Anatomical Structure of Leaves of Different Evolutionary Type within Subgenus Soja

To explore the evolutionary characteristics of subgenus Soja plants, we compared anatomical structure differences among leaves of four soybean germplasm from Jilin Province by paraffin section. Results showed that there were significant differences in the anatomical structure of the four taxa of plant leaves within subgenus Soja. In accordance with the order of wild soybean to cultured soybean, the leaves and primary veins thickened, the number of epidermal hairs increased, vessel elements in the primary vein vascular bundle increased, abnormal vascular bundles appeared, the palisade tissue layers and CTR and SR values increased, and four cell layers evolved in the palisade tissue of cultured soybean. The evolutionary pattern (from lower to higher evolution) of the subgenus Soja plants determined from the structural characteristics was wild soybean → semi-wild soybean → semi-cultured soybean → cultured soybean.