Full text in pdf format

Flowering behavior and 2n pollen production in dihaploid Solanum tuberosum x Solanum chacoense hybrids^*

Andréa Luiza Cunha^I; César Augusto Brasil Pereira Pinto^II; Lisete Chamma Davide^II

^IDepartamento de Biologia, Universidade Federal do Mato Grosso do Sul, Caixa Postal 649, 79069-000 Campo Grande, MS, Brasil
^IIDepartamento de Biologia, Escola Superior de Agricultura de Lavras, Caixa Postal 37, 37200-000 Lavras, MG, Brasil. Send correspondence to C.A.B.P.P.

ABSTRACT

The flowering characteristics of 81 dihaploid Solanum tuberosum (2n=2x=24) x Solanum chacoense (2n=2x=24) hybrid clones were studied. Two screenhouse experiments were carried out in the Biology Department at "Escola Superior de Agricultura de Lavras" between October and December 1991 (Spring) and March and May 1992 (Fall). The experimental design used was randomized complete blocks with three replications. Each experimental unit (plot) was formed by a single plant. The results showed wide variation among the clones for all the characteristics assessed. Clone flowering was abundant in both periods but more pronounced in the Spring. Clones were found with high 2n pollen frequencies making them promising for 4x - 2x crossings. The frequency and viability of 2n pollen were higher under mild temperatures (Fall). The amount of pollen produced on the anthers was normal and did not show any significant difference between the flowering periods.

Keywords: flowering behavior; pollen; dihaploid; Solanum tuberosum; Solanum chacoense; hybrids.

REFERENCES

Carrol, C.P. and Low, R.J. (1975). Flowering behaviour and seed fertility in dihaploid (Solanum tuberosum). Potato Res. 18: 416-427.

Hermundstad, S.A. and Peloquin, S.J. (1985). Male fertitily and 2n pollen production in haploid-wild species hybrids. Am. Potato J. 62: 479-487.

Iwanaga, M. and Schmiediche, P. (1989). Uso de espécies silvestres para mejorar los cultivares de papa. CIP Circular 17: 1-7.

Mendoza, H.A. (1989). Population breeding as a tool for germplasm enhancement. Am. Potato J. 66: 639-653.

Miller, J.C. (1936). The effect of length of dormant period upon the subsequent flowering of the potato plant. Am. Potato J. 13: 141-144.

Mok, D.W.S. and Peloquin, S.J. (1975). Breeding value of 2n pollen (diplandroids) in tetraploid x diploid crosses in potato. Theor. Appl. Genet. 46: 307-314.

Quinn, A.A., Mok, D.W.S. and Peloquin, S.J. (1974). Distribution and significance of diplandroids among the diploid Solanums. Am:. Potato J. 51: 16-21.

Ramanna, M.S. (1979). A re-examination of the mechanisms of 2n gamete formation in potato and its implications for breeding. Euphytica 28: 537-561.

Simmonds, N.W. (1976). Potatoes. In: Evolution of Crop Plants (Simmonds, N.W., ed.), pp. 279-283.

Turner, A.D. and Ewing, E.E. (1988). Effects of photoperiod night temperature, and irradiance on flower production in potato. Potato Res. 31: 257-268.

Yerk, G.L. and Peloquin, S.J. (1989). Comparison of 2n and non-2n pollen-producing haploid x wild species hybrids in potato. H. Hered 80: 468-471.

Yerk, G.L. and Peloquin, S.J. (1990). Performance of haploid x wild species 2x hybrids (involving five newly evaluated species) in 4x x 2x families. Am. Potato J. 67: 405-417.

* Part of a thesis presented by A.L.C. to Escola Superior de Agricultura de Lavras, in partial fulfillment of the requirements for the Master's degree.