Rapeseed consists of seed coat, embryo and endosperm. The seed coat is the "armor" of the seed and plays a role in protecting the seed. Embryo is the most important part of seeds, which can develop into roots, stems and leaves of plants. Endosperm is the place where seeds concentrate nutrients, and the endosperm of different plants contains different nutrients.

Embryo includes radicle, embryo, hypocotyl and cotyledon, radicle sheath and coleoptile sheath. Developed from fertilized eggs. A fully developed embryo consists of germ, hypocotyl, cotyledon and radicle. The embryos of gymnosperms are all in the middle of the seeds.

Endosperm develops from fertilized polar nuclei. The endosperm of gymnosperms is a haploid female gametophyte, which is relatively developed and stores more starch or fat, and some of them contain aleurone grains.

Extended data:

Choose dry land or vegetable garden soil with loose and fertile soil, convenient irrigation and drainage, flat terrain and no rape planted for more than 2 years as seedbed. Seedbed area: The best ratio of field area is 1:5-6.

2. Apply sufficient base fertilizer. Before sowing, the seedbed should be carefully arranged, and the decomposed pig cow dung 1.25 tons, ammonium bicarbonate 20 kg, calcium magnesium phosphate 25 kg and potassium chloride 6 kg should be mixed and stacked 10 day, and the seedbed arrangement should be used as the base fertilizer of the land.

Rapeseed is evenly sown at the rate of per mu 1 kg borax+fireclay ash +0.4-0.5 kg rapeseed. Before sowing, the border surface should be kept at a certain humidity, and irrigation should be done in time in case of dry weather, otherwise the seedling emergence rate will be greatly affected.