Effect of in vitro induced water deficit on lipid peroxidation intensity and antioxidant capacity of sugar beet

Accompanied by oxidative stress as a signal to activate defense mechanisms, various abiotic factors induce peroxidation of membrane lipids. The aim of this research was to analyse changes in lipid peroxidation (LP) intensity and antioxidant capacity of selected sugar beet genotypes during micropropagation under the conditions of water deficit. Performed research represents a part of a more comprehensive study, the purpose of which is understanding the difference in acclimation to drought as the major abiotic factor limiting sugar beet production in Serbia. The best solution for overcoming this obstacle in successful sugar beet growing is breeding for drought tolerance. Tested sugar beet genotypes were grown and multiplied in vitro on standard nutrient medium. Axillary shoots were placed on the micropropagation media with 3% and 5% PEG for 28 days, which caused physiological drought stress. All genotypes could be divided into three groups according to the level of LP, however only two of eight genotypes had significantly higher LP intensity during drought conditions when compared to their controls (10.1-29.1%), as well as significantly reduced antioxidant activity (22.2-59.9%). A slight decrease in LP intensity and enhanced antioxidant capacity (up to 92.9%) in comparison to control were recorded in treatments of the rest of investigated genotypes. As for correlation between tested biochemical parameters and growth conditions, all genotypes differed in their response to PEG concentration. Obtained results showed that LP intensity and antioxidant capacity could be used as biochemical parameters in assessing drought tolerance of individual genotypes in further selection of sugar beet

Development and application of qRT-PCR for sugar beet gene expression analysis in response to in vitro induced water deficit

Abstract Sugar beet is a significant industrial crop, often grown in the areas where summer drought can severely limit root yield and sugar content. In order to improve development of sugar beet cultivars with increased drought tolerance it is necessary to understand plant response to water stress at the genomic level. Since recent research efforts have focused on the molecular response of the plant in order to identify water deficit inducible genes, the aim of this investigation was to develop qRT-PCR methodology for the quantification of gene expression in sugar beet under conditions of water deficiency in vitro. Sugar beet genotypes, selected for different response to water deficit, were grown and multiplied in vitro. Axilary shoots were placed on micropropagation media with 0%, 3% and 5% PEG, for 28 days. To determine reaction of sugar beet genotypes to in vitro induced water deficit changes in number of axillary shoots, shoot fresh weight and dry matter content were measured. Total RNA was extracted from leaves and reverse transcribed into cDNA, which served as matrix in real-time PCR reaction using TaqMan technology. The housekeeping gene for glutamine synthetase was used as endogenous control, while the genes for alpha amylase and osmotin-like protein were target genes. The relative quantification values for each target gene were calculated by the 2- 06 06Ct method. Selected candidate genes differed in relative gene expression among genotypes and applied PEG treatments. The obtained results indicated that qRT-PCR protocol was efficient and accurate, showing the potential to be used in further expression analysis of candidate genes involved in sugar beet reaction to water stress

Estimation of the Genetic Diversity in Tetraploid Alfalfa Populations Based on RAPD Markers for Breeding Purposes

Alfalfa is an autotetraploid, allogamous and heterozygous forage legume, whose varieties are synthetic populations. Due to the complex nature of the species, information about genetic diversity of germplasm used in any alfalfa breeding program is most beneficial. The genetic diversity of five alfalfa varieties, involved in progeny tests at Institute of Field and Vegetable Crops, was characterized based on RAPD markers. A total of 60 primers were screened, out of which 17 were selected for the analysis of genetic diversity. A total of 156 polymorphic bands were generated, with 10.6 bands per primer. Number and percentage of polymorphic loci, effective number of alleles, expected heterozygosity and Shannon's information index were used to estimate genetic variation. Variety Zuzana had the highest values for all tested parameters, exhibiting the highest level of variation, whereas variety RSI 20 exhibited the lowest. Analysis of molecular variance (AMOVA) showed that 88.39% of the total genetic variation was attributed to intra-varietal variance. The cluster analysis for individual samples and varieties revealed differences in their population structures: variety Zuzana showed a very high level of genetic variation, Banat and Ghareh were divided in subpopulations, while Pecy and RSI 20 were relatively uniform. Ways of exploiting the investigated germplasm in the breeding programs are suggested in this paper, depending on their population structure and diversity. The RAPD analysis shows potential to be applied in analysis of parental populations in semi-hybrid alfalfa breeding program in both, development of new homogenous germplasm, and identification of promising, complementary germplasm

Composição de subunidades de proteínas de reserva em genótipos de soja com alto teor de proteína

The objective of this work was to quantify the accumulation of the major seed storage protein subunits, β-conglycinin and glycinin, and how they influence yield and protein and oil contents in high-protein soybean genotypes. The relative accumulation of subunits was calculated by scanning SDS-PAGE gels using densitometry. The protein content of the tested genotypes was higher than control cultivar in the same maturity group. Several genotypes with improved protein content and with unchanged yield or oil content were developed as a result of new breeding initiatives. This research confirmed that high-protein cultivars accumulate higher amounts of glycinin and β-conglycinin. Genotypes KO5427, KO5428, and KO5429, which accumulated lower quantities of all subunits of glycinin and β-conglycinin, were the only exceptions. Attention should be given to genotypes KO5314 and KO5317, which accumulated significantly higher amounts of both subunits of glycinin, and to genotypes KO5425, KO5319, KO539 and KO536, which accumulated significantly higher amounts of β-conglycinin subunits. These findings suggest that some of the tested genotypes could be beneficial in different breeding programs aimed at the production of agronomically viable plants, yielding high-protein seed with specific composition of storage proteins for specific food applications.O objetivo deste trabalho foi quantificar o acúmulo das principais subunidades de proteínas de reserva da soja, β-conglicinina e glicinina, e como elas influenciam a produtividade e os conteúdos de proteína e de óleo em genótipos de soja com alto conteúdo de proteína. A acumulação relativa de subunidades foi calculada por escaneamento em géis SDS-PAGE, com uso de densitometria. O conteúdo de proteínas dos genótipos testados foi maior que o da cultivar controle dentro do mesmo grupo de maturação. Vários genótipos com conteúdo de proteína aumentado, mas com produtividade ou conteúdo de óleo inalterados, foram desenvolvidos como resultados de novas iniciativas de melhoramento. Esta pesquisa confirmou que as cultivares com alto conteúdo de proteína acumulam maior quantidade de glicinina e â-conglicinina. Os genótipos KO5427, KO5428, e KO5429, que acumularam menor quantidade de todas as subunidades de glicinina e β-conglicinina, foram as únicas exceções. Deve-se atentar para os genótipos KO5314 e KO5317, que acumularam quantidades significativamente maiores das duas subunidades da glicinina, e para os genótipos KO5425, KO539 e KO536, que acumularam quantidades significativamente maiores das subunidades de β-conglicinina. Estes resultados indicam que alguns dos genótipos testados poderiam ser benéficos em programas de melhoramento que visem à produção de plantas agronomicamente viáveis, com sementes com alto conteúdo de proteínas e composição específica de proteínas de reserva para fins alimentícios definidos

Shoot development from hypocotyl protoplasts of sunflower ( Helianthus annuus L.)

The plant regeneration from sunflower protoplast was achieved by protocols that considerably differ with respect to basal medium and concentration of growth regulators added. In most cases regeneration was restricted to a small proportion of genotypes. In this experiment, sunflower inbred line Ha-74A, with a high regeneration ability was used for protoplast isolation from etiolated hypocotyls. Isolated protoplasts were embedded in agarose droplets and cultured according to different regeneration protocols. The best results were obtained when protoplasts were cultured on L4 medium followed by transfer of regenerated microcalluses to solid regeneration media. Shoot regeneration was achieved by culture of calluses on SE regeneration medium after the treatment with 2.2 μM thidiazuron

Table_1_Effect of Sugar Beet Genotype, Planting and Harvesting Dates and Their Interaction on Sugar Yield.DOCX

<p>Climate changes are affecting the plant production, including sugar beet growing especially in the southern and central parts of the Europe. Modifying the sowing and harvesting dates are one of the most often used adaptations in sugar beet cultivation. The aim of this study was to assess the interactions between planting date and sugar beet genotypes for different harvest dates with recommendation for duration of vegetation period for specific hybrids in order to achieve the best performance and to evaluate influence of climatic factors on sugar yield. Three-way analysis of variance and AMMI (Additive main effect and multiple interactions) analysis were performed to investigate interaction between main factors. Analysis of variance revealed that genotypes (G), planting date (PD), harvest date (HD) and interaction G × PD significantly affected sugar yield in 2016. In 2017 genotypes, planting date, harvest date and G x PD interaction significantly affected sugar yield on probability level of 1%, while PD × HD interaction had significant effect on probability level of 5%. Results of AMMI analysis enabled discrimination of genotypes with the highest level of stability in certain planting dates. Hybrids with combined yield and sugar content (NZ type) should have the advantage in earlier planting dates compared to of sugar beet hybrids with higher sugar content (Z type). However, in shortened vegetation period Z type hybrids are more stable and with better sugar yield results. Results of our study suggest that delaying the harvest date decreases differences between sugar yields obtained from hybrids sown in different planting dates. Major factors in the study affecting sugar yield were growing degree days, insolation and number of days from planting to harvest.</p

Towards reducing genotype specificity in regeneration protocols after somatic hybridization between cultivated sunflower and wild helianthus species

Successful application of somatic hybridization in sunflower breeding is limited by low regeneration percentage from fusion products. The effect of pre-treatment media composition on shoot regeneration from electrofusion products of wild and cultivated sunflower was investigated in this paper, with the aim to determine if there is room for improvement of the existing regeneration protocols in order to make them less genotype-dependent. Protoplasts isolated from hypocotyls of two inbred lines of cultivated sunflower were electrofused with mesophyll protoplasts of H. mollis and H. maximiliani. The regeneration was induced only on calluses that were grown on the media with low auxin and high cytokinin contents during the development of calluses from microcalluses (pre-treatment), with silver nitrate as a medium component. Regeneration from fusion products was induced by treatment with a high concentration of TDZ or 2,4 D for a short period of time