Fire blight cases in Almaty Region of Kazakhstan in the proximity of wild apple distribution area

Fire blight caused by Erwinia amylovora reached Kazakhstan in 2008. Here, the disease poses a threat not only to agricultural production of apples and pears, but also to the forests of wild Malus sieversii, the progenitor of most domesticated apple varieties worldwide. In the period 2019–2021, the spread of fire blight in the growth area of wild apples was limited by the weather conditions. In 2022, late spring and early summer were characterized by increased rainfall and moderate temperatures favorable for the disease. The goal of this study was to monitor the distribution of fire blight in private households and small orchards in the zones adjacent to wild apple distribution areas. A total of 91 samples with fire blight-compatible symptoms were collected from cultural apples (68), wild apple (10), pear (5), hawthorn (7), and quince (1) in south-eastern and eastern Kazakhstan, resulting in 21 isolates (one from pear, one from quince, and 19 from apple) of E. amylovora. All isolates belonged to the archetypal CRISPR genotype A. Considering the relative proximity of the infections to the forests of wild M. sieversii, additional measures for fire blight control and prevention will have to be implemented, including state monitoring of the wild apple forests for disease symptoms and awareness campaigns for specially protected natural territories that safeguard M. sieversii, as well as for local pomaceous-fruit growing communities

Optimization of core phases of biolistic transformation of potato

We have established the optimal exposure time for internodes and callus plant material of Aksor potato variety on the OSS osmotic medium before and after biolistics and the type of plant explant that is most suitable for that. The optimal objects were explants from internodes of test plants. The best time for exposure of plant material to the osmotic medium before bombardment is 24 hours, and after biolistics – 48 hours. Callus tissue developed on the MS medium with zeatin two weeks later in internodes that were cultivated before bombarding on the OSS for 24 hours and we observed an increase in the callus mass by the end of fourth week. Not a single callus was obtained with rhizogenesis on the R4 medium from internodes and potato calli that were on the osmotic medium within 24 and 72 hours after biolistics. The regenerative capacity of internodes after cultivation on an osmotic medium for 48 hours after bombarding was higher than that of calli. We obtained 12 regenerant plants out of 200 internode explants and 4 regenerant plants out of 150 calli that were used in the experiment