Biochemical factors associated in controlling fibre elongation in different cotton genotypes

The role of biochemical constituents and metabolically vital enzymes during fibre elongation was studied in three cotton genotypes Arogya, LRA 5166 and Suvin, differing in fibre length. Arogya has short staple length), LRA 5166 has medium staple whereas Suvin has extra long staple. It was observed that 80–90% ofthe fibre elongation was achieved by 20–25 days after anthesis (DAA). The short staple cotton Arogya had higher seed reducing sugar and total phenol during the peak fibre elongation period compared to LRA 5166 and Suvin. On the other hand, the reducing sugar content in the fibre was maintained at higher level in Suvin, followed by LRA 5166 and Arogya. Higher levels of IAA oxidase and peroxidase was noticed in Arogya, while Suvin had lower levels. The study revealed that high total phenols coupled with higher IAA oxidase and peroxidase activities and lesser fibre to seed reducing sugar content as the regulating factors for cotton fibre elongation during development.