Abstract

Cotyledons that affect the plant development are important part of soybean. We describe a recessive soybean mutant, designated as curled-cotyledons mutant which is derived from sodiumazide (NaN₃) and ⁶⁰Coγ ray mutagenized seeds of the ‘Nannong 94-16’ cultivar. The curled-cotyledons mutant has defective morphology in cotyledons development, compared to the wild-type plants. Additionally, it also has other aberrant agronomic character, such as longer growth period, and smaller plants. In the mutant, the embryo sac becomes smaller and bulbous, and ultrastructure of developing cotyledons exhibits larger vacuole, some organelles degradation, and membranous multilamellar appear at different stages. Protein and amino acid contents in seeds of mutant are higher than those of the wild type, especially methionine and cysteine. These results suggest that the curled-cotyledonsmutant is a novel cotyledon development mutant, which could serve as a basic material to study seed composition and cotyledon development in soybean.

Key words: Soybean, mutant, curled-cotyledons, genes.

Abbreviation

Abbreviations: DAF, Days after flowering; NaN₃, sodiumazide; EMS, chemical mutagen.