关键词: 胡麻, 株高, QTL-seq, 细胞壁转化酶

Abstract: Linseed flax (Linum usitatissimum L.) is one of the main oil crops in China, with strong drought tolerance, cold resistance and resistance to poverty characteristics. Plant height not only affects the yield of flax, but also relates to plant lodging and seed quality. This study used a recombinant inbred line population  consisting of 155 lines as experimental materials, which was constructed with Macbeth and Heiya 14 as parents, to analyze the plant height traits in Lanzhou and Jingtai at Gansu province, Yuanmou at Yunan province and Langfang at Hebei province. The QTL-seq based on high-throughput sequencing and the traditional QTL localization method were used to locate the QTL of flax plant height, and a main effect gene of plant height, LuCWINV1-1, was obtained. It belonged to the cell wall invertase of acid invertase and contained the conserved domains NDPNG, RDP and MWECP. There was mutation  in genome sequence of LuCWINV1-1 between the parents, which resulted the 21st glutamate and 523rd isoleucine in Macbeth were glycine and alanine in Heiya 14, respectively. By transformed into Arabidopsis, it was found that the plant height overexpressed LuCWINV1-1Mac became higher, while the plant height overexpressed LuCWINV-11 Hei became lower, which indicated that the gene controlled the plant height in flax. Those results laid a foundation for analyzing the mechanism of plant height in flax, and also explored that QTL-SEQ could be used to clone QTL candidate genes quickly and effectively in this small genome crop, which provided technical support for the subsequent identification of genes controlling the important agronomic characters of flax.

Key words: linseed flax, plant height, QTL-seq, cell wall invertase