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Several high-elevation plant species would experience an increased risk of regional extinction due to various climatic and anthropogenic factors. Information about the effects of climate change is urgently needed for modeling vegetation dynamics because it influences the various seed parameters like seed germination, seed maturation, seed mass, and seed bank in the soil. The present study was conducted at an elevation of 3145-3560 m in the treeline area of the western Himalayan region of India. The change in seed color is correlated with other seed parameters such as seed moisture content, seed germination, seed mass, and seed fall density. A decline in moisture content in maturing seeds is closely related to seed maturity (p < 0.05). Quercus semecarpifolia contains the highest seed mass followed by Abies spectabilis. Reportedly, the species with higher seed mass have an advantage in light-restricted environments for seed germination and seedling development. In addition, the fruit mass was observed to be the highest for Rhododendron campanulatum, while both Betula utilis and R. arboreum had similar fruit mass. The seed fall density varied between 1.55 and 7.85 seeds m-2 and the maximum mortality of up to 32% of seedlings was observed during post-monsoon season from November to February. The potential disruption in the timing of seed fall, soil seed bank, and seed germination due to climatic irregularities has broader implications for forest ecosystems. Generally, the soil in treeline areas gets frozen during winter, resulting in seedlings facing severe water stress and a high rate of transpiration. The present study addresses the issue regarding the survival and proliferation of important treeline species in the western Himalayan region of India. [ABSTRACT FROM AUTHOR]

Abies spectabilis (East Himalayan Fir), a dominant timber-producing species in the Himalayas, plays a dynamic role in ecological balance and sustains various habitats across temperate to subalpine altitudes. Himalayan montane forests express signs of changes in the growth, regeneration, and population density of forest tree species due to ongoing climate change, including its upper distribution limit. The research was conducted at 30°11'02˝N and 79°39′36˝E, ranging from 3,100 to 3,500 m asl elevation in the treeline ecotone of western Himalaya. The study presents a comprehensive perspective on how water availability and its intricate interactions with climatic and ecological variables shape the dynamics of treeline ecosystems. The study's phytosociological analysis of treeline sites revealed the complex interplay between species composition, adaptability, and regeneration potential. The eco-physiological aspects of water balance were thoroughly explored, underscoring how plants employ various strategies to cope with changing water availability. The soil moisture content ranged from 32.17 to 73.50%. The dynamic nature of water potential (pre-dawn (ΨPD) and mid-day (ΨMD)) across seasons and years reflects and varies between -0.13 and - 1.25 MPa, the species' ability to adjust and manage water balance according to environmental shifts. Osmotic potential at full turgor varied from -0.72 to -1.77 MPa, these adjustments are crucial for key life cycle events of vegetative and reproductive phases of species. The strong correlation of water potential (Ψ) and phenophases emphasizes the importance of water status in regulating these vital processes. Furthermore, the study delved into the maturation and germination processes, highlighting the significance of Ψ and moisture content in seed development and germination success. The maximum germination of 46.33% was observed when the seed moisture content was 30.90 ± 3.11%. The observed correlations between cone characteristics and seed parameters indicate the existence of trade-offs that impact seed size, weight, and germination capacity, contributing to the overall fitness of the species. [ABSTRACT FROM AUTHOR]

Several high-elevation plant species would experience an increased risk of regional extinction due to various climatic and anthropogenic factors. Information about the effects of climate change is urgently needed for modeling vegetation dynamics because it influences the various seed parameters like seed germination, seed maturation, seed mass, and seed bank in the soil. The present study was conducted at an elevation of 3145–3560 m in the treeline area of the western Himalayan region of India. The change in seed color is correlated with other seed parameters such as seed moisture content, seed germination, seed mass, and seed fall density. A decline in moisture content in maturing seeds is closely related to seed maturity (p < 0.05). Quercus semecarpifolia contains the highest seed mass followed by Abies spectabilis. Reportedly, the species with higher seed mass have an advantage in light-restricted environments for seed germination and seedling development. In addition, the fruit mass was observed to be the highest for Rhododendron campanulatum, while both Betula utilis and R. arboreum had similar fruit mass. The seed fall density varied between 1.55 and 7.85 seeds m–2 and the maximum mortality of up to 32% of seedlings was observed during post-monsoon season from November to February. The potential disruption in the timing of seed fall, soil seed bank, and seed germination due to climatic irregularities has broader implications for forest ecosystems. Generally, the soil in treeline areas gets frozen during winter, resulting in seedlings facing severe water stress and a high rate of transpiration. The present study addresses the issue regarding the survival and proliferation of important treeline species in the western Himalayan region of India.

Physiological maturity impacts seed quality through various mechanisms including vigor, desiccation tolerance, dormancy induction, synthesis of raw materials (including seed storage proteins), and the reorganization of metabolisms. Peanut seed development can be classified into seven classes with four incremental stages per class. Based on the mesocarp color, the final three stages are commonly referred to as "orange", "brown", and "black". In 2017, freshly harvested pods from one genotype of runner market-type peanuts grown under conventional practices were obtained from the University of Georgia research facility. The pods were removed from the plant material and 'pod blasted' to reveal the mesocarp. After separation, the remainder of the pod outer layer was removed, and the seeds were segregated for proteomic analysis. The raw peanuts were analyzed by bottom-up LC-MS/MS proteomics, which was conducted by the Proteomics Resource Center at the Rockefeller University, to identify the significant protein composition differences in each maturity class. The proteomic data revealed differentially expressed proteins as a function of maturity class with multiple functions including plant defense, metabolism, cell signaling, nutrient accumulation, and packaging. Understanding the processes needed for seed maturation will enable peanut scientists to evaluate the traits needed for robust germination, hardiness of the seed in response to disease, and nutrient quality. [ABSTRACT FROM AUTHOR]

Palms have high ecological and economical importance in tropical and subtropical regions around the world. Preserving genetic resources of palms is hampered by poor understanding of the complex seed physiology, which differs in desiccation tolerance and germination requirements depending on species and ecoregion. This study investigates Butia catarinensis embryo water content threshold, in vitro germination using gibberellin 3 (GA3) (0 and 8µM) and cryopreservation methods (cooling rate and cryoprotectant solution) for propagation and ex situ preservation of an endemic Arecaceae from Brazil. We use light and electronic microscopy to study the effect of desiccation and low temperatures in embryos cells. B. catarinensis embryos exhibit physiological and cytological traits from both, desiccations tolerant (small vacuoles, lipid and protein reserves) and sensitive (many mitochondria and endoplasmic reticulum) palms seeds. Embryos excised from mature seeds lacked differentiated cells, especially above the cotyledonary axis, but showed 90% of germination on MS medium containing 8µM of GA3, suggesting that B. catarinensis seeds exhibit morphophysiological dormancy. Embryos from mature fruits were quite moist (1.42 gH2O•gDW− 1). Extreme embryo dehydration to 0.13gH2O•gDW− 1 caused ultrastructural deformation, but did not reduce the capacity of the embryo to germinate (83%) upon rehydration. As a step toward cryobanking, embryo response to immersion in liquid nitrogen (LN) were 77% normal seedlings post-thawing and in vitro cultivation. B. catarinensis embryos are rudimentary, desiccation tolerant and can be stored in LN and revived using cryobiotechnology strategies. This can be effective at protecting genetic diversity of threatened species as B. catarinensis from anthropogenic threats.Key message: Butia catarinensis embryos are rudimentary, desiccation tolerant and can be stored at liquid nitrogen temperatures and revived using cryobiotechnology strategies. [ABSTRACT FROM AUTHOR]

Abies spectabilis (East Himalayan Fir), a dominant timber-producing species in the Himalayas, plays a dynamic role in ecological balance and sustains various habitats across temperate to subalpine altitudes. Himalayan montane forests express signs of changes in the growth, regeneration, and population density of forest tree species due to ongoing climate change, including its upper distribution limit. The research was conducted at 30°11´02˝N and 79°39′36˝E, ranging from 3,100 to 3,500 m asl elevation in the treeline ecotone of western Himalaya. The study presents a comprehensive perspective on how water availability and its intricate interactions with climatic and ecological variables shape the dynamics of treeline ecosystems. The study’s phytosociological analysis of treeline sites revealed the complex interplay between species composition, adaptability, and regeneration potential. The eco-physiological aspects of water balance were thoroughly explored, underscoring how plants employ various strategies to cope with changing water availability. The soil moisture content ranged from 32.17 to 73.50%. The dynamic nature of water potential (pre-dawn (ΨPD) and mid-day (ΨMD)) across seasons and years reflects and varies between −0.13 and − 1.25 MPa, the species’ ability to adjust and manage water balance according to environmental shifts. Osmotic potential at full turgor varied from −0.72 to −1.77 MPa, these adjustments are crucial for key life cycle events of vegetative and reproductive phases of species. The strong correlation of water potential (Ψ) and phenophases emphasizes the importance of water status in regulating these vital processes. Furthermore, the study delved into the maturation and germination processes, highlighting the significance of Ψ and moisture content in seed development and germination success. The maximum germination of 46.33% was observed when the seed moisture content was 30.90 ± 3.11%. The observed correlations between cone characteristics and seed parameters indicate the existence of trade-offs that impact seed size, weight, and germination capacity, contributing to the overall fitness of the species.

The research was carried out over a period of two years to study the effects of ripening treatments at different temperatures on the viability, vigour and antioxidant composition of seeds of eggplant varieties 'Kemer 27', 'Aydın Siyahı' and 'Manisa Kır Çizgili' harvested at different periods. In the study, the controlled deterioration tests were kept at two different moisture content and the measurements of the electrical conductivity test were carried out in four different times. Antioxidant analyses were conducted individually for each maturity period. In both years, there were statistically significant differences in all maturation treatments of the cultivars 'Aydn Siyah', 'Kemer 27', and 'Manisa Kır Çizgili' as determined by the controlled deterioration test with 18% and 20% seed moisture content, electrical conductivity, and antioxidant tests for all ripeness seed groups (p<0.05). In the germination test of the control group seeds at 30 °C, the best results were between 58% and 99%, while the highest germination rates at the end of the controlled deterioration test ranged between 97% and 100%. After analysing the test results, it was found that the seed groups subjected to the 20/35 °C and 35 °C ripening processes performed better than the control group. Furthermore, it was found that the seeds obtained from the fruits harvested on the 75th day after anthesis (DAA) had higher viability than the other groups. [ABSTRACT FROM AUTHOR]

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The research was carried out over a period of two years to study the effects of ripening treatments at different temperatures on the viability, vigour and antioxidant composition of seeds of eggplant varieties ‘Kemer 27’, ‘Aydın Siyahı’ and ‘Manisa Kır Çizgili’ harvested at different periods. In the study, the controlled deterioration tests were kept at two different moisture content and the measurements of the electrical conductivity test were carried out in four different times. Antioxidant analyses were conducted individually for each maturity period. In both years, there were statistically significant differences in all maturation treatments of the cultivars ‘Aydn Siyah’, ‘Kemer 27’, and ‘Manisa Kır Çizgili’ as determined by the controlled deterioration test with 18% and 20% seed moisture content, electrical conductivity, and antioxidant tests for all ripeness seed groups (p

Hairy roots generated by Rhizobium rhizogenes-mediated transformation of yew (Taxus spp.) is a promising approach to enhance production of Taxol® (paclitaxel), which is one of the most effective anticancer drugs. As a prerequisite, it is pivotal to successfully produce Taxus seedlings for transformation. However, the deep dormancy of Taxus seeds leads to extreme difficulties in seed germination. Therefore, embryo rescue has been used to break the dormancy of Taxus baccata seeds, thereby producing seedlings for transformation. In the current study, a successful strategy of embryo rescue was to sterilize the surface of T. baccata seeds collected from the field at two different maturity stages (low and high). The strategy resulted in 100% germination rate, but it was worth noting that not all germinated embryos grew into fully developed plants. As a result, the present experiment introduced an innovative indicator—fully developed seedling index—to describe the growth of seedlings developed by germinated embryos. Collectively, the data revealed that 21 ± 4% of the seedlings eventually grew into fully developed plants. Regarding the development of the seedlings, the fully developed seedling index increased initially along with seedling growth, reaching a peak after 2 weeks. Subsequently, the fully developed seedling index from low maturity seeds and high maturity seeds began to decrease until it stabilized after 4 weeks and 7 weeks, respectively. Consequently, the new findings proved helpful to select T. baccata seeds with appropriate maturity, hence developing a reliable technique to produce viable seedlings for a transformation pipeline. [ABSTRACT FROM AUTHOR]

Physiological maturity impacts seed quality through various mechanisms including vigor, desiccation tolerance, dormancy induction, synthesis of raw materials (including seed storage proteins), and the reorganization of metabolisms. Peanut seed development can be classified into seven classes with four incremental stages per class. Based on the mesocarp color, the final three stages are commonly referred to as “orange”, “brown”, and “black”. In 2017, freshly harvested pods from one genotype of runner market-type peanuts grown under conventional practices were obtained from the University of Georgia research facility. The pods were removed from the plant material and ‘pod blasted’ to reveal the mesocarp. After separation, the remainder of the pod outer layer was removed, and the seeds were segregated for proteomic analysis. The raw peanuts were analyzed by bottom-up LC-MS/MS proteomics, which was conducted by the Proteomics Resource Center at the Rockefeller University, to identify the significant protein composition differences in each maturity class. The proteomic data revealed differentially expressed proteins as a function of maturity class with multiple functions including plant defense, metabolism, cell signaling, nutrient accumulation, and packaging. Understanding the processes needed for seed maturation will enable peanut scientists to evaluate the traits needed for robust germination, hardiness of the seed in response to disease, and nutrient quality.

Introduction Plant development is defined as a series of phenological events that are controlled by external factors and determine changes in the shape or function of some organs. Temperature and photoperiod are two of the most important environmental factors affecting phenological development. Papaver rhoeas L. and Papaver dubium L., from the Papaveraceae family, are common annual winter weeds in northern Iran. The life cycle of these species is closely related to winter crops such as wheat (Triticum aestivum L.) and other winter cereals that compete severely with them. The Papaver species are capable of producing a huge amount of small-sized seeds that remain dormant at maturity. The timing of emergence, growth and sexual reproduction is highly important for the success of invasive weeds. Checking the phonological behavior of these plant species along with their seed production would be useful for decision-support systems helping managers select the best management strategies and, thereby, improving P. rhoeas and P. dubium control. Also, the phenology data would allow predicting these species invasibility of new areas. The present study was aimed to quantify the phonological behavior of these weeds. Materials and Methods In the present study, the phenology of P. rhoeas and P. dubium were studied in the research field at Agricultural Sciences and Natural Resources University of Sari, Iran, with an annual rainfall of 851 mm per year. Seeds of these species were collected from a wheat field located in Mazandaran province, north of Iran during spring 2018. These species seeds were cultivated on 12 November 2018. The phenological stages were recorded from emergence to the end of the seeding stage. The phenology was studied based on the growing degree day. At the end of the experiment, the period of each phenological stage was calculated based on the day and the growing degree day. In order to determine the morphological traits of the plant, eight sampling steps were performed. Morphological traits such as plant height, number of leaves, number of flowers, number of capsules, and dry matter were measured. Results and Discussion The results showed that P. rhoeas and P. dubium grow from 0 to 1723.56 and 1759.06 growth degrees day, respectively. During this period, seven phenological stages were recorded for these two species. These stages were included emergence, rosette (7-8 leaves), stem elongation and branching, blooming, flowering, fruiting, and seed maturity. The flowering stage period in both species was long, 48 days in P. dubium and 46 days in P. rhoeas. The results showed that the shortest and longest stages of development of these two weeds were emergence and stem elongation, respectively. In this study, the growth period of P. rhoeas and P. dubium took about eight months. It has some variation with regard to height, the number of flower, number of capsule and dry matter between both species under the same environmental conditions but both plants started their developmental stages at the same time and finished at almost the same rate. The trend of changes in height, number of leaves, number of flowers, number of capsules, and dry matter were similar in both species. The life cycle of these two species begins with germination in autumn and ends with seed production in late June. The longest period of growth stage in both species was in spring and this trend decreases in late spring. The flowering stage begins in late March and ends in mid-June. The maturity period of these two species was from mid-June to the end of the first decade of July. One of the characteristics of these two species is high seed production. In P. rhoeas, at the end of the fruiting stage, each plant produced an average of 13 capsules and each plant produced an average of 5000 seeds. Also, in P. dubium, each plant produced an average of 14 capsules, and each plant of this species produces an average of 5922 seeds. Conclusion Based on knowledge of the different phenological stages of the two species, it is possible to plan for proper management. From a managerial point of view, these two species should be controlled before the blooming stage; so that their seeds do not enter the seed bank, because their seeds are considered as causes of contamination in the field.

Abutilon theophrasti (velvetleaf) is a widespread and problematic annual weed. Greenhouse and field experiments were conducted to investigate the effects of different cutting methods on the viability of A. theophrasti seeds. Three cutting methods were assessed: (1) Entire plant cut and dried (EPD)—plants were cut at soil level and dried with capsules attached on the greenhouse bench or soil surface for 4 weeks; (2) capsules detached and dried (CD)—capsules were removed from plants and dried for 4 weeks; and (3) capsules detached and tested while fresh (CF)—a control treatment. Before drying, the developmental stage (stage one, dark green; stage two, light green; stage three, yellowish‐green; or stage four, black with the slightly open capsule) and age (days after flowering, DAF) of each capsule was recorded. Seed viability was measured immediately in the CF treatment and after the 4‐week drying period in the EPD and CD treatments. No seeds in the EPD and CD treatments were viable when harvested at the first developmental stage (1–8 DAF) in either experiment, but 100% of seeds in the CF treatment in the field were viable when harvested at 8 DAF. In both greenhouse and field experiments, seeds attained full viability at earlier harvest ages in CF than in EPD or CD treatments, suggesting that seeds might become viable relatively early in development but lose viability if allowed to dry. These findings could be applied to optimise late‐season mechanical control of A. theophrasti. [ABSTRACT FROM AUTHOR]

The lentil is a valuable crop for human nutrition and is cooked to adequate softening prior to consumption. The objective of the study was to use a model to point out the effects of seed maturity on optimum cooking time (OCT). Two lentil seed samples (cv 'Dimitra') exhibiting short (SCT) and long (LCT) cooking times (CT) were visually separated into brown- and green-colored categories, corresponding to mature and immature seeds, respectively. The 1000-seed mass and the percentages of maturity categories were measured in samples before they were subjected to 20–60 min CT. Absolute positive force (APF)-based texture analysis parameters were monitored during CT. OCT thresholds were established by correlating the organoleptic with the texture analyzer parameters. The averaging and weighted averaging of the texture analysis parameters, or even their modeling, failed to produce a realistic OCT due to texture values exceeding the OCT threshold. However, the modeling of the percentage of cooked seeds during CT predicted a realistic OCT, which was also validated later. In this model, all seeds (overcooked or intact, mature or immature) were taken into account. Among the texture parameters, APF better described cooking. Mature seeds softened faster and produced more overcooked seeds than did the immature seeds. The different proportions of maturity categories within the SCT and LCT seeds greatly affected the sample OCT. [ABSTRACT FROM AUTHOR]

AhFAD2 is a key enzyme catalyzing the conversion of oleic acid into linoleic acid. The high oleic acid characteristic of peanut mainly comes from the homozygous recessive mutation of AhFAD2A and AhFAD2B genes (aabb). However, even in high-oleic-acid varieties with the aabb genotype, the oleic acid content of seeds with different maturity varies significantly. Therefore, in addition to AhFAD2A and AhFAD2B, other FAD2 members or regulators may be involved in this process. Which FAD2 genes are involved in the regulatory processes associated with seed maturity is still unclear. In this study, four stable lines with different genotypes (AABB, aaBB, AAbb, and aabb) were used to analyze the contents of oleic acid and linoleic acid at different stages of seed development in peanut. Three new AhFAD2 genes (AhFAD2–7, AhFAD2–8, and AhFAD2–9) were cloned based on the whole-genome sequencing results of cultivated peanuts. All peanut FAD2 genes showed tissue preference in expression; however, only the expression level of AhFAD2-7 was positively correlated with the linoleic acid concentration in peanut seeds. These findings provide new insights into the regulation of oleic acid accumulation by maturity, and AhFAD2-7 plays an important role in the maturity dependent accumulation of oleic acid and linoleic acid in peanut. [ABSTRACT FROM AUTHOR]

The J. Derek Bewley Career Lectures presented at the triennial meetings of the International Society of Seed Science support early-career seed scientists by providing retrospective views, from those late in their careers, of lessons learned and future implications. Ambition, ability, inspiration, foresight, hard work and opportunity are obvious career requirements. The importance of mentoring and teamwork combined with the clear communication of results, understanding and ideas are emphasized. The role of illustration in research, and its dissemination, is outlined: illustration can support hypothesis development, testing and communication. Climate change may perturb the production of high-quality seed affecting conservation as well as agriculture, horticulture and forestry. An illustrative synthesis of the current understanding of temporal aspects of the effects of seed production environment on seed quality (assessed by subsequent seed storage longevity) is provided for wheat (Triticum aestivum L.) and rice (Oryza sativa L.). Seed science research can contribute to complex global challenges such as future food supplies from seed-propagated crops in our changing climate whilst conserving biological diversity (through seed ecology and technologies such as ex situ plant genetic resources conservation by long-term seed storage in genebanks), but only if that research can be – and then is – applied. [ABSTRACT FROM AUTHOR]

Variation in floral characteristics and growth habits within the native range of the North American wildflower Ratibida columnifera (Nutt.) Wooton & Standl. suggests potential for breeding and selection efforts to develop improved cultivars for commercial and residential landscapes. Experiments in seed propagation were performed to enable perpetuation of unique germplasms. Overnight hydration, storage condition variations, stratification and scarification, and seed maturation effects were assessed to determine impacts on viability and percent germination. Overnight hydration had no impact on percent germination. Germplasm had a significant effect on germination for all remaining experiments. Seed maintained viability at the same rate through 18 months, when slight reductions were noted. Cold storage at 3 oC had no effect on viability or percent germination of dry seed compared with storage at 23 oC. All three germplasms exhibited increased percent germination with some stratification period, and declined significantly in percent germination with all acid scarification treatments. Experiments indicated that most germplasms benefit from between 30 to 60 days of cold, moist stratification. There was a significant interaction effect among germplasms, location on the inflorescences, and maturity stages for R. columnifera. Data suggest that seed should be harvested as close as possible to when natural dispersal would occur for optimum germination. The degree of improvement in viability and percent germination associated with harvesting at various developmental stages, seed pretreatments, and storage conditions suggests that to achieve germination success, pretreatments should be used for propagation of seed from mature inflorescences and that variation can be expected within different genotypes of this species. [ABSTRACT FROM AUTHOR]

In the absence of a reliable seed supply for the African eggplant (Solanum aethiopicum L.), farmers source their seeds from fruits harvested for fresh market (precocious harvests) but ripen later in the market. Some also source seeds from traders who extract seeds from unsold fruits. Fruits harvested at 20 days after anthesis (DAA) failed to germinate while those extracted from 34 DAA fruits had less than 10% germination in a preliminary study. This study was, therefore, conducted to determine whether the seeds within fruits harvested at 30 days after anthesis upwards could be after-ripened prior to seed extraction to improve seed physical and physiological quality characteristics. The treatments were laid in a randomized complete block design in a 2 x 5 x 4 factorial arrangement involving two cultivars, five harvest maturity stages: 30, 40, 50, 60 and 70 days after anthesis, four after-ripening periods: 0, 5, 10 and 15 days with four replications. Fruits were harvested at different maturity stages & seeds were extracted at 0, 5, 10 and 15 days of storage under ambient condition (24 ± 3 °C) after each harvest. Seed dry weight, seed moisture content, 1000 seed weight, first germination count and germination percentage were determined. It was established that precocious harvest (30 days after anthesis, DAA) was not beneficial to physiological seed quality even when subjected to 15 days after-ripening. Fruits harvested 40 DAA failed to germinate while 50 DAA fruits had not more than 50% germination in both cultivars. However, when seeds extracted from these fruits were ripened for 15 days in storage, the germination percentage increased significantly by 63 to 72%. Seeds extracted from fruits harvested 60 or 70 DAA achieved the maximum germination, varying between 93 to 94% (cv. Oforiwa) & 78 to 96% (cv. Kpando) independent of after-ripening treatment. It is concluded that after-ripening is inconsequential & not necessary when seeds are harvested at physiological maturity (60-70 DAA). For the purpose of seed production, it is recommended to harvest seeds of African eggplant at physiological maturity. [ABSTRACT FROM AUTHOR]

In recent years, technological innovations have allowed significant advances in the diagnosis of seed quality. Seeds with superior physiological quality are those with the highest level of physiological maturity and the integration of rapid and precise methods to separate them contributes to better performance in the field. Autofluorescence-spectral imaging is an innovative technique based on fluorescence signals from fluorophores present in seed tissues, which have biological implications for seed quality. Thus, through this technique, it would be possible to classify seeds in different maturation stages. To test this, we produced plants of a commercial cultivar (MG/BR 46 "Conquista") and collected the seeds at five reproductive (R) stages: R7.1 (beginning of maturity), R7.2 (mass maturity), R7.3 (seed disconnected from the mother plant), R8 (harvest point), and R9 (final maturity). Autofluorescence signals were extracted from images captured at different excitation/emission combinations. In parallel, we investigated physical parameters, germination, vigor and the dynamics of pigments in seeds from different maturation stages. To verify the accuracy in predicting the seed maturation stages based on autofluorescence-spectral imaging, we created machine learning models based on three algorithms: (i) random forest, (ii) neural network, and (iii) support vector machine. Here, we reported the unprecedented use of the autofluorescence-spectral technique to classify the maturation stages of soybean seeds, especially using the excitation/emission combination of chlorophyll a (660/700 nm) and b (405/600 nm). Taken together, the machine learning algorithms showed high performance segmenting the different stages of seed maturation. In summary, our results demonstrated that the maturation stages of soybean seeds have their autofluorescence-spectral identity in the wavelengths of chlorophylls, which allows the use of this technique as a marker of seed maturity and superior physiological quality. [ABSTRACT FROM AUTHOR]

Variation in floral characteristics and growth habits within the native range of the North American wildflower Ratibida columnifera (Nutt.) Wooton & Standl. suggests potential for breeding and selection efforts to develop improved cultivars for commercial and residential landscapes. Experiments in seed propagation were performed to enable perpetuation of unique germplasms. Overnight hydration, storage condition variations, stratification and scarification, and seed maturation effects were assessed to determine impacts on viability and percent germination. Overnight hydration had no impact on percent germination. Germplasm had a significant effect on germination for all remaining experiments. Seed maintained viability at the same rate through 18 months, when slight reductions were noted. Cold storage at 3 °C had no effect on viability or percent germination of dry seed compared with storage at 23 °C. All three germplasms exhibited increased percent germination with some stratification period, and declined significantly in percent germination with all acid scarification treatments. Experiments indicated that most germplasms benefit from between 30 to 60 days of cold, moist stratification. There was a significant interaction effect among germplasms, location on the inflorescences, and maturity stages for R. columnifera. Data suggest that seed should be harvested as close as possible to when natural dispersal would occur for optimum germination. The degree of improvement in viability and percent germination associated with harvesting at various developmental stages, seed pretreatments, and storage conditions suggests that to achieve germination success, pretreatments should be used for propagation of seed from mature inflorescences and that variation can be expected within different genotypes of this species.

In recent years, technological innovations have allowed significant advances in the diagnosis of seed quality. Seeds with superior physiological quality are those with the highest level of physiological maturity and the integration of rapid and precise methods to separate them contributes to better performance in the field. Autofluorescence-spectral imaging is an innovative technique based on fluorescence signals from fluorophores present in seed tissues, which have biological implications for seed quality. Thus, through this technique, it would be possible to classify seeds in different maturation stages. To test this, we produced plants of a commercial cultivar (MG/BR 46 “Conquista”) and collected the seeds at five reproductive (R) stages: R7.1 (beginning of maturity), R7.2 (mass maturity), R7.3 (seed disconnected from the mother plant), R8 (harvest point), and R9 (final maturity). Autofluorescence signals were extracted from images captured at different excitation/emission combinations. In parallel, we investigated physical parameters, germination, vigor and the dynamics of pigments in seeds from different maturation stages. To verify the accuracy in predicting the seed maturation stages based on autofluorescence-spectral imaging, we created machine learning models based on three algorithms: (i) random forest, (ii) neural network, and (iii) support vector machine. Here, we reported the unprecedented use of the autofluorescence-spectral technique to classify the maturation stages of soybean seeds, especially using the excitation/emission combination of chlorophyll a (660/700 nm) and b (405/600 nm). Taken together, the machine learning algorithms showed high performance segmenting the different stages of seed maturation. In summary, our results demonstrated that the maturation stages of soybean seeds have their autofluorescence-spectral identity in the wavelengths of chlorophylls, which allows the use of this technique as a marker of seed maturity and superior physiological quality.

Maturity is not only critical for vigour and other seed quality characteristics but also impacts the subsequent plant performance. If these impacts on the subsequent plant are long lasting, the potential to produce vigorous, mature seed may also be affected. This scenario lends itself to the concept of seed maturity memory (SMM) – an understanding of how seed maturity may impact subsequent generations of plants and the vigour of the seeds with different maturity they produce. This study aimed to assess the existence and perpetuation of SMM in peanut, with an emphasis on early seedling vigour. Field physiological measurements and bioassay assessments were carried out on the second generation (G2) and third generation (G3) of peanut seeds with distinct parental maturity backgrounds. Our results suggested maintaining mature seed in both prior and offspring generations helped maintain high seed vigour in subsequent generations. The SMM effects varied between cultivars, with TUFRunner™ '727' exhibiting SMM, whereas FloRun™ '107' did not show SMM in the effects from first generation (G1) to G2 maturities. Overall, a seed resulting from parental plants established from immature seed somewhere in their pedigree was less vigorous than that maintained mature seeds in their pedigree. However, patterns of possible SMM were not always consistent, which could be partially attributed to differing environmental conditions each generation of seed experienced during development. These results highlight the importance of maintaining mature seeds in agricultural production and bring up the issue of ensuring seed maturity consistency during stress memory research assessing vigour characteristics. [ABSTRACT FROM AUTHOR]

Morning glory (Ipomoea spp.), a problematic weed in soybean fields, is difficult to control due to its long emergence period. The intermittent germination of morning glory prolongs the emergence period, and the factors remain unclear. Therefore, we aimed to clarify the effects of different storage periods under natural conditions on germination conditions and emergence percentages of physically dormant entire‐leaf morning glory (Ipomoea hederacea var. integriuscula) seeds in the field. In 2017–2020, I. hederacea var. integriuscula was cultivated in outdoor planters. Each plant was tagged on the blooming flower peduncle to record the flowering date. The seeds of I. hederacea var. integriuscula germinated 23 days after flowering (DAF). The water content of the seeds decreased rapidly until 30 DAF, and no water absorption occurred thereafter. The germination percentage of seeds in bags outdoors was low from 45 to 210 DAF, and it increased after 270 DAF irrespective of the temperature (20–35°C). On the field surface, the shorter the period of storage in bags outdoors, the lower the cumulative emergence percentage of I. hederacea var. integriuscula. The cumulative emergence was 0% in the soil for seeds of more than 90 DAF. The survival percentage of seeds in the soil increased with the number of DAFs. Therefore, the longer the DAF of the seeds, the higher the emergence of the field and survival percentage in the soil. The long period of storage on mother plants may be one of the factors associated with the long emergence period. [ABSTRACT FROM AUTHOR]

The lentil is a valuable crop for human nutrition and is cooked to adequate softening prior to consumption. The objective of the study was to use a model to point out the effects of seed maturity on optimum cooking time (OCT). Two lentil seed samples (cv ‘Dimitra’) exhibiting short (SCT) and long (LCT) cooking times (CT) were visually separated into brown- and green-colored categories, corresponding to mature and immature seeds, respectively. The 1000-seed mass and the percentages of maturity categories were measured in samples before they were subjected to 20–60 min CT. Absolute positive force (APF)-based texture analysis parameters were monitored during CT. OCT thresholds were established by correlating the organoleptic with the texture analyzer parameters. The averaging and weighted averaging of the texture analysis parameters, or even their modeling, failed to produce a realistic OCT due to texture values exceeding the OCT threshold. However, the modeling of the percentage of cooked seeds during CT predicted a realistic OCT, which was also validated later. In this model, all seeds (overcooked or intact, mature or immature) were taken into account. Among the texture parameters, APF better described cooking. Mature seeds softened faster and produced more overcooked seeds than did the immature seeds. The different proportions of maturity categories within the SCT and LCT seeds greatly affected the sample OCT.

• Using hyperspectral imaging combined with machine learning to detect the maturity of individual maize seeds. • Partial least square-linear discriminant analysis (PLS-LDA), the transfer learning algorithm transfer component analysis (TCA), and manifold embedded distribution alignment (MEDA) were proposed. • Transfer learning algorithms were applied to construct transferable maturity detection models between different varieties of maize seeds. • The method used in this paper has the advantages of being fast, simple, low-cost, and accurate. Seed maturity is closely related to seed germination, seed storage and the yield of the next generation of crops and it is an important indicator of seed quality. Maize is an important food, feed, and industrial raw material crop in China. Hyperspectral imaging technology has the advantages of spectral technology and machine vision technology and it can obtain information inside and outside the seed without damaging it. On the basis of hyperspectral imaging technology, transfer learning algorithms were used in this study to explore the transfer feasibility of maize seed maturity models amongst different varieties. Three transfer tasks were designed between different varieties on the basis of the model established for the Xianyu 335 variety. Cross-variety detection models were constructed using the classical machine-learning algorithm partial least square-linear discriminant analysis (PLS-LDA), the transfer learning algorithm transfer component analysis (TCA), and manifold embedded distribution alignment (MEDA). Results showed that the PLS-DA direct transfer model had varying degrees of model failure in all three transfer tasks. However, the average recognition accuracies of the TCA migration model and the MEDA migration model were 89.3% and 91.2%, respectively. Both of the two Transfer learning models can effectively solve the problem of different data feature distributions amongst different varieties, making the model more universal. It solves the problem of transferring the single-grain maize seed maturity detection model amongst different varieties, providing effective, stable and universal technical support for maize seed detection, which is conducive to the promotion of single-grain sowing technology and the improvement of agricultural automation level. [ABSTRACT FROM AUTHOR]

DOR: 98.1000/2383-1251.1398.6. 19.11.1. 1603.1606 Extended Abstract Introduction: Guar (Cyamopsis tetragonolob) which belongs to fabaceae and leguminosae families is self-pollinating and is indigenous to India and Pakistan. This plant is suitable for growth in dry, damp and sandy soils, and can tolerate saline and relatively alkaline soils. Determining the best time for harvesting seeds and its timing with maximum quality is one of the important issues in the field of seed production management. The changes in the physiological quality of seeds occur during development until seed treatment. The use of high-quality seeds plays an important role in the final yield of crops. The purpose of this study was to determine the most suitable time for harvesting seeds because seed moisture content at harvest time is one of the most important factors affecting seed quality. Materials and Methods: This research was carried out in July 2013 at Iraqi Research Station in Gorgan, Golestan, Iran in a split-plot design with four replications. The treatments consisted of the time of harvesting the seeds from the motherchr('39')s base in six stages (with different moisture content) and harvesting places (upper, middle, and bottom pods) so that, starting from the podding, every 7 days, the seeds were removed from the base. The mother was harvested and such traits as germination rate, germination percentage, seedling vigor, seed moisture content, and alpha-amylase activity were calculated. In this research, a logistic model was used to study the changes in germination percentage, germination rate, seedling vigor index and straw index during seed dressing on Guar. Results: The results of this study showed that the hypothesis that seed reaches its maximum quality at the end of the period of seed filling is confirmed, suggesting that with a moisture content of 30 and 14% in late seed filling period, Guar seeds have the highest quality. In general, the results of the present study confirm that the stages of development and management of Guar seeds on maternal basis have an impact on its quality. In the early stages of growth (humidity 85, 80 and 62 percent), due to prematurity and lack of essential seed structures, the qualitative traits of germination percentage, germination rate, seedling vigor, and strawberry index were low, and with the evolution of essential structures and reduced seed moisture content (58, 30 and 14%), the quality traits increased. Conclusions: In general, it can be concluded that the best timing for harvesting Guar seeds with the highest quality in Golestan province is when seed moisture reaches 14% or 100 days after planting, and the pods formed at the bottom are the ones with the highest quality. Highlights: To investigate the qualitative indices of Guar seed on the mother plant during seed filling period To determine the best harvest time and its adaptation with the highest quality of Guar seed

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The developmental stage of durum wheat (Triticum durum) may affect seed germination and seed damage by lesser grain borer, Rhyzopertha dominica F. (Coleoptera: Bostrichidae), which is considered a major pest damaging the quality of the stored seeds in Jordan. The objective of this experiment was to evaluate the effect of the developmental stage of durum wheat on seed germination and seed damage by R. dominica during storage. Spikes were harvested weekly at six developmental stages: 1) early milk stage (EML); 2) late milk stage (LML); 3) soft-dough stage (SD); 4) hard-dough stage (HD); 5) yellow-spike stage (Y) (physiological maturity); and 6) brown-spike stage (B) (harvest maturity). Seed standard germination and seed damage by R. dominica were evaluated for the air-dried seeds at harvest time and after an 18-month storage period. At harvest time, the standard germination of the seeds harvested at the early and late milk stages (<62%) was lower than the seeds harvested at the SD, HD, Y and B stages (>95%). The seeds harvested at all developmental stages had no damage by R. dominica at harvest time. However, the seeds harvested at the HD and Y stage had the highest seed germination (averaged 90%) after 18-month storage. As the seeds matured from the EML to SD stage, the percentage of normal seedlings in standard germination increased from 18% to 81%, respectively. The seeds harvested at the B stage had 0% germination. Only the seeds harvested at the B stage had 100% seed damage by R. dominica after 18-month storage. These results suggested that harvesting durum wheat at seed physiological maturity (Y stage) preserved seed germination and reduced seed damage by R. dominica after 18-month storage. Early harvest at physiological maturity can be a very useful practice to reduce durum wheat seed infestation by R. dominica. [ABSTRACT FROM AUTHOR]

Besides the lack of studies regarding applying elevated CO2 (eCO2) as a strategy to improve the chemical composition of anise (Pimpinella anisum L.) seeds, studies on its interaction with seed developmental stages and origin are very limited. The seed yield, chemical composition, and biological activity of 6 aniseed accessions (Egypt, Tunisia, Syria, Turkey, Yemen, and Morocco) were investigated during three developmental stages (immature, premature, and mature) under control and elevated CO2 conditions. Mature seeds from all aniseed accessions had significantly higher (p < 0.05) dry weight (DW) percentages than premature and immature seeds. The highest DW percentages were recorded in Egypt and Morocco accessions. Seed maturation increased nutrients and antioxidant metabolites in most eCO2-treated accessions. In contrast, essential oils were decreased by seed maturation, while eCO2 reversed this effect. Essential oil-related precursors (e.g., phenylalanine) and enzyme activities (3-Deoxy-d-arabino-heptulosonate-7-phosphate synthase (DAHPS) and O–methyltransferase) decreased with seed maturity. However, high CO2 reduced this impact and further induced the other essential oil-related precursors (shikimic and cinnamic acids). Consequently, eCO2 provoked changes in the antioxidant and hypocholesterolemic activities of aniseeds, particularly at mature stages. Overall, eCO2 application, as an efficient way to improve aniseed growth, essential oil metabolism, and chemical composition, was affected by seed maturation and origin. Future studies of eCO2-treated aniseeds as a nutraceutical and pharmaceutical product are suggested.

To obtain seeds of high physiological quality, it is of paramount importance to define the ideal harvest moment, which oftentimes corresponds to the period when the physiological maturity is reached. This experiment aimed to study the maturation process and determine the best harvest season of maroon cucumber fruits (Liso Gibão cultivar), in order to reach the maximum physiological seed quality. The flowers were labeled during the anthesis and the fruits harvested at 14, 21, 28, 35, 42, 49 and 56 days after the anthesis (DAA). The fruits had their visual aspects registered by photography analysis and, later, the seeds were extracted for physical (water and dry matter contents) and physiological (germination, seedling emergence, emergence speed index, accelerated aging and electrical conductivity) analyses. It was observed that the seeds reach the maximum dry mass (8.08 mg seed-1) between 47 and 49 DAA. However, the seed physiological maturity, characterized by a maximum germination (70 %) and vigor, occurs at 56 DDA. The best season to harvest seeds with a higher physiological quality takes place from 49 to 56 DDA, when the fruits present a yellowish color.

The long-standing hypothesis that seed quality improves during seed filling, is greatest at the end of seed filling, and declines thereafter (because seed deterioration was assumed to begin then), provided a template for research in seed quality development. It was rejected by investigations where seed quality was shown to improve throughout both seed development and maturation until harvest maturity, before seed deterioration was first observed. Several other temporal patterns of seed quality development and decline have also been reported. These are portrayed and compared. The assessment suggests that the original hypothesis was too simple, because it combined several component hypotheses: (a) the seed improvement (only) phase ends before seed deterioration (only) commences; (b) there is only a brief single point in time during seed development and maturation when, in all circumstances, seed quality is maximal; (c) the seed quality improvement phase coincides perfectly with seed filling, with deterioration only post-seed filling. It is concluded that the search for the single point of maximum seed quality was a false quest because (a) seed improvement and deterioration may cycle (sequentially if not simultaneously) during seed development and maturation; (b) the relative sensitivity of the rates of improvement and deterioration to environment may differ; (c) the period of maximum quality may be brief or extended. Hence, when maximum quality is first attained, and for how long it is maintained, during seed development and maturation varies with genotype and environment. This is pertinent to quality seed production in current and future climates as it will be affected by climate change and a likelihood of more frequent coincidence of brief periods of extreme temperatures with highly sensitive phases of seed development and maturation. This is a possible tipping point for food security and for ecological diversity. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drying reduces seed moisture content, which improves subsequent seed survival periods. Diverse maximum temperatures have been recommended to limit or avoid damage to seeds, but some high-temperature drying regimes may improve subsequent seed quality. Seeds from 20 different accessions of five rice (Oryza sativa L.) variety groups (aromatic, Aus, Indica, temperate Japonica, tropical Japonica) were harvested over several seasons at different stages of maturation and either dried throughout at 15°C/15% relative humidity (RH) or for different initial periods (continuous or intermittent) in different drying regimes at 45°C before final equilibrium drying at 15°C/15% RH. Subsequent seed longevity in hermetic storage at 45°C with 10.9% moisture content was determined. In no case did initial drying at 45°C provide poorer longevity than drying at 15°C/15% RH throughout. There was a split-line relation, which did not differ amongst investigations, between longevity after initial drying at 45°C relative to that at 15°C/15% RH throughout and harvest moisture content, with a break point at 16.5% (a seed moisture status of about –14 MPa). Below 16.5%, relative longevity did not differ with harvest moisture content with little or no advantage to longevity from drying at 45°C. Above 16.5%, relative longevity showed a positive relation with harvest moisture content, with substantial benefit from drying at 45°C to subsequent longevity of seeds harvested whilst still moist. Hence, there are temporal (immediately ex planta cf. subsequent air-dried storage) and water status discontinuities (above cf. below 16.5%) in the effect of temperature on subsequent air-dried seed longevity. [ABSTRACT FROM AUTHOR]

Quercus leucotrichophora A. Camus is a dominant forest forming species in Central Himalayan region between 1600 and 2100 m elevation. The species is under severe anthropogenic pressure and failing to regenerate in its natural environment. Climatic irregularities may further aggravate the problem as acorn ripening time may shift. Acorns of Q. leucotrichophora were collected from three sites located along the altitudinal limits of the species to determine the acorn maturation time. Across the sites the mean weight of acorns between the first and final collection ranged from 9.3±2.2 gm to 21.6±2.1. Inspite of variation in moisture content initial germination commenced at the same time across the sites. Maximum acorn germination was between 56.7±1.2 and 59.6±0.6. The mean acorn size was larger at the lower elevation site than higher elevation site across the collection dates. The change in acorn colour from green to dark brown, the removal of acorns cap with ease and acorn moisture content between 36.4±0.8 – 37.6±1.2 at the time of maximum germination appear to be reliable indication of maturity. Comparison with an earlier study indicates that acorns are now maturing earlier which can be severely affects its regeneration potential.

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Post-harvest drying prolongs seed survival in air-dry storage; previous research has shown a benefit of drying moist rice seeds at temperatures greater than recommended for genebanks (5-20°C). The aim of this study was to determine whether there is a temperature limit for safely drying rice seeds, and to explore whether the benefit to longevity is caused by high-temperature stress or continued seed development. Seeds of two rice varieties were harvested at different stages of development and dried initially either over silica gel, or intermittently (8 h day-1) or continuously (24 h day-1) over MgCl2 at temperatures between 15 and 60°C for up to 3 days. Seeds dried more rapidly the warmer the temperature. Subsequent seed longevity in hermetic storage (45°C and 10.9% moisture content) was substantially improved by increase in drying temperature up to 45°C in both cultivars, and also with further increase from45 to 60°C in cv. 'Macassane'. The benefit of high-temperature drying to subsequent longevity tended to diminish the later the stage of development at seed harvest. Intermittent or continuous drying at high temperatures provided broadly similar improvements to longevity, but with the greatest improvements detected in a few treatment combinations with continuous drying. Heated-air drying of rice seeds harvested before maturity improved their subsequent storage longevity by more than that which occurred during subsequent development in planta, which may have resulted from the triggering of protection mechanisms in response to high-temperature stress. [ABSTRACT FROM AUTHOR]

Flowering in buckwheat continues until the harvesting period. Besides, the seed ripening in buckwheat begins from the bottom branches up and continues upwards, and the flowers, green grains and mature grains, are present on the plants at harvest time. Therefore, the determination of the optimum harvest time in buckwheat is important for high grain yield and its nutritive value. The aim of the study was to investigate the effects of harvest at different stages of seed maturation (about 75, 80, 85, 90, 95, and 100% of the seed ripening) on the grain yield and the grain nutrient content of the buckwheat. The experiments were set up according to a randomized complete block design with three replications during the 2014 and 2015 growing seasons in Isparta in Turkey. The Aktas variety was used as the buckwheat cultivar. The results revealed statistically significant effects at the harvest times on the yield and nutrient contents of the buckwheat. In both subsequent years (2014 and 2015), the highest grain yield was obtained from the second harvest stage (1501.2 and 1559.4 kg ha- 1, respectively), and it was followed by the third harvest stage (1422.8 and 1380.4 kg ha- 1, respectively), and the grain yield decreased in the later harvest stages. The seed moisture lowed by delaying the harvest stage in both 2014 and 2015 years. The grain nutrient contents varied according to the harvest stages. Generally, N, K, Ca and Mn decreased while P, Mg, Fe, Zn and Cu increased depending on delaying harvest stage in both years. However, in terms of the grain nutrient contents, the second and third harvest stages that obtained the highest grain yield can be accepted as the desired seed nutrient quality. [ABSTRACT FROM AUTHOR]

Quercus leucotrichophora A. Camus is a dominant forest forming species in Central Himalayan region between 1600 and 2100 m elevation. The species is under severe anthropogenic pressure and failing to regenerate in its natural environment. Climatic irregularities may further aggravate the problem as acorn ripening time may shift. Acorns of Q. leucotrichophora were collected from three sites located along the altitudinal limits of the species to determine the acorn maturation time. Across the sites the mean weight of acorns between the first and final collection ranged from 9.3±2.2 gm to 21.6±2.1. Inspite of variation in moisture content initial germination commenced at the same time across the sites. Maximum acorn germination was between 56.7±1.2 and 59.6±0.6. The mean acorn size was larger at the lower elevation site than higher elevation site across the collection dates. The change in acorn colour from green to dark brown, the removal of acorns cap with ease and acorn moisture content between 36.4±0.8 - 37.6±1.2 at the time of maximum germination appear to be reliable indication of maturity. Comparison with an earlier study indicates that acorns are now maturing earlier which can be severely affects its regeneration potential. [ABSTRACT FROM AUTHOR]

Recent years have witnessed a growing interest in calendula ( Calendula officinalis L.), as an oil-bearing plant whose seeds contain unique polyunsaturated fatty acids that can be used in pharmaceutical, paint and coatings industries. The influence of harvest date on seed yield and oil biosynthesis in calendula seeds has not been widely researched. A three-year field experiment was carried out to examine the effect of harvest dates at 50%, 65% and 80% seed maturity on the yield and fatty acid composition of seven calendula cultivars. The highest seed (1096–1950 kg ha −1 ) and oil (181–391 kg ha −1 ) yield and the highest oil content (16.39–20.55%) were achieved when calendula plants were harvested with 65% of mature seeds, and yields were somewhat smaller with 80% of mature seeds. The oil from calendula seeds harvested at 80% seed maturity was characterized by the highest content of α-calendic acid (43.60%–54.39%) and the lowest content of the remaining fatty acids. The Partial Least Squares Regression analysis revealed that oil ( r 2 = 95.8) and seed ( r 2 = 98.1) yield depends on the morphological features of the examined cultivars, such as the number of flower heads, percentage of morphological seed types and climatic factors (mean temperature and total precipitation during the growing season). The results clearly indicate that seed and oil yield was highest in cultivars with the highest percentage of winged and hooked seeds and the highest number of flower heads. [ABSTRACT FROM AUTHOR]

The goal of the research was to determine the influence of two locations (Osijek and Vinkovci) and seed age on field germination, vegetative mass and dry matter of vegetative mass yields, grain yield, 1000 grain weight and grain crude protein yield of foreign spring field pea cultivar (Timo) during two successive years (2004 and 2005). The year has significantly influenced the grain yield, and the location influenced the grain yield and 1000 grain weight. In the first year of research, the greater grain yield by 70 % was accomplished on Osijek location, and in the second year it almost doubled. 1000 grain weight was by 19 % greater in the second year of research on Osijek location in relation to Vinkovci location. The same cultivar seed stored for 9 and 21 months were sown on both locations in the second year of investigation. Field germination of 9 month old seed was for 12.1 % greater than 21 month old seed. Seed maturity and location interaction was significant (p=0.05) for vegetative mass yield, dry matter of vegetative mass yield, grain yield and grain crude protein yield.

The influence of salt priming (3% KNO3 for 3 days and 1% NaCl for 2 days at 20 degree) on germination, seedling emergence and seedling dry weight of two Iranian cucumber cultivars of Basmenj and Varamin harvested at 25, 35 and 45 days after anthesis (DAA) was investigated in an unheated glasshouse. Seed germination and seedling emergence and growth were significantly affected by seed maturity and priming. Maximum advantage of priming seedling vigour was observed in seeds harvested at 25 DAA. Smaller effects of priming were also seen in the decreased mean germination and emergence times and increased seedling dry weight of seeds harvested at 35 and 45 DAA. Priming reduced percentage of seeds that germinated, but failed to emerge. In all cases, KNO3 priming was more effective than NaCl priming. Therefore, KNO3 priming can be used to improve cucumber seedling emergence and establishment, particularly in early spring sowings at low temperatures.

During two years, the influence of agroecological growth conditions and seed maturity on field emergence, grain yield, above-ground vegetative mass production, above-ground dry matter production, a 1000 seed weight and grain crude protein yield of field pea was investigated. Field trial was established as randomised block design with four replicates at two locations (Osijek i Vinkovci) of Eastern Croatia characterised by eutric brown soils. Different maturity seeds of Czech spring pea variety "Zekon", were used for sowing. Significantly higher values of above-ground vegetative mass production (50.602 t/ha) and above-ground dry matter production (9.650 t/ha) across locations were found in the first year of research. Values of field emergence (88.1%), grain yield (4.464 t/ha) and a 1000 seed weight across locations were significantly higher in the second year of research.

Assay-guided fractionation of the methanol extract from black seeds of sesame (Sesamum indicumL.) led to the isolation of an active compound that had a 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. This antioxidant was confirmed to be anthrasesamone F, an anthraquinone derivative previously isolated from different black sesame seeds and biogenetically related to other anthrasesamones in sesame roots. The radical scavenging assay showed that anthrasesamone F had more potent activity than Trolox. The content of anthrasesamone F in different parts and at different developmental stages of black sesame seeds was investigated to clarify the accumulation pattern of this antioxidant in the black seeds. Anthrasesamone F was localized in the seed coat of black seeds and accumulated after the seed coat color changed to black. The content of anthrasesamone F increased gradually with seed maturation and drastically on air-drying, the final stage in sesame cultivation. Comparison of the content of anthrasesamone F, a potent antioxidant in black sesame seeds, at different seed developmental stages. [ABSTRACT FROM PUBLISHER]

Seed maturity is a critical process of seed vigor establishment. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential (GP), germination rate (GR), germination index (GI), and time for 50 % of germination (T), at 4, 5, and 6 weeks after heading in 2 years. Significant differences of seed vigor were observed among two parents and RIL population; the heritability of four traits was more than 90 % at three maturity stages. A total of 19 additive and 2 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program, respectively, in 2012, while 16 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The phenotypic variation explained by each additive, epistatic QTL, and QTL × seed maturity interaction ranged from 9.19 to 22.94 %, 7.23 to 7.75 %, and 0.05 to 0.63 %, respectively. Ten additive QTLs were stably expressed in 2 years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of ten stably expressed additive QTLs with those previously identified, they might be true QTLs for seed vigor; the regions of QTLs for seed vigor are likely to coincide with QTLs for seed dormancy, seed reserve mobilization, low-temperature germinability, and seedling growth. Using four selected RILs, three cross-combinations were predicted to improve seed vigor; 9 to 10 elite alleles could be pyramided by each combination. The selected RILs and the identified QTLs might be applicable for the improvement of seed vigor by marker-assisted selection (MAS) in rice. [ABSTRACT FROM AUTHOR]

Chlorophyll fluorescence (CF) analysis was explored as a potential tool to identify the optimal time to harvest rice seed germplasm for maximum storage longevity. Seeds of 20 diverse genebank accessions were harvested at 24, 31, 38 and 45 d after peak flowering (DAF) and half of each seed lot was sorted by hand, following normal practice at the T.T. Chang Genetic Resources Center. CF analysis was carried out on both non-sorted and sorted seeds, while storage experiments were carried out on sorted seeds. Seed longevity (the time for viability to fall to 50%, p50) was significantly correlated with the skewness, kurtosis, mode and mean of the CF histograms when the data for every accession at all the harvest times were included in the correlation analysis. However, these correlation coefficients were ≤ 0.481. The correlation coefficient between p50 and DAF was similarly low (0.461). For individual accessions, there was wide variation in the correlation coefficients. While for some accessions, there appeared to be a strong relationship between p50 and mean CF that could be used to guide when to harvest seeds in the field, for other accessions, a unique mean CF to inform when to harvest seeds or for use in seed sorting could not be identified; this was also true for DAF over the harvesting schedule used in this study. Given the number and diversity of accessions managed by a genebank, it seems unlikely that CF analysis would be an appropriate tool to help manage the regeneration or processing of seeds intended for storage in the genebank. [ABSTRACT FROM AUTHOR]