Nonstructural carbohydrates in leaves subtending cotton bolls, fibers and embryos in response to nitrogen stress

ABSTRACT

A field study was conducted in 2013 and 2014 where cotton was exposed to three N regimes: (1) the control without N application (low N); (2) 260 kg N ha⁻¹ (medium N); (3) 520 kg N ha⁻¹ (high N). Boll size, lint mass per boll, seed mass per boll, fiber length and strength were significantly decreased under N deprivation in the two years. The increased carbohydrate levels of LSCB (leaf subtending the cotton boll) led to decreased carbohydrate levels of fibers in the low N relative to the other N treatments. The low N embryos exhibited lower starch concentrations at 17 and 31 DPA (days post anthesis), and TNC (total nonstructural carbohydrate) concentrations at 17, 31, 45 and 52 DPA compared to medium N embryos. Starch levels in LSCB had negative associations with those in fibers at 17, 31 and 45 DPA, but positive associations with those in embryos at 24 and 45 DPA. Fibers expressed negative associations with embryos in glucose level at 24 and 38 DPA, and in TNC levels at 17 and 45 DPA. The study suggests that carbon assimilate levels in fibers and embryos could explain the difference in boll yield components and fiber quality.

KEYWORDS:

• Gossypium hirsutum
• carbon metabolism
• fiber quality
• boll yield components
• nitrogen deficiency

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was financially supported by grants from the National Natural Science Foundation of China (31560364 and 31260302).