Marker-assisted selection of maintainer lines within an onion tropical population

Carlos Antonio Fernandes Santos,Daniela Lopes Leite,Marciene Amorim Rodrigues,Valter Rodrigues Oliveira

doi:10.1590/s0103-90162010000200015

Carlos Antonio Fernandes Santos, Daniela Lopes Leite + Show 2 more

Open Access

https://doi.org/10.1590/s0103-90162010000200015

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Abstract

The traditional onion (Allium cepa) hybrid production requires the development of maintainer and male sterile lines and also a pollinator line with good specific combination ability. We report the identification of maintainer and male-sterile onion lines within the Brazilian 'Baia Periforme' derived population, 'Alfa São Francisco', associating random field pairing of male-fertile plants with selected male-sterile plants and PCR-based marker system monitoring S, T and N-cytoplasms. Male-sterile plants produced flowers with light green anthers which were easily detected in the field. A frequency of 2.0% of male-sterile plants was estimated in the 'Alfa São Francisco' sampled population. Male-sterile plants produced the 5'cob-marker 180-bp and the orfA501-marker 473-bp fragments, suggesting the T-cytoplasm type, while the maintainer line produced only the 5'cob-marker 180-bp. These identified lines will be important to develop tropical onion hybrids well-adapted to Brazilian low latitudes and to future comparative studies with other onion cytoplasmic genic male sterility systems.

Highlights

The production of hybrid seeds of onion (Allium cepa L.) became economically feasible with the discovery of cytoplasmic-genic male-sterility (Jones and Clarke, 1943)
Male-sterile plants in the ‘Alfa São Francisco’ onion population produced flowers detected with light green anthers and when the anthers were squeezed between thumb and finger they did not leave any trace of pollen
Leite (1999) failed to find male sterile plants within the ‘Alfa Tropical’ by molecular screening which may have been due to some sample size problem because in the ‘Alfa São Francisco’, which was derived from ‘Alfa Tropical’, we have field-screened at least 1,500 plants

Summary

Introduction

The production of hybrid seeds of onion (Allium cepa L.) became economically feasible with the discovery of cytoplasmic-genic male-sterility (Jones and Clarke, 1943). We report the identification of lines ‘A’ and ‘B’ within the ‘Baia Periforme’ derived onion population, ‘Alfa São Francisco’, based on a PCR marker system monitoring cytoplasm type and by random field pairing of fertile plants with selected sterile plants.

Results

Conclusion