Mutation breeding of butterfly pea

Abstract

© 2020 International Society for Horticultural Science. All rights reserved. A low-energy nitrogen ion beam at 50 keV was used to induce mutation in butterfly pea (Clitoria ternatea L.) seeds. Ion fluences of 1×1016 to 12×1016 N-ions cm-2 did not affect the seed survival percentage. However, the 12×1016 N-ions cm-2 caused variegated and deformed leaves on some plants in ‘M1’ (the 1st generation of mutation induction) population. The ‘M1’ population (n=137) also had lower average internode and leaflet lengths than the wild type population (n=50). All ‘M1’ plants were self-pollinated and their seeds were grown as ‘M2’ population following the pedigree method. Four dwarf mutant plants derived from one line were found among 516 ‘M2’ plants, and coded ‘M2S’. They were self-pollinated and their seeds were grown as ‘M3S’. All seeds from the ‘M2S’ plants grew out to be dwarf plants. Characteristics of the ‘M3S’ plants (n=15) were compared to the wild type plants (n=6) at 70 days after sowing in December 2017. The ‘M3S’ plants had significant shorter internodes, smaller leaflets, and smaller flowers than the wild type plants (at p<0.05). The mutant plants drastically reduced their climbing habit. Thus, their average height was only 19.3±3.4 cm, while the average plant height of wild type was 53.7±33.6 cm. The dwarf mutants could be developed as a pot plant.