A panel of 89 local commercial cultivars of bread wheat was tested in field trials in the dry conditions of Northern Kazakhstan. Two distinct groups of cultivars (six cultivars in each group), which had the highest and the lowest grain yield under drought were selected for further experiments. A dehydration test conducted on detached leaves indicated a strong association between rates of water loss in plants from the first group with highest grain yield production in the dry environment relative to the second group. Modern high-throughput Amplifluor Single Nucleotide Polymorphism (SNP) technology was applied to study allelic variations in a series of drought-responsive genes using 19 SNP markers. Genotyping of an SNP in the TaDREB5 (DREB2-type) gene using the Amplifluor SNP marker KATU48 revealed clear allele distribution across the entire panel of wheat accessions, and distinguished between the two groups of cultivars with high and low yield under drought. Significant differences in expression levels of TaDREB5 were revealed by qRT-PCR. Most wheat plants from the first group of cultivars with high grain yield showed slight up-regulation in the TaDREB5 transcript in dehydrated leaves. In contrast, expression of TaDREB5 in plants from the second group of cultivars with low grain yield was significantly down-regulated. It was found that SNPs did not alter the amino acid sequence of TaDREB5 protein. Thus, a possible explanation is that alternative splicing and up-stream regulation of TaDREB5 may be affected by SNP, but these hypotheses require additional analysis (and will be the focus of future studies).

In dry conditions, tall and fast‐growing wheat plants with good tolerance to drought may offer higher grain yields than ‘Green revolution’ wheat.

The genetic diversity of 116 spring bread wheat cultivars released in Kazakhstan from 1929Kazakhstan from -2004 was studied by means of a genealogical analysis. The tendency of genetic diversity to change over time was traced by analysing a series of n × m matrices, where n is the number of released cultivars and m is the number of landrace ancestors. The pool of landrace ancestors of spring wheat cultivars in 1929-2004 contained a total of 114 landraces and old varieties, including 19 from Kazakhstan and Central Asia and 23 from neighbouring regions of Russia. The original ancestors differ significantly in frequency of presence and hence in their importance in the genepool of spring wheats cultivated in Kazakhstan. Significant differences in the contributions of dominant ancestors to cultivars for various regions have been revealed, showing that those ancestors were specifically adapted to different growing conditions. During the past 75 years, genetic diversity has increased due to the wide use of foreign materials in breeding programmes. A more detailed study has shown that during the period analysed, 15 landraces from Kazakhstan and neighbouring regions of Central Asia and Russia (35% of local germplasm) were lost from the pedigrees. The cluster structure of modern cultivars included in the Kazakhstan Official List (2002) was established. By analysing coefficients of parentage, significant differences in the genetic diversity of cultivars from various growing regions were revealed.

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BackgroundThe pathogens from Fusarium species can cause Fusarium root rot (RR) and other diseases in plant species including sugar beet (Beta vulgaris L.), and they have a strong negative impact on sugar beet yield and quality.MethodsA total of 22 sugar beet breeding lines were evaluated for the symptoms of RR after inoculation with Fusarium oxysporum Sch., isolate No. 5, and growth in a field trial. Two candidate genes for RR resistance, BvSP2 and BvSE2, 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.ResultsA strong association of two SNP markers for BvSP2 and BvSE2 with resistance to RR in sugar beet was found in our study. Very high BvSP2 expression (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 of BvSP2 18 days after inoculation. The gene BvSE2, 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 of F. oxysporum.