Photoperiodic induction of flowering in some sugarcane genotypes

Abstract

The study was conducted at the Sugar Crop Research Institute breeding facilities, Agriculture Research Center (ARC), Giza, Egypt, during the 2018 and 2019 growing seasons to evaluate the flowering response of nine sugarcane genotypes. They were subjected to either 30 or 60 photo-inductive cycles at a constant 12.30 hrs day length, followed by a 30 sec/day decrease in day length until they reached 11.30 hrs day lengths. The outcomes of Individual and combined analysis of variance over two inductive cycles revealed significant differences between genotypes for the duration of the Pre flag leaf stage, the duration of the flag leaf stage, the duration of the emergence stage, the minimum days to flower, the maximum days to flower, and the duration of the flowering period. For all traits, the difference between inductive cycles was significant. The interaction between genotypes and inductive cycles was significant for all studied characters. According to the findings, the nine sugar cane genotypes under investigation could be divided into four groups. The first included four genotypes that responded to 30 and/60 inductive cycles: G 99-160, CP 57-614, CP 31-294, and G 73-211. The second group included two genotypes: CP 44-101 and G 84-47, both of which flowered only after 30 inductive cycles. The third group contained only one genotype, EH 94-119, which flowered after 60 inductive cycles. The fourth group contained two genotypes, GT 54-9 and CO 997, which showed no response under 30 or 60 inductive cycles. This suggests that these genotypes are either reluctant to flower or require more inductive cycles to induce flowering.