Correlations between low-temperature tolerance of anther donor clones of potato and the production of anther-derived embryos and calli at low temperatures.

The main purpose of this study was to investigate whether the degree of tolerance to low non-freezing temperatures of immature microspores in anther culture was correlated to the degree of low-temperature tolerance, measured by chlorophyll fluorescene, in the anther donor clone. Anther cultures of six tetraploids and eight dihaploids, derived from anther cultures of clone 199.13, were incubated at 10, 15, 20, 25 or 30 °C respectively. The embryo and callus production were determined and subsequently two quotients/clone, designated "temperature-related embryo and callus production," were established. The quotients were defined as embryo and callus production at 10 or 15 °C divided by the embryo and callus production, for the individuals clone, at the optimal temperature (20 or 25 °C) for the same production. These quotients were thereafter correlated to the low-temperature tolerances of the anther donors. The tetraploid and dihaploid group were treated separately and significant positive correlations were found in both cases. This indicates that tolerance to low temperatures is expressed in the anther donor plant as well as in the microspores grown in anther culture. It is suggested that in vitro selection through anther culture may be a useful tool for breeding for increased tolerance to low temperatures in potato.