Study on the Biological Characteristics of Morphology, Anatomy and Germination of Akebia trifoliate Seeds

With an aim to clarify the biological characteristics of morphology, anatomy and germination of Akebia trifoliata seeds, the fresh seeds were used as materials in this study and morphological characteristics, anatomical structure, water absorption characteristics, germination characteristics, and dehydration sensitivity of the seeds were investigated and analyzed. The results showed that the seeds were oblong or oblate with a dark brown color, and had a 1 000-grain-weight of 62.29 g. The length, width, and thickness of the seeds were 8.62 mm, 5.80 mm and 3.21 mm, respectively, and the morphological characteristics varied greatly. The seed was composed of seed coat, caruncle, endosperm and embryo, and contained abundant endosperm with a straight embryo. The seed embryo contained four parts namely cotyledon, hypocotyl, embryo and radicle, with a length of 3.01 mm. The damage treatment to seed coat could extremely significantly increase the water absorption rate and promote the germination rate of the seeds, which indicated that the A. trifoliata seeds had dormancy characteristics caused by the mechanical hindrance of seed coat. Wet sand stratification temperature had a significant impact on the germination rate of A. trifoliata seeds, and the optimum temperature for seed germination was 16 ℃ during stratification and seed germination rate reached 80.81%. The vigor of the seeds decreased with the drying time, and the seed vigor was only 11.2% when treating by silica gel for 96 hours, which indicating that A. trifoliata seeds were dehydration-sensitive.