Articles
Avances recientes en inducción floral, desarrollo de fruto y cuajado en mango (Mangifera indica L.)
Article number
1415_32
Pages
265 – 278
Language
English
Abstract
Mexico is the fifth largest mango producer worldwide, with an area of more than 308 thousand ha and a production of almost 2.1 million t.
The average yield is 10.8 t ha‑1. However, climatic vulnerability is one of the main problems in the four cultivars that exist in Mexico (‘Ataulfo’, ‘Tommy Atkins’, ‘Kent’ and ‘Keitt’), especially the temperature and precipitation that prevail during the differentiation and flower budding period, causing irregular flowering, low fruit set, production of small fruits, pests, and disease presence. among others.
Irregular mango production is attributed to flowering variation and in subtropical areas to fruit retention.
Flower variation can change from year to year, between trees of the same year, and between buds on the same tree.
Although the accepted factor for inducing flowering is temperature (≈15-20/10-15°C day/night), it does not guarantee that flower initiation will occur due to interactions with vegetative growth.
Paclobutrazol (PBZ) has been heavily relied upon to regulate flowering; however, there is the possibility of contamination risks if its use is improper; moreover, it is not authorized for use on mangoes in the United States.
On the other hand, there are other products with a similar effect to PBZ; as well as the use of biostimulants or practices such as pruning that have little or no impact on the environment and human health.
Looking for an alternative to PBZ, this document presents the results of research carried out in Mexico on the flowering process and its relationship with temperature, to avoid irregular flowering, modify, and increase flowering, fruit size and yield in different mango cultivars.
The studies to achieve the objective were carried out in Nayarit, Mexico, as follows: 1) bud morphology, temperature effect and gibberellin inhibitors in floral induction in ‘Ataulfo’; 2) Flowering Locus T (MiFT) gene expression in relation to environment and growth regulators in ‘Ataulfo’; 3) calcium prohexadione (P-Ca) effect on flowering and ‘Ataulfo’ mango production; 4) gibberellin inhibitors effect on flowering and ‘Tommy Atkins’ and ‘Kent’ production.
Four stages of terminal bud development were characterized: Stage 1 – apical vegetative meristem (E1); Stage 2 – floral initiation (E2); Stage 3 – determined flower bud (E3); Stage 4 – differentiated bud (E4). Earlier initiation and floral differentiation were achieved in buds with PBZ and P-Ca (46 and 31 days, respectively) compared to the control, these products promoted greater flowering in the presence of cool temperatures, indicating that these temperatures, together with the regulators, stimulated the process.
The MiFT gene expression was detected in ‘Ataulfo’ mango mature leaves, the highest expression was found in December and January on the sunny side and coincided with cold temperatures below 20°C. The gene expression was also found to be related to PBZ (30.3%) and P-Ca, although in lower expression (4.7%); while gibberellins inhibited MiFT expression.
In ‘Ataulfo’ mango, P-Ca in 500 mg L‑1 doses (3×) and 1500 (1×) favored flower budding and yield, this was the same the effect of PBZ and surpassing the control; in this last dose ‘Tommy Atkins’ (two years of evaluation) and ‘Kent’ (one year of evaluation) match the PBZ effect, and in some cases, they surpassed it by increasing flowering and yield.
In these cultivars, a single P-Ca application (1500 mg L‑1) may be an alternative to the use of PBZ.
The average yield is 10.8 t ha‑1. However, climatic vulnerability is one of the main problems in the four cultivars that exist in Mexico (‘Ataulfo’, ‘Tommy Atkins’, ‘Kent’ and ‘Keitt’), especially the temperature and precipitation that prevail during the differentiation and flower budding period, causing irregular flowering, low fruit set, production of small fruits, pests, and disease presence. among others.
Irregular mango production is attributed to flowering variation and in subtropical areas to fruit retention.
Flower variation can change from year to year, between trees of the same year, and between buds on the same tree.
Although the accepted factor for inducing flowering is temperature (≈15-20/10-15°C day/night), it does not guarantee that flower initiation will occur due to interactions with vegetative growth.
Paclobutrazol (PBZ) has been heavily relied upon to regulate flowering; however, there is the possibility of contamination risks if its use is improper; moreover, it is not authorized for use on mangoes in the United States.
On the other hand, there are other products with a similar effect to PBZ; as well as the use of biostimulants or practices such as pruning that have little or no impact on the environment and human health.
Looking for an alternative to PBZ, this document presents the results of research carried out in Mexico on the flowering process and its relationship with temperature, to avoid irregular flowering, modify, and increase flowering, fruit size and yield in different mango cultivars.
The studies to achieve the objective were carried out in Nayarit, Mexico, as follows: 1) bud morphology, temperature effect and gibberellin inhibitors in floral induction in ‘Ataulfo’; 2) Flowering Locus T (MiFT) gene expression in relation to environment and growth regulators in ‘Ataulfo’; 3) calcium prohexadione (P-Ca) effect on flowering and ‘Ataulfo’ mango production; 4) gibberellin inhibitors effect on flowering and ‘Tommy Atkins’ and ‘Kent’ production.
Four stages of terminal bud development were characterized: Stage 1 – apical vegetative meristem (E1); Stage 2 – floral initiation (E2); Stage 3 – determined flower bud (E3); Stage 4 – differentiated bud (E4). Earlier initiation and floral differentiation were achieved in buds with PBZ and P-Ca (46 and 31 days, respectively) compared to the control, these products promoted greater flowering in the presence of cool temperatures, indicating that these temperatures, together with the regulators, stimulated the process.
The MiFT gene expression was detected in ‘Ataulfo’ mango mature leaves, the highest expression was found in December and January on the sunny side and coincided with cold temperatures below 20°C. The gene expression was also found to be related to PBZ (30.3%) and P-Ca, although in lower expression (4.7%); while gibberellins inhibited MiFT expression.
In ‘Ataulfo’ mango, P-Ca in 500 mg L‑1 doses (3×) and 1500 (1×) favored flower budding and yield, this was the same the effect of PBZ and surpassing the control; in this last dose ‘Tommy Atkins’ (two years of evaluation) and ‘Kent’ (one year of evaluation) match the PBZ effect, and in some cases, they surpassed it by increasing flowering and yield.
In these cultivars, a single P-Ca application (1500 mg L‑1) may be an alternative to the use of PBZ.
Publication
Authors
M.H. Pérez-Barraza, M.V. Santos-Cárdenas, A. Álvarez-Bravo, R. Cano-Medrano, I.J. González-Acuña
Keywords
flowering, temperature, gibberellin inhibitors, fruit size, production
Groups involved
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