Mutagenic effects of carbon ion beam irradiation on rice and screening for induced mutants

Objective  To enrich rice (Oryza sativa L.) mutant library, rapidly create genetically stable new germplasm, and provide valuable materials for following study of mutation mechanisms and rice genetic breeding.

Method  The breeder seeds of ‘IR55’, ‘IR60’, ‘Sanlicun’ and ‘Yunnan Ludao’ were irradiated by carbon ion beam, and the agronomic traits of induced generations were consecutively investigated.

Result  The mutants of four cultivars varied over a large range of variation in plant height, flag leaf length, spikelet length, length-width ratio of grain and other traits, and displayed obvious positive or negative mutation. Seed setting rate decreased respectively with the lowest value of 2%. Large genetic diversity variations were detected between the mutants and breeder seed populations of four cultivars using randomly selected SSR markers, indicating that heavy ion irradiation induced big fragment variations at DNA sequences, rather than subtle site mutation.

Conclusion  Carbon ion beam irradiation can cause positive or negative mutation of plant height, flag leaf length, grain shape and other agronomic traits of rice. New rice germplasms with variation in agronomic traits can be screened out from mutation progenies.