Seed Science Research最新文献_第8页

Stimulatory and inhibitory effects of light on Cereus repandus (Cactaceae) seed germination are strongly dependent on spectral quality 光对谷神星（仙人掌科）种子发芽的刺激和抑制作用强烈依赖于光谱质量

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-09-01 DOI: 10.1017/S0960258522000150

X-Y. Yang, H. Pritchard

{"title":"Stimulatory and inhibitory effects of light on Cereus repandus (Cactaceae) seed germination are strongly dependent on spectral quality","authors":"X-Y. Yang, H. Pritchard","doi":"10.1017/S0960258522000150","DOIUrl":"https://doi.org/10.1017/S0960258522000150","url":null,"abstract":"Abstract In small seeds, light often promotes germination and longer-term exposure to darkness reduces light sensitivity. In cacti inhabiting harsh environments, a rapid response to light exposure is potentially advantageous for seedling establishment. We exposed dark-imbibed seeds of the cactus Cereus repandus to doses of red (RED) light and far-red (FR) light. The seeds exhibited positive photoblastism to RED light. Although the initial levels of germination varied between seed lots, the sensitivity to increasing the RED dose did not. As little as 5 min per day for 4 d was sufficient to saturate the light requirement for germination. The effects of RED light were reversed by FR exposure as long as the interval between RED and FR did not extend to 2 d, by which time the seeds had ‘committed’ to germinate. Dark incubation for 1–2 weeks prior to RED exposure reduced light sensitivity in two seed lots, such that RED only promoted around 20% germination. Phytochrome is assumed to mediate the reversibility of the RED:FR response. High sensitivity to light spectral quality suggests that seeds of C. repandus are able to germinate quickly in high-quality microsites, but seed burial or shading may commit the seeds to form a soil seed bank. The light characteristics of the germination trait in this species are typical of many small seeded species of the drylands.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"32 1","pages":"166 - 174"},"PeriodicalIF":2.1,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42764538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seed germination, initial growth and leaf anatomy of seedlings of four tree species grown in mine tailings in Brazil 巴西矿山尾矿中生长的四种树种种子萌发、初期生长和叶片解剖

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-08-10 DOI: 10.1017/s0960258522000174

Ana Lívia Martins Scarpa, F. A. Rodrigues, Yasmini da Cunha Cruz, V. Duarte, E. D. de Castro, M. Pasqual, F. J. Pereira

{"title":"Seed germination, initial growth and leaf anatomy of seedlings of four tree species grown in mine tailings in Brazil","authors":"Ana Lívia Martins Scarpa, F. A. Rodrigues, Yasmini da Cunha Cruz, V. Duarte, E. D. de Castro, M. Pasqual, F. J. Pereira","doi":"10.1017/s0960258522000174","DOIUrl":"https://doi.org/10.1017/s0960258522000174","url":null,"abstract":"\u0000 The objective of this study was to test the tolerance of two species of Schinus and two species of Handroanthus cultivated in iron mining tailings from the rupture of the dam in Mariana, Brazil. Samples of mining tailings were collected 1 km away from the dam location and then dried, stored in plastic bags and further analysed for elemental composition. The seeds, later seedlings, were cultivated in the mining waste and in sand in two experiments separately and the experimental design was in a 2 × 3 factorial scheme (two substrates and three combinations of species), with six replications (n = 36). After 60 d of the establishment of the experiments, the germination data, biometric and anatomical measurements of the leaves were evaluated, in addition to the elemental characterization of the tailings. Mining tailings showed macro and micronutrients in addition to potentially toxic elements (As, Al, Cr, Pb and Ni). Seeds germinated and seedlings survived in the mining tailings. Mining tailings reduced the seedling emergence in Handroanthus, whereas it increased the emergence in S. molle and had no significant effect in S. terebinthifolia. Mining tailings reduced the number and length of roots in Schinus but increased these traits in Handroanthus species. Moreover, mining tailings reduced the fresh mass in Handroanthus but had no effect in the Schinus species. Mining tailings reduced the palisade and spongy parenchyma Handroanthus but only the spongy parenchyma was reduced in Schinus species. Therefore, mining tailings provided conditions for seed germination and seedling growth and Schinus species showed higher tolerance.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"1 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43795256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Seed dormancy and germination behaviour of tropical rainforest tree species from Sri Lanka 斯里兰卡热带雨林树种的种子休眠和发芽行为

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-08-08 DOI: 10.1017/s0960258522000162

B. Samarasinghe, K.M.G.G. Jayasuriya, A. Gunaratne, Mahesh C. Senanayaka, K. Dixon

{"title":"Seed dormancy and germination behaviour of tropical rainforest tree species from Sri Lanka","authors":"B. Samarasinghe, K.M.G.G. Jayasuriya, A. Gunaratne, Mahesh C. Senanayaka, K. Dixon","doi":"10.1017/s0960258522000162","DOIUrl":"https://doi.org/10.1017/s0960258522000162","url":null,"abstract":"\u0000 Plant community-level studies on seed dormancy traits are important to understand and determine the significance of seed dormancy in different ecosystems. Hence, we studied seed dormancy and other related seed biological traits of 42 selected tropical lowland rainforest tree species from Sri Lanka, aiming to address seed dormancy class(es) for a biodiverse tropical lowland wet zone forest community and the relationship between dormancy classes, forest strata and seed dispersal mechanisms. Seed germination, imbibition, embryo length:seed length ratio, embryo morphology and the effect of gibberrelic acid on seed germination were determined. Sixty-two percent of the species with T50 < 30 days were identified as having fast-germinating seeds and the remaining 38% with T50 > 30 possessed slow-germinating seeds. Seeds of 33 species had fully developed embryos, while nine species had underdeveloped embryos; three had morphological dormancy (MD) and six morphophysiological dormancy (MPD). Treatment with gibberellic acid revealed physiological dormancy (PD) in seeds of six species, and the response to manual scarification confirmed physical dormancy (PY) in seeds of Pericopsis moonina. The majority of tropical lowland rainforests had non-dormant (ND) species (62%), and 14.3, 14.3, 7 and 2.3% of the species had MPD, PD, MD, and PY, respectively. Non-dormancy decreased for taxa from the upper strata to the lower strata of the forest. ND seeds were dispersed during the rainy season. Thus, non-dormancy seems to be the most dominant germination behaviour among the tree species in the lowland rainforest of Sri Lanka with the class of dormancy related to forest strata and dispersal time.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44486004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

From germination to seedling development: the effects of smoke on a native and an invasive grass species of the Cerrado 从萌芽到幼苗发育:烟雾对塞拉多一种本地和入侵禾本科植物的影响

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-08-05 DOI: 10.1017/s0960258522000137

L. G. Sanchez, A. B. Dantas-Junior, Ana Clara Caixeta Queiroz Pôrto, C. Musso, Margarete N. Sato, H. Miranda

{"title":"From germination to seedling development: the effects of smoke on a native and an invasive grass species of the Cerrado","authors":"L. G. Sanchez, A. B. Dantas-Junior, Ana Clara Caixeta Queiroz Pôrto, C. Musso, Margarete N. Sato, H. Miranda","doi":"10.1017/s0960258522000137","DOIUrl":"https://doi.org/10.1017/s0960258522000137","url":null,"abstract":"\u0000 The Brazilian Cerrado, a Neotropical savanna, is a fire-prone ecosystem where the ground layer biomass consists mainly of graminoids. However, as for other savannas, the effects of fire cues (such as smoke) on Cerrado grasses do not present a clear pattern, either for germination or seedling development. Smoke can stimulate different stages of the plant life cycle, which can alter the community and invasion processes. So far, most research on the subject focuses on germination, not addressing post-germinative phases, a sensitive stage of plant development. Here, we investigated the effect of smoke on a native (Echinolaena inflexa) and an invasive (Urochloa decumbens) grass species common in the Cerrado. We analysed germinative parameters and seedling mass and length after exposing the seeds to dry smoke for 5, 10, 15 or 20 min. Seedling development was assessed by measuring shoot and root systems after cultivating germinated seeds for 3, 7 or 15 d. Smoke did not affect germination percentages. However, fumigation reduced the mean germination time of both species and the germination onset of E. inflexa. U. decumbens had higher length values in all periods of cultivation, whereas mass values only surpassed that of E. inflexa at 15 d. Smoke exposure reduced the aboveground length of 7-d seedlings of U. decumbens, and mass of 15-d plants of both species. Also, smoke enhanced the root investment of the native and invasive species in different cultivation periods. Therefore, studying post-germinative parameters on seedling development may bring further insights into the smoke effects.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47714129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of light and temperature on seed germination of eight Cistus species 光照和温度对八种肉苁蓉种子发芽的影响

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-08-02 DOI: 10.1017/s0960258522000149

B. Luna, Paula Piñas-Bonilla, G. Zavala, B. Pérez

{"title":"Effects of light and temperature on seed germination of eight Cistus species","authors":"B. Luna, Paula Piñas-Bonilla, G. Zavala, B. Pérez","doi":"10.1017/s0960258522000149","DOIUrl":"https://doi.org/10.1017/s0960258522000149","url":null,"abstract":"Cistus species have seeds with hard coats which impose physical seed dormancy that can be released after seed scarification. In fire-prone habitats, the break of physical seed dormancy is usually related to the heat produced during fires. It is commonly accepted that most hard-seeded species, including those of the genus Cistus, are able to germinate under a wide range of temperatures in light as well as in darkness, once the seed becomes permeable. However, although many studies have focused on the release of physical dormancy only, a few have done so on the effect of environmental factors once dormancy is released. In this research, through a factorial experiment, we analysed the effects of light (light and darkness) and a range of temperatures (10, 15, 20, 25 and 30°C) on the seed germination of eight Cistus species after a heat shock. On average, almost 60% of the seeds did not germinate despite being viable, and this lack of germination increased with higher temperatures during the treatment. Although an idiosyncratic germination response emerged, temperature had a significant effect in all the species, reaching the highest levels of germination between 10 and 20°C. Light interacted with temperature in four cases by increasing the germination, especially under the least favourable temperatures. Environmental factors, such as temperature and light, appear to modulate the germination of the studied Cistus species after the release of physical seed dormancy.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46760136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Seed-coat thickness explains contrasting germination responses to smoke and heat in Leucadendron 种皮厚度解释了亮子树对烟和热的不同萌发反应

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-07-05 DOI: 10.1017/s0960258522000113

B. Lamont, Pablo Gómez Barreiro, R. Newton

{"title":"Seed-coat thickness explains contrasting germination responses to smoke and heat in Leucadendron","authors":"B. Lamont, Pablo Gómez Barreiro, R. Newton","doi":"10.1017/s0960258522000113","DOIUrl":"https://doi.org/10.1017/s0960258522000113","url":null,"abstract":"Fire stimulates the germination of most seeds in fire-prone vegetation. Fruits of Leucadendron (Proteaceae) are winged achenes or nutlets that correlate with their requirements for smoke and/or heat in promoting germination. We describe five possible smoke–heat dormancy-release/germination syndromes among plants, of which Leucadendron displays three (no response, smoke only, smoke and heat). As seed-coat thickness varies with seed-storage location (plant or soil) and morphology (winged or wingless), we tested its possible role in water uptake and germination. Species with winged seeds achieved 100% germination in the absence of smoke/heat, seed coats were an order of magnitude thinner, and their permeability greatly exceeded that of nutlets. As seed-coat thickness increased (1) imbibitional water uptake declined at a decreasing rate, and (2) the response to smoke, and to a lesser extent heat, increased linearly to reach levels of germination approaching those of winged seeds. For species responsive to smoke and heat, there was no additive effect when applied together, suggesting that they may have promoted the same physiological process. We conclude that seed-coat thickness holds the key to germination requirements in this genus, independent of seed-storage location or morphology. By what mechanisms (1) the smoke response is greater the thicker the seed coat and (2) smoke chemicals might increase water permeability to explain the non-additive effect of smoke and heat, warrant further investigation.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49137856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cold stratification in winter is more than enough for seed dormancy-break of summer annuals in eastern North America: implications for climate change 冬季的冷分层足以使北美东部夏季一年生植物的种子休眠:对气候变化的影响

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-06-29 DOI: 10.1017/s0960258522000125

Carol C. Baskin, Jerry M. Baskin

{"title":"Cold stratification in winter is more than enough for seed dormancy-break of summer annuals in eastern North America: implications for climate change","authors":"Carol C. Baskin, Jerry M. Baskin","doi":"10.1017/s0960258522000125","DOIUrl":"https://doi.org/10.1017/s0960258522000125","url":null,"abstract":"<p>Germination of seeds of some summer annuals in Kentucky (eastern USA) in late-winter lead to the hypothesis that under present climate conditions the whole length of the winter cold stratification (CS) period is not required for dormancy-break of seeds of summer annuals with physiological dormancy (PD). We evaluated our data from germination phenology studies of 45 species (69 datasets) and buried-seed studies of 33 species (44 datasets). We determined time and temperature of germination after CS and percentage of the total number of hours of CS during winter (% of winter CS) seeds received prior to start of germination. In the phenology studies, mean temperature during the week of first germination for C3 and C4 species was 11.1 and 14.4°C, respectively, and % of winter CS was 80.8 and 87.4, respectively. In the buried-seed studies, % of CS for C3 and C4 species was 40.8 and 48.1, respectively, when they germinated to 25% at 20/10°C. For 32 of 33 species in the buried-seed studies, the minimum temperature at which seeds germinated decreased with increased CS; thus, seeds had Type 2 non-deep PD. The time of germination is controlled by a number of hours of CS, a decrease in minimum temperature at which seeds can germinate and a temperature increase in early spring. Seeds can germinate at relatively high temperatures as early as December and January, but they continue to be CS until spring. Temperature increases in eastern North America due to global warming are not likely to inhibit the germination of summer annuals with PD in spring.</p>","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"41 36","pages":""},"PeriodicalIF":2.1,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138519032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxygen, a key signalling factor in the control of seed germination and dormancy 氧气，控制种子发芽和休眠的关键信号因子

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-06-28 DOI: 10.1017/S096025852200006X

F. Corbineau

{"title":"Oxygen, a key signalling factor in the control of seed germination and dormancy","authors":"F. Corbineau","doi":"10.1017/S096025852200006X","DOIUrl":"https://doi.org/10.1017/S096025852200006X","url":null,"abstract":"Abstract Oxygen is a major factor of seed germination since it allows resumption of respiration and subsequent metabolism reactivation during seed imbibition, thus leading to the production of reducing power and ATP. Most studies carried out in the 60s to 85s indicate that oxygen requirement depends on the species and is modulated by environmental factors. They have also demonstrated that the covering structures mainly inhibit germination by limiting oxygen supply to the embryo during imbibition through enzymatic oxidation of phenolic compounds by polyphenol oxidases (catechol oxidase and laccase) and peroxidases. Recent use of oxygen-sensitive microsensors has allowed to better characterize the oxygen diffusion in the seed and determine the oxygen content at the level of embryo below the covering structures. Here, I will also highlight the major data obtained over the last 30 years indicating the key role of oxygen in the molecular networks regulating seed germination and dormancy through (1) the hormonal balance (ethylene, ABA and GA), the hormone-signalling pathway and, in particular, the ABA sensitivity, (2) the emerging role of mitochondria in ROS production in hypoxia and (3) the involvement of the N-degron pathway in the turnover of proteins involved in seed tolerance to hypoxia.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"32 1","pages":"126 - 136"},"PeriodicalIF":2.1,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46029800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Antioxidant depletion during seed storage under ambient conditions 环境条件下种子贮藏过程中抗氧化剂的消耗

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-06-28 DOI: 10.1017/S0960258522000101

Moritz Stegner, Johanna Wagner, Thomas Roach

{"title":"Antioxidant depletion during seed storage under ambient conditions","authors":"Moritz Stegner, Johanna Wagner, Thomas Roach","doi":"10.1017/S0960258522000101","DOIUrl":"https://doi.org/10.1017/S0960258522000101","url":null,"abstract":"Abstract Cumulative oxidative damage from the unavoidable formation of reactive oxygen species (ROS) contributes to seed ageing. Low-molecular-weight (LMW) antioxidants, such as water-soluble glutathione (GSH) and lipid-soluble tocochromanols, can prevent ROS from causing damage, especially when antioxidant enzymes are inactive due to desiccation. However, loss of tocochromanols does not always accompany seed ageing, such as during accelerated ageing or controlled deterioration, despite the presence of oxygen and prevalent loss of GSH. To assess relationships between total germination (TG) and antioxidant changes under storage conditions with practical relevance, commercial seeds of Cucumis sativus, Daucus carota, Helianthus cucumerifolius, Latuca sativa, Lepidium sativum, Phaseolus vulgaris and Raphinus sativus of the same cultivar were obtained over multiple years and stored under ambient conditions (21.9 ± 2.1°C; 36.8 ± 6.6% relative humidity). Sigmoidal fitting of TG revealed time to when 50% of seeds had lost viability, which ranged from <5 years (D. carota) to >15 years (C. sativus). Cellular redox states were quantified via the half-cell reduction potential of LMW thiol/disulphide couples. These negatively correlated with TG (i.e. cell redox states were more oxidized in lots with lower TG), with an average R2 value of 0.62 for the most abundant thiol (GSH, or γ-glutamyl-cysteine in P. vulgaris). Concentrations of tocochromanols positively correlated with TG, with an average R2 value of 0.50 for the most abundant tocochromanol (γ or α in L. sativa and H. cucumerifolius). Therefore, during viability loss under ambient ageing conditions leading to the cytoplasm having a glassy state, the lipid domain in all species experienced oxidative damage.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"32 1","pages":"150 - 156"},"PeriodicalIF":2.1,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49517096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Oxidant system and ABA drive germination in seeds of palm species with differences in desiccation tolerance 氧化系统和ABA驱动干燥耐受性不同的棕榈种子萌发

IF 2.1 3区生物学

Seed Science Research Pub Date : 2022-06-01 DOI: 10.1017/S0960258522000095

Talita R. Silva dos Santos, E. M. Bicalho, Q. Garcia

{"title":"Oxidant system and ABA drive germination in seeds of palm species with differences in desiccation tolerance","authors":"Talita R. Silva dos Santos, E. M. Bicalho, Q. Garcia","doi":"10.1017/S0960258522000095","DOIUrl":"https://doi.org/10.1017/S0960258522000095","url":null,"abstract":"Abstract We investigated the thermal thresholds to seed germination and the variations in abscisic acid (ABA) levels and oxidative metabolism during seed dormancy-breaking and germination in two palm species with differences in desiccation tolerance. We used Mauritia flexuosa (buriti palm, desiccation-sensitive seeds) from swampy habitats (Veredas) and Attalea speciosa (babassu, desiccation-tolerant seeds) from the transition zone between the forest and semi-arid region (drained soils). Germination was evaluated at 15–40°C after dormancy-breaking (operculum removal). At optimal temperature for both species (30°C), embryos were sampled in distinct germination phases – dry, imbibed, after operculum removal and at early germination – and used for quantifying ABA and hydrogen peroxide (H2O2) content, antioxidant enzyme activities and for histolocalization of superoxide anion (O2−). Seeds of M. flexuosa germinated only in a narrow temperature range (25–35°C), while A. speciosa seeds germinated between 15 and 40°C. After operculum removal, reduced ABA levels in embryos of M. flexuosa were accompanied by constant H2O2 levels, while in A. speciosa, similar levels of ABA and H2O2 were maintained throughout all germination phases. The presence of O2− was restricted to the haustorium, and an increase in O2− accumulation was observed in both species after operculum removal. Similarities were noted between both species regarding enzyme activities; however, the activities were higher in embryos from M. flexuosa. The presence of O2− only in the haustorium indicates that this region of the embryo is an active structure following imbibition and is involved in germination itself, not just functioning in reserve mobilization.","PeriodicalId":21711,"journal":{"name":"Seed Science Research","volume":"32 1","pages":"157 - 165"},"PeriodicalIF":2.1,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47926427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0