Darkening of boiled tuber pulp of interspecies potato hybrides, their backcrosses

Abstract

The article presents data on the prospects of selection of accessions with non-darkening pulp after boiling among interspecies potato hybrids, their backcrosses. The categorization of the material under investigation into classes according to resistance to darkening and the averages of this parameter can confirm the foregoing. The high frequency of this trait expression in the offspring of individual populations and their genealogical closeness highlight the value of the selected accessions for practical breeding.

The aim and tasks of the study. The study purpose was to evaluate the prospects of interspecies potato hybrids, their backcrosses for selection of accessions with high resistance to boiled tuber pulp darkening. The purpose was completed through the following objectives: to investigate the distribution of the test accessions by boiled tuber pulp darkening and to reveal the dependence of this trait expression on the environmental conditions during the potato growing season; to identify interspecies hybrids, their backcrosses with strong expression of the trait; to evaluate the selected acсessions for genealogy; to establish the possibility of combining the trait under investigation with other agronomic traits.

Material and methods. Interspecies hybrids differing by backcrossing complexity and degree were taken as the test material. The resistance to tuber pulp darkening after boiling was evaluated by the approved method.

Results and discussion. A specific distribution of the interspecies hybrids, their backcrosses with respect to boiled tuber darkening was detected. This trait expression depended on conditions during the potato vegetation and on survey timing. These changes were smaller in the varieties-standards. The interspecies hybrids, their backcrosses with stronger expression of the trait ranging within 0.9–13.3% from year to year and from survey to survey were distinguished. Differences in the trait average across the surveys ranging within 1.1–0.3 points were recorded. The difference in the average across the years was 1.0, but no differences were observed in the second survey in 2015 and 2016.

A weak relationship between boiled tuber darkening and other cooking characteristics of the material was only found. A negative correlation coefficient in all the variants was only observed between boiled pulp darkening and water content in tubers. In some cases, the index decreased across the surveys (gustatory qualities), and in others – increased (mealiness).

Combinations with high frequencies of offspring with non-darkening pulp were selected. Some populations were characterized by very close origin, which indicates their value as initial breeding material for creating varieties with strong expression of the trait.
In was proved that hybrids with non-darkening pulp could combine this trait with high performance parameters, i.e. the total number of tubers per bunch and the number of marketable tubers per bunch.

Conclusions. The value of complex interspecies hybrids, their backcrosses for selection of accessions with non-darkening pulp was proved. The weak relationship between this parameter and other cooking qualities was only established. Combinations with high frequencies of offspring with non-darkening boiled tubers were selected. A lot of hybrids combine were noticeable for strong expression of the studied trait with other agronomic traits.