‘Tais’: a new pear cultivar for the Middle Urals

Expanding the assortment through the development of new highly adaptable cultivars is the main task of pear breeding in the Middle Urals. The most significant agronomic traits are winter hardiness, high fruit yield, and good fruit quality. The zoned pear assortment for the Middle Urals includes six cultivars. Six more cultivars now undergo the State Variety Trials. One of them is the new pear cultivar ‘Tais’ (breeding number DL-33-104), the result of crossing Dyuymovochka × Zhanna d’Ark. Cv. ‘Tais’ has been in variety studies at Sverdlovsk Horticultural Breeding Station (Yekaterinburg) since 2006. The new cultivar is characterized by good winter hardiness and productivity. The average yield at the age of 10–14 years is 9.42 tons per hectare, while the maximum yield is 19.81 t/ha. Fruits are yellow, with a good sweet taste, weighing 94 g. The content of dry matter is 11.9%, sugars 9.0%, and titratable acids 0.4%. According to the results of long-term research, the new pear cultivar ‘Tais’ was submitted to the State Variety Trials in 2017.

S-Genotyping and Seed Paternity Testing of the Pear Cultivar ‘Celina’

The diploid Celina/QTee® (‘Colorée de Juillet’ × ‘Williams’), one of the most promising pear cultivars developed by the Norwegian breeding program Graminor, was launched in 2010. In Norway, the flowering is medium to late, while the fruits ripen in the beginning of September. The fruits are attractive with an intense red blush (50%) on a green background. Although, ‘Celina’ is cultivated in the most climatically suitable regions for fruit cultivation, present in Norway, unfavorable environmental conditions for pear pollination can have a very negative effect on fruit set and consequent yield. The aim of this study was to determine the S-alleles of ‘Celina’, as well as its frequently used pollinizers, and, through paternity testing of ‘Celina’ seeds, give a recommendation regarding the most important pollinizers of this pear cultivar. In order to accomplish this, ‘Celina’ and its potential pollinizers were all S-genotyped. After harvest, seeds collected from ‘Celina’ fruit in 2017 and 2018 were genotyped using eleven microsatellite markers. Genomic DNA was also extracted from leaf material collected from ‘Celina’, as well as from five pear cultivars used as pollinizers in the three examined orchards, and analyzed using the same marker set. Subsequently a simple sequence repeat (SSR) database was constructed and used for gene assignment analyses with the aim of quantifying pollen donor contribution from individual pollinizers. The obtained results indicate that ‘Anna’, the only examined pollinizer that was fully cross-compatible with ‘Celina’, together with ‘Fritjof’, the genotype which had the highest flowering overlap with ‘Celina’, proved to be the most successful pollinizers across all seasons and orchards. Although both cultivars were ubiquitous in the examined orchards, either as planted trees or as branches introduced during the flowering period, they were the most abundant pollinizers in only one orchard each. It is therefore possible to conclude that pollinizer abundance has a secondary significance in pollinizer success within investigated ‘Celina’ orchards.

Morphological characteristics of Packham’s Triumph pear cultivar fruiting wood

Pear as a fruit species forms various categories of fruit-bearing branches during its life cycle. Depending on how many years it takes to form a young fruiting wood of pear cultivar from its meristem, there can be an annual, biennial, or perennial organogenesis cycle, which in the first place depends on cultivar’s genotype, the rootstock on which the cultivar is grafted, the applied agricultural techniques in nursery and other conditions. Knowledge of the individual pear cultivars organogenesis cycle is the basis for planning regular and stable yields. In order to determine the structure of a fruiting wood for an individual pear cultivar, it is necessary to make analyses on individual increment categories; what is developing from those increments in the following year. The morphological characteristics of annual increments are analysed (spurs, stems, and long shoots) of Packham’s Triumph pear cultivar, as well as the morphological characteristics of each category’s annual increment bourse-over-bourse, all with statistically significant difference between studied factors and factorial levels. Peckham’s Triumph had higher average length of long shoots in both examining years 2011 (53.63) and 2012 (45.33) and William's cultivar had the shorter ones.