Yam Tuber Dormancy and Sprouting: The Role of Concentration Dynamics of Endogenous Gibberellic Acid
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Date
2021-12
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Agricultural and Food Science Journal of Ghana.
Abstract
The role of endogenous gibberellic acid (GA3 ) in the regulation of yam (Dioscorea spp.) tuber dormancy was investigated by determining the changes in the endogenous GA3 levels during natural dormancy progression. Two Dioscorea rotundata cultivars ('Pona' and 'Labreko') and one Dioscorea alata cultivar ('CRI-Ahoɔdenfoɔ') used in these studies have varying dormancy duration. Endogenous GA3 levels determined for the yam tubers ranged from 1.53 – 3.05 mg/g dw and 1.23 – 1.58 mg/g dw for 'Pona'; 1.53 – 3.40 mg/g dw and 1.25–1.57 mg/g dw for 'Labreko'; 1.48 – 3.62 mg/g dw and 1.28 – 1.60 mg/g dw for 'CRI-Ahoɔdenfoɔ', respectively, for the outer and inner portions. 'Pona' and 'Labreko' had dormancy break at 60 days after harvest (DAH), but at 90 DAH for 'CRI-Ahoɔdenfoɔ'. Generally, GA3 levels increased from harvest to the maximum at 30 DAH, then declined to the minimum at 60 DAH before finally increasing again at 90 DAH for the outer portions of the yam tuber. For the inner portions of the tuber, GA3 levels rather declined significantly to the minimum at 30 DAH, increased at 60 DAH and then decreased again at 90 DAH. GA3 levels in the outer portions of the tubers increased by 84-122%, 65-77% and 61- 65%, respectively, in 'CRI-Ahoɔdenfoɔ', 'Labreko' and 'Pona', but decreased in the inner portions by 19-23%, 24-26% and 26-28%. Essentially, higher amounts of endogenous gibberellins in yam tubers induced longer dormancy duration whereas lower amounts were indicative of dormancy termination and subsequent initiation of sprouting.
Description
This is an article published in Agricultural and Food Science Journal of Ghana. Vol. 14. December 2021; https://dx.doi.org/10.4314/afsjg.v14i1.4
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Citation
Agricultural and Food Science Journal of Ghana. Vol. 14. December 2021; https://dx.doi.org/10.4314/afsjg.v14i1.4