Seed Cryostorage Enhances Subsequent Plant Productivity in the Forage Species Teramnus Labialis (L.F.) Spreng.

BACKGROUND: Teramnus labialis is an herbaceous legume that serves as a source of carbohydrates and proteins for animals and humans, and is valued for its nitrogen contribution to soil. The benefits of this species are, however, limited by low seed availability, small seed size and low in situ seed germination levels, due to physical dormancy. Cryostorage has been shown to be beneficial for both seed storage and breaking physical dormancy in seeds of various species. However, its potential effects on subsequent seedling emergence, plant growth and seed production need to be studied before large-scale implementation for T. labialis. OBJECTIVE: To record agricultural traits of T. labialis after seed exposure to liquid nitrogen. MATERIALS AND METHODS: Seeds were maintained at 5 degree C (control) or stored in LN before sowing. Seedling emergence percentage and traits related to plant growth and seed production were evaluated for 6 months. RESULTS: Except for seed weight, all traits differed significantly between seedlings generated from cryostored and control seeds. Except for pod number, seedling emergence and plant growth traits were enhanced by cryostorage to a greater extent than seed production traits. Cryostorage resulted in cracks and breaks in the seed coat which were absent in control seeds (scanning electron microscopy), and in breaking physical dormancy may have facilitated more rapid seedling emergence than for control seeds. CONCLUSION: Seed cryostorage enhances subsequent plant productivity in terms of growth and to a lesser extent seed production in Teramnus labialis, validating its use for commercial growth of this species.

Field Performance of Cryopreserved Seed-derived Maize Plants.

BACKGROUND: Cryo-preservation of plant materials in liquid nitrogen (LN) has been described as a suitable technology to conserve genetic resources of several species. However, the potential effects of LN in the subsequent plant growth in the field should be studied before large-scale implementation of cryopreserved germplasm banks. OBJECTIVE: To describe the field performance of cryopreserved seed-derived maize adult plants. MATERIALS AND METHODS: Germination percentage and numbers of leaves and ears per plant, internodes in stems, middle - aged leaf length, plant height, ear traits and weight of 100 seeds were recorded. RESULTS: Statistically significant differences between adult plants derived from cryopreserved seeds and the control treatment were not observed (t-test, p=0.05). CONCLUSION: The results presented confirm at the phenotype level the effectiveness of maize seed cryostorage to preserve and regenerate true-to-type plants.

Phenotypic and molecular characterization of plants regenerated from non-cryopreserved and cryopreserved wild Solanum lycopersicum mill. Seeds.

BACKGROUND: Before cryopreservation is routinely used, its effect on the trueness-to-type of the regenerated plant material needs to be evaluated. OBJECTIVE: In this work, we studied the effect of seed cryopreservation on the phenotypic and molecular characteristics of wild Solanum lycopersicum Mill. plants. METHODS: Thirty-five morphological traits of plants regenerated from cryopreserved seeds were compared to those measured on plants regenerated from non-cryopreserved seeds. RESULT: No statistically significant differences were observed between cryopreserved and non-cryopreserved samples, either in the first or in the second generation post-liquid nitrogen exposure. However, at the molecular level, the genetic analyses performed on the second generation plants germinated from control and cryopreserved seeds using 14 nuclear Simple Sequences Repeats (SSR) markers uncovered some changes in microsatellite length between control and cryopreserved samples. These results confirm at the botanical phenotype level the effectiveness of seed cryostorage for conservation and regeneration of true-to-type S. lycopersicum plants. CONCLUSION: Further experiments are required to clarify potential phenotypic effects of the changes observed in the DNA.

Biochemical characterization of ecuadorian wild Solanum lycopersicum Mill. plants produced from non-cryopreserved and cryopreserved seeds.

This paper presents some of the effects of cryopreservation of wild Solanum lycopersicum Mill. seeds on the early stages of germination post liquid nitrogen exposure. Percentage of germination, conversion into plantlets and plant fresh mass were evaluated after cryostorage. Levels of chlorophyll pigments (a, b, total), malondialdehyde, other aldehydes, phenolics (cell wall-linked, free, and total) and proteins were determined. Peroxidase and superoxide dismutase activities were recorded. Liquid nitrogen exposure increased the percentage of seed germination at 5 days but at 7 days, the conversion into plantlets and the plant fresh mass were not statistically different between non-cryopreserved and cryopreserved samples. Several significant effects of cryopreservation were recorded at the biochemical level at 7 days of germination under controlled conditions. Highly significant effects due to liquid nitrogen exposure were observed in leaves: increased levels of peroxidase enzymatic and specific activities and cell wall-linked phenolics. Very remarkable effects were also recorded in roots: decreased contents of chlorophylls and cell wall-linked phenolics.