Role of antioxidant activity in the longevity of seeds of wheat species and minor forms

Abstract

The aim and tasks of the study. To evaluate the role of antioxidant activity in the longevity of seeds of representativesof minor species and intraspeciesdiversity of wheat basing on experimental simulation of natural aging of seeds.

Material and methods. The longevity of seeds was experimentally evaluated bysimulation of accelerated aging using two methods: Hampton, TeKrony (2005) and B.S. Likhachev (1980).In addition, seeds were stored hermetically sealed glass containers in a freezer at -20°C for 30 days, which corresponds to the long-term regimen of seed storage in the National Plant Genebank of Ukraine. Antiradical activity was determined usingthe stable DPPH radical, as described by S.Arabshahi (2007).

Results and discussion. Correlation between the longevity of seeds and the level of antioxidant activity was found.

The antioxidant activity (AOA) of einkorns T.sinskajae and T.monococcum was 32.54%–35.08% and 38.51%–39.10%, respectively, and was lower in all the experimental variants than that in polyploidwheat species (39.81%–53.83%). It was lower in T.sinskajae than in T.monococcum.

The ranking of the test accessions by the AOA level established in the control remained unchanged after accelerated aging by the both methods and after freezing.

Accelerated aging carried out byHampton andTeKrony’smethod reduced the viability and AOA of seeds of the test accessions in comparison with the control. The level of AOA in the control closely correlated with this parameter after accelerated aging by this method: positively with the AOA value (r = 0.91) and negatively with the AOA index (r = -0.86).

There is a clear significant positive correlation between the AOA level in the control and the indices of germination power, germinability, sprout length and primary root length after accelerated aging: r = 0.52–0.85. This makes it possible to predictthe response of seeds of wheat accessions to accelerated aging, and consequently, the suitability of seeds for long-term storage, from the initial AOA index. In particular, a higher AOA level means a greater longevity of seeds.

The results of the accelerated aging experiment by B.S. Likhachev’s method showed thatthe moisture level of 6% was closer to the optimal one for long-term storage as compared to the moisture content of 5% and 7%.

Freezing either had a positive effect on seed parameters or did not change them. The AOA had a positive significant correlation with the germination power: r = 0.98. The indices of the freezing effect on the germination power, germinability and sprout length closely and positively correlated with the AOA of seeds after freezing: r = 0.79 - 0.87.

Conclusions. The close significant positive correlation between the AOA level in the control and the indices of germination power, germinability and sprout length after freezing (r = 0.79–0.87) allows us to predict (to some extent)the response of seeds of wheat accessions to freezing from the initial AOA index. More specifically,the higher AOA level is, the greater the seed parameters increase under the influence of freezing