignin and cellulose content in the hull of Tartary buckwheat seed. S1, S3 and S5 indicate different developmental stages, stage 1, 3 and 5, of MQ 1 (M) and XQ 1 (X), respectively. (A) Lignin and cellulose content in the hull of mature seed (n = 3); (B,C) Lignin and cellulose content in the hull of different developmental stages of XQ 1 (B) and MQ 1 (C). Bars with different letter indicates significant differences (p < 0.05). (D) The total content of lignin and cellulose in the hull of XQ 1 and MQ 1 at each developmental stage; asterisk indicates the significant difference (p < 0.05) between XQ 1 and MQ 1.