Pre-germination treatments and storage of cassava seeds and their correlation with emergence of seedlings

Itamara Mezzalira,Caroline Jácome Costa,Eduardo Alano Vieira,Karina Nascimento Da Silva,Marilia Santos Silva,Josefino De Freitas Fialho,Marcelo Luiz Denke

doi:10.1590/s2317-15372013000100016

Abstract

Despite propagation of the cassava crop be done by cuttings for commercial purposes, the majority of accesses keeps active the sexual propagation system; what is essential to genetic breeding programs. Cassava seeds, however, have low and uneven germination rates. Considering such event, the objective of this study was to evaluate the efficiency of the storage, and different pre-germination treatments, on cassava seedling emergence. For this, an experiment was carried out with seeds obtained by open pollination between plants of four sweet cassava cultivars, with 10 pre-germination treatments; in addition to a control treatment. The viability of seeds subjected to different treatments was assessed by tetrazolium test; and the assessment of seedling emergence was performed by daily counts of the number of emerged seedlings. Data obtained were expressed in: emergence percentage; emergence speed index; and mean time of seedling emergence. It was concluded that storage, at 4 °C, during one year, increases seed emergence percentage and favors cassava seedling emergence speed; and that the dry heat (60 ºC), during seven and 14 days, also favors their emergence speed .

Highlights

Cassava (Manihot esculenta Crantz) is a bushy perennial, whose probable center of origin and diversity is Brazil (Olsen, 2004)
For commercial purposes or livelihood, the cassava cultivation is exclusively performed by means of vegetative propagation by using “seed-cuttings”, majority of accesses maintains active the sexual propagation system (Vieira et al, 2008)
The seeds of cassava used in the experiment were obtained in an area of Embrapa Cerrados, originating from crossings by open pollination among plants of sweet cassava varieties IAC 576-70 (Japonesinha), IAPAR 19 (Pioneira), BGNC 751 (Japonesa), and BGMC 1289 (Moura); which are the most cultivated in the region of Federal District and surroundings

Summary

Introduction

Cassava (Manihot esculenta Crantz) is a bushy perennial, whose probable center of origin and diversity is Brazil (Olsen, 2004). The species is cultivated for the use of its tuberous roots, rich in starch, which are consumed i. For commercial purposes or livelihood, the cassava cultivation is exclusively performed by means of vegetative propagation by using “seed-cuttings”, majority of accesses maintains active the sexual propagation system (Vieira et al, 2008). The maintenance of sexual propagation system active through crossbreeding, allows constant gene recombination and gene combination of different origins in a single genotype; what confers higher adaptation capacity to environmental changes to the species. The vegetative reproduction allows immediate adaptation to environmental conditions, by means of higher genetic characteristics fixation, selected consciously or unconsciously within the segregating population (Elias et al, 2001; Duputié et al, 2009)

Objectives

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Results