doi:

DOI: 10.3724/SP.J.1011.2014.31028

Chinese Journal of Eco-Agriculture (中国生态农业学报) 2014/22:3 PP.308-313

Exogenous GA3 influence on the development of summer cultivated carrot fleshy root on plateau


Abstract:
This study determined the mechanism of the effect of exogenous GA3 on the development of fleshy carrot roots and to provide theoretical base for efficient and safe cultivation of summer carrots planted on plateau areas of the Northwest China. To do so, the study analyzed the effect of exogenous GA3 on immature bolting carrot cultivar (‘Xinxiusanhong’) in terms of fleshy root thickening, lignification and endogenous hormones contents. The results showed that weight, growth rate and sink activity of fleshy roots of carrot significantly reduced after spraying with 5.78 × 10-4 mol·L-1 of exogenous GA3 once during vigorous leaf growth period (45 days after seedling emergency) or during root thickening period (75 days after seedling emergency). The weight, growth rate and sink activity of fleshy roots of carrots also significantly reduced following 3 rounds of continuous spray of 5.78 × 10-4 mol·L-1 of exogenous GA3 at seedling stage (25 days after seedling emergency), vigorous leaf growth period and root thickening period. However, the level of lignification of fleshy roots of carrot was enhanced by spraying 5.78 × 10-4 mol·L-1 of exogenous GA3. Compared with CK (the control), fleshy carrot root contents of endogenous GA3, IAA, GA4, ABA, DHZR, IPA were significantly reduced and ZR significantly increased at seedling stage after spraying with exogenous GA3. GA3, IAA, GA4 and IPA contents significantly decreased at vigorous leaf growth stage while endogenous IAA, GA4, ZR contents significantly increased during the period of rapid thickening of fleshy carrot roots. Also, ZR content increased at vigorous leaf growth stage of carrot. The ratios of endogenous IAA/ZR and GA4/ZR significantly decreased before the period of rapid thickening of fleshy carrot roots after spraying one to three times with exogenous GA3. IAA/ZR and GA4/ZR ratios significantly increased during the period of rapid thickening of fleshy carrot roots following several rounds of spraying with exogenous GA3. Exogenous GA3 influenced the development of fleshy roots of summer carrots cultivated in the plateau region of the Northwest China by changing the content and balance of endogenous hormones.

Key words:Summer carrot (Daucus carrot L. var. sativa DC.),Fleshy root,Lignification,Endogenous hormone,Exogenous GA3

ReleaseDate:2014-07-21 17:06:29



[1] 杨永岗, 张化生, 李亚莉, 等. 高原夏季胡萝卜肉质根内源激素变化及其与先期抽薹的关系[J]. 园艺学报, 2010, 37(7): 1102–1108 Yang Y G, Zhang H S, Li Y L, et al. Endogenous hormone content of fleshy root in relation to early bolting in summer cultivated carrot on plateau[J]. Acta Horticulturae Sinica, 2010, 37(7): 1102–1108

[2] Nieuwhof M. Effect of gibberellic acid on bolting and flow-ering of carrot (Daucus carota L.)[J]. Scientia Horticulturae, 1984, 24(3/4): 211–219

PDF