Further progress with in vitro anther culture of European hazelnut

Abstract

The fastest way to reach homozygosis is doubling the chromosome number of a haploid genotype. Doubled haploids are useful for fixing traits in desirable combinations, and facilitating marker development, mapping, and marker-assisted selection (MAS). Immature catkins were harvested from branches of selected plants of ‘Nocchione’, ‘Tonda di Giffoni’ and ‘Tonda Gentile Romana’ when the pollen had reached the uninucleate and early bi-nucleate stages. The catkins were surface-sterilized by vigorous shaking in 70% ethanol for 30 s, immersion for 10 min in a 20% solution of commercial bleach with a few drops of Tween 20, and washing three times in sterile distilled water. The catkins were stored in sealed plastic bags and maintained for three days at 4°C in darkness. The anthers were placed on two basal media (N6 and BN) with three combinations of growth regulators. The results confirmed the remarkable influence of the genotype on callus formation. No clear information was obtained, as the analysis of variance revealed a marked interaction among the factors studied. 2,4-D plays a key role in callus formation in hazelnut. No haploid tissues were obtained, although many cells showed chromosome number instability. The better medium and growth regulator combinations were identified to induce callus formation from the inner parts of the anthers. This information could be useful for future investigations.