Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand
There is no published information on the seed germination or seed storage physiology of <i>Lophomyrtus bullata</i>, <i>Lophomyrtus obcordata</i>, and <i>Neomyrtus pedunculata.</i> This lack of information is hampering conservation efforts of these critically endan...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/12/5/1067 |
| _version_ | 1827752326038814720 |
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| author | Karin van der Walt Jayanthi Nadarajan |
| author_facet | Karin van der Walt Jayanthi Nadarajan |
| author_sort | Karin van der Walt |
| collection | DOAJ |
| description | There is no published information on the seed germination or seed storage physiology of <i>Lophomyrtus bullata</i>, <i>Lophomyrtus obcordata</i>, and <i>Neomyrtus pedunculata.</i> This lack of information is hampering conservation efforts of these critically endangered species. This study investigated the seed morphology, seed germination requirements, and long-term seed storage methods for all three species. The impact of desiccation, desiccation and freezing, as well as desiccation plus storage at 5 °C, −18 °C, and −196 °C on seed viability (germination) and seedling vigour was assessed. Fatty acid profiles were compared between <i>L. obcordata</i> and <i>L. bullata</i>. Variability in storage behaviour between the three species was investigated through differential scanning calorimetry (DSC) by comparing thermal properties of lipids. <i>L. obcordata</i> seed were desiccation-tolerant and viability was retained when desiccated seed was stored for 24 months at 5 °C. <i>L. bullata</i> seed was both desiccation- and freezing-sensitive, while <i>N. pedunculata</i> was desiccation-sensitive. DSC analysis revealed that lipid crystallisation in <i>L. bullata</i> occurred between −18 °C and −49 °C and between −23 °C and −52 °C in <i>L. obcordata</i> and <i>N. pedunculata</i>. It is postulated that the metastable lipid phase, which coincides with the conventional seed banking temperature (i.e., storing seeds at −20 ± 4 °C and 15 ± 3% RH), could cause the seeds to age more rapidly through lipid peroxidation. Seeds of <i>L. bullata</i>, <i>L. obcordata</i> and <i>N. pedunculata</i> are best stored outside of their lipid metastable temperature ranges. |
| first_indexed | 2024-03-11T07:13:53Z |
| format | Article |
| id | doaj.art-b0ab44d730914f0bbd8d8448159c47f6 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-11T07:13:53Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-b0ab44d730914f0bbd8d8448159c47f62023-11-17T08:23:44ZengMDPI AGPlants2223-77472023-02-01125106710.3390/plants12051067Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New ZealandKarin van der Walt0Jayanthi Nadarajan1Ōtari Native Botanic Garden, Wellington City Council, 150 Wilton Road, Wellington 6012, New ZealandThe New Zealand Institute for Plant and Food Research Limited, Fitzherbert Science Centre, Batchelar Road, Palmerston North 4474, New ZealandThere is no published information on the seed germination or seed storage physiology of <i>Lophomyrtus bullata</i>, <i>Lophomyrtus obcordata</i>, and <i>Neomyrtus pedunculata.</i> This lack of information is hampering conservation efforts of these critically endangered species. This study investigated the seed morphology, seed germination requirements, and long-term seed storage methods for all three species. The impact of desiccation, desiccation and freezing, as well as desiccation plus storage at 5 °C, −18 °C, and −196 °C on seed viability (germination) and seedling vigour was assessed. Fatty acid profiles were compared between <i>L. obcordata</i> and <i>L. bullata</i>. Variability in storage behaviour between the three species was investigated through differential scanning calorimetry (DSC) by comparing thermal properties of lipids. <i>L. obcordata</i> seed were desiccation-tolerant and viability was retained when desiccated seed was stored for 24 months at 5 °C. <i>L. bullata</i> seed was both desiccation- and freezing-sensitive, while <i>N. pedunculata</i> was desiccation-sensitive. DSC analysis revealed that lipid crystallisation in <i>L. bullata</i> occurred between −18 °C and −49 °C and between −23 °C and −52 °C in <i>L. obcordata</i> and <i>N. pedunculata</i>. It is postulated that the metastable lipid phase, which coincides with the conventional seed banking temperature (i.e., storing seeds at −20 ± 4 °C and 15 ± 3% RH), could cause the seeds to age more rapidly through lipid peroxidation. Seeds of <i>L. bullata</i>, <i>L. obcordata</i> and <i>N. pedunculata</i> are best stored outside of their lipid metastable temperature ranges.https://www.mdpi.com/2223-7747/12/5/1067cryopreservationdesiccationdifferential scanning calorimetry (DSC)lipidmyrtle rustseed banking |
| spellingShingle | Karin van der Walt Jayanthi Nadarajan Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand Plants cryopreservation desiccation differential scanning calorimetry (DSC) lipid myrtle rust seed banking |
| title | Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand |
| title_full | Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand |
| title_fullStr | Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand |
| title_full_unstemmed | Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand |
| title_short | Seed Storage Physiology of <i>Lophomyrtus</i> and <i>Neomyrtus</i>, Two Threatened Myrtaceae Genera Endemic to New Zealand |
| title_sort | seed storage physiology of i lophomyrtus i and i neomyrtus i two threatened myrtaceae genera endemic to new zealand |
| topic | cryopreservation desiccation differential scanning calorimetry (DSC) lipid myrtle rust seed banking |
| url | https://www.mdpi.com/2223-7747/12/5/1067 |
| work_keys_str_mv | AT karinvanderwalt seedstoragephysiologyofilophomyrtusiandineomyrtusitwothreatenedmyrtaceaegeneraendemictonewzealand AT jayanthinadarajan seedstoragephysiologyofilophomyrtusiandineomyrtusitwothreatenedmyrtaceaegeneraendemictonewzealand |