Does Storage under Gene Bank Conditions Affect Seed Germination and Seedling Growth? The Case of Senecio morisii (Asteraceae), a Vascular Plant Exclusive to Sardinian Water Meadows.

Marco Porceddu,Alba Cuena-Lombraña,Martina Sanna,Gianluigi Bacchetta

doi:10.3390/plants9050581

Abstract

Understanding seed viability under long-term storage conditions provides basic and useful information to investigate the effectiveness of seed banking. Besides the germination success, seedling establishment is also an important requirement, and a decisive step to ensure plant propagation. We used comparative data of germination, seedling growth, and survival percentage between fresh and 10-years-stored seeds of Senecio morisii, a narrow endemic and vulnerable species of Sardinia (Italy), in order to evaluate if differences exist in these traits between fresh and 10-years-stored seeds. Stored seeds showed higher germination percentages than fresh ones, whereas seedling growth and survival did not present significant differences between them, except for seedling growth in plants produced from seeds germinated at 25 °C. This study allowed us to assess if seeds of S. morisii were able to germinate under controlled conditions, and if they maintained their viability and germination capacity for at least 10 years of long-term storage in the seed bank. In addition, the high seedling survival detected in both fresh and stored seeds suggests that stored seeds of S. morisii can be used to support reinforcement or reintroduction actions when fresh materials are not available.

Highlights

Seed banking, as an integral part of the ex situ conservation, has a pivotal role in safeguarding plant species for long times in order to avoid loss of genotypes from populations
final germination percentages (FGPs) ranging from 60% to 70% at the temperature range from 10 ◦ C to 25 ◦ C including alternate temperature, were as follows: the highest FGPs were detected at 10 ◦ C (69.79 ± 10.33%), followed by 15 ◦ C (66.39 ± 8.02%), 25 ◦ C (65.44 ± 8.48%), 25/10 ◦ C (62.36 ± 23.90%), and 20 ◦ C (62.26 ± 11.42%)
The survival percentage between seedlings obtained from Seeds stored (SS) and fresh seeds (FS) did not show significant differences (t = –0.0432; P = 0.966, Table S4)

Summary

Introduction

As an integral part of the ex situ conservation, has a pivotal role in safeguarding plant species for long times in order to avoid loss of genotypes from populations. Target 8 of the Global Strategy for Plant Conservation (GSPC) calls for “at least 75% of threatened plant species in ex situ collections, preferably in the country of origin, and at least 20% available for recovery and restoration programmes” [7,8]. Extra attention is necessary to ensure the ex situ conservation of endangered plants in seed banks and to develop effective germination and multiplication protocols for these species. Seed banking is a important conservation strategy for species with orthodox seeds (desiccation-tolerant, sensu [9]). These seeds can be gradually dried at 15 ◦ C and 15% of relative

Methods

Results

Conclusion