(ISHS, 2022) Miranda Jiménez, Carlos; Crespo Martínez, Sara; Oneka Mugica, Oihane; Laquidain Imirizaldu, María Jesús; Urrestarazu Vidart, Jorge; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Apple cider-making has a long tradition in many northern Spanish regions, such
as Gipuzkoa in the Basque Country. The production in this region is largely based on
traditional local cider cultivars for which very little information is available on their
pollination requirements, resulting in a generalized low productivity of the orchards.
In this work the self-(in)compatibility, S-alleles and pollen quality have been studied
for the main cider varieties grown in Gipuzkoa, which represent a wide genetic
diversity. The S-RNase genotype of 25 cultivars is firstly reported here, which allows
allocating the cultivars in their corresponding incompatibility group. All the S-alleles
have been previously described, being S26, S3 and S5 the most frequently found.
Regarding pollen quality triploid cultivars, as expected, showed lower viability (<70%)
and germination rates (<20%). Whereas most diploid cultivars showed good pollen
viability (>80%) and germination (>30%) rates, it is noteworthy the low performance
of ‘Urtebete’, very similar to that of triploids. Self-compatibility tests both in vitro and
in situ showed low rates of fruit set and, together with an upper position of the stigmas
related to stamens, reveal a low degree of self-compatibility for most cultivars.
Surprisingly, two cultivars called ‘Moko’ and ‘Txalaka’, showed certain selfcompatibility with around 7% fruit set. All in all, the results will enable to improve
traditional varieties orchard design as well as the profitability of apple cider farms in
the region.
