Segregation for Aborted Anthers in Hybrid Seedlings Using Citrus nobilis*C. deliciosa cv. Encore as the Seed Parent.

Abstract

In citrus, it has been suggested that hybrid seedlings with aborted anthers appear only from crosses of varieties having cytoplasm of satsuma mandarin (Citrus unshiu Marc.) as a seed parent. However, in this paper, we reveal the appearance of hybrid seedlings with aborted anthers by using 'Encore' (C. nobilis Lour. × C. deliciosa Ten.) as a seed parent. When 'Encore' was crossed with 'Minneola', 'Murcott', and 'Seminole', 8 out of 61, 10 out of 43, and 7 out of 26 seedlings had aborted anthers, respectively, but 'Encore' × Ponkan crosses were all male-fertile. Approximately half of the seedlings from 'Kiyomi' × 'Encore' crosses were male-sterile (aborted anthers). These results probably support the concept that the genotype of Ponkan is dominant-homozygous and the genotype of 'Encore', 'Minneola', 'Murcott' and 'Seminole' is heterozygous for the male sterility gene. The results also suggest that the genotype of 'Minneola' differed from other heterozygous varieties because it has a different segregation ratio.