Abstract

DIAZ-LEYVA, Carlos Eduardo et al. Irradiation of tomato seeds with UV-B and UV-C: impact on germination, vigor and growth. Rev. Mex. Cienc. Agríc [online]. 2017, vol.8, n.1, pp.105-118. ISSN 2007-0934.  https://doi.org/10.29312/remexca.v8i1.75.

The UV-B and UV-C radiation modifies plant metabolism and morphology. Under the hypothesis that the irradiation of the seeds with UV-B and UV-C changes not only the germinative behavior but the morphology of the plants, this study was carried out with the objective of evaluating if the irradiation of the seeds induces changes in the germination, vigor and morphological variables of the leaf epidermis of tomato plants. In a first experimental stage, germination and vigor were evaluated using the following treatments: 0 (control), 1.8, 5.4, 10.8, 16.2, 21.6, 27 and 32.4 kJ m-2 of UV-B and 0 (control), 0.9, 2.7, 5.4, 8.1, 10.8, 13.5 and 16.2 kJ m-2 irradiation UV-C applied to the seed. The following variables were evaluated: (%) of germinated seeds and normal seedlings, root and hypocotyl length and dry weight. The irradiation with 5.4 kJ m-2 of UV-B favored the emergence and quantity of normal seedlings. Irradiation with UV-C caused negative effects on the emergence and quantity of normal seedlings. Based on the results of the first stage, irradiation doses were selected to be applied in the second stage, which were: 1.8, 5.4 and 10.8 kJ m-2 of UV-B and 0.9 and 2.7 kJ m-2 of UV-C. The irradiated seeds were sown in pots under greenhouse and the plants obtained were taken to flowering to evaluate the following variables: plant height, stem diameter, stomatal beam and back density, fresh and dry weight and SPAD units. The experimental design used was completely randomized. All treatments increased the stomatal density in the plants, in addition to the doses of 5.4 and 10.8 UV-B decreased SPAD units. It was concluded that seed irradiation is useful for seed pretreatment and phenotypic modification of plants.

Keywords : induction of tolerance; irradiance; phenotypic modification; signaling; stress.

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