Thursday, 14 July 2016

Priming effects on seed germination in Tecoma stans (Bignoniaceae) and Cordia megalantha (Boraginaceae), two tropical deciduous tree species

Published Date

November 2014, Vol.61:65–70, doi:10.1016/j.actao.2014.10.007

Original article

Title

Priming effects on seed germination in Tecoma stans(Bignoniaceae) and Cordia megalantha(Boraginaceae), two tropical deciduous tree species

Author

Sandra Alvarado-López^a,1

Diana Soriano^a,1

Noé Velázquez^b

Alma Orozco-Segovia^a

Alicia Gamboa-deBuen^a,^,

aInstituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, 04510 México, D.F., Mexico
bCentro de Investigaciones Tropicales, Universidad Veracruzana. Interior de la Ex hacienda de Lucas Martín, Xalapa C. P. 91010, Veracruz, Mexico

Received 8 May 2014. Revised 21 October 2014. Accepted 21 October 2014. Available online 29 October 2014.

Highlights

•
Natural and priming effects were examined on the seed germination of two tree species.
•
Priming treatments promoted seed germination of the tropical pioneer tree Tecoma stans.
•
Matrix priming promoted seed germination of the tropical tree Cordia megalantha.
•
Priming treatments are useful tools for restoration and reforestation programs.

Abstract

Successful revegetation necessarily requires the establishment of a vegetation cover and one of the challenges for this is the scarce knowledge about germination and seedling establishment of wild tree species. Priming treatments (seed hydration during a specific time followed by seed dehydration) could be an alternative germination pre-treatment to improve plant establishment. Natural priming (via seed burial) promotes rapid and synchronous germination as well as the mobilisation of storage reserves; consequently, it increases seedling vigour. These metabolic and physiological responses are similar to those occurring as a result of the laboratory seed priming treatments (osmopriming and matrix priming) applied successfully to agricultural species. In order to know if natural priming had a positive effect on germination of tropical species we tested the effects of natural priming on imbibition kinetics, germination parameters (mean germination time, lag time and germination rate and percentage) and reserve mobilisation in the seeds of two tree species from a tropical deciduous forest in south-eastern México: Tecoma stans (L Juss. Ex Kunth) and Cordia megalantha (S.F Blake). The wood of both trees are useful for furniture and T. stans is a pioneer tree that promotes soil retention in disturbed areas. We also compared the effect of natural priming with that of laboratory matrix priming (both in soil). Matrix priming improved germination of both studied species. Natural priming promoted the mobilisation of proteins and increased the amount of free amino acids and of lipid degradation in T. stans but not in C. megalantha. Our results suggest that the application of priming via the burial of seeds is an easy and inexpensive technique that can improve seed germination and seedling establishment of tropical trees with potential use in reforestation and restoration practices.