“…Environmental and intrinsic factors such as season, temperature, photoperiod, light, age of plant, nutrition level, vegetative activity, pruning and plant hormones affect sex expression in castor 11 , 14 , 20 , 23 – 29 . Though pachytene chromosome morphology did not vary between monoecious and pistillate lines, haploid plants had sterile racemes and trisomic castor plants had only male flowers, with occasional single terminal hermaphrodite flowers, indicating that cytogenetic or chromosomal aberrations may influence sex expression 12 , 30 , 31 . More than 3000 differentially expressed genes were identified between monoecious and pistillate genes, possibly involved in sex determination in castor 29 .…”