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ARTICLE • J. Seed Sci. 46 • 2024 • https://doi.org/10.1590/2317-1545v46291663 linkcopy

Open-access Physiological, anatomical, and histochemical changes in lentil (Lens culinaris Medik) seeds at different stages of maturation

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ABSTRACT:

Understanding the changes that occur in seeds during the maturation process is essential to determine the optimal harvest time and to obtain high quality seeds. In this study, anatomical, histochemical and physiological quality data of lentil seeds at different stages of maturation were evaluated. Lentil seeds, cv. Precoz, were produced in an experimental field at the Universidade Federal de Viçosa. Pods were harvested at five stages of maturity: super-green, green, green-yellow, yellow and brown. The anatomical and histochemical characterization of the seeds was performed by light microscopy, with sections stained with Toluidine Blue, Xylidine Ponceau (XP), Lugol and Ruthenium Red. The physiological quality of the seeds was evaluated by germination, seedling emergence index (IVG), seedling emergence, electrical conductivity and accelerated ageing. During lentil seed maturation, protein, and starch reserve deposition occurs when the pods are at the green stage and stabilizes from the yellow stage. Seed coat cracks were observed in seeds from brown pods. Seed germination was similar among the different stages of maturity. Seeds from yellow pods were more vigorous than those from green and brown pods.

Index terms:
physiological quality; pulse; seed anatomy; seed development

RESUMO:

Conhecer as alterações que ocorrem nas sementes durante o processo de maturação é importante para definir o ponto ideal de colheita e obter de sementes de alta qualidade. Neste trabalho, dados de anatomia, histoquímica e qualidade fisiológica de sementes de lentilha foram obtidos em diferentes estádios de maturação. Sementes de lentilha, cv. Precoz, foram produzidas em campo experimental da Universidade Federal de Viçosa. Foram colhidas vagens em cinco estádios de maturação: super-verde, verde, verde-amarelo, amarelo e marrom. A caracterização anatômica e histoquímica das sementes foi realizada em microscopia de luz, sendo os cortes corados com Azul de toluidina, Xylidine Ponceau (XP), Lugol e Vermelho de Rutênio. A qualidade fisiológica das sementes foi avaliada por meio dos testes de germinação, IVG, emergência de plântulas, condutividade elétrica e envelhecimento acelerado. Durante a maturação das sementes de lentilha, a deposição de reservas de proteínas e amido ocorre quando as vagens estão no estádio verde, se estabilizando a partir do estádio amarelo. Fissuras no tegumento foram observadas nas sementes obtidas de vagens marrons. O potencial de germinação das sementes foi semelhante nos diferentes estádios de maturação. Sementes obtidas de vagens amarelas tiveram maior vigor em relação às de vagens verdes e marrons.

Termos para indexação:
qualidade fisiológica; pulse; anatomia de sementes; desenvolvimento de sementes

INTRODUCTION

Pulses-edible dry seeds of legumes such as beans, dry peas, chickpeas, and lentils-are rich in protein, fiber, minerals, and vitamins, all nutritional aspects that have encouraged efforts to expand their cultivation and consumption (Nascimento e Silva, 2019).

Lentil (Lens culinaris Medik) is one of the five most important legumes in the world (Nascimento et al., 2016) and is promising for crop rotation systems in Brazil. Research is underway to develop cultivars adapted to local soil and climatic conditions, with a focus on appropriate technologies and increasing production to meet domestic demand and export to Asian countries, which are major consumers (Madruga et al., 2021). In this context, studies on seed production technology are essential, particularly with regard to the field maturation process and its effects on seed quality.

Seed development, from ovule fertilization to seed maturity, involves physical, anatomical, physiological, and biochemical changes. Seeds act as a sink during development, receiving photosynthetic products that increase their dry matter content, which is mainly represented by proteins, carbohydrates, and lipids (Marcos-Filho, 2015). The kinetics and nature of this sink deposition have important implications for seed production. In more detailed maturation process studies using staining techniques, it was possible to observe, in addition to the seed structure, the clear differentiation of compounds such as starch granules, cell walls and protein bodies (Wood et al., 2011; Miranda et al., 2017; Ribeiro et al., 2021). In pea, it was observed alterations in the cell wall pectic polysaccharides during seed development (McCartney et al., 2000; Zablatzká et al., 2021), as also observed in check pea seeds (Trancoso et al., 2021). In soybean seeds, lignin content in the seed coat and pod wall plays an important role related to seed physical, health, and physiological qualities (Krzyzanowski et al., 2023; Menino et al., 2023).

Physiological maturity of the seeds is reached when the maximum dry matter content is accumulated (Marcos-Filho, 2015; Ellis, 2019; Trancoso et al., 2021). Along with this accumulation, germination and vigor increase, reaching peak values close to physiological maturity. From that point onward, seeds become susceptible to deterioration, which can reduce germination and vigor (Trancoso et al., 2021; Pinheiro et al., 2023). The pattern of acquisition of physiological quality in soybean seeds shows that the acquisition of vigor and longevity proceeds, and they are complete at the end of the late maturation phase, after the maximum dry matter stage (Lima et al., 2017). Monitoring changes in reserve compounds in tissues and the physiological quality of seeds can help identify when seed quality is at its peak and establish criteria for determining the optimal time to harvest. These criteria are particularly important for indeterminate species such as lentils, where continuous flowering and uneven maturation make it difficult to determine the best time to harvest.

Early harvesting can result in a high proportion of immature seeds, as observed by Khatun et al. (2009) when harvesting green-yellow lentil pods. Conversely, leaving seeds in the field longer than necessary may cause deterioration process, compromising their physiological and sanitary quality (Pinheiro et al., 2023). Thus, understanding and monitoring metabolic and structural changes during seed maturation is essential to obtaining high quality seeds. Research on lentil seed maturation has shown that pod color is an appropriate parameter for determining harvest time (Khatun et al., 2009). However, despite the interest and market potential in Brazil, there is a lack of information and studies on the maturation process and optimal harvest time for lentil varieties used in the Brazilian market.

Therefore, the aim of this study was to evaluate physiological, anatomical and histochemical aspects of lentil seeds harvested at different stages of maturation.

MATERIAL AND METHODS

The experiment was conducted in an experimental area of the Universidade Federal de Viçosa (UFV), state of Minas Gerais, Brazil. The experimental area is located at an altitude of 689.7 m and geographic coordinates of 20° 45’ South latitude and 42° 51’ West longitude (IBGE, 1991). The climate classification of the experimental area is Cwb, defined as mesothermal, humid with rainy summers and dry winters according to Köppen (Vianello and Alves, 1991). Climatological data recorded during the experimental period indicated an average relative humidity around 80% and temperatures ranging from 22.9 °C (maximum) to 12.0 °C (minimum).

After conventional soil preparation, lentil seeds of the Precoz cultivar were sown on April 6, 2017, in rows 21 m long and 0.20 m apart, with a planting density of 40 plants per linear meter. Fertilization was based on the results of soil analysis, following the technical recommendations for the crop (Nascimento et al., 2016). Cultural practices were performed according to the guidelines by Giordano et al. (1988).

During flowering, flowers were marked at anthesis to determine the number of days after anthesis (DAA) required to obtain pods with the following external colors: super green (SV), green (V), green-yellow (VA), yellow (A), and brown (M), with pods harvested at each stage. After harvest, the pods were manually threshed to obtain a seed sample for anatomical and histochemical characterization, except for super-green stage seeds. The remaining seeds were dried in a laboratory environment (20 oC temperature and 55% relative humidity) until they reached a moisture content of approximately 13% for subsequent analysis.

Anatomical and Histochemical Analyses

Seeds from each treatment were fixed in a solution of formaldehyde, acetic acid and 50% ethyl alcohol (5:5:90 v/v) (FAA 50) for 48 h (Johansen, 1940). The samples were kept under vacuum and then subjected to a graded ethanol dehydration series and embedded in methacrylate (Historesin - Leica®) according to the manufacturer’s instructions. Cross sections of 5 μm thick from the center of the seed were obtained using an automated rotary microtome (modelo RM 2155, Leica) and evaluated for anatomical characteristics. For anatomical characterization, sections were stained with toluidine blue (O’Brien et al., 1964) and mounted on slides with synthetic resin (Permount). Lugol’s reagent (Johansen, 1940) was used to identify starch and Xylidine Ponceau (Vidal, 1970) to identify proteins for histochemical localization of reserve compounds in resin-embedded material. Periodic acid-Schiff (PAS) tests for total polysaccharides (McManus, 1948), ruthenium red (Johansen, 1940) and Sudan for lipids (Lison, 1960) were also performed. Histochemical evaluations were performed under a light microscope (model AX-70 TRF, Olympus Optical, Tokyo, Japan) equipped with a digital camera (Zeiss Axio Cam HRc, Göttingen, Germany) and a computer running Axion Vision imaging software.

Physiological Quality Analysis

Seeds from each treatment (except super-green stage) were submitted to the following tests and determinations:

Moisture content: determined in an oven at 105 °C for 24 hours (Brasil, 2009), with four replicates of 50 seeds. Results were expressed as a percentage (wet basis).

Dry matter mass: assessed alongside seed moisture content (Brasil, 2009), calculated as the average final weight of seeds after drying. Results were expressed in mg seed-1.

Germination: four replicates of 50 seeds were sown in rolls of paper towels moistened with water at 2.5 times the dry paper weight and kept in a germinator at 20 °C. Counts were conducted on the fifth and tenth days after sowing (Brasil, 2009), with results expressed as the percentage of normal seedlings.

Germination speed index (GSI): conducted alongside the germination test, with daily counts of normal seedlings. GSI was calculated as Maguire (1962).

Seedling emergence: four replicates of 50 seeds were sown at a depth of 1.0 cm in a soil-sand mixture (1:1) in polystyrene trays and kept in a greenhouse. Daily counts were performed until the number of emerged seedlings stabilized, and emergence percentage was calculated.

Electrical conductivity: four replicates of 50 seeds were weighed, immersed in 75 mL of deionized water, and maintained in a B.O.D. chamber at 25 °C (Torres et al., 2009) for 16 hours, a period determined by preliminary tests. Electrical conductivity was then measured using a conductivity meter, with results expressed in μS.cm-1.g-1.

Accelerated aging: seeds were spread in a single layer on a metal screen inside gerbox-type boxes containing 40 mL of saturated sodium chloride (NaCl) solution (40 g NaCl per 100 mL water) to achieve 76% relative humidity. The boxes were sealed and kept in a B.O.D. incubator at 41 °C for 48 hours (Freitas and Nascimento, 2006). After this period, the germination test was performed as described above, with the percentage of normal seedlings recorded on the fifth day after sowing.

Statistical Analysis

A completely randomized design with four replicates was used. The values obtained for each variable were subjected to Shapiro-Wilk and Bartlett tests to confirm residual normality and variable homogeneity, respectively data were then analyzed by analysis of variance (ANOVA), with treatment means compared by using Tukey’s test at a 5% significance level. Statistical analyses were conducted using the SISVAR software (Ferreira, 2012). Descriptive analysis was performed for the anatomical and histochemical characterization results.

RESULTS AND DISCUSSION

Lentil pods and their respective seeds were harvested at different stages of maturity (Figure 1). At 15 days after anthesis (DAA) - super-green stage, the pods were green, underdeveloped, with an average length of about 1.2 cm, and the seeds were in the early stages of formation with rudimentary internal structures. So, it was not possible to use these seeds for anatomical, histochemical and physiological quality evaluations. At 20 and 25 DAA, the pods and seeds were green; at 30 DAA, the pods and seeds had turned green-yellow, and at 35 DAA, they were fully yellow, with seeds reaching an average size of 1.68 cm. At 40 DAA, the pods and seeds (with an average size of 1.55 cm) showed a brown color. Seeds from green pods harvested before 25 DAA did not germinate, while pod dehiscence already occurred in the field at 45 DAA. The super-green stage was excluded from descriptive anatomical, quality and germination analyses.

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Figure 1
Lentil pods harvested at different maturation stages and their respective seeds. DAA - Days After Anthesis. Super Green - 15 DAA; Green - 25 DAA; Green-Yellow - 30 DAA; Yellow - 35 DAA; Brown - 40 DAA. Scale bar corresponds to 2 cm.

Structurally, lentil seeds consist of a seed coat, cotyledons, and an embryonic axis (Figure 2D).

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Figure 2
Lentil seeds (A). Illustration of the cutting plane used for anatomical and histochemical characterization (B). Main structures of lentil seeds (C) and (D). Transverse sections stained with Toluidine Blue at different developmental stages: green (E); green-yellow (F); yellow (G); brown (H). Co: cotyledon; Te: seed coat; Ei: embryonic axis; PC: cell wall; C: cytoplasm; P: parenchyma; Ma: macrosclereids; Os: osteosclereids. B and C: 5 mm; D: 500 µm; E, F, G, and H: 100 µm; I and J: 25 µm. Red arrows: tegument fissures.

The bluish, purplish coloration of the cell walls indicates the presence of cellulose and pectins, while the lighter or colorless outer portions of the macrosclereids indicate an uneven wall composition with a higher proportion of hemicellulose in this region, which does not react with toluidine blue. According to Dongen et al. (2003). the legume seed coat generally consists of parenchymatic cells, vascular tissue, and two layers of sclereids: an outer layer of macrosclereids and an underlying layer of osteosclereids. Legume seeds are typically testal, derived from bitegmic ovules, with the inner integument (tegmen) often disappearing (Corner, 1976). The exotid consists of a layer of macrosclereids that do not undergo lignification (Figures 2E, 2F, 2G, and 2H) and are composed primarily of cellulose and pectins, as inferred from the toluidine blue metachromasia seen in Figure 2.

As development progresses, this layer of macrosclereids shows wall thickening from the green (Figure 2I) to the brown stage (Figure 2J). This variation in composition and thickening contributes to the appearance of fissures in this seed coat layer (Figures 2H and 2J). Observation of these cracks in brown stage seeds supports the hypothesis that they result from a combination of factors, such as increased hardness of internal seed structures due to reserve deposition, seed desiccation, and differential thickening and composition of the outer seed coat cells. This is likely to result in increased stress in these cells which, combined with water loss, leads to seed coat cracking.

These fissures occur widely across the seed coat of brown pods (Figures 2H, 2J) and may facilitate water uptake for germination. On the other hand, they can also serve as entry points for opportunistic microorganisms, potentially reducing seed germination or quality.

The seed coat has a variable number of cell layers; from the outside to the inside, we can observe a layer of macrosclereids, followed by a layer of osteosclereids and an area of parenchymatic cells (Figures 2E - 2J). At the stages examined, the collapse of the parenchymatic cells made it impossible to determine the exact number of cell layers composing the seed coat. Occasionally, pieces of vascular tissue can be seen in this region. Similar to the outer layer of the seed coat, these osteosclereids do not show lignification of their walls, which, according to toluidine staining, indicates a higher proportion of pectins among other structural wall components.

Other parenchyma layers are found in the inner part of the seed coat (Figures 2E and 2H). These parenchyma layers may occasionally have a structural function as the layers adjacent to the cotyledons tend to collapse, a phenomenon observed more frequently from the yellow stage onwards. Along with water loss and reserve deposition, this layer may act as a potential buffer against mechanical impacts on the seed.

Accumulation of reserve compounds during seed development occurs primarily in the cotyledons (Borek et al., 2013), as observed in lentils (Figure 3A). In exalbuminous species, starch typically serves as the major reserve compound, followed by proteins and, to a lesser extent, lipids (Nakamura and Oliveira, 2005). In this study, lipids were not detected due to a negative reaction with Sudan Red and Sudan Black reagents (data not shown).

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Figure 3
Cross-section view of the lentil seed and sampled position for histochemical tests (A). Transverse sections stained with XP (B and C), Ruthenium Red (D and E), and Lugol (F and G) for green (V); green-yellow (VA); yellow (A); and brown (M) developmental stages. Te - seed coat; Pr - reserve parenchyma; Fv - vascular bundle; Co - cotyledon; Pa - parenchyma. Scale: A: 1000 µm; B, C, D, E, F, G: 100 µm.

Histochemical tests highlight the location of reserves in the cotyledons of lentil seeds (Figure 3A). Tests with phloroglucinol for lignin and Sudan III and Sudan Black for lipids yielded negative results (data not shown), confirming the absence of lignification in the cell layers of the lentil seed coat, indicating a reduced role for mechanical resistance. Nevertheless, the outer layer of macrosclereids shows a thickened, albeit unlignified, wall. These results contrast with the observations of Corner (1976) in soybean seeds, where macrosclereids underwent lignification as maturation progressed. Gradual lignification of seed coat cells has also been observed in pepper (Capsicum spp.) during seed development (Abud et al., 2017).

A higher presence of proteins is observed in the sclereid layers and the more peripheral parenchyma of the seed coat at the green stage (Figure 3B). In the cotyledons, however, the protein content decreases in later stages of maturation, such as the brown stage (Figure 3C). Protein bodies are visible and isolated, probably smaller in the first two stages of maturation (green and green-yellow) (Figure 3B), whereas in the last two stages (yellow and brown) the cytoplasm is denser and individual protein bodies cannot be distinguished by the XP reaction (Figure 3C).

As seed development progresses, pectin deposition occurs on the macrosclereid layer of the seed coat (Figures 3D and 3E), forming a thin layer that reacts positively to ruthenium red, indicating the presence of pectic substances. Pectins are highly hydrated, branched, and heterogeneous polysaccharides composed of galacturonic acid (Diener et al., 2019). They play a crucial role in ion transport, determine wall porosity, regulate cell-cell adhesion via the middle lamella, and participate in cell defense, among other functions (Wang et al., 2022). The presence of pectins in the seed coat cell layers and in the parenchyma reserve cells of the cotyledon mesophyll is evident at all stages of lentil seed development (Figures 3D and 3E). The differentiated structure of the sclereid cell walls can also be seen in response to ruthenium red; the outermost layer of the macrosclereid wall is less stained at the green stage (Figure 3D) and appears more homogeneous at the brown stage (Figure 3E).

In soybean seeds, variations in temperature and relative humidity can cause expansion and contraction, resulting in wrinkles or fissures in the seed coat due to the absence of the ampullary hypodermis layer (Souza and Marcos-Filho, 2001). According to Forti et al. (2013) the size of the ampullary or hourglass cells gradually decreased until no cells in the opposite hilum region, where wrinkles caused by weathering damage are usually observed in soybean seeds. This phenomenon may have contributed to the fissures observed in lentil seeds from brown pods, as they were exposed to field environmental conditions longer than others until harvest (Figure 2J). Fissures occur when surface of cotyledons cells expand and exert pressure, or when inner cells contract and exert tension on the inner portion due to the decreasing pressure gradient within the seed after rapid drying (Souza and Marcos-Filho, 2001). Seed coat cracking contributes to increased seed deterioration in soybean when seeds are stored under high-temperature conditions (Teixeira et al., 2024).

Lugol’s solution confirmed the presence of starch in seeds at all stages of maturity (Figures 3F and 3G). According to Zeeman et al. (2010), starch can be temporarily accumulated in certain cells at certain stages of development. The starch present in the early stages of maturation has likely been converted to other compounds, such as soluble sugars. Transient starch serves as a primary carbon source for cell division, expansion, and differentiation. It can also be used as a carbon source for the synthesis of other reserve compounds, such as proteins and lipids, or as an energy source for cellular metabolism (Dadlani and Yadava, 2023).

The water content of seeds from green pods was high (54.9%) and gradually decreased during development to 36.6%, 23.4%, and 18.3% at the green-yellow, yellow, and brown stages, respectively (Figure 4). High moisture content during early maturation is essential for cell expansion (Bewley et al., 2013) and gradually decreases as development progresses and tissue water is replaced by dry matter (Marcos-Filho, 2015). The decrease in water content was accompanied by an increase in seed dry matter, reaching higher levels in the green-yellow, yellow, and brown stages, which were not significantly different from each other (Figure 4). A similar behavior was observed in seeds of Vigna unguiculata (Cruz et al., 2019) and chickpea (Trancoso et al., 2021).

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Figure 4
Moisture content and dry mass of lentil seeds obtained from pods at different maturation stages. Means followed by the same letter do not differ statistically by Tukey’s test (p ≤ 0.05).

The lowest dry matter content was observed in seeds from green pods, while the maximum value was recorded in seeds from green-yellow pods, with no significant increase beyond this stage, indicating that the seeds had reached physiological maturity and no further translocation of assimilates from the plant to the seeds occurred (Trancoso et al., 2021). These findings are consistent with Samarah and Abu-Yahya (2008) and Trancoso et al. (2021), who observed that chickpea seeds reached physiological maturity at 40-50% moisture content and yellow pods. In the present study, seeds from green-yellow pods also had a moisture content close to this range, around 37% (Figure 4A). Linking plant, fruit, and seed characteristics to physiological maturity is important to produce high-quality seeds, as it is known that from this point onward, seeds remain in the field until they dry to a level compatible with harvesting, making them susceptible to deterioration (Trancoso et al., 2021).

Throughout the development of the lentil seed, reserve materials have accumulated. These are mainly starch and protein (Figure 3). In seeds from green pods, starch granules were observed in cotyledon cells (Figure 3F); however, seed dry mass was still low at this stage (1.9 g/100 seeds). From the green-yellow stage, protein bodies were observed in addition to starch in the parenchyma reserve cells, with no significant changes in subsequent stages (Figures 3C and 3G). These observations confirm the dry matter data, which showed no significant increase from the green-yellow stage (Figure 4).

Seed germination was statistically similar at different stages of maturity (Figure 5A). For example, seeds from both green and fully mature (brown) pods showed similar germination rates, with values above 80%. Khatun et al. (2009) observed higher germination rates for lentil seeds from brown, dry pods compared to those from green-yellow pods and attributed this to the high proportion of immature and poorly formed seeds at this stage. In the present study, even seeds from green pods had embryos capable of germination, probably due to sufficient reserves to be mobilized during germination, as shown in the light micrographs (Figure 3). In addition, the highest dry mass values were recorded for seeds in the green-yellow, yellow and brown stages. However, seeds from the earlier (green) stage were able to germinate even without reaching maximum reserve accumulation.

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Figure 5
Average values obtained in germination, germination speed index (GSI), seedling emergence, electrical conductivity, and accelerated aging tests of lentil seeds from pods at different maturation stages. Means followed by the same letter do not differ by Tukey’s test at a 5% probability level. Green (V), Green-Yellow (YG), Yellow (A), and Brown (M).

Based on the germination speed index (GSI) and seedling emergence, higher values were generally observed for seeds from yellow pods, which were not significantly different from those from green-yellow pods, but were superior to those from green and brown pods (Figures 5B and 5C). Thus, although there was no difference in seed germination between maturation stages, vigor was affected by both early (green pods) and late (brown pods) harvesting.

When evaluating the electrical conductivity of seeds, which reflects the loss of cell membrane integrity and is inversely related to vigor (Limão et al., 2024), lower conductivity or less ion leakage (indicating higher vigor) was observed in seeds from yellow pods compared to those from brown pods (Figure 5D). In Figures 2H and 2J, fissures are visible along the seed coat of seeds from brown pods, likely due to expansion and contraction caused by fluctuations in temperature and relative humidity at the end of the ripening process. These variations can cause seed coat cracks in seeds exposed to adverse field conditions for prolonged periods, as observed by Pinheiro et al. (2021) in soybean seeds. Such fissures may have contributed to greater electrolyte leakage and consequently higher conductivity in seeds from brown pods.

The accelerated aging test (Figure 5E), in which seeds are subjected to high humidity and temperature stress, showed higher vigor in seeds from the yellow stage and lower vigor in seeds from the brown stage, which were not significantly different from those from the green-yellow stage. Therefore, the highest vigor was found in seeds from yellow pods, which was corroborated by the seedling emergence and electrical conductivity results (Figures 5C and 5D). There was no significant increase in seed dry mass from the green-yellow stage (Figure 4). However, greater vigor was observed in seeds from yellow pods, indicating that despite the high dry mass accumulation at the green-yellow stage, maximum vigor was not yet reached. According to Bareke (2018), seed vigor increases during maturation and peaks around or at the same time as maximum dry mass accumulation.

Protein and starch reserves were deposited as early as the green stage and stabilized from the yellow stage onwards. This may explain why green-stage seeds already showed germination rates similar to those at later stages (Figure 5), as the accumulated reserves were probably sufficient to produce seedlings under ideal germination test conditions. However, in terms of vigor expression-reflected in membrane system organization, emergence rate and stress tolerance-both green and brown stage seeds showed poorer performance. This could be due to incomplete reserve accumulation in the green stage and prolonged field exposure after physiological maturity for brown stage seeds, which can lead to field deterioration (Avelar et al., 2018). Prolonged field exposure can accelerate the deterioration process and reduce the physiological potential of seeds (Ebone et al., 2019; Trancoso et al., 2021).

In summary, although there was no significant difference in germination, seed vigor was generally higher in seeds from yellow pods, especially compared to those from green and brown pods. Similar results were reported by Khatun et al. (2009), where lentil seeds from yellow pods with brown spots showed higher vigor than seeds from completely dry brown pods.

An important aspect of seed maturity studies is the identification of parameters such as plant, fruit and/or seed characteristics that can help determine not only the physiological maturity of seeds, but also the maturity stage at which seed quality is at its peak (Trancoso et al., 2021).

CONCLUSIONS

During lentil seed maturation, protein, and starch reserves are deposited when the pods are in the green stage and stabilize from the yellow stage onward. It was observed fissures in the seed coat of seeds from brown stage pods. Seed germination was similar at all maturation stages evaluated. Seeds from yellow pods were more vigorous than those from green and brown pods.

ACKNOWLEDGMENTS

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil (Funding Code: 001).

REFERENCES

Publication Dates

  • Publication in this collection
    16 Dec 2024
  • Date of issue
    2024

History

  • Received
    05 Nov 2024
  • Accepted
    19 Nov 2024
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