Male Sterility Induced by Chemical Hybridizing Agent SQ-1 in Common Millet

Abstract

Effect of chemical hybridizing agent SQ-1 on common millet was studied with the split plot design. The different treatment stages and dosages of SQ-1 were designed as main plot and sub-plot respectively. Male sterility induced by SQ-1 was evaluated according to the three indexes: male sterile rate, crossing rate, and seed-setting rate of natural pollination. The results showed that treatment stages, dosages of SQ-1 and the interaction between them affected male sterile rate and crossing rate sig- nificantly or highly significantly. The induced male sterile rate and crossing rate were both over 95% with treatments of different dosages (4.0 and 5.0 kg ha?1) in the differentiation stage of the anlage of gynoecium and stamen, and also under the dosage of 5.0 kg ha?1 at the primary stage of forming pollen. The seed-setting rate of natural pollination was not affected significantly by the treatment stages, but affected significantly by the dosages and interaction between the treatment stages and dosages, and decreased with the dosage. Considering all the three indexes and the cost of production of hybrid seed, the optimum treatment stage is the differentiation stage of the anlage of gynoecium and stamen and the optimal dosage is 4.0 kg ha?1.