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Full Length Research Paper
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Phenotypic
variations of F1 and F2 populations
from three species of Solanum L. (Solanaceae)
O. A. Oyelana1*
and R. E. Ugborogho2
1Babcock
University, Department of Basic and Applied Sciences, PMB
21244, Ikeja, Lagos, Nigeria.
2University of Lagos, Department of Cell Biology
and Genetics, Akoka, Yaba, Lagos, Nigeria.
*Corresponding author. E-mail:
oyelana2@yahoo.com.
Tel: +234-805-521-3933.
Accepted
18 June, 2008 |
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Abstract |
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Emerging
chromosome types in some Solanum species underscore
inherent potentials and possible new and expanded genome.
Interspecific crosses involving the varieties of Solanum
melongena L., Solanum macrocarpon L. and
Solanum aethiopicum L. were carried out to assess
species phylogenetic relationships and the extent of
evolutionary changes with a view to improving the agronomic
characters in the hybrids. The dimensions of leaves, petals
and fruits in the F1 hybrids were intermediate in
values between parents while parental influence was
significant in such characters as growth habit,
inflorescence types and colour of flowers. Pollen viability
was depressed from 97.3 – 71% in parents to 56.8 - 48.8% in
the F1 and consistently lowered from 48.6 – 38.2%
in the F2 hybrids but restored (63.8%) in an F2
plant. Fruits were few on inflorescence, small sized with
generally fewer seeds in the F1 (67 - 132) and F2
(52 – 135) hybrids compared with the parents (87 – 384). A
single flowered inflorescence from a cross (S. melongena
‘Melongena’ x S. aethiopicum) revealed a novel gene
and possible selective ecological advantage over other
hybrids. The incomplete restoration of some of the masked
characters in the F2 hybrids suggests a
near-complete homogenization of parental genomes and/or
chromosomal disharmony through silent genomic changes. These
might have prevented sufficient chromosomal rearrangement
and full homology for improved vigour in many of the F2
hybrids.
Key words: Solanum, genome, phenotype,
taxonomy, evolution, interspecific hybridization, pollen
viability, hybrid fertility fruit set. |
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