A novel virescence mutant simplifies hybridization in finger millet breeding

A virescent mutant (v1) was induced with ethyl methane sulphonate in the improved finger millet cultivar Indaf 8. The v1 mutant expresses yellow leaf color stably at seedling stage and gradually turns green as the growth progress. The Soil Plant Analysis Development (SPAD) value (indicating chlorophyll content) in v1 seedlings was half of that in wild type, which increased as growth advanced from tillering to grand growth and grain filling stages. Virescence mutation had pleiotropic effect on flowering (delayed) and plant height (reduced) but no significant influence on other agronomic traits including grain yield. Genetic analysis using F_2-3 generations revealed the control of the trait by recessive state of a single nuclear gene. Hybrid recovery assessed in contact method of crossing using virescent lines ranged from 0.2% to 15.7% with an average of 5.1%. In finger millet breeding, hybridization is limited due to low hybrid recovery and non-availability of robust markers for F₁ identification. This study demonstrated the potential of seedling stage virescence marker in F₁ identification to make hybridization more simple and rapid. This is the first time reporting on the utilization of virescence phenotypic marker in finger millet breeding.