Micropropagation of the endangered species Malus niedzwetzkyana for conservation biodiversity in Kazakhstan

In Vitro Cellular & Developmental Biology - Plant - Biodiversity conservation requires advanced and effective ex situ plant propagation techniques. The present study was conducted to optimize...     

GWAS for plant growth stages and yield components in spring wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) harvested in three regions of Kazakhstan

Background

Spring wheat is the largest agricultural crop grown in Kazakhstan with an annual sowing area of 12 million hectares in 2016. Annually, the country harvests around 15 million tons of high quality grain. Despite environmental stress factors it is predicted that the use of new technologies may lead to increases in productivity from current levels of 1.5 to up to 3 tons per hectare. One way of improving wheat productivity is by the application of new genomic oriented approaches in plant breeding projects. Genome wide association studies (GWAS) are emerging as powerful tools for the understanding of the inheritance of complex traits via utilization of high throughput genotyping technologies and phenotypic assessments of plant collections. In this study, phenotyping and genotyping data on 194 spring wheat accessions from Kazakhstan, Russia, Europe, and CIMMYT were assessed for the identification of marker-trait associations (MTA) of agronomic traits by using GWAS.

Results

Field trials in Northern, Central and Southern regions of Kazakhstan using 194 spring wheat accessions revealed strong correlations of yield with booting date, plant height, biomass, number of spikes per plant, and number of kernels per spike. The accessions from Europe and CIMMYT showed high breeding potential for Southern and Central regions of the country in comparison with the performance of the local varieties. The GGE biplot method, using average yield per plant, suggested a clear separation of accessions into their three breeding origins in relationship to the three environments in which they were evaluated. The genetic variation in the three groups of accessions was further studied using 3245 polymorphic SNP (single nucleotide polymorphism) markers. The application of Principal Coordinate analysis clearly grouped the 194 accessions into three clades according to their breeding origins. GWAS on data from nine field trials allowed the identification of 114 MTAs for 12 different agronomic traits.

Conclusions

Field evaluation of foreign germplasm revealed its poor yield performance in Northern Kazakhstan, which is the main wheat growing region in the country. However, it was found that EU and CIMMYT germplasm has high breeding potential to improve yield performance in Central and Southern regions. The use of Principal Coordinate analysis clearly separated the panel into three distinct groups according to their breeding origin. GWAS based on use of the TASSEL 5.0 package allowed the identification of 114 MTAs for twelve agronomic traits. The study identifies a network of key genes for improvement of yield productivity in wheat growing regions of Kazakhstan.

     

Phenotypic and allozyme variation in Mediterranean and desert populations of wild barley,Hordeum spontaneum Koch

Populations of wild barley, Hordeum spontaneum Koch, were collected in two distinct climatic regions, desert and Mediterranean. Plants from five desert and five Mediterranean populations were compared and contrasted for extent and structure of phenotypic variation. These same 10 and one other population from each region were analyzed for allozyme variation. In a field trial of phenotypic diversity, two phenological and 14 morphological traits were examined. Study of allozyme variation was performed using eight enzyme systems encoding for 13 loci. Plants from the desert and Mediterranean regions were significantly different in seven of 16 phenotypic traits, exhibited a high (30%) interregional component of phenotypic variation, and showed a high degree of segregation on a principal component scattergram indicating ecotypic differentiation. Mediterranean populations were twice as variable as desert populations in reproductive growth parameters (stem and spike length) and grain filling (spikelet weight), but half as variable for onset of reproduction. The extent and structure of phenotypic and allozyme variation did not match. The Mediterranean and desert populations did not differ in amount of allozyme variation as estimated by mean number of alleles per locus, effective number of alleles, polymorphism, and gene diversity (n(a), n(e), P, and H(e)), did not segregate on the basis of population genetic distances, and exhibited a low proportion of interregion allozyme diversity (2%). No effect of selection on allozyme distribution was detected. Our results suggest that the adaptation of plants originating from desert and Mediterranean environments is reflected in phenotypic but not in allozyme variation.     

Morphological description and DNA barcoding study of sand rice (<Emphasis Type="Italic">Agriophyllum squarrosum</Emphasis>, Chenopodiaceae) collected in Kazakhstan

Background

Sand rice (Agriophyllum squarrosum (L.) Moq.) is an annual shrub-like plant adapted to the mobile sand dunes in desert and semi-desert regions of Asia. It has a balanced nutrient composition with relatively high concentration of lipids and proteins, which results in its nutrition being similar to legumes. Sand rice’s proteins contain the full range of essential amino acids. However, calories content is more similar to wheat. These features together with desert stress resistance make sand rice a potential food crop resilient to ongoing climate change. It is also an important fodder crop (on young stages of growth) for cattle in arid regions of Kazakhstan. In our work, sand rice samples were collected from two distant regions of Kazakhstan as a part of the nation-wide project to determine genetic variation of the native flora.

Results

Samples were collected in western and southeastern parts of Kazakhstan separated by distances of up to 1300 km. Sequences of the nuclear ribosomal DNA ITS1-5.8S-ITS2 region and the chloroplast matK gene confirmed the identity of species defined by morphological traits. Comparison with GenBank sequences revealed polymorphic sequence positions among Kazakh populations and GenBank references, and suggested a distinction among local populations of sand rice. The phylogenetic analysis of nucleotide sequences showed a clear partition of A. squarrosum (L.) Moq. from Agriophyllum minus Fisch. & C.A. Mey, which grows in the same sand dunes environment.

Conclusions

DNA barcoding analyses of ITS and matK sequences showed a segregation of A. squarrosum from A. minus into separate clades in Maximum-Likelhood dendrograms. ITS analysis can be successfully used to characterize A. squarrosum populations growing quite distant from each other. The data obtained in this work provide the basis for further investigations on A. squarrosum population structure and may play a role in the screening of sand rice plants growing in desert and semi-desert environments of Central Asia and China.

     

Modeling the Potential Distribution of Bacillus anthracis under Multiple Climate Change Scenarios for Kazakhstan

Anthrax, caused by the bacterium Bacillus anthracis, is a zoonotic disease that persists throughout much of the world in livestock, wildlife, and secondarily infects humans. This is true across much of Central Asia, and particularly the Steppe region, including Kazakhstan. This study employed the Genetic Algorithm for Rule-set Prediction (GARP) to model the current and future geographic distribution of Bacillus anthracis in Kazakhstan based on the A2 and B2 IPCC SRES climate change scenarios using a 5-variable data set at 55 km² and 8 km² and a 6-variable BioClim data set at 8 km². Future models suggest large areas predicted under current conditions may be reduced by 2050 with the A2 model predicting ∼14–16% loss across the three spatial resolutions. There was greater variability in the B2 models across scenarios predicting ∼15% loss at 55 km², ∼34% loss at 8 km², and ∼30% loss with the BioClim variables. Only very small areas of habitat expansion into new areas were predicted by either A2 or B2 in any models. Greater areas of habitat loss are predicted in the southern regions of Kazakhstan by A2 and B2 models, while moderate habitat loss is also predicted in the northern regions by either B2 model at 8 km². Anthrax disease control relies mainly on livestock vaccination and proper carcass disposal, both of which require adequate surveillance. In many situations, including that of Kazakhstan, vaccine resources are limited, and understanding the geographic distribution of the organism, in tandem with current data on livestock population dynamics, can aid in properly allocating doses. While speculative, contemplating future changes in livestock distributions and B. anthracis spore promoting environments can be useful for establishing future surveillance priorities. This study may also have broader applications to global public health surveillance relating to other diseases in addition to B. anthracis.     

Allozyme Variation in Turkmenian Populations of Wild Barley, Hordeum spontaneum Koch.

The extent and structure of genetic variation in 720 individualsrepresenting 36 populations of wild barley, Hordeum spontaneum,from Central Asia (Turkmenistan) were determined using starchgel electrophoresis of eight water soluble leaf proteins encodedby 13 loci. The populations were grouped into seven ecogeographicregions. The study found: (a) a similar amount of within populationgenetic diversity (H_e = 0.106), but lower total genetic diversity(H_T = 0.166) to that reported for Middle East populations ofH. spontaneum; (b) of the total genetic diversity, 61% was attributableto variation within populations, 27% between populations ofa region, and 12% among regions; (c) of the 42 alleles found,11 were ubiquitous, 22 were widespread and common, three localand common and seven local and rare; (d) there was a poor correlationbetween population genetic and geographic distances; and (e)the frequencies of only a few alleles correlated significantlywith climatic or geographic parameters. The extent and structureof genetic variation of Turkmenian populations, which representthe Central Asian part of the species' range, were significantlydifferent in some important aspects from Middle Eastern andeastern Mediterranean populations. The mosaic pattern of geneticvariation found in wild barley in the Middle East is less pronouncedin populations from Central Asia where there is less geneticdifferentiation among populations and regions, and more ubiquitousor common and fewer localized alleles. Copyright 2001 Annalsof Botany Company Allozyme, Central Asia, genetic diversity, Hordeum spontaneum, wild barley     

Morphological and physiological analysis of cleistogamy in barley (Hordeum vulgare)

We previously reported that cleistogamy/chasmogamy (CL/CH) of barley ( Hordeum vulgare L.) is controlled by either two tightly linked genes or one gene with multiple alleles. To clarify the morphological and physiological mechanisms of barley CL, we analysed the lodicule size and auxin response of two cultivars whose CL/CH was controlled by two different genes, cly1 and Cly2 . In both cases, lodicules of the CL parent were smaller than those of the CH parent. Analyses of lodicule size and flowering phenotype of f ₁ plants and segregation analyses of the mapping population indicated that lodicule size co-segregated with the flowering phenotype. Indole-3-acetic acid (IAA) and other synthetic auxins, such as 2,4-dichlorophenoxyacetic acid, induced abnormal flowering in CH ears, in which florets remained open for a few days instead of the normal hour or so, but not in CL ears. This auxin effect also co-segregated with the flowering phenotype. Analyses of auxin-related compounds in the floret organs revealed that the anther contained high levels of IAA, whereas indole-3-carboxylic acid, a putative decarboxylated metabolite of IAA, accumulated only in lodicules of CH plants just at flowering. These results indicate that lodicule size and auxin response are pleiotropic effects of the CL gene, which may play a role in auxin response or metabolism.