Seeds, Volume 2, Issue 1 (March 2023) – 13 articles

Geranium (Pelargonium graveolens L’Hér.) is an important commercial horticultural plant extensively used in outdoor landscaping. Seed emergence has always remained a problem in geranium due to its hard seed nature. Hence its germination and other emergence-related attributes need to be adequately tested. The purpose of this study was to evaluate the germination and seedling growth of geraniums under different types of containers. In this regard, the seeds of two varieties of geranium viz. Large FID mixed and Star mixed were planted in different types of containers. The containers included black trays plastic pots, plastic bags, and nonwoven fabric bags. The seed emergence and other germination related parameters were significantly affected by the different types of containers. However, varieties exhibited similar responses for most germination and growth characteristics. Data were collected for seed germination, mean germination time, germination index and seedling vigor index. The type of containers showed a significant impact on seedling growth and development. The taller plants with more leaves and maximum biomass production were recorded from seeds sown in nonwoven fabric type bags. The results pertaining to varieties demonstrated that Star mixed showed better emergence and vigorous seedlings in comparison with large FID mixed. The taller seedlings with maximum leaves and shoot biomass were also recorded from Star mixed grown in nonwoven fabric type bags. Based on the results, it is concluded that germanium may be raised in nonwoven fabric bags for better seed emergence and seedling growth and development. Full article

There is evidence of the negative effects on canola seed yield caused by shading (SH) and high temperature stress (HT) separately, but the combined effect of both stresses has not been studied. This work aimed to (i) evaluate the effects of SH and HT stresses, alone and combined, on floral development, seed yield and quality, (ii) quantify the resulting effect (additive, synergistic, antagonistic) of combined stresses, and (iii) examine the utility of the photothermal quotient (PTQ, solar radiation/temperature ratio) to predict seed yield in stressed canola crops. Two field experiments were performed in Buenos Aires (Argentina) applying HT daytime temperature stress (25–30 °C from 1000 to 1500 h), SH (−80% irradiance), and SH + HT combined stresses, with C unstressed (20 °C and 100% irradiance) crops. Long and short duration SH and HT strongly affected floral development (fewer flowers and pods, with smaller ovules) and seed yield (reduction from −40 to −90% respect to C). Combined SH + HT exhibited detrimental synergistic effects on seed yield and oil concentration for long duration stresses, whereas antagonistic effects were mainly observed for short stresses. We conclude that the PTQ (cumulative from 100 to 500 °Cd after flowering) summarizes adequately the detrimental effects of combined post-flowering abiotic stresses on canola seed productivity. Full article

Teramnus labialis (L.f.) Spreng shows dormancy as a result of impermeability of the seed coat, which requires scarification treatment before sowing. Liquid nitrogen (LN) as a scarifying treatment has recently been used on this species, with excellent results. However, moisture content and immersion time on LN are factors that may affect seed germination and dormancy break. This report studies (i) the effects of dehydration on T. labialis seed viability and germination and (ii) the appropriate moisture content and extent of LN to make this scarification an effective treatment. Moisture contents of 4%, 6%, 8%, and 10% fresh weight basis (FWB) and extension to LN for 15, 30, 45, and 60 min were performed. Seed viability did not change after seed dehydration up to a moisture content of 4% FWB, whereas the percentage of germination decreased as a result of increasing the percentage of hard seeds. The seed moisture content did not affect germination after immersion in LN, but at least 30 min of exposure was required for dormancy break. The mean germination time, germination index, and time to 50% germination improved with the increasing germination from 33% to 91% and a greater duration of immersion in LN. The dormancy of T. labialis seeds with a moisture content between 4% and 10% FWB was only broken when exposed to LN for 30 to 60 min. Full article

In an experimental investigation, we looked into how different zinc (Zn) and boron (B) dosages affected the production and the amount of oil in mustard. Zn and B treatments, respectively, were separated into four levels: 0, 1, 2, 4, and 0, 0.4, 0.6, and 0.8 kg per hectare. We observed considerable Zn as well as B effects on mustard yield and its oil content. The maximum (1.6 Ton per hectare) and minimum (1.3 T ha⁻¹) seed output, the maximum (1.9 T ha⁻¹) and minimum (1.5 T ha⁻¹) stover production, the maximum (4.9) and minimum (3.99) number branches plant⁻¹, and the longest (114.6 cm) and shortest (87.44 cm) plant height were observed from 4 kg of Zn ha⁻¹ and 0 kg of Zn ha⁻¹, respectively. On the other hand, we discovered that applying 0.8 kg and 0 kg of B ha⁻¹, respectively, resulted in the highest (1.6 T ha⁻¹) and lowest (1.3 T ha⁻¹) seed yield, the highest (1.8 T ha⁻¹) and lowest (1.5 T ha⁻¹) stover yield, the maximum (4.75) and minimum (4.02) number of branches plant⁻¹, and the longest (118.7 cm) and shortest (85.15 cm) plant heights. The maximum seed (1.9 T ha⁻¹) and stover output (2.0 T ha⁻¹), tallest plant (140.9 cm), and most branches per plant⁻¹ (5.47) were obtained when 4 kg of Zn ha⁻¹ was given with 0.8 kg of B ha⁻¹. However, while Zn and B were not applied, the lowest output for all of the crop attributes assessed was observed. As a result, for mustard, 4 kg of Zn ha⁻¹ combined with 0.8 kg of B ha⁻¹ may be advised as an effective approach in terms of seed yield and oil content. Full article

The second phase of the Yam Improvement for Income and Food Security in West Africa (YIIFSWA II) project was implemented through a strong collaboration between research and private sector. Private seed companies were provided with a wide variety of training and development activities on good agronomic practices (GAPs). However, the effects of the training activities were yet to be evaluated. This paper evaluated the contribution of the training on high-quality seed yam production through paying particular attention to how it was tailored to the needs of various farmers, and how the knowledge gained was transferred to the field. The study employed an applied Kirkpatrick model and descriptive statistics to measure the indicators of training effectiveness. Results from a statistical population of 172 farmers using 179 demonstration fields showed that the farmers’ training on GAPs was effective, based on four criteria of the Kirkpatrick training evaluation process. The satisfactory results at the beginning of the hierarchical model have implications on the satisfactory results at the end. Improving the effectiveness of a training depends on defining factors such as (i) Training based on satisfaction in meeting the needs of your trainees and the seed production business; (ii) Training based on learning objectives in improving the trainees’ skills and knowledge; and (iii) Training based on learner attitude change in applying new skills and knowledge in the fields. Conclusions drawn from this study indicated that the training was a reasonable value-added mechanism of improved agricultural knowledge and practices for enhancing high-quality seed yam production in Nigeria. Full article

Presoaking seeds in water (hydropriming) or in a solution, usually of polyethylene glycol (PEG) or various salts at low water potential (osmopriming), has been demonstrated to improve the germination of seeds of numerous species including vegetables (carrot, celery, leek, lettuce, tomato), floral plants (cyclamen, primrose, pansy) and others (sugar beet, rape, soybean, sunflower). This treatment allows the germination stricto sensu to occur but prevents the radicle protrusion. Germination of primed seeds is more rapid and uniform than that of unprimed ones. Primed seeds germinate in a wider range of temperatures and are less sensitive to oxygen deprivation. Interestingly, priming also improves the germination of aged seeds. The stimulatory effect of priming persists after redrying and often during storage; however, primed seeds often deteriorate faster during storage or accelerated aging than unprimed ones. A better understanding of the mechanisms involved during priming allows us to suggest markers of the effectiveness of priming. Among these markers, ethylene production during imbibition, cell-cycle processes (DNA replication, ß-tubulin), soluble sugar metabolism (raffinose family oligosaccharides, in particular), reactive oxygen species scavenging through antioxidant systems and energy metabolism are correlated to seed vigor. Global approaches (proteomic, metabolomic or transcriptomic) could also result in the identification of new markers. Full article

The growth and performance of cowpea seedlings are negatively impacted by climate change and the subsequent occurrence of drought stress. Osmotic stress leads to the formation of reactive oxygen species, causing membrane breakdown, and impairs metabolic activities. The harmful effects of osmotic stress can be reduced by using seed priming techniques. Seeds of cowpea var. Anaswara were treated with polyethylene glycol (PEG) and β-amino butyric acid (BABA) as priming agents. The seedlings emerged from the primed seeds have been found to reduce the lipid peroxidation rates and improve plant water status by accumulating osmolytes such as proline, total free aminoacids, and total soluble sugars, and also enhanced the production of non-enzymatic antioxidants such as total phenolics, ascorbate, and glutathione, as well as increased the activities of enzymatic antioxidants such as catalase, peroxidase, and superoxide dismutase, which effectively scavenge ROS and maintain the homeostasis of the cell. PEG priming (cis-priming) and BABA priming (trans-priming) exhibited differential physiochemical responses in cowpea subjected to PEG stress. The current work investigates the extent of stress tolerance acquired through seed priming, and it will help to make a sensitive variety to a more tolerant one. Physiochemical responses of seedlings emerged from BABA-primed seeds towards PEG stress were better regulated to encounter the PEG-induced osmotic stress than the seedlings emerged from PEG-primed seeds. Full article

Soybean (Glycine max) is one of the most important proteins and oilseed crops in the world due to a boom in its demand. In order to meet this demand, various modern agricultural methods are being employed, of which magneto-priming (treatment of seeds with magnetic field) is becoming the most popular technique owing to its efficiency and eco-friendly nature to improve seed vigour, growth and yield of soybean plants. Therefore, we conducted a field experiment to evaluate the impact of magneto-priming of seeds with static magnetic field on soybean var. JS-335 plants. We used static magnetic field (SMF) strengths of 150 mT (1 h) and 200 mT (1 h) for this study. Both the SMF treatments improved growth (shoot as well as root growth parameters), carbon fixation (PSII efficiency, gas exchange parameters, carbonic anhydrase activity) and nitrogen fixation (leghemoglobin content, total protein content, nitrate reductase activity). We observed an association between these parameters which contributed to biomass accumulation and hence to the enhanced crop yield. In addition, reduced levels of ASA (reduced form of ascorbate), MDA (malondialdehyde) and antioxidant enzymes suggest that magneto-priming alleviates oxidative stress in SMF-primed soybean plants. Field strength of 200 mT (1 h) proved to be more effective in improving all the parameters as compared to 150 mT. Our study suggested that pre-sowing SMF treatment can be efficaciously employed for improving the growth, development and production of soybean. Full article

The conservation of endemic plant species is a major concern, as the species are with restricted distribution range. Since in situ conservation alone will not guarantee their maintenance, ex situ conservation measures must be undertaken to support the conservation of these species. Investigation of the impact of the storage environment of seeds gives baseline information. Therefore, this study was conducted to investigate the effect of different storage conditions (room temperature, 4 °C and −10 °C) and different storage periods over one year. Four Ethiopian endemic plant species, namely Euryops pinifolius, Kniphofia foliosa, Lobelia rhynchopetalum, and Solanecio gigas, were considered. Multivariate analyses revealed a significant (p < 0.05) effect of storage condition and period on seed germination. The storage of seeds at room temperature before drying may not be recommended for short-term storage of the studied species, except K. foliosa. After drying of seeds, E. pinifolius, K. foliosa, and L. rhynchopetalum seeds showed high germination percentage (above 80%) after storage even at sub-zero temperatures for one year. The germination percentage of S. gigas stored at room temperature before drying for thirteen months was 60% and that stored at 4 °C was 6%, which indicates that the seeds may be categorized under intermediate storage behavior. The three species can be grouped in the orthodox seed storage category. Research on desiccation screening should be undertaken to predict an optimal combination of storage moisture content and suitable storage temperature to determine storage category with certainty. Full article

Seed-borne fungi are solemn and deleterious pathogens capable of causing significant losses of quantity and quality losses in maize seeds and seedlings. They infect the crop at all points of the production chain from farms to stores. A yield loss of up to 50% can be encountered. Currently, chemical control of the disease is being implemented, though it is accompanied by several negative effects. This study aimed at identifying seed-borne fungi of maize and effective management options. A deep-freezing blotter method and morphological identification of the fungal species were implemented. The seed-borne fungi detected were Fusarium verticillioides, Aspergillus flavus, Aspergillus niger, Penicillium spp., Rhizopus spp., and Curvularia spp. However, in farmer-saved seeds, fungal incidences were significantly higher (p < 0.01) than in certified seeds. To identify more effective management options, the efficacy of water and ethanol-extracted bio-fungicides from three plant species, namely, neem (Azadirachta indica), ginger (Zingiber officinale), and coffee (Coffea arabica) were evaluated. From in vitro assays, ethanol-extracted bio-fungicides have a 100% inhibitory effect on fungal growth, whilst the inhibitory effects of water-extracted bio-fungicides are 55.88% (Azadirachta indica) and 46.31% (Zingiber officinale), followed by 5.15% (Coffea arabica). For the case of an in vivo assay, maize seeds treated with water-extracted bio-fungicides have higher seed germination and seedling vigor percentages. For germination, seeds treated with water-extracted bio-fungicides have higher percentages (neem and ginger (90%) followed by coffee (72.5%)) than ethanol-extracted bio-fungicides (neem (0%), ginger (2.5%), and coffee (0%)). A similar observation is made for seedling weight. Therefore, the tested water-extracted bio-fungicides can be used in treating seeds before sowing them. Further studies on effective methods of extracting bioactive compounds, and improving their shelf life, are recommended. Full article

Gloriosa superba L. is a horticulturally and medicinally important plant. Its seeds have poor, erratic, and deferred germination. The detailed seed structure components and water imbibition mechanism facilitating the process of seed germination in G. superba remain unexplored. Therefore, it is essential to develop methods to ensure consistent and enhanced seed germination in G. superba. Various pre-sowing treatments along with the Brunauer-Emmett-Teller (BET) surface area analysis and 3D X-ray micro-tomography (micro-T) were employed to elucidate seed structure components, porosity network, and the water imbibition mechanism during germination in G. superba. The study revealed that consistent and significantly improved seed germination (>85%) was observed using the pre-sowing treatment mechanical scarification followed by 24 h water soaking in G. superba. BET and micro-T showed that the tegmen of the seed coat exhibited porosity (21%) with a well-connected porosity network (17.50%) that helped in water movement through hilum, which was confirmed by phosphotungstic acid staining. However, the sarcotesta and endosperm were water-impermeable due to their negligible porosity. Multidisciplinary techniques such as BET and micro-T along with conventional methodologies can be employed to address the seed coat structure, porosity, and water imbibition mechanism aiding seed germination. Mechanical scarification enabled the water to penetrate internal seed layers through the permeable tegmen via the reticulate pore network, which significantly improved seed germination. The developed seed germination method can produce a large number of plants in less time and conserve the natural populations of this high-value medicinally important species. Full article

Grafting techniques are being used to improve economically important horticultural crops including Cucumis melo L. This 2-year study was carried out at Cukurova University, Adana, Turkey. This study aimed to evaluate the effects of grafting using different rootstocks on plant, fruit and seed quality in cantaloupe melons. The double haploid (DH) female (H27) and male (H4) parental lines of Solmaz F₁ (Cucumis melo L. var. cantalupensis) variety developed by Cukurova University Faculty of Agriculture were used as scion and three commercial interspecific hybrid Cucurbita (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne) varieties, Nun-9075 F₁ (Nunhems), Ares F₁ (ITU) and TZ-148 (Clause) were used as rootstocks. The parental lines were also self grafted and ungrafted parents were used as the control group. The grafted and ungrafted parents were crossed during pollination. Graft combinations and control were compared for performances in measured parameters such as the main stem length (cm), main stem diameter (mm), node number, harvest time (day), fruit weight (g), fruit length (cm), fruit diameter (cm), fruit cavity length (cm), fruit cavity diameter (cm), fruit flesh thickness (cm), fruit rind thickness (mm), total soluble solids (TSS, %), fruit flesh productivity (%), number of full and empty seeds (number/fruit), 1000 seeds weight (g), seed germination rate (%) and time (day), seed emergence rate (%), and time (day). Most of the plant, fruit and seed parameters have been positively affected by grafting. The use of commercial interspesific Cucurbita hybrid rootstocks resulted in high values compared to the control group however, harvest time, fruit cavity length and diameter, fruit rind thickness and fuit flesh productivity parameters were not statistically significant between rootstocks. Considering seed emergence and germination rate Cucurbita hybrid rootstocks performed lower values than self grafted and ungrafted control. The current study concludes that grafting plays a crucial role in plant growth, fruit and seed characters in cantaloupe melons. Statistically significant differences were mostly observed based on evaluated parameters. Full article