ENZYME VARIABILITY AND QUALITY OF SEED PROGENY IN POPULATIONS OF PLANTAGO MAJOR L. FROM THE ZONE OF THE EAST

URALS RADIOACTIVE TRACE (EURT)

N.S. Shimalina1, E.V. Antonova 2, V.N Pozolotina3

Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Science

Ekaterinburg, Russia

1nadia_malina@mail.ru, 2 selena@ipae.uran.ru,3pozolotina@ipae.uran.ru

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Research purpose

Assessment of the seed progeny viability and the enzymevariability in Plantago major L. populations from radioactivecontaminated areas.

Test sites

We collected seeds from populations exposed to radioactivecontamination for a long time (The East Ural RadioactiveTrace – EURT). Background plots were located beyond thezone of contamination.

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The East Urals Radioactive Trace (EURT) appeared in 1957 after the accident at the Mayak Production Association, where a tank with radioactive waste exploded (Urals, Russia). The main contaminant in the EURT is 90Sr. Additional contamination of this zone occurred in 1967 as a result of the wind transfer of radioactive sand from the shores of Lake Karachay, which had been used as a reservoir for radioactive wastes (with 137Cs being the main contaminant).

Absorbed doze rates

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Plot

Specific radioactivity in the soil, Bq/kg Concentration ratios Absorbed

dose

rate, μGy/h90Sr 137Cs 239, 240 Pu 90Sr 137Cs 239, 240 Pu

Backgr

ound6.92 ± 2.60 9.89 ± 4.46 n.о.

0.66

±

0.76

0.054

±

0.054

0.0014

±

0.0012

0.107

EURT-1 24000 ± 15400 1010 ± 871 103 ± 53.9 19.1

EURT-2 90900 ± 73500 4400 ± 3810 235 ± 153 72.1

EURT-3 195000 ± 85000 9860 ± 5570 514 ± 397 156.1

Allozyme analysis

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Electrophoresis was carried out in 6.4% PAAG using a Tris–EDTA borate system.

Histochemical staining of the proteins was carried out according to a standard method

ADH (EC 1.1.1.1)GOT (EC 2.6.1.1)

IDH (EC 1.1.1.42) EST-c (EC 3.1.1.1)EST-f (EC 3.1.1.1) SOD (EC 1.15.1.1) PGM (EC 5.4.2.2.)

FDH (EC 1.2.1.2)PGI (EC 5.3.1.9) SKDH (EC 1.1.1.25)6-PGD (EC 1.1.1.44) DIA (EC 1.6.4.3) GDH (EC 1.4.1.2)

13 allozyme loci were analyzed:

Polymorphic Monomorphic Not recognizable

Material and methods

Laboratory experiment

- Seed germination rate %-Seedling survival, %

-True leaves formation, %- Root length, mm

Seeds were germinated by aroll culture method for 3 weeks

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Viability of seed progenies of plants from different zones

Germination rates and seedling survival rates were identical in all samples. Variability of these parameters within background zone exceeded differences between impact and background zones. Therefore, germination rates, seedling survival rates of Plantago major L. samples from EURT did not differ significantly from background samples as well as proportion of seedlings with true leaves.

Indices of genetic variation in the samples

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P95 – Percentage of polymorphic Loci; Na – number of different alleles; Ho – observed heterozygosity; He – expected heterozygosity; F – fixation Index

Population P95,% Na Ho He F

Background-1 22,22 1,556±0,338 0,023±0,015 0,114±0,074 0,541±0,162

Background-2 22,22 1,333±0,167 0,058±0,036 0,098±0,064 0,265±0,089

Background-3 33,33 1,667±0,441 0,068±0,035 0,124±0,063 0,459±0,034

Background-4 33,33 1,778±0,434 0,049±0,026 0,111±0,063 0,46±0,109

Background-5 22,22 1,444±0,242 0,052±0,03 0,104±0,063 0,462±0,049

Background-6 33,33 1,556±0,338 0,04±0,022 0,105±0,057 0,606±0,015

Background-7 33,33 1,333±0,167 0,115±0,06 0,151±0,076 0,248±0,042

EURT-1 22,22 1,333±0,167 0,026±0,017 0,077±0,047 0,662±0,029

EURT-2 22,22 1,333±0,167 0,044±0,032 0,093±0,058 0,591±0,051

EURT-3 22,22 1,333±0,167 0,027±0,018 0,101±0,061 0,688±0,056

EURT-4 33,33 1,444±0,242 0,049±0,027 0,112±0,063 0,564±0,002

EURT-5 11,11 1,333±0,167 0,04±0,031 0,058±0,048 0,105±0,073

EURT-6 22,22 1,444±0,242 0,043±0,027 0,112±0,069 0,619±0,025

EURT-7 22,22 1,333±0,167 0,03±0,019 0,094±0,059 0,677±0,014

EURT-8 33,33 1,333±0,167 0,035±0,02 0,13±0,065 0,722±0,05

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Locus Fis Fit Fst

Got-1 0.455 0.550 0.175

Got-2 0.588 0.659 0.172

Adh 0.570 0.605 0.081

0.537 ± 0.072 0.604 ± 0.054 0.143 ± 0.053

Wright’s F-statistics

FIS – The inbreeding coefficient within individuals, relative to the population; FIT – The inbreeding coefficient within individuals, relative to the total; FST – The inbreeding coefficient within populations, relative to the total.

According to FST only 14.3% of the genetic differentiation is divided among coenopopulations, 85.7% is divided within coenopopulations.

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Genetic distances (Nei, 1978)

According to genetic distances there is no relation between enzyme

variability and level of radioactive contamination.

Conclusions

1) Viability of Plantago major seed progeny from EURT did notdiffer significantly from background samples;

2) The observed (Ho) heterozygosity varied from 0.023 to 0.115,and expected (He) varied from 0.058 to 0.151. In all plantainpopulations high level of inbreeding was revealed. This is indicativeof predomination of homozygote genotypes and high self-pollination rate in Plantago major populations;

3) Only 14.3% of the genetic differentiation is divided amongcoenopopulations, 85.7% is divided within coenopopulations;

4) According to proportion of polymorphic loci and mean numbersof alleles per locus the lowest genetic variation was in EURTpopulations. But according to genetic distances there is no relationbetween enzyme variability and level of radioactive contamination.

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This study was supported by RFBR (project №15-04-01023)

Acknowledgements

Thank you for your attention!