Promoting deep-sowing germinability of corn (Zea mays) by seed soaking with gibberellic acid

ABSTRACT

The effects of seed soaking with gibberellic acid (GA₃) on germinability of conventional corn variety ‘Nongda 108’ and super sweet corn variety ‘Chaotian 3’ were investigated under deep-sowing condition. GA₃ soaking significantly improved seed germination and mesocotyl elongation of both varieties under 10 or 6 cm sowing depth. The most significant promotion occurred at 0.175 g L⁻¹ GA₃ in ‘Nongda 108’ and 0.035 g L⁻¹ GA₃ in ‘Chaotian 3’. To further illustrate the physiological explanations, seed respiration was estimated from dehydrogenase activity test and oxygen-sensing test. Dehydrogenase activities of both varieties were dramatically promoted after GA₃ soaking. Compared with water soaking, the dehydrogenase activity in 0.175 g L⁻¹ GA₃-soaked seeds of ‘Nongda 108’ and 0.035 g L⁻¹ GA₃-soaked ones of ‘Chaotian 3’ was increased by 15.4% and 78.8%, respectively. Oxygen-sensing test showed that increased metabolism time (IMT) critical oxygen pressure (COP) and relative germination time (RGT) were decreased while oxygen metabolism rate (OMR) and relative germination rate (RGR) were increased in GA₃-soaked seeds, suggesting that exogenous GA-accelerated seed respiration. Our results suggested that seed soaking with exogenous GA₃ was a simple and practicable method to improve deep-sowing tolerance during corn seed germination, and the significant promotions were attributed to vigorous respiratory metabolism.

KEYWORDS:

• Corn
• deep-sowing
• germinability
• gibberellic acid
•  seed respiratio n

Acknowledgments

We give our thanks to Professor Zhu Zhujun, Zhejiang Agriculture & Forestry University and Netherlands ASTEC Global Seed Technology Corporation for oxygen-sensing technology.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [31371712], Zhejiang Provincial Natural Science Foundation [LY13C130011, LY13C160007], Special Fund for Agro-scientific Research in the Public Interest of China [201303002], Crop Germplasm Resource Protection Project of Zhejiang [2015004] and 13th Five-Year Major Scientific and Technological Project for Agricultural (Grain) New Varieties Breeding of Zhejiang [2016C02050-9-5, 2016C02050-9-4]