Fresh Seeds Research Articles

Effects of burial in soil on seed longevity and germinability of the winter annual weed wild barley (Hordeum spontaneum)

AbstractHordeum spontaneum is a winter annual weed that reduces crop yields in Iran. The aim of this study was to quantitatively analyze the effects of burial on seed longevity and germinability and of water potential and temperature on germination. Seeds were placed in nylon‐mesh bags and buried in soil in a semi‐arid region on 1 July 2018 and exposed to natural temperature regimes. After 2 months of burial, seed viability started to decline with a slope of 0.0169%, and after 9 months all seeds were nonviable. Fresh seeds were dormant, but became non‐dormant during summer via dry after‐ripening. Thus, by late autumn (December) the seeds germinated to 100% in dark at 5 and 15°C. The base, optimum, and ceiling temperatures were 0.27, 17.5, and 25°C, respectively, at a water potential of 0 MPa. The hydrotime constant was 50.6–426.9 MPa h, base water potential −1.23 to −0.333 MPa and hydrothermal constant 1350.5 MPa °C h. These results can be used to predict timing and extent of weed emergence of H. spontaneum in crops and in planning for sustainable management strategies.

Effect of microencapsulated/photoresistant extract of Azadirachta indica A. Juss seeds on Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctudae) and its persistence in semi-field

The development of bioinsecticides as an alternative to synthetic insecticides can benefit the economy of exporting and importing countries, family farming, production of high-quality commodities, food security, quality of life, and the natural environment. This study aimed to evaluate the effect of microencapsulated extracts of Azadirachta indica A. Juss on Spodoptera frugiperda J.E. Smith and their persistence in the plant under semi-field conditions. The fresh seeds of A. indica, collected in Brazil, were separated for the preparation of the microencapsulated dry extract (MDE) according to criteria registered in the patent. Lethal concentrations for S. frugiperda were determined using a dose response curve. The treatments were compared: MDE, control and positive control based on azadirachtin, evaluating mortality and growth inhibition. There was a significant difference in mortality between the treatments tested. The lethal concentrations LC50 and LC95, expressed in azadirachtin for the bioinsecticide, were 194.98 and 630.95 ppm, respectively. The growth inhibition of S. frugiperda was above 98 % in the treatments, except for the control. The MDE presented lethal times LT50 and LT90 lower than the other treatments (lethal time LT50 = 2.79 d; lethal time LT90 = 3.97 d). The MDE of A. indica seeds was effective in controlling S. frugiperda up to the fifth instar and is considered as slightly persistent to persistent depending on environmental conditions and irrigation, based on IOBC/WPRS parameters. The MDE has the potential to be a phytosanitary product approved for use in organic agriculture and with greater effectiveness in controlling S. frugiperda compared to similar pesticides.Abbreviations: BOD, Biochemical Oxygen Demand; CPA, commercial product based on azadirachtin; CLE, concentrated liquid extract; DAS, days after spraying; GI, growth inhibition; LC50, lethal concentration for 50% of the population; LC95, lethal concentration for 95% of the population; LT50, lethal time for 50% of the population; LT90, lethal time for 90% of the population; MDE, microencapsulated dry extract.

Germination alters the bioactive compounds of pigmented and non-pigmented rice varieties in fresh and year-old stored seeds

Germination alters the bioactive compounds of pigmented and non-pigmented rice varieties in fresh and year-old stored seeds

Wild pear (Pyrus pyraster (L.) Burgsd.) fruit and seed morphology depending on fruit size

The current study aims to evaluate the effects of fruit size of wild pear (Pyrus pyraster (L.) Burgsd.) on morphological fruit and seed traits. Wild pear fruit was collected from 10 trees in the area of Žumberačko gorje in the fall of 2022. The fruit was randomly collected from the ground and divided into three groups according to their weight (small (<10 g), medium (10 – 15 g) and large (>15 g)). Fruit size had a significant effect on the following morphological traits: fruit weight, fruit length, fruit width, the number of filled seeds, the weight of fresh seeds per fruit, the weight of 1 fresh seed and the weight of air-died seed, while no significant difference was found for fruit shape index, the number of empty seeds, the weight of 1 air dried seed and the share of seed dry matter. For all the aforementioned traits where the difference was significant, large fruit had significantly highest values, while in most cases (with the exception of the weight of 1 fresh seed), medium fruit had significantly higher values than small fruit. Comparing the correlation coefficients between different fruit size groups, it is evident that higher fruit size traits had a significant effect on the number of filled seeds in medium and large wild pear fruit only. In addition, it is visible that fruit weight and width, and not fruit length, had of the largest impact on the number of filled seeds. The principal component analysis revealed 3 significant principal components with eigenvalues greater than 1, which explained 75.88% of the total variability. It was shown that large fruit distinguish themselves from small and partly between medium by F1 axis. F1 was mainly influenced by fruit weight, fruit length, fruit width, the number of filled seeds, the weight of fresh seeds per fruit and the weight of air-dried seed per fruit. Based on the results obtained from this study, it can be concluded that for nursery production of wild pear seedlings bigger fruit should be used due to the higher number of filled seeds.

Determination of Seed Physiological Maturity and Invigoration using Plasma-Activated Water and Ultrafine Bubble Water on Okra Seeds

Seeds physical and physiological qualities are primarily determined by seed physiological maturity. Seed enhancement technology has developed rapidly, including using ultrafine bubbles (UFB) and plasma-activated water (PAW) to increase seed viability. This study aimed to determine seed physiology maturity on okra seed to get the optimal harvesting period seeds and to examine the most effective seed enhancement plasma-activated water and ultrafine-bubble Water. The first experiment was arranged using completely randomized design with fruit maturity as the single factor, harvested at 3, 4, 5, or 6 weeks after anthesis (WAA), with three replications. The second experiment used factorial completely randomized design; the first factor is seed lots with different storage times (fresh seed and one-year storage seed), and the second factor seed invigoration using UFB (20 ppm dissolved oxygen) and PAW (10-, 20-, and 30-min exposure) as the second factor. Untreated seeds were used as control. Fifty seeds were used in each treatment. Okra seed physiological maturity was reached at 5 WAA based on seed dry weight, germination capacity, seedling vigor, and speed of germination. The pod color at 5 WAA is olive brown, and seed testa has dark greyish purple. Plasma-activated water at 10 minutes exposure increased the vigor index of seed lots stored for one year by 86% and PAW20 by 87%. Plasma activated water at 10-, 20- and 30-minutes exposures significantly increased the seedling vigor index and germination speed of fresh seeds harvested at 5 WAA.

Evaluating the Lethal Dose (LD50) and Mutagenic Effects of Sodium Azide on Germination and Quality Traits in Two Varieties of Tomato (Solanum lycopersicum)

Study’s Excerpt Lethal dose (LD50) of sodium azide for two distinct tomato varieties, Beefsteak and San Marzano was quantified. The optimal mutagen doses that can be leveraged for enhancing quality traits in tomatoes is determined. Sodium azide has potential to improve crop resistance and productivity in tomato breeding programs. Full Abstract Sodium azide is a chemical mutagen that has been used to produce resistance in various susceptible crops to improve their yield and quality traits against harmful pathogens. The lethal dose and mutagenic effects of sodium azide on the germination percentage of two varieties of tomatoes (Beefsteak and San Marzano) were investigated with the aim of optimizing a suitable mutagen concentration with variability that could be exploited in the improvement of quality traits in Tomato plants. This study was carried out in the Green House at the Department of Biotechnology, Alex Ekwueme Federal University Ndufu-Alike, Ebonyi State (AE-FUNAI). The two varieties of tomato seeds were collected locally as fresh seeds from the taxonomic department and were treated with sodium azide at different concentrations of 0.0%, 0.2%, 0.4%, and 0.6% w/v. The seed was sown and monitored for 30 days with everyday documentation of germination percentage, survival percentage, and lethal dose. Statistical analysis using significant difference (LSD) at 95% probability level was employed to analyze the effects. The results obtained from this study show that there is a steady decrease in germination and survival percentage with increased concentration of sodium azide in both varieties of tomatoes when compared with the control. The lethal dose (LD50) was determined upon germination and survival of the tomato varieties. The highest LD50 was calculated by linear regression to be 0.950 for the beefsteak variety, which was significantly higher than 0.794 for the san marzano variety at 50% germination was recorded under treatment 0.6% NaN3. These concentrations are therefore considered as the LD50 values. Sodium azide via mutation at low concentrations improves some important quality traits of tomatoes.

Bioaccessibility and potential bioactivity of fresh and mature fava bean flavonoids

The bioaccessibility of total flavonoids, catechin, epigallocatechin, epigallocatechin gallate, epicatechin, rutin, quercetin, isoquercetin, and kaempferol, and changes in antioxidant activities in fresh and mature fava bean seeds during simulating gastrointestinal conditions has been investigated. The portion of bioaccessible flavonoids potentially available for further uptake varies between pods. Flavonoids of mature and fresh seeds after the gastric phase, intestinal phase, and dialysable fraction, simulating bioaccessible flavonoids, were 6.62% and 1.78%, respectively, compared with no-digested pods. Total antioxidant capacities in the bioaccessible fractions were significantly lower than the control. Furthermore, potential bioactivity as a PPAR-gamma antagonist was evaluated, where epigallocatechin gallate presents at -9.50 Kcal/mol vs. -6.53 Kcal/mol, present in troglitazone. These results highlighted that gastrointestinal digestion may substantially affect the absorption of flavonoids in mature and green fava beans and present a potential bioactivity against obesity.

Effect of Storage Duration on the Insecticidal Activity of Neem (<i>Azadirachta indica</i>) Seeds Against Fall Armyworm (<i>Spodoptera frugiperda</i>)

Neem (<i>Azadirachta indica</i>), native to India, thrives in tropical and sub-tropical climates. Its efficacy against economically significant pests is attributed to the pesticidal properties found in its leaves, bark, and roots. Neem seeds are always harvested by smallholder farmers and stored for use in crop-growing seasons when their availability is scarce. This study aimed to determine if storage duration can affect the toxicity of these neem seeds. Neem seed extracts were tested for toxicity after being stored at different durations, they were stored for 1-3 years. The objective of this study was to analyze the effects of storage time on the insecticidal activity of neem seeds. Fall armyworm larvae were used to test for the neem seed extracts’ toxicity by feeding on maize plants which were sprayed with these extracts. The experimental design used was a complete randomized design in the laboratory. Extracts were made from neem seeds stored for 1-3 years which were harvested from year 2019, 2020, 2021 and 2022. Analysis of FAW larvae mortality at different concentrations (0.5%, 1.0%, 1.5%, and 2.0%) together with the control treatment under laboratory conditions was done. Damage severity rates of maize leaves in which the FAW larvae were allowed to feed were measured and FAW larvae mortality was calculated. The results showed a significant interaction between neem seed storage time and FAW mortality. The results showed that extracts from fresh neem seeds and those stored for one year had the lowest plant damage score. Also, the lowest mortality was obtained from seeds stored for 1 year and the fresh seeds because the larvae refrained from feeding. Following this study, we recommend the usage of fresh neem seeds and those stored for up to a year in the management of fall armyworms.

High density promotes the germination of the recalcitrant seeds of submerged macrophyte Vallisneria natans

Seed germination is a critical process in the seed life cycle, especially for annual submerged macrophytes Vallisneria natans which is a model species for the restoration of degraded shallow lakes. Fresh seeds of V. natans have a very high germination rate but with no significant responses to the aggregation effect; meanwhile, these recalcitrant seeds quickly lose seed viability under dry storage. This study aims to explore the response of seed germination of V. natans after dry storage to aggregation effect by several microcosm experiments. We observed that seed aggregation has a significant positive effect on germination, and among the seven experimental densities between 10 ∼ 640 seeds, higher seed densities resulted in significantly enhanced germination. In contrast, daily removal of germinated seeds led to a significant decrease in the overall germination rate, suggesting that germinated seeds may secrete chemicals that promote the germination of ungerminated seeds. However, further experiments indicated that ethylene and gibberellins had no noticeable impact on seed germination, which was consistent with additional experiment results from spectrophotometer and high-throughput targeted metabolomics. We concluded that the promoting effect of aggregation on the seed germination of V. natans may be an adaptation of this species to its natural habitat but detailed mechanisms warranted further study.

The Potential of Deleterious rhizobacteria to Control Primary Weed <i>Echinochloa </i>sp. on Rice

Deleterious rhizobacteria (DRB) is one of the rhizobacteria that can be used as a bioherbicide and can stimulate plant growth. The objectives that can be obtained from this study are to determine the potential of DRB on the growth of weeds Echinochloa crusgalli and Echinochloa colona on rice. Variables observed in this study were identification of secondary metabolites, measurement of weed sprouts, percentage effectiveness of bacterial isolates against weed seeds, normal sprouts, abnormal sprouts, fresh seeds that did not grow and dead seeds. The aim of this study is to explore biological agents that can be used to control the main weeds of rice crops. This candidate could be a recommendation for environmentally friendly controls. Exploration of the DRB group was obtained by collecting soil samples around the roots of rice crops. Then isolate it, identify as morphologically and physiologically, and test it in vitro studies. The results showed that DRB had the potential to control weed growth and could stimulate the growth of rice. The application of PFA and PFB isolates had a significant effect on inhibiting the length of weed roots and buds, the average percentage of control effectiveness > 80-90%. Novelty in this study could be found as candidate groups of DRB bacteria with specific locations to control the weed Echinochloa sp. on rice crops. For society, this research could be an alternative to reduce dependence on synthetic herbicides . DRB has the potential to be formulated into a bioherbicide to control weeds.

Unveiling the molecular dynamics of low temperature preservation in postharvest lotus seeds: a transcriptomic perspective

BackgroundPostharvest quality deterioration poses a significant challenge to the commercial value of fresh lotus seeds. Low temperature storage is widely employed as the primary method for preserving postharvest lotus seeds during storage and transportation.ResultsThis approach effectively extends the storage life of lotus seeds, resulting in distinct physiological changes compared to room temperature storage, including a notable reduction in starch, protein, H2O2, and MDA content. Here, we conducted RNA-sequencing to generate global transcriptome profiles of postharvest lotus seeds stored under room or low temperature conditions. Principal component analysis (PCA) revealed that gene expression in postharvest lotus seeds demonstrated less variability during low temperature storage in comparison to room temperature storage. A total of 14,547 differentially expressed genes (DEGs) associated with various biological processes such as starch and sucrose metabolism, energy metabolism, and plant hormone signaling response were identified. Notably, the expression levels of DEGs involved in ABA signaling were significantly suppressed in contrast to room temperature storage. Additionally, nine weighted gene co-expression network analysis (WGCNA)-based gene molecular modules were identified, providing insights into the co-expression relationship of genes during postharvest storage.ConclusionOur findings illuminate transcriptional differences in postharvest lotus seeds between room and low temperature storage, offering crucial insights into the molecular mechanisms of low temperature preservation in lotus seeds.

The implications of various seed priming treatments on seed yield in proso millet (Panicum miliaceum)

The experiment was conducted during rainy (kharif) season of 2021 and winter (rabi) season of 2022 at Annamalai University, Annamalai Nagar, Chidambaram, Tamil Nadu to identify suitable seed priming technique, soaking duration and priming agents for halo, osmo, and bio-priming in proso millet (Panicum miliaceum L.). To increase crop yield and sustainability in present-day agriculture, seed priming continues to be essential by utilizing scientific knowledge and technical breakthroughs. The experiment was laid out in factorial completely randomized design (FCRD) with three replications. The fresh seeds of proso millet cv. CO4 were imposed for halo, osmo, and bio priming treatments, viz. Agent for halo-priming: Control, hydropriming, KH2PO4 (1 and 2%), ZnSO4 (1 and 2%), and CaCl2 (1 and 2%); Agent for osmo-priming: Control, hydropriming, NaCl (1 and 2%), Mannitol (1 and 2%), and PEG (-10 and -15 Bar); Agent for bio-priming: Control, hydropriming, Azospirillum (15 and 20%), P. fluorescens (LF) (10 and 15%), Prosophis LE (5 and 10%), and soaked in equal volumes for 6 and 8 h. The results revealed that for halo priming, seeds soaked in 2% KH2PO4 for 8 h; for osmo priming seeds soaked in 2% mannitol for 8 h and for bio-priming seeds soaked in 15% P. fluorescens (LF) for 8 h outperformed other treatments. Field experiments were also conducted to determine the productivity of seed primed proso millet. The results showed that the crop performance was superior in seeds primed with 2% KH2PO4 for 8 h during kharif season than rabi.

Nutraceutical and Pharmacological Benefits of Some Leguminous Plants of North‐Western Himalaya

ABSTRACTLegumes have various types of active constituents with disinfection and disease‐prevention properties. They are highly nutritious, providing carbohydrates, proteins, fibre, vitamins, copper, zinc, iron, magnesium and phosphorus. They are free of saturated fats and cholesterol. The Fabaceae or Leguminosae is regarded as legume family, which includes a major group of plant resources in the north‐western Himalayan region, primarily used as food as well as medicine. The term ‘Nutraceutical’ is derived from two words ‘nutrient’ means nourishing food component and ‘pharmaceutical’, which means a medicinal drug. It refers to any product derived from food resources having extra health benefits and nutritional value. These include minerals, vitamins, herbs and their extracts, which provide us with health benefits and play a significant role in the prevention and treatment of various diseases like diabetes, renal disorders, gastrointestinal ailments, cardiovascular diseases, cancer, Alzheimer's disease, Parkinson's disease, allergies, eye conditions, obesity and so forth. Therefore, nutraceuticals may contribute to preventing chronic diseases, improving health, postponing the ageing process and increasing life expectancy by supporting the functions and integrity of the body. The north‐western Himalayan region has several species of legumes of utmost significance due to their nutraceutical and therapeutic potential. Among these, major legumes are lentil, chickpea, soybean, kidney bean and groundnut, while several others legumes have rather limited commercial significance. Various parts, that is, young pods, fresh or mature seeds, leaves and flowers, of these legume plants are used for human consumption. In this article, efforts have been made to compile the nutraceutical and medicinal inferences of leguminous plants of north‐west Himalaya. The information provided also pertains to the nutritional benefits, antinutritional properties and distribution of legumes in various regions of north‐western Himalaya through the analysis of different works available in the literature.

Seed germination requirements of the rare Helosciadium repens (aka Apium repens) determine persistence of seeds in the soil seed bank.

The rare and threatened Heliosciadium repens grows in moist grasslands and has a distinct life cycle. Plants reproduce both clonally, although ramets tend to be short-lived, and sexually, with seeds that can form a persistent soil seed bank. The germination requirements of H. repens were investigated, yielding important information for its habitat management and conservation. We examined the soil seed bank in three populations and carried out germination experiments and embryo growth measurements with fresh seeds in laboratory, greenhouse and outdoor conditions. We also investigated the effects of storage and burial of seeds. H. repens formed a long-term persistent (>6 years) soil seed bank with very pronounced primary dormancy, but no secondary dormancy or dormancy cycles. Seeds can germinate throughout the growing season when temperatures are sufficiently high. Embryo growth and seed germination are triggered by light and, to a lesser extent, daily temperature fluctuations. Seeds of H. repens seem to have developed a unique germination syndrome with several strategies to remain dormant in the soil until optimal conditions are present for seedling establishment and survival. Both sexual reproduction and seed bank formation are crucial for the long-term survival of the populations.

Emergence Pattern of Argemone mexicana, Brassica tournefortii, and Rapistrum rugosum in Eastern Australia

A study assessed the potential for using cumulative growing degree days (CGDD) to predict the weed emergence periodicity of three weed species: Argemone mexicana, Brassica tournefortii, and Rapistrum rugosum. Weed emergence was monitored regularly by placing 200 fresh seeds of each weed species on the soil surface. Weed emergence data was fit using a three-parameter sigmoidal Gompertz model. The CGDD required for 50% emergence of A. mexicana ranged from 3380 to 5302, depending upon the seasonal variation in temperature and rainfall. The majority of emergence appeared from March to June. The seeds of A. mexicana exhibited dormancy, as the majority of seeds germinated in the second season. The CGDD required for 50% emergence of B. tournefortii ranged from 824 to 2311, depending upon the seasonal variation in temperature and intensity of rainfall. Most cohorts of B. tournefortii appeared in the first season from February to June, indicating little dormancy in seeds. The CGDD required for 50% emergence of R. rugosum ranged from 2242 to 2699, depending upon weather parameters (temperature and rainfall). The main cohorts of R. rugosum appeared from February to June, and 60% of seeds germinated in the first season, while 40% germinated in the second season, indicating dormancy in seeds. The coefficients of determination for the model verification on the emergence pattern of three weeds were > 85%, suggesting that CGDD are good predictors for the emergence of these weeds. These results suggest that forecasting the emergence of three weed species on the basis of CGDD and rainfall patterns will help growers to make better weed management decisions.

Tracing metabolic route of thymoquinone biosynthesis in diverse Nigella sativa L. cultivars using RP-HPLC technique

Although the therapeutic role of Nigella sativa has been known for a long time, for optimal utilization of plant parts, the developmental profiling of bioactive constituents and their dependence on germplasm diversity need to be assessed.Different cultivars of Nigella sativa(covering 3 samples from northern states of India and 3 reference samples) were taken to explore the relative accumulation of thymol (Thy) and thymoquinone (TQ) in different plant parts, i.e., stem, leaf, bud, flower, fruit, and seeds. Amongst all N. sativa cultivars, the maximum TQ content was found in the seed (45.3885 ± 0.3616 mg/g fresh weight) of the RS cultivar. Seeds of the AN1 cultivar showed the maximum Thy content (2.7853± 0.3535 mg/g fresh weight). The minimum Thy content was found in leaves of Haryana (0.0009 ± 0 mg/g fresh weight) and leaves from RS showed the minimum TQ content (0.0029 ± 0.0001 mg/g fresh weight). There are indications that mature seeds are the best source for both Thy and TQ, followed by fresh seeds collected from the intact fruit of N. sativa. In addition, Thy (precursor) and TQ (product)contentin many plant parts are inversely related to each other, especially in the buds. This indicatedthe interdependence of these two bioactive constituents, but not necessarily in all plant parts. It appears that there might be another functional precursor (in addition to Thy)leading to TQ biosynthesis (speculated to be Carvacrol) in Nigella. Such relative dominance of bioactive compounds and their precursors may be used for designing formulations and setting biotransformation experiments for further value addition.

EFFECT OF CRYO-STORAGE ON STORABILITY OF PAPAYA SEEDS

A fruit crop of significant economic importance, papayas are often propagated from seeds. Based on their freezing injury even at low moisture content, papaya seeds are classified as "intermediate seeds"; and rapid loss of viability in storage is assumed to be the primary cause of poor germination; thus, the development of appropriate technology is necessary to prolong the storability of papaya seeds. One such effective technology for prolonged seed storability is cryo-storage. The purpose of the current study was to investigate how cryostorage affects papaya seed storability. For this investigation, TNAU Papaya variety CO 8 seeds were utilised. Five distinct treatments were applied to the seeds, which were then kept for approximately six months at liquid nitrogen's vapour phase (-140°C). The biochemical parameters such as protein content, free amino acid, total carbohydrates, free sugars, total lipids, and dehydrogenase activity were measured on a monthly basis along with seed germination and seedling vigour in the cryopreserved papaya seeds. Results indicated that papaya seeds that had been vitrified (seeds with a 10% moisture content that had been soaked in loading solution for 20 minutes, then immersed in Plant Vitrification Solution 2 (PVS2) for another 20 minutes, packed in cryovials and kept in cryo-storage at -140°C) compared to papaya seeds that were packed in cloth bags and stored in ambient conditions had higher seed germination, dry matter production and vigour index at six months after storage. In comparison to fresh seeds, the results also showed that, after six months of cryo-storage, biochemical proximate, protein content, total carbohydrate content, total lipid content, and dehydrogenase activity were maintained in the aforementioned treatment with minimum reduction, while electrical conductivity, free amino acid content, and free sugar content gradually increased with the storage period at minimum rate. In crux, vitrified papaya seeds packaged in cryovials and kept in cryo-storage at -140°C preserved their quality for six months, meeting Indian Minimum Seed Certification Standards. This could be useful for storing papaya seeds for longer periods of time. Keywords: Papaya, vitrification, differential scanning calorimetry, liquid nitrogen, cryo-storage

Gardenia (Rubiaceae) seed conservation physiology with emphasis on rare Hawaiian species

Background and aims – Gardenia species are ecologically, culturally, and economically significant but the three native species of Gardenia in Hawai‘i are assessed as Critically Endangered. Seed banking is the most cost effective and efficient means of conserving plant material ex situ. To better understand the conservation physiology of Hawaiian and South Pacific Gardenia spp. and support their conservation, we asked 1) How do seeds respond to different temperatures and light and dark regimes? 2) What class of dormancy, if any, do seeds exhibit? 3) How does seed germinability respond over time in a seed bank? and 4) What is the conservation status and level of ex situ representation of Gardenia globally? Material and methods – To answer these questions, we used 19 accessions of fresh seeds and seeds stored for varying periods of time in the National Tropical Botanical Garden’s Conservation Seed Bank and Laboratory of Hawaiian (G. brighamii, G. remyi), New Caledonian (G. aubryi, G. oudiepe), and Tahitian (G. taitensis) species. Seeds were incubated at varying temperatures and in light, and in dark. Key results – We found that (1) seeds of all species tested germinated slowly and only at higher temperatures in the light and dark, (2) seeds have non-deep physiological dormancy, (3) seeds of the Hawaiian species are short lived at conventional seed bank conditions, and (4) only 40% of Gardenia spp. are represented in ex situ facilities, and 66% of the species have not been evaluated for the IUCN Red List. Conclusion – Seeds of Hawaiian Gardenia spp. are short lived in storage. Since seeds germinate in darkness, they are unlikely to form a persistent soil seedbank. Although seeds of all species tested are physiologically dormant, they can be easily propagated from seed at warmer temperatures, giving some hope to the conservation and restoration of the Critically Endangered Hawaiian species. Since our dataset was limited by a lack of continuous viability monitoring, we emphasize the need for initial germination testing and ongoing viability tests to better understand seed longevity. Lastly, we discuss the ecological relevance of our results in the context of the Hawaiian archipelago.

Seed Germination of Syzygium Cumini (Java Plum) Under Different Desiccation Period in Borno State, Nigeria

The study assessed seed germination of Syzygium cumini commonly known as Java plum or Malmo in Hausa under different desiccation periods in Maiduguri, Borno State. Understanding the germination behaviour of its seeds under different desiccation periods is essential for effective propagation and conservation efforts. Fresh seeds of S. cumini were collected, and subjected to different desiccation periods (fresh, one, two and three weeks). Germination percentage, height measurement and stem diameter were recorded and analyzed. The result showed that, 44%, 52%, 64%, 68%, 76% and 80% germinated at 10,11,12.13,14 and 15 DAS respectively while 100% of the fresh seeds germinated at 18 DAS. About 4% of the one-week desiccated seeds germinated at 23 DAS and16%, and 28%, 64%, and 76% germinated at 24, 27, 28, and 29 DAS respectively, while 100% of the one-week desiccated seeds germinated at 31 DAS. The height of the fresh seed reached 21.76cm at 60 DAE and 18.90cm height at 60 DAE during one-week desiccated period of S. cumini seed. The results indicated that seed germination was influenced by the duration of desiccation. Fresh seeds exhibited a higher germination percentage and faster germination compared to seeds desiccated for longer periods. The study provides valuable insights into the germination behaviour of S. cumini seeds under different desiccation periods, emphasizing the importance of proper seed handling and storage for successful propagation. It was recommended that fresh seeds for S. cumini were best for germination and growth performance.

Testing seed germination from herbaria: Application of seed quality enhancement techniques and implication for plant resurrection and conservation

AbstractHerbaria are an important source of data and material useful in many fields, including plant conservation. Seeds preserved in herbarium specimens may have the potential to germinate, although few studies focused on this topic. Here, the first systematic assessment of six techniques, including priming techniques and melatonin application, aimed at improving the germination of seeds from herbarium specimens is presented. Seed germination of 26 species common in Europe, some of which congeneric to extinct species, collected in herbaria and in the wild (20,549 seeds in total, including 19,509 from 297 herbarium specimens from 8 different herbaria) was tested with the following treatments: exogenous melatonin addition to the germination medium, priming with melatonin, osmopriming, hydropriming for 24 and 48 hours, standard soil, heat sterilization and gibberellins addition. More than 85% of the fresh seeds and 1% of the seeds collected in herbaria germinated, including seeds older than 50 years. Data show that treatment with exogenous melatonin had a positive effect on the germination of fresh seeds, but a negative effect on the germination of herbarium‐derived seeds. Furthermore, osmopriming treatment had a slightly positive effect on the germination of herbarium‐derived seeds. Osmopriming and exogenous melatonin addition seem to be promising techniques that need further investigation and improvement and might be useful for the development of an optimal germination protocol for old and herbarium‐derived seeds. The germination of seeds from herbaria could be an important tool in plant conservation, with the aim of reversing the extinction trend of many species through de‐extinction, safeguarding biodiversity, and genetic variability. This study provides preliminary data for the development of germination protocols, especially for old seeds of species of conservation interest, to maximise the chance of recovering lost genetic diversity and leading to the first de‐extinction ever.