关键词: 花生, 单粒精播, 产量, RNA-Seq, 光合作用, 苯丙素途径

Abstract:

【Objective】In China, in order to ensure the emergence rate and quality of seedlings, the field often adopts multiple seed seeding. However, inter-plant competition in multi-seeds sowing often limits the growth and eventual yield of subsequent plants. In order to solve this contradiction, the team studied and established the high-yield cultivation technology of single-seed precision seeding. The combination of seed saving and yield increase effect of single-seed precision seeding technology can bring greater benefits and realize cost savings and increased efficiency. The differentially expressed genes in peanut leaves, roots and pods under different planting methods were used to explore the regulatory mechanism of single-seeding precision sowing to improve peanut pod yield, providing theoretical basis and technical support for further promoting peanut high yield and high efficiency. 【Method】Peanut variety Huayu 25 was used as the test material, while the yield related indexes of single-seed sowing and multi-seeds sowing were determined. Inverted three leaves, taproot and lateral root of peanut at 30 days after flowering and peanut pod at young fruit stage of chicken head were selected for transcriptome sequencing, and the yield differences of peanut under different sowing methods were revealed on the molecular level. 【Result】Compared with multi-seeds sowing, the pod number per plant, full fruit number per plant, fruit weight per plant and economic coefficient of single-seed sowing were significantly increased. After the transcriptome data is assembled, each library contains an average of 44.3 million readings. Through the analysis of differentially expressed genes, GO and KEGG pathways in different combinations, it was found that the expression levels of transcription factors, photosystem Ⅱ oxygen-releasing complex, chloroplast membrane, oxidation-reduction reaction and other genes involved in the processes of GA signal and light signal transduction were increased in the leaves of plants under single-seed sowing compared with multi-grain cave seeding. Genes related to phenylpropyl metabolism pathway induced by biological and abiotic stress were significantly enriched in roots, including cytochrome P450 gene, oxidation-reduction gene, stress response transcription factor and signal regulatory protein. The accumulation of starch and sucrose metabolism genes was more conducive to seed kernel enrichment during pod development. 【Conclusion】The up-regulated expression of photosynthetic related genes in peanut leaves at seedling stage could promote the increase of photosynthetic efficiency, which was closely related to the increase of yield. Single-seed sowing improved the ability of root system to resist biological and abiotic stress, and combined with the up-regulation of energy and material related genes in the early stage of pod development, it was beneficial for the development of underground peanut pod and increased peanut yield.

Key words: peanut, single seed precision sowing, yield, RNA-Seq, photosynthesis, phenylpropanoid pathway