Intact floral buds and anthers with microspores in late mononuclear stage were placed on the
basic medium of Murashige and Skoog (1962) with vitamins (Nitsch and Nitsch, 1969) and different
dosages of NAA, GA3 and 6BA. Sucrose (20 g/1) and agar (7 g/1) were added to the medium; pH was
adjusted to 5.8. A number of pretreatments with 2-4 D(10 ppm) were carried out.
After 7 days of culture (dark, 27oC) several microspores in the cultured buds and anthers
were found to contain more than 2 nuclei (up to 8 in certain cases). The proportion of
polynucleated microspores was higher in material pretreated with 2-4 D. In some of the anthers
pretreated with 2-4 D and exposed to photoperiodical light during two weeks (16h, 6000 lux) after
5 days of culture in darkness, microspores could be clearly observed to have evolved into globular
embryos (up to 32 cells).
References
Murashige, T. and F. Skoog, 1962. Physiol. Plantarum 15:473-497.
de Nettancourt, D., et al., 1974. Theoretical and Applied Genetics 44:278-288.
Nitsch, J. P., and C. Nitsch, 1969. Science 163:85-87.
Daskaloff, H., M. Konstantinova, and K.
Moinova Inheritance of lycopene content in
tomato fruits.
Analysis determining the lycopene content of
tomato fruits in P1, P2 and F1 plants of a 6 x 6 (n2)
diallel cross were made during the 1974-1977
period within the breeding program
for high quality tomatoes. Results obtained showed that lycopene content, which is controlled by
genes regulating the ability for its synthesis, is a hereditary character and although influenced
by environmental factors it is typical for each tomato species or cultivar.
Correlation relationships between lycopene content and the parental dominance indicator Wr
+ Vr prove that the parents with low lycopene content have a larger number of dominant genes,
while the genes in parents with high lycopene content are mostly recessive (Table).
4
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