Scab, caused by Venturia inaequalis, is the most destructive fungal disease of apple worldwide. Apple scab incidence was studied in apple orchards in the south and southeast of Kazakhstan, including the Almaty, Zhambyl, and Turkestan regions, during 2022 and 2023. Disease incidence was higher in the Zhambyl region than in the Turkestan and Almaty regions in both years. The field evaluation suggested that 19 genotypes showed resistance to apple scab. Molecular screening was carried out using eight gene-specific molecular markers (AM19, CH05e03, OPL19, Hi07f02, AL07, K08, HB09, and CH02f06). The results of the molecular screening revealed that in 38 of the 45 studied cultivars, which included 11 Kazakh cultivars and 34 foreign cultivars, the Rvi (Rvi2, Rvi4, Rvi5, Rvi6, Rvi8, Rvi9, Rvi11, Rvi14, and Rvi15) resistance genes were amplified. Resistance genes such as Rvi2, Rvi4, Rvi6, and Rvi9 are still useful for breeding, but their use is recommended only in extended pyramids of multiple resistance genes. Several cultivars will be strong candidates for further breeding programs against apple scab and for the pyramiding of scab resistance genes in new cultivars.

The most effective method to combat desertification is planting artificial forests of Populus pruinosa. In the Zhetysu and Almaty regions, samples were gathered from natural stands, which P. pruinosa and P. diversifolia likely displaced. The morphological attributes of 27 samples were related to one species, but one sample was causing doubt. PCR analyses were performed using eight microsatellite markers. The genotyping results revealed that all of the 28 samples collected were of the same type of P. pruinosa. They can effectively be introduced into in vitro culture in winter when physiological dormancy has ended. Annual lignified cuttings 6 to 7 cm long with 1 to 2 buds from selected plus trees were sterilized from saprophytic microflora by bleach NaOCl (1:1) for 10 min and 0.1% HgCl₂ solution for 5 min and placed on the medium. Both male and female plants were propagated in the medium that contained ½ Murashige and Skoog (MS), 0.1 mg L^-1 BAP; 0.02 mg L^-1 GA; 20 g L^-1 Glucose; pH 5.7, where the multiplication rate averaged 3.8 to 4.5, and the shoot length at 5.7 to 7.0 cm in 4 to 6 wk. For the transferring regenerated plants to soil in pots, the best substrate was found as peat, humus, and sand at a ratio of 50:40:10, respectively.

The monogenic resistance to powdery mildew (caused by Podosphaera leucotricha) of apple trees is crucial when selecting them. DNA markers allow it to differentiate apple cultivars by individual resistance traits and determine prospective genotypes with high reliability. The presented research determines the results of molecular genetics and phytopathological analyses of apple cultivars on loci Pl-2, Pl-1, Pl-w, and Pl-d for reactions to powdery mildew. The molecular screening procedure involved using seven gene-specific markers (EM M01, EM M02, AT20-450, OPN18 SCAR, OPU02 SCAR, dr70F/dr339, and dr55F/dr336R). The resistance genes Pl-1, Pl-2, Pl-w, and Pl-d were amplified in 30 of the 34 research cultivars, with 8 Kazakh and 26 other country apple cultivars among the ones researched, according to the results of a molecular screening. Although resistance genes are still helpful for breeding, they are only recommended for use in extended pyramids of multiple resistant genes. Several cultivars are excellent candidates for additional breeding programs against powdery mildew and for pyramiding the Podosphaera leucotricha resistant genes in new cultivars.