Study on some factors involved in the chromosome number variation of pollen plants
1994
Badea, E.M. | Lupusanschi, I. (Institutul de Biologie, Bucuresti (Romania)) | Verzea, M. (Institutul de Cercetari pentru Cereale si Plante Tehnice, Fundulea (Romania)) | Raicu, P. (Bucuresti Univ. (Romania). Facultatea de Biologie)
All plants of pollen origin, irrespective of their way of regeneration (direct or via callus), are characterized by the variation of the chromosome number. The stage of microspore development at the moment of anther culture as well as the type and quantity of hormones added to the culture media influence the amplitude of phenomenon and the frequency of the different variation classes haploids, dihaploids, polyhaploids, but the main factor which determine the frequency of these classes is the ploidy level of the anther donor-plants. At diploid species, non-haploids are predominant whereas at polyploid ones haploids are predominant in the population of pollen-origin regenerants. In genom spores, the more advanced the development stages of the microspores are the higher the nuclear fusion tendency is. Moreover, the type and quantity of hormones added to the culture medium control the frequency of these fusions: auxines inhibit them, and cytokinines stimulate them. The existence in the spores undergoing androgenesis of several genomes diminishes the effects of these factors and, therefore, the variability of the chromosome number in regenerated plants.
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