Exogenous application of 6-BA and GA₃ collaboratively improves cottonseed yield and seed quality via altering production of carbohydrates in the embryo

ABSTRACT

Cottonseed produces oil for human consumption and protein meals for ruminant feed, and carbohydrate metabolism takes responsibility for seed oil and protein biosynthesis. Here, 6-BA and GA₃ were evaluated by seed or foliar application for its effect on physiological and productive parameters of cottonseed in two-year field experiment. Results showed that 6-BA and GA₃ significantly enhanced cottonseed yield because of increased boll number and seed index. Boll number was the dominant driver of yield increment for seed priming with 6-BA, and the increase was greater than GA₃, resulting in higher yield for seed priming with 6-BA (18.8–20.1%) than with GA₃ (10.7–14.5%) while the increase in yield was statistically at par between spraying of 6-BA and GA₃. Although seed coat weight was not affected by 6-BA and GA₃, embryo weight, oil and carbohydrate content were significantly increased by any given treatments. Higher carbohydrate content was attributed to increased sucrose, hexose and starch contents, which were closely associated with higher sucrose synthase, acid invertase, and sucrose phosphate synthase activities. Moreover, increases in the activities of these sucrose metabolism enzymes were larger for seed priming with 6-BA than GA₃, accounting for the difference observed in sucrose content between 6-BA and GA₃ seed application.

KEYWORDS:

• Cottonseed
• 6-BA and GA₃
• carbohydrate
• sucrose metabolism

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China (2017YFD 0201900) and Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP).