Seed coat patterns in rapid-cycling Brassica forms

摘要

The micromorphological typology of seed surfaces was investigated in rapid-cycling Brassica (RCBr) forms, using scanning electron microscopy. Four types of basic ornamentation pattern were recognized: reticulate (B. rapa, B. juncea), reticulate-foveolate (B. nigra), randomly reticulate (B. oleracea, B. napus) and reticulate-rugose (B. carinata). The seed coats showed variation in the shape and size of the testa epidermal cells and the structure of the outer periclinal and anticlinal cell walls. The surface patterns in RCBr seeds were less exposed and were moderately reticulated compared to cultivated Brassica species. The micromorphological characteristics of the seed coats may provide valuable additional diagnostic criteria for delimitation of RCBr forms, and can be used in identification of seeds.