Donnees sur les possibilites de restauration de fertilité d'hybrides interspecifiques entre cafeiers malgaches et africains et sur la variabilite observee dans une descendance issue de backcross
This paper intends to describe some methodological problems about the gene transfer by means of back-crossing from a Mascarocoffea species (C. kianjavatensis) to an Eucoffea species (C. canephora). The simultaneous observations of morphological characters, pollen colorability (as mesure of fertility) and meiotic behaviour lead to the following results. A multivariate analysis shows that the morphological characters can be distributed among two classes: 1. the first class exhibits in the back-cross 1 family a range of variations from the F1 to the recurrent parent C. canephora. The more they look like F1, the more sterile the plants are 2. The second class shows new combinations and some transgressions out of the range F1 to C. canephora. Here, there is no connection between the C. kianjavatensis aspect of back-cross 1 plants and their level of sterility. Most of the morphological variation is described by a linear combination (c) of the characters from the first class and very strong correlations are observed between C and pollen fertility (r = 0,84), C and a synthetic measure of meiotic regularity (r = 0,82), and pollen fertility and M (r = 0,81). Multiple and partial correlation analysis demonstrate that C and M measures, for the main, shart the same common cause of sterility. It looks as if major source of transfer problem was the consequence of the missing of homology for about three chromosomes among the eleven of the complete genom of both species. Some consequences for a plant breeding program are suggested
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
París (Francia)
1979
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| Subjects: | COFFEA CANEPHORA, COFFEA KIANJAVATENSIS, RETROCRUZAMIENTO, MEIOSIS, HIBRIDACION INTERESPECIFICA, VARIACION GENETICA, |
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