Self-incompatibility in passionfruit: evidence of gametophytic-sporophytic control.
Self-incompatibility in passionfruit was studied in families originated from crosses among plants that presented differences in reciprocal crosses. The three families, obtained by crossing S(3) plants, exhibited one incompatible group; no reciprocal differences were observed. The phenotype of the families was the same as the parent plants, S(3). These results suggest the presence of a gene ( G), gametophytic in its action, associated to the sporophytic gene S, modifying the incompatibility reaction in passionfruit. The reciprocal difference exhibited in the crosses among the parents could be explained as a matching between plants homozygous for S, but homozygous and heterozygous for G. Actually this would be a partially compatible cross, not detectable when the evaluation is done based on fruit set data. As the family originated from this kind of cross is homozygous for S and heterozygous for G, no reciprocal differences are expected, and the phenotype should be the same as the parental plants, as observed in the present work.
Suassuna
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Embrapa-Algodão, Rua Osvaldo Cruz 1148, Centenário, 58107-720, Campina Grande/PB, Brazil.
Bruckner
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de Carvalho
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Borém
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D003433:Crosses, Genetic; D005838:Genotype; D029598:Passiflora / Q000235:genetics*; D010641:Phenotype; D011058:Pollen / Q000235:genetics*; D012098:Reproduction / Q000235:genetics* / Q000502:physiology