Dihaploid Plant Production from 4 × ‐Genotypes of Potato by the Use of Efficient Anther Plants Producing Tetraploid Strains (4 × EAPP‐Clones) — Proposal of a Breeding Methodology

摘要

AbstractTetraploid clones of potato with a superior efficiency in producing androgenetic plants (4 × EAPP‐clones) have been obtained by culturing in vitro anthers of 2 × EAPP‐clones. The latter were isolated by three cycles of recurrent selection from diploid breeding material (UHRIG 1985 a). In this paper we report on the capacity of 4 × EAPP‐clones, when crossed to in vitro unresponsive 4 × genotypes, to transmit to their F1their androgenetic potential, Five 4 ×× 4 × F1crosses were considered, which produced on average 35 embryoids per flower – a value higher than that of nonresponsive 4 × genotypes (no embryoids obtained), but‐also significantly better than the value found for 4× EAPP‐clones (9.8 embryoids per flower). The hybrid families behaved differently from each other, with one producing up to 63 embryoids per flower. A range of per plant values was, moreover, found, revealing the existence of a large variability among sister plants belonging to the same F1cross. The presented data indicate a rather simple inheritance of dominant genetic factors acting in favor ot androgenesis. They also suggest that the utilized 4× EAPP‐clones were possibly heterozygous for such genes.Data are also reported on the ploidy level of anther plants obtained from 4× and 2× EAPP‐clones. In this respect 2× EAPP‐clones show the interesting capacity of generating, via anther culture, a consistent fraction of tetraploid plants (13,7 ).Based on the findings reported in this paper we propose, for tetraploidS. tuherosumL., a cyclic breeding procedure making use of anther culture and where ploidy level alternates, wit