Higher Germination Research Articles

Morpho-anatomy of in vitro germination and cryopreservation of the orchid Cattleya crispa (Orchidaceae)

Introduction: Cattleya crispa is an ornamental epiphytic orchid with geographic distribution restricted to the Brazilian Atlantic Forest. Due to predatory extractivism and human-induced habitat loss, this species appears on the Red List of Brazilian Flora. Objective: To characterize morpho-anatomical aspects regarding germination and post-seminal development from C. crispa seeds; as well as studying the effect of cryopreservation on these seeds. Methods: We used light microscopy and electron microscopy to describe the microstructure of a 100 ripe seeds. We evaluated seed viability, seed germination, survival rate and protocorm weight in cryopreserved and non-cryopreserved material, with four replicas per treatment using 20 mg of plant material. Results: The seeds are fusiform, whitish yellow with a length from 700 to 900 µm and a water content of 5 %. Germination began seven days after sowing, the formation of the globular protocorm at 30 days and the formation of the seedling occurred 150 days. The persistent seed coat can compress the protocorm and cause it to collapse. The cryopreserved seeds presented 87.15 % viability, 78.32 % germination, 8.48 % survival and protocorms with 104.27 mg five months after sowing. Data wasn’t different to non-cryopreserved seeds. Conclusions: The cryocapability of the seeds shows that cryopreservation can be used for long-term conservation. The results of this work contribute to the overall biology of C. crispa and to the propagation and storage of genetic material for conservation purposes. Objective: To characterize morpho-anatomical aspects regarding germination and initial development from C. crispa seeds; as well as studying the effect of cryopreservation on these seeds. Methods: Mature capsules of C. crispa were collected from the ex-situ conservation collection of the Orquidário Frederico Carlos Hoehne - Institute of Botany (São Paulo-Brazil). We used light microscopy, scanning electron microscopy and transmission electron microscopy. Seed viability (%), seed germination (%), survival rate (%) and protocorms weight (mg) were evaluated. Results: Our analyses showed that the globular embryo has a homogeneously early germination that occurs by the 7th day. The germinating protocorm shows bipolarity, with shoot apex and basal region. The embryo is composed mostly of lipid and protein bodies and contains a few small grains of starch. Scanning electron microscopy images revealed a persistent seed coat that does not influence the onset of germination, however, can compress the protocorm and lead to its collapse. The initial water content of the seeds was 5 %. Seeds submitted to cryopreservation resulted in a high germination rate (81.14 %). However, the survival rate of non-cryopreserved (8.48 %) and cryopreserved (11.12 %) protocorms, evaluated five months after sowing, was reduced. Conclusions: The cryocapability of the seeds shows that cryopreservation can be used for long-term conservation. The results of this work contribute to the overall biology of C. crispa and to the propagation and storage of genetic material for conservation purposes.

Effects of Type and Size of Growing Media on Seed Germination and Seedling Growth of Pinus gerardiana

Chilgoza pine (Pinus gerardiana Wall.) is an important but endangered tree species in Afghanistan. Due to poor natural regeneration, seed-related dormancy and anthropogenic factors, the IUCN put this species on the red list. Therefore, this study was undertaken to investigate the effect of growing medium and polybag sizes on seed germination and seedling growth. In this study, four growing media of soil (So), compost (Co), forest soil (Fs) and sand (Sa), viz., M1 (So + Co + Fs); M2 (Fs + Co + Sa); M3 (So + Fs + Sa); and M4 (Sa + Co + Fs) and three polybag sizes including P1 (16 cm×16 cm), P2 (18 cm×18 cm), and P3 (21 cm×26 cm) were used and arranged in the frame of 4×3 factorial design to assess their effects on germination and seedling growth. The results revealed that among different growing media treatments, higher germination and seedling growth parameters were observed on treatment M4 (Sand + Compost + Forest Soil). Seedling growth parameters were significantly affected by polybag size, and the highest seedling growth parameters were obtained for Large Polybag size (P3).

Evaluation of Sugarcane varieties against Pokkah boeng disease, role of meteorological factors and its management

Sugarcane (Saccharum officinarum L.) is widely grown as cash crop in India and provides employment to over a million of people directly or indirectly. Recently, increasing trends of Pokkah boeng disease caused by (Fusarium proliferatum) incidence were noticed in most of the sugarcane varieties grown in Bihar which ranged between 5-15%. A field trial was conducted during 2016-2018 at sugarcane research Institute farm, RPCAU, Pusa. In this study, thirty one sugarcane varieties were evaluated against Pokkah boeng disease, out of thirty one sugarcane varieties evaluated against Pokkah boeng disease, sixteen varieties showed resistant, ten varieties showed moderately susceptible while, four varieties were graded as susceptible to Pokkah boeng disease. The correlation analysis between meteorological factors and disease incidence signify that minimum temprature showed significant positive correlation whereas, relative humidity of 07 hrs, 14 hrs. and rainfall showed highly positive correlation while, sunshine displayed significant but statistically was negative relationship with Pokkah boeng disease incidence. Sett treatment with fungicide Carbendazim @ 0.1% and three foliar sprays with Carbendazim @ 0.1% at 15 days intervals revealed that highest germination and maximum control of disease incidence in all the tested varieties.

Asymbiotic and symbiotic seed culture of Polystachya concreta (Jacq.) Garay & H.R. sweet from Ecuador

The Orchidaceae is the most numerous and diverse family in Ecuador with more than 4200 species. Information on the interaction between these neotropical orchids seed and mycorrhizal fungi during germination and seedling development in situ is very limited. Symbiotic seed germination culture allows screening for compatible mycobionts resulting in mycorrhizal associations to develop under sterile and controlled environmental conditions. A previously developed symbiotic seed culture protocol was used to screen seed germination and seedling development in the neotropical orchid Polystachya concreta. Mature seeds collected from native populations in the northwest Andes Mountains of Ecuador display high viability (92%) and germination percentage (96%). Light was not a limiting factor for gemination and seedling development in this orchid species. Tulasnella isolates from roots of different orchid species in situ facilitated seed germination only, whereas Tulasnella calospora (UAMH 9824), isolated from Spiranthes brevilabris in Florida, facilitated both seed germination and seedling development in P. concreta. Ceratobasidium strains, isolated from roots of different orchid species in Ecuador, neither promoted seed gemination or seedling development. Symbiotic seed culture did not significantly improve germination compared to that observed in the absence of fungi. Higher germination rates and percentages of more advanced seedling development were observed on asymbiotic PhytoTechnology Orchid Seed Sowing Medium (P723). However, significantly larger seeds seedlings were observed when seeds were cocultured with certain fungal isolates. Information obtained from this study confirm that this symbiotic seed culture application will be both beneficial for screening potential mycobiont isolates and seedling production for conservation of native orchid species in Ecuador.

First Report of the Physiological Race (XXIV) of Hemileia vastatrix (Coffee Leaf Rust) in Hawaii.

Hawaii's coffee industry, produced commercially on six islands by over 1,470 growers on ~10,000 acres, is conservatively valued at $100M per year (USDA NASS 2023). Until late October 2020, Hawaii was the only major coffee producing region of the world that was free of Coffee Leaf Rust (CLR). Growers are currently facing their most formidable production challenge with the arrival of Hemileia vastatrix Berk. & Broome, the most economically devastating pathogen of coffee worldwide. Since its introduction (Keith et al. 2022), CLR has rapidly spread throughout the state and can be found on coffee farms and feral coffee throughout the six islands. Implementation of CLR control measures will be difficult in Hawaii, given the extreme environmental heterogeneity, differences in management practices, high production costs, and labor shortages. Compounding these challenges is that all coffee genotypes grown on a large scale in the state are susceptible to CLR. More than 55 different rust races from coffee growing countries worldwide have been identified (Silva et al. 2022). Since key control measures include developing and establishing resistant coffee cultivars, determining the rust race(s) present in Hawaii was imperative. In June 2021, nine spore samples from symptomatic cultivated and feral plants ('Typica') growing on three islands (Hawaii Island: 3, Maui: 5, Molokai: 1) were collected in gelatin capsules using a G-R Electric Manufacturing portable vacuum pump with a mini cyclone spore adapter. The samples were sent to the Coffee Rust Research Center (CIFC) in Portugal. At CIFC, the urediniospores were bulked on susceptible genotype 849/1 Matari and inoculated on a set of coffee differentials following a standard race-typing procedure (Várzea and Marques 2005). The genotype of virulence of rust samples was inferred according to Flor's gene-for-gene theory (Silva et al. 2022). The genes of virulence v2, v4, and v5 (Race XXIV) were identified in all rust samples from all islands in Hawaii, supporting the theory of a single introduction to the state, which subsequently spread (Ramírez-Camejo et al. 2022). Race XXIV was previously characterized at CIFC and is commonly found in the majority of coffee-growing countries in South and Central America, Africa and Asia (CIFC's data base). According to Figueiredo & Arruda (1974), race XXIV is considered highly aggressive with a high spore germination rate, medium germ tube length, and short incubation period required for infection. Race XXIV is pathogenic to all coffee Arabica genotypes with the resistance genes SH5 or SH2,5 like varieties Blue Mountain, Bourbon, Catuaí, Caturra, Kent's, Kona, K7, Mundo Novo, SL 28, SL 39, as well as Accession "Agaro" with resistance genes SH4,5 (CIFC's records). On the other hand, this race is not virulent to some other Arabica genotypes, such as Geisha (SH1,5), S.288 (SH3,5), and Dilla & Alghe (SH1). Race XXIV is unable to infect derivatives of interspecific tetraploid hybrids like the groups Catimor and Sarchimor (Bettencourt and Rodrigues 1988). This is the first report of race XXIV on Coffea arabica in Hawaii. This finding is essential to evaluate the potential resistance of coffee germplasm existing in Hawaii or to be introduced in this region to develop new varieties. Since the emergence of new H. vastatrix races occur preferentially at germplasm collections (Li et al. 2021), proper management is imperative where multiple genotypes/varieties are planted.

Deciphering the role of zinc oxide nanoparticles on physiochemical attributes of Zea mays exposed to saline conditions through modulation in antioxidant enzyme defensive system

Use of zinc oxide nanoparticles (ZnONPs) has the potential to increase the plant growth and development in agricultural sectors. Mode of application of NPs to plants is also of considerable importance. In present study, zinc oxide nanoparticles were prepared by using black seed extract and zinc salt. Characterized zinc oxide nanoparticles were then used to treat Zea mays L. in two types of treatments namely nano-priming and foliar nano-spray of zinc oxide nanoparticles. For each treatment a range of concentration was used i.e., 100, 200, 400, and 1000 mg/L. Experiment was conducted in randomized complete block design. Hydro-priming was used as a control. Whereas foliar spray was given after 30, 45, and 60 days of sowing. Plants were harvested after 90 days and various growth, physiological, biochemical, yield and stress parameters were studied. Results showed that monodispersed nanoparticles of average size of 45.56 nm were synthesized. Priming with ZnONPs showed better results as compared to foliar spray of ZnONPs. Highest germination (100%), Leaf length (350 cm), plant height (65 cm), and no. of leaves (10 leaves per plant) were recorded for corn plants with seed priming treatment of 200 mg/L of ZnONPs. These values were significantly higher than comparative positive control treatment values (salt-treated plants) as well. Whereas biochemical analysis also supported the results of growth parameters i.e., ZnONPs treated plants (200–1000 mg/L) showed higher values of sugar (0.6 µg), chlorophyll (1800 µg) and carotenoid content (400 µg). Protein and proline content was higher for zinc salt-treated (positive control) plants. Photosynthetic rate, CO2 sub-stomatal conductance, stomatal conductance and rate of transpiration was also higher for ZnONPs treated plants particularly in nano-primed plants. Whereas study of yield attributes showed highest cob length (14 cm), cob weight (80 g), cobs per plant (4) in ZnONPs treated plants that was significantly higher than the both controls. Stress studies of plant samples showed that peroxidase activity was highest in plants treated with 1000 mg/L zinc salt-treated salts, both in case of priming and foliar spray. Whereas catalase activity was found highest in ZnONPs (200 mg/L) foliar spray treated plants. Zinc content analysis of plant sample showed significantly higher amount of zinc in ZnONPs treated corn plants. It is concluded from present study that ZnONPs in priming treatment significantly enhanced the growth and yield attributes of corn plants through the balance of biochemical and stress indicators. Priming and foliar spray of ZnONPs also fortified the crop with enhanced zinc content. Future study with combination of both priming and foliar spray may be further optimized.

L-Alanine promotes anti-infectious properties of Bacillus subtilis S-2 spores via the germination receptor gerAA.

Bacillus species, which have two cell-type forms (vegetative cells and spores), demonstrate a variety of probiotic functions in animal feed additives and human nutrition. We previously found that the probiotic effect of Bacillus subtilis S-2 spores with high germination response to L-alanine was specifically enhanced by the L-alanine pretreatment. The germination response of Bacillus is highly associated with the germination receptors of spores. However, how L-alanine-induced germination of spores exerts anti-infectious effect in epithelial cells remains unclear. In this study, we constructed the mutant strain of B. subtilis S-2 with germination receptor gerAA knockout to further explore the role of spore germination in resisting pathogen infection to cells. The differential probiotic effects of B. subtilis S-2 and S-2ΔgerAA spores pretreated with L-alanine were evaluated in intestinal porcine epithelial cells (IPEC-J2) or Caco2 cells infected with enterotoxigenic Escherichia coli (ETEC) or following IL-1β stimulation. The results showed that the germination response of the S-2ΔgerAA spores to L-alanine was significantly reduced. Compared with the S-2ΔgerAA spores, the L-alanine-induced germination of B. subtilis S-2 spores significantly increased the activity of anti-adhesion of ETEC to IPEC-J2 cells and reduced the expression of inflammatory factors and cell receptors. L-alanine induction also significantly promoted the expression of autophagy-related proteins in the B. subtilis S-2 spores. These findings demonstrate that the gerAA germination receptor is essential for the probiotic function of Bacillus spores and that L-alanine treatment promotes the anti-infectious properties of the germinated spores in porcine intestinal epithelial IPEC-J2 cells. The result suggests the importance of germination receptor gerAA in helping spore germination and enhancing anti-infectious activity. The findings in the study benefit to screening of potential Bacillus probiotics and increasing probiotic efficacy induced by L-alanine as an adjuvant.

Effects of Storage Periods and Methods on Seed Quality of Chamomile (Matricaria chamomile.L) in Wondogenet, Ethiopia

Chamomile (Matricaria chamomile L.) seeds were stored in a polypropylene bag, cotton and bottle for twelve months. Data on seed quality were evaluated within three months of interval. The analysis of variance of the result showed that the interaction effect of storage methods and periods had significantly influenced the seed quality (germination percentage, moisture content, speed of germination and vigour index) of chamomile. The highest germination (75 %) was recorded for the seeds stored in the bottle during the third month of storage. Whereas the highest (41.2 mg %) vigour index was reported for the seeds stored in the bottle for three months. The result of the study concluded that prolonged storage periods had a significant effect on seed quality of chamomile.

Plant biomass and seed production of the legumes Aeschynomeme histrix and Stylosanthes hamata and the potential of endozoochory by cattle and sheep in semi-arid native pastures

Endozoochory is a substantial vector for seed dispersal and plays an important role in vegetation dynamics, mainly in colonisation processes through seed input to the vegetation and soil seed bank. We investigated the endozoochorous seed input by cattle and sheep on a pasture located in the western region of Burkina Faso. Through germination experiments, we assessed viable seed content of the dung of these grazing animals to estimate their suitability and efficiency for seed dispersal of fodder legumes. Cattle and sheep were daily fed seeds of Sthylosanthes hamata and Aeschynomene histrix, mixed with cotton seed cake. Faeces containing seeds of both legumes were collected 24 h after feeding. One part of faeces samples was spread in buckets of soil for direct germination in the greenhouse to evaluate germinating seed content. To improve pastures, a randomized completed design with 6 replications was conducted with both legumes and phosphorus fertilization (0 and 100 kg/ha of P2O5) and year as experimental factors. Recovery of A. histrix seeds was better than that of S. hamata with cattle (18 and 9%, respectively) compared to sheep. Seed recovered from faeces had higher germination with sheep than cattle. Thus, S. hamata seed recovered from faeces germinated well (12 and 45% with cattle and sheep, respectively, than fresh seeds used as control. However, A. histrix's seeds recovered from faeces germinated less than control (P < 0.001). The findings confirmed that ruminants could be used for targeted legume seed dispersal in natural pastures. A. histrix and S. hamata have high potential for plant biomass and seed production when phosphorus is applied. Seed ingestion by ruminants should be undertaken for improving natural pastures in semi-arid zones as lower cost practice.

Germination of seeds of Dianthus plumarius L. (Caryophyllaceae Juss.) after storage period of 43 and 44 years

The seed germination tests of long-term (1978- and 1979-year harvest) storage seeds of Dianthus plumarius were carried out. The seeds were stored in a cold chamber (0-5 °C) for 43- and 44-year period, respectively, in the hermetically sealed glass containers. The experiment was conducted in laboratory conditions, on filter-paper, in three consequent stages: initial screening (Sept/Oct. 2022, sample 1978); 6 seed samples of 100 seeds each: 3 samples from 1978 and 3 samples from 1979 year (Oct/Nov. 2022) and 12 x 100 seeds with the highest germination taken from the previous experimental batch (Nov/Dec.2022). The temperature and air humidity were monitored daily by an Electronic Temperature station. The results from trials Oct./Nov.2022 showed that the highest germination energy (GE) was found in the seed sample from 1978 (65%) while the GE varied between 42 and 46% in the samples of the 1979’ harvest. The maximum percentage of germination, in almost all experimental samples, was achieved on the 14th day and until the end of the experiment remained unchanged. The highest percentage of germination was found in sample from 1978 year - 82%. A statistically significant difference was observed between samples from 1978 and the two samples from 1979 (p≤0.05, ANOVA). The germination process took place at relatively low temperatures and at a relatively small day-night amplitude. The two consecutive experiments confirmed the fact that the seed samples from 1978 year showed a higher germination energy, which could be explained by a higher water content in the seeds which were initially placed in cold storage and were preserved during the storage conditions for the specified long-term period. The high germination rates observed in the present experiment encourages further investigations.

Hidroponik Sistemle Üretilen Bazı Yem Bitkilerinin Ruminant Hayvan Beslemesinde Kullanımı

Green fodder plants have an important place in animal nutrition in terms of meeting the nutritional needs of animals and increasing their appetite. Especially in dairy cattle breeding, green feeds are needed for milk yield and quality. In meeting the green feed needs of ruminant animals, the scarcity of agricultural areas, water use, environmental and climatic factors have negative effects on agricultural production. The tendency to soilless agriculture is increasing due to the lack of transportation of green feeds, which cannot be sustained in production throughout the year, and the high prices of green feed. For this purpose, it is thought that the elimination of the negative conditions related to the environment and soil will be occurred by hydroponic production, the continuity of green feed production can be ensured throughout the year and feed costs can be reduced. However, the digestibility and feed efficiency of the products to be obtained by green feed production with the hydroponic system will be increased. Meat, milk yield and quality, animal performance and health will, also, be positively affected by the increase in feed utilization.This review was aimed to give information about the use of cereals with a high germination rate grown by hydroponic systems as green feed in animal nutrition and their disadvantages.

Seed diversity and germination behavior in Nerium oleander L.

Nerium oleander var. ‘Villa Romaine’, commonly called oleander, is an ornamental shrub that exists in Tunisia in the wild and cultivated form. This plant is frequently propagated and produced in nurseries and used in urban plantings and on roadsides. The effects of nature of the plants (spontaneous or cultivated), climatic conditions (localities), and altitude (from 6 to 447 m) on seed shape, size, and germination of Tunisian populations, were investigated. Seeds were harvested from 23 locations belonging to six bioclimatic stages and distributed from North to South of Tunisia. The seed parameters studied were area, roundness, J index, and germination rate. A significant variation was obtained between populations, categories (cultivated and spontaneous), bioclimatic zones and altitudes. Seeds of cultivated plants were the smaller and showed the higher germination rates, compared with spontaneous populations, which had large seeds and a low germination rate. Climatic conditions and geographical location had an effect on seed morphology; seeds in lower humid were small for both cultivated and spontaneous types, they also showed a low J index value and a high germination rate. On the other hand, in upper Saharan, seeds were large and roundness and germination rate were the lowest. Also, seeds from plants in higher altitudes were the smaller and presented the lower values of the J index compared with those collected from low-altitude sites.

Does shading and ground cover of moss and litter improve germination and establishment of Betula pendula Roth, Salix caprea L. and Populus tremula L. seedlings during drought stress in climate change? – A greenhouse study

The climate change is leading to a significant increase in temperatures and dry periods in spring, for example in parts of middle and north Europe. Thus, the important factor for tree growth, the water availability, decreases on forest sites. It is to be expected that the successful establishment of pioneer tree species as pre-forests on large damaged areas will considerable be limited in the future. The phases of germination and establishment are the most dangerous phase in the life of trees. In this greenhouse study, we tested how different microsite conditions (open soil, moss and litter cover as well as different shading) under reduced water availability influence establishment success and growth of Betula pendula, Populus tremula and Salix caprea.The initial high germination success were reduced to 14%, 7% and 12% for Populus tremula, Salix caprea and Betula pendula, respectively, and the growth were significantly slower when the relevant soil water resource was just above the permanent wilting point. Therefore, in the first year the germination and establishment is linked to persistent moist conditions. If the soil dries out during germination, e.g. if there is no watering for more than 3 weeks, all seedlings died. Equivalent germination microsites (shading or ground cover) with comparable possible seedling densities to the moist open soil does not exist under water stress. Although moss and litter cover retain longer soil moisture under extremely dry conditions and guarantee significantly better seedling development than on open soil, initially significantly fewer seeds germinate on these substrate types.Radiation shows no influence on germination and seedling survival. The seedlings are able to survive radiation conditions of 3% and 27% of open area radiation. This makes establishment possible under (remaining) light canopy, at the edge of damaged areas or in small islands of remaining shelter trees on damaged areas. However, radiation had a significant effect on growth. With increasing radiation, shoot lengths and above ground biomasses are higher and the root collar diameter larger.Overall, Betula pendula is the most drought stress resistant of the tested tree species. While Populus tremula and Salix caprea already had problems establishing themselves on dry sites, the problem will become more serious under climate change. The lack of moist, vegetation-free open soils will result in a significant reduction of establishment success for tested pioneer tree species in climate change.

Comparative Effects of Hydropriming and Iron Priming on Germination and Seedling Morphophysiological Attributes of Stay-Green Wheat.

Seed priming is considered to play an essential role in the overall improvement of agricultural crops. The current research work was carried out in order to investigate the comparative effects of hydropriming and iron priming on the germination behavior and morphophysiological attributes of wheat seedlings. The experimental materials consisted of three wheat genotypes including a synthetically derived wheat line (SD-194), stay-green wheat genotype (Chirya-7), and conventional wheat variety (Chakwal-50). The treatments included hydro (distilled and tap water)- and iron priming (10 and 50 mM) of wheat seeds for 12 h duration. Results indicated that both priming treatment and wheat genotypes exhibited highly different germination and seedling characteristics. These included germination percentage, root volume, root surface, root length, relative water content, chlorophyll content, membrane stability index, and chlorophyll fluorescence attributes. Furthermore, the synthetically derived line (SD-194) was the most promising in majority of the studied attributes by exhibiting a high germination index (2.21%), root fresh weight (7.76%), shoot dry weight (3.36%), relative water content (19.9%), chlorophyll content (7.58%), and photochemical quenching coefficient (2.58%) when compared with stay-green wheat (Chirya-7). The study also found that hydropriming with tap water and priming wheat seeds with low concentrations of iron yielded better results when a comparison was made with wheat seeds primed at high concentrations of iron. Therefore, wheat seed priming with tap water and iron solution for 12 h is recommended for optimum wheat improvement. Furthermore, current findings suggest that seed priming may have the prospect of an innovative and user-friendly approach for wheat biofortification with the aim of enhanced iron acquisition and accumulation in grains.

Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) Spectroscopy: A Tool to Determine Groundnut Seed Quality

Background: ATR-FTIR spectroscopy is proved to be a simple, reliable, rapid and easy-to-use technique to assess the groundnut seed quality. Groundnut seeds are highly sensitive to deterioration mainly due to their chemical composition and moisture content. The high oil content and fatty acids of groundnut seeds reduces the seed viability well in advance due to lipid peroxidation process, which is the most frequent cause of seed ageing. As a result, not only lipid peroxidation, but also a series of reactions that produce toxic products occur. Methods: Eleven groundnut seed lots were tested for their seed germination potential as well as the oil quality parameters, ATR-FTIR analysis, antioxidant enzyme activities and physiological seed quality parameters. Result: The results indicated that the FTIR spectra of the seed lots having higher germination ( greater than 70%) exhibited deviations at different wave numbers within the range of 4000-400 cm-1 when compared with seed lots having lower germination ( less than 70%). The peak intensity was found to follow an increasing trend to a decrease in germination percentage of the seed lots. The seeds lose its viability, the activity of antioxidant enzyme decreases leading to an alteration in free fatty acid, acid value, saponification value, iodine value and peroxide value. Finally, the study concluded that the changes in seed germination from 92 to 12 per cent and their corresponding enzyme activity are closely correlated with FTIR spectral data. Hence, ATR FTIR may be used as a tool to predict the quality of the groundnut seeds during storage.

Seed Priming Improves Enzymatic and Biochemical Performances of Rice During Seed Germination under Low and High Temperatures

As an abiotic stress, adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination. Using a factorial experiment, we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures. Each of the rice genotypes (Hashemi, Sadry-domsefid, IRON-70-7053-7 and NORIN-22) was primed with hydro-hardening, KCl, CaCl2 and ascorbic acid (AsA) and without a priming agent as a control at low (15 ºC), optimum (25 ºC) and high (35 ºC) germination temperatures. The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents, especially under the low germination temperature. At 15 ºC, seed priming with AsA was found to be the best agent for the activities of amylase, α-amylase, catalase (CAT), peroxidase (POX), ascorbate peroxidase (APOX) and superoxide dismutase (SOD) as well as the content of soluble sugars in the NORIN-22 genotype, and for protease activity and soluble protein content in the IRON-70-7053-7 genotype. SOD at the low germination temperature and CAT, POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length, vigor index, normal seedling rate and germination rate. Under the priming agents, the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes, and at the high germination temperature under KCl priming in the Hashemi genotype.

Seed priming mitigates high salinity impact on germination of bread wheat (Triticum aestivum L.) by improving carbohydrate and protein mobilization.

Salinity is increasingly considered as a major environmental issue, which threatens agricultural production by decreasing yield traits of crops. Seed priming is a useful and cost-effective technique to alleviate the negative effects of salinity and to enable a fast and uniform germination. In this context, we quantified the effects of priming with gibberellic acid (GP), calcium chloride (CP), and mannitol (MP) on seed germination of three bread wheat cultivars and investigated their response when grown at high salinity conditions (200 mM NaCl). Salt exposure strongly repressed seed imbibition and germination potential and extended germination time, whereas priming enhanced uniformity and seed vigor. Seed preconditioning alleviated the germination disruption caused by salt stress to varying degrees. Priming mitigating effect was agent-dependent with regard to water status (CP and MP), ionic imbalance (CP), and seed reserve mobilization (GP). Na+ accumulation in seedling tissues significantly impaired carbohydrate and protein mobilization by inhibiting amylase and proteases activities but had lesser effects on primed seeds. CP attenuated ionic imbalance by limiting sodium accumulation. Gibberellic acid was the most effective priming treatment for promoting the germination of wheat seeds under salt stress. Moreover, genotypic differences in wheat response to salinity stress were observed between varieties used in this study. Ardito, the oldest variety, seems to tolerate better salinity in priming-free conditions; Aubusson resulted the most salt-sensitive cultivar but showed a high germination recovery under priming conditions; Bologna showed an intermediate behavior.

How Scarification, GA3 and Graphene Oxide Influence the In Vitro Establishment and Development of Strelitzia.

The propagation of strelitzia plants can be carried out in vitro as an alternative to combine the aseptic conditions of the culture medium with the use of strategies to promote germination and controlled abiotic conditions. However, this technique is still limited by the prolonged time and low percentage of seed germination, which is the most viable explant source, due to dormancy. Thus, the objective of this study was to evaluate the influence of chemical and physical scarification processes of seeds combined with gibberellic acid (GA3), as well as the effect of graphene oxide in the in vitro cultivation of strelitzia plants. Seeds were subjected to chemical scarification with sulfuric acid for different periods (10 to 60 min) and physical scarification (sandpaper), in addition to a control treatment without scarification. After disinfection, the seeds were inoculated in MS (Murashige and Skoog) medium with 30 g L-1 sucrose, 0.4 g L-1 PVPP (polyvinylpyrrolidone), 2.5 g L-1 Phytagel®, and GA3 at different concentrations. Growth data and antioxidant system responses were measured from the formed seedlings. In another experiment, the seeds were cultivated in vitro in the presence of graphene oxide at different concentrations. The results showed that the highest germination was observed in seeds scarified with sulfuric acid for 30 and 40 min, regardless of the addition of GA3. After 60 days of in vitro cultivation, physical scarification and scarification time with sulfuric acid promoted greater shoot and root length. The highest seedling survival was observed when the seeds were immersed for 30 min (86.66%) and 40 min (80%) in sulfuric acid without GA3. The concentration of 50 mg L-1 graphene oxide favored rhizome growth, while the concentration of 100 mg L-1 favored shoot growth. Regarding the biochemical data, the different concentrations did not influence MDA (Malondialdehyde) levels, but caused fluctuations in antioxidant enzyme activities.

Heavy metals tolerance on seed germination and growth of serpentine plant species Alyssum murale L.

Alyssum murale L. is a nickel hyperaccumulator herbaceous perennial species in a natural serpentine soil and adapted to arid, infertile soils. The objective of this study was to investigate how the seed germination, root, and hypocotyl growth of this plant species respond to exposure to different concentrations of heavy metals such as lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr) and manganese (Mn). The highest germination, even higher than in the control group, was observed at lower concentrations of Ni, Cd, Pb and Mn, while almost all higher concentrations of the metals decreased germination. Germination time was significantly slower (from about 6 to 10 days) for seeds treated with higher metal concentrations, especially Mn, Cd and Ni, and faster (from about 3 to 5 days) for seeds treated with lower concentrations. The strongest inhibitory effect on root and hypocotyl length occurred in treatments with different concentrations of Pb, Cd, and Mn, and seeds treated with lower concentrations of Ni showed a positive effect on root and hypocotyl growth. Seeds treated with Ni showed relatively high tolerance to this metal, presenting the potential for practical use in various fields of phytoremediation technology.

Rice OsGA2ox9 regulates seed GA metabolism and dormancy.

Rice OsGA2ox9 regulates seed GA metabolism and dormancy.