Background: The pathogens fromFusariumspecies can cause Fusarium root rot (RR) and other diseases in plant species including sugar beet (Beta vulgarisL.), and they have a strong negative impact on sugar beet yield and quality.Methods: A total of 22 sugar beet breeding lines were evaluated for the symptoms of RR after inoculation withFusarium oxysporumSch., isolate No. 5, and growth in a field trial. Two candidate genes for RR resistance,BvSP2andBvSE2, encoding chitinases Class IV and III, respectively, were previously identified in sugar beet, and used for genotyping using modern Amplifluor-like single nucleotide polymorphism (SNP) genotyping approach. The qPCR expression analysis was used to verify responses of the candidate genes for RR infections.Results: A strong association of two SNP markers forBvSP2andBvSE2with resistance to RR in sugar beet was found in our study. Very highBvSP2expression (100-fold compared to Controls) was observed in three RR resistant accessions (2182, 2236 and KWS2320) 14 days after inoculation which returned to the control level on Day 18. RR sensitive breeding line 2210 showed a delay in mRNA level, reaching maximal expression ofBvSP218 days after inoculation. The geneBvSE2, showed a strong expression level in leaf samples from the infected field trial only in the breeding line 2236, which showed symptoms of RR, and this may be a response to other strains ofF. oxysporum.

A.M. ABEKOVA, R.S. YERZHEBAYEVA, S.O. BASTAUBAYEVA, K. KONUSBEKOV, T.A BAZYLOVA., D.I. BABISSEKOVA, and A.A. AMANGELDIYEVA SUMMARY Sugar beet is a highly valuable and profitable crop in the Republic of Kazakhstan. It is the only source of raw materials for the production of crystalline sugar and incidentals (tops, bagasse, and molasses).

The photoperiodic sensitivity of soybean (Glycine max L.) is one of the limiting factors affecting plant growth and yield. At higher latitudes, early flowering and maturity with neutral reaction to photoperiods are required for adaptation of soybean plants to long-day conditions. Currently, the production and distribution of new varieties of soybeans adapted to widespread agricultural regions in northern Kazakhstan is in strong demand. Eleven soybean hybrid populations were obtained from crosses between 17 parents with four maturity groups, MG 000, 00, 0, and I. Marker-assisted selection (MAS) was assessed for suitable SSR markers and successfully applied for genes E1, E3, E4, and E7, targeting homozygous genotypes with recessive alleles. The identified and selected genotypes were propagated and tested in the conditions of 53° N latitude in the Kostanay region of northern Kazakhstan. Finally, 20 early maturing F₄ breeding lines were identified and developed with genotypes e1 e3 E4 e7, e1 E3 E4 e7, and e1 E3 e4 e7, all completing their growth period within 92–102 days. These breeding lines were developed by MAS and should provide very prospective superior varieties of soybean for northern Kazakhstan through a strategy that may be very helpful to other countries with high latitudes.

Soybean is a major legume and oilseed crop with enormous economic importance, but its production is highly dependent on optimal rainfall or ample irrigation. In Kazakhstan, soybean production is highly vulnerable to drought and irrigation shortages. The aim of this study was to assess the level of drought escape and tolerance of soybean genotypes in different maturity groups, grown in well-watered conditions or without irrigation. Field trials were conducted in the very dry conditions of Kazakhstan with the hydrothermal coefficient 0.46–0.67. Nineteen soybean cultivars from five maturity groups were tested over four seasons under two conditions, with and without irrigation. The main indicators of drought tolerance were seed yield, seed weight per plant, percentage of seeds with smooth coats compared to wrinkled and shriveled ones, and 1000 seed weight. Under drought, seed yield of the studied genotypes decreased by 45.5–69.5% compared to well-watered controls. The most optimal genotypes for cultivation without irrigation were soybean cultivars from medium maturity group MG I (Vilana, Cheremosh, Xin-D11-252, and Desna) with a vegetation period of 115–128 days when avoiding drought during flowering, and the average yield for the group (1.7 t/ha) was slightly below that of those in drought-tolerant genotypes from medium–late/late maturity groups MG II–III (1.9–2.0 t/ha). Based on yield under drought, the best cultivars were identified as follows: Ivushka (1.2 t/ha) for MG 00 group; Ustya (1.3 t/ha) for MG 0; Vilana (1.8 t/ha) for MG I; Zen (2.3 t/ha) for MG II; and Sponsor (2.5 t/ha) for MG III. The identified genotypes can be used in breeding programs to reduce drought effects on soybean crops.

Development of drought tolerant cultivars of soybean is the single best way to address the challenge of global climate change and very limited water resources for crop irrigation in Central Asia including Kazakhstan. A set of 188 soybean cultivars with diverse origins was assessed for genome-wide association study (GWAS) for yield and eight yield-related traits in both irrigated (well-watered, WW) and non-irrigated (drought) conditions during 2 years in field trials in South-Eastern Kazakhstan. The 295K Diversity array technology (DArT) analysis was applied, and 16K filtered DArT markers were used for genotyping of 183 soybean accessions. In the results, 41 quantitative trait nucleotides (QTN) were identified as significantly associated with nine studied traits. To verify these results, bulk segregant analysis (BSA) was carried out in six breeding lines originating from two crosses between high-yielding under drought cvs, Sponsor and Zen, with drought sensitive cv Lastochka. The evaluation of combined results revealed 10 most significant QTN and eight most promising putative candidate genes, which were selected and tested for their gene expression using RT-qPCR under drought compared with WW controls. Among them, glucose-6-phosphate isomerase (G6PI), pentatricopeptide repeats (PPR) protein, and ABC transporter, associated with seed yield, seed weight per plant, and plant height, were highly upregulated in drought tolerant genotypes. In contrast, two other genes, Rab-GDP dissociation inhibitor (Rab-GDI) and Transducin with WD40 repeats, associated with seed yield, showed repression in the same genotypes. These verified genes involved in the control of yield and yield-related traits can be used for marker-assisted selection to develop novel genotypes and new soybean cultivars tolerant to strong drought in Kazakhstan and in other countries with similar conditions.