Search

Information about seed source effects on germination and stress tolerance of the multipurpose exotic Prosopis juliflora (Sw.) DC. is scarce. Here, we investigate the influence of seed provenance on salinity tolerance and germination requirements of P. juliflora. Seeds collected from saline (SH) and nonsaline (SNH) habitats were treated with different NaCl concentrations (0–600 mM) and incubated in two photoperiods and three thermoperiod regimes. The results showed that tolerance of seeds from SH and NSH to salinity depended on thermoperiod, but not on photoperiod or interactions between photoperiod with both NaCl and thermoperiod. Germination of seeds from the two habitats did not differ significantly across thermoperiods in control and 200 mM NaCl. However, in 400 and 600 NaCl, germination was significantly greater for seeds from NSH than those from SH at lower thermoperiod in both light and darkness; whereas the reverse was true at higher temperatures in light. Seed germination of both habitat types was significantly lower at higher than at both lower and intermediate thermoperiods in all salt solutions, but the difference was more pronounced at higher salinities. Germination recovery failed in darkness at all photoperiod and thermoperiod regimes. Partial germination recovery happened only for seeds that failed to germinate in 400 mM NaCl in light and intermediate thermoperiod. Germination was significantly faster for seeds from SH than from NSH at higher salinities. The results emphasize the importance of considering the seed source for the restoration of salt-affected lands. [ABSTRACT FROM AUTHOR]

In this study, salt tolerance during germination of Aeluropus lagopoides (L.) Trin. was tested using fresh seeds collected from three different maternal habitats under three thermoperiods and two light regimes. Additionally, we tested the ability of non-germinated seeds that had been exposed to different concentrations of NaCl to recover their germination in distilled water. The results showed a significant effect of seed source, temperature, and salinity, and some of their two- and three-way interactions on final germination and recovery percentage. The seeds from non-saline provenances had the highest percentages for germination (ca. 79%) under the 35/25 °C temperature regime, whereas the lowest percentages for germination (ca. 21%) was recorded for seeds from saline conditions under the 25/15 °C treatment. Additionally, percent germination was significantly lower for the seeds incubated in the saline solutions (100, 200, 400, and 600 mmol/L NaCl) and germinated under colder conditions (15/25 °C), compared with the seeds incubated in non-saline solutions (control group, 0 mmol/L NaCl) and germinated under warmer conditions (35/25 °C). The highest recovery percentage was recorded for seeds of the hyper-saline habitat incubated at 35/25 °C. Thus, seeds maintained their viability despite experiencing a range of saline conditions and were able to germinate upon the arrival of suitable conditions, which can be an adaptation to its saline arid desert habitat. [ABSTRACT FROM AUTHOR]

Suaeda aegyptiaca is a facultative halophyte found in saline and non-saline habitats of the Arab Gulf desert, which produces small-sized undispersible seeds. The interactive effects of maternal salinity and other environmental conditions, such as salinity, light and temperatures, that are prevailing during seed germination have received little attention for a facultative halophyte. This study tested the effects of maternal salinity on salt tolerance during seed germination of S. aegyptiaca under different light and temperature regimes. Seeds collected from both saline and non-saline habitats of the United Arab Emirates ( UAE) were germinated in 0, 50, 100, 200 and 400 mM NaCl, and incubated at 15/25°C, 20/30°C and 25/35°C in both 12-h light/12-h dark regimes and continuous darkness. Generally, seeds of the non-saline habitat were 56% heavier and attained greater germination at the lower temperatures than seeds of the saline habitat. Seeds of the saline habitat germinated better in saline solutions at higher temperatures and in light. Germination was faster for seeds of the saline habitat than for seeds of non-saline habitats. Germination recovery after transfer to distilled water was significantly greater for seeds from the non-saline habitat, compared with seeds from saline habitats. Recovery was greater at lower and/or moderate temperatures, compared with at higher temperatures. Germination was significantly faster during recovery, compared with in the saline solutions. The study indicates that the maternal effect of salinity was confounded with the seed-size effect and it cannot be conclusively confirmed. [ABSTRACT FROM AUTHOR]

• Size, germinability and tolerance of Suaeda fruticosa seeds varied spatially. • Seeds from moist-moderately saline habitat of Manora were largest. • Light requirement for germination was lowest in seeds from high-saline habitat Gaddani. • Germination recovery from salinity was generally higher in seeds from dry habitats. • Recovery from salinity was generally higher than that from dark in all provenances. Information about provenance-based differences in seed attributes of potential cash crop halophytes is limited but important to define sources for the highest quality seeds. This study examined inter- provenance variations in seed morphology, germination, and tolerance responses of Suaeda fruticosa to common abiotic factors. Seed size varied significantly among provenances, and the largest sized seeds were developed in the highly moist moderately-saline coastal area of Manora. Seed germination responses also varied among provenances and seeds from highly moist provenance of Manora showed the highest germination in 400 mM NaCl in light under low to moderate temperature regimes. The light requirement for germination was lowest in the seeds from highly saline provenance of Gaddani. The highest germination recovery of un-germinated seeds from the high salinity (600 mM NaCl) was for seeds from dry provenance of Bahawalpur irrespective of temperature regime. Recovery for seeds from the (moderately) moist (highly) saline provenances of Gaddani and Hawke's Bay was highly temperature-dependent. However, recovery of dark-incubated un-germinated seeds after transfer to light was salinity-dependent, but not dependent on provenance. Thus, these data indicate that provenance can affect the size, germinability, and stress tolerance of S. fruticosa seeds. Generally, seeds from less stressful provenance of Manora had better quality, i.e., larger size, higher germination, and qualify for mass-scale cultivation / restoration programs under most environmental conditions. [ABSTRACT FROM AUTHOR]