ABSTRACT
Strasburger in 1878 first observed the regular occurrence of polyembryony in certain species of Citrus in nature. Subsequently, Webber in 1920 observed the utility of nucellar seedlings in the propagation of nursery trees as they are true to the mother type. Although polyembryony is a common phenomenon in citrus seeds not all the species exhibit polyembryony to the same extent between and also within them (Table 4.1). Some species of Citrus are, however, monoembryonic. These are Citron, Pomelo, Clementine mandarin, and Bergamot. Variation in the rate of polyembryony within a species did not draw the attention of many citriculturists. Comprehensive data are available in the study conducted by Pio et al. (1984). They worked out the polyembryony of 26 cultivars of Trifoliate Orange and found wide variation in the extent of polyembryony both by directly counting the embryos in seeds and counting the seedlings after their emergence (Table 4.2).
