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Berberis koreana Palibin is an endemic plant native to Korea. In this study, we aimed to study the seed germination of this species using a water imbibition experiment, gibberellic acid (GA3) treatment (0, 10, 100, or 1000 mg·L−1), cold stratification (0, 2, 4, 8, or 12 weeks at 4 °C), move-along experiment, and phenology studies. In the water imbibition experiment, the weight of the seeds increased by more than 120% in 24 h. An analysis of the internal and external morphological characteristics of the seed revealed that the embryo was already fully grown from the fruit and did not grow thereafter. The final germination percentages for the cold stratification at 0, 2, 4, 8, and 12 weeks at 4 °C were 12 ± 3.65, 32 ± 9.09, 59 ± 1.00, 59 ± 9.59, and 71 ± 1.91%, respectively. In the move-along experiment and phenology studies, a longer low-temperature treatment period resulted in a higher germination percentage. However, the GA3 treatment had little effect on the seed germination. Our results indicate that B. koreana exhibits an intermediate physiological seed dormancy.

The sexual species of the Dilatata complex (Paspalum dasypleurum, P. flavescens, P. plurinerve, P. vacarianum, and P. urvillei) are closely related phylogenetically and show allopatric distributions, except P. urvillei. These species show microhabitat similarities and differences in germination traits. We integrated species distribution models (SDMs) and seed germination assays to determine whether germination divergences explain their biogeographic pattern. We trained SDMs in South America using species’ presence–absence data and environmental variables. Additionally, populations sampled from highly favourable areas in the SDMs of these species were grown together, and their seeds germinated at different temperatures and dormancy-breaking conditions. Differences among species in seed dormancy and germination niche breadth were tested, and linear regressions between seed dormancy and climatic variables were explored. SDMs correctly classified both the observed presences and absences. Spatial factors and anthropogenic activities were the main factors explaining these distributions. Both SDMs and germination analyses confirmed that the niche of P. urvillei was broader than the other species which showed restricted distributions, narrower germination niches, and high correlations between seed dormancy and precipitation regimes. Both approaches provided evidence about the generalist-specialist status of each species. Divergences in seed dormancy between the specialist species could explain these allopatric distributions.

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence of the germination pattern of Phoenix canariensis Chabaud colonizing sub-tropical climates is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark cycles of 30/25 °C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have morphological dormancy and the others have morphophysiological dormancy. Removal of the pericarp and operculum resulted in 100% germination within five days in a light/dark cycle of 30/25 °C. Cold and warm stratification as well as treatment with GA3significantly increased the germination speed but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to seedling establishment.

Background and Aims Interactions between ecological factors and seed physiological responses during the establishment phase shape the distribution of plants. Yet, our understanding of the functions and evolution of early-life traits has been limited by the scarcity of large-scale datasets. Here, we tested the hypothesis that the germination niche of temperate plants is shaped by their climatic requirements and phylogenetic relatedness, using germination data sourced from a comprehensive seed conservation database of the European flora (ENSCOBASE). Methods We performed a phylogenetically informed Bayesian meta-analysis of primary data, considering 18 762 germination tests of 2418 species from laboratory experiments conducted across all European geographical regions. We tested for the interaction between species’ climatic requirements and germination responses to experimental conditions including temperature, alternating temperature, light and dormancy-breaking treatments, while accounting for between-study variation related to seed sources and seed lot physiological status. Key Results Climate was a strong predictor of germination responses. In warm and seasonally dry climates the seed germination niche includes a cold-cued germination response and an inhibition determined by alternating temperature regimes and cold stratification, while in climates with high temperature seasonality opposite responses can be observed. Germination responses to scarification and light were related to seed mass but not to climate. We also found a significant phylogenetic signal in the response of seeds to experimental conditions, providing evidence that the germination niche is phylogenetically constrained. Nevertheless, phylogenetically distant lineages exhibited common germination responses under similar climates. Conclusion This is the first quantitative meta-analysis of the germination niche at a continental scale. Our findings showed that the germination niches of European plants exhibit evolutionary convergence mediated by strong pressures at the macroclimatic level. In addition, our methodological approach highlighted how large datasets generated by conservation seed banking can be valuable sources to address questions in plant macroecology and evolution.

PREMISE In temperate sand dunes, rising air temperature owing to climate change could not only further elevate surface soil temperatures during summers but also drastically change the range of soil temperatures in other seasons. Winter warming may shift the timing of seed germination of dune species that require cold stratification for dormancy release. METHODS We assessed the effects of temperature on dormancy and germination of Viola grayi seeds and evaluated whether winter warming could affect its germination phenology by conducting germination experiments and analyzing soil temperature data in cold and warm winters. RESULTS Viola grayi seeds were dormant when dispersed in spring. One-month moist-chilling treatment (4°C) effectively released dormancy, while short, intermittent lower temperatures (alternating 20/5°C) did not. Continuous higher temperatures induced secondary dormancy in non-dormant seeds. During a cold, snowy winter, the surface soil temperatures of the sand dune remained at 0-2°C for approximately one month owing to the accumulated snow, while the period of such stable low soil temperatures was much shorter during a warm, less snowy winter, and the highest soil temperature class reached 20-25°C. These results suggest that dispersed seeds germinate in the following spring after winter chilling, but they may remain dormant after warm winters. CONCLUSIONS With winter warming, prolonged seed dormancy and associated germination delay could occur in V. grayi seeds. Assessing the minimum requirements for dormancy release and the potential to form persistent soil seed banks is important for judging the necessity and urgency of conservation efforts for temperate dune species. This article is protected by copyright. All rights reserved.

Information regarding germination and dormancy of Parrotia persica seeds is limited and there is no report on cardinal temperatures and germination modeling of this tree species. Thus, the main aims of this study were to model dormancy and germination of P. persica seeds and to identify the best way(s) to overcome seed dormancy in this species. Freshly matured seeds had spatulate, fully developed embryos (FA1 type) and the seed coat was water permeable. Fresh seeds germinated less than 20% at 5–30 °C, and gibberellic acid (GA) increased germination to about 40% at 5–30 °C, peaking at 53% at at 20 °C. Population thermal parameters (Tl and Th) had changed among dormancy breaking treatments. After-ripened seeds and those treated with GA had the lowest lower limit (Tl) and the highest higher limit temperatures which were 0.0 and 37 °C, respectively. The highest Tl and the lowest Th were observed in freshly matured seeds without any treatments (Control-MT) which were 24 and 26 °C; the narrowest temperature range for germination, implying the highest seed dormancy. Base (Tb) and ceiling (Tc) temperatures for the final germination percentage of non-dormant seeds were 0, and 40°C. Cardinal temperatures for the rate (speed) of germination of non-dormant seeds were almost the same as the observed values for final germination percentage. Seeds of P. persica must have Type 3 of non-deep physiological dormancy based on the graphical method, since Tb decreased and Tc increased as dormancy breaking progresses in a population. Population thermal parameters (Tl and Th) also showed the same change in different dormancy breaking treatments in which dormant seeds had higher Tl and lower Th than non-dormant seeds (after-ripened plus GA). For commercial usage or conservation projects, it is suggested to use a period of after-ripening followed by GA treatment to break dormancy.

Magnolia sinica is one of the most endangered Magnoliaceae species in China. Seed biology information concerning its long-term ex situ conservation and utilization is insufficient. This study investigated dormancy status, germination requirements and storage behavior of M. sinica. Freshly matured seeds germinated to ca. 86.5% at 25/15 °C but poorly at 30 °C; GA3 and moist chilling promoted germination significantly at 20 °C. Embryos grew at temperatures (alternating or constant) between 20 °C and 25 °C, but not at 5 °C or 30 °C. Our results indicate that M. sinica seeds possibly have non-deep simple morphophysiological dormancy (MPD). Seeds survived desiccation to 9.27% and 4.85% moisture content (MC) as well as a further 6-month storage at −20 °C and in liquid nitrogen, including recovery in vitro as excised embryos. The established protocol ensured that at least 58% of seedlings were obtained after both cold storage and cryopreservation. These results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods, although further optimized approaches are recommended for this critically endangered magnolia species.

International audience; Native plants of the Sahara are remarkably resistant to prolonged droughts and are important sources of forage, food, and medicine. Their regeneration from seeds after strong anthropogenic disturbances is a challenging step toward their conservation and to mitigate desertification. We studied the germination responses of 43 dominant native species of the Sahara desert that could be propagated from seeds for future ecological restoration projects, exploring the effects of cold stratification and temperatures on seed germination. Seeds were stratified at 4°C for 3 days and then tested for germination at 5, 10, 15, 20, 25, 30, 35, and 40°C. While cold stratification negatively affected four species, it improved the germination of 36 species. Five of these species required cold stratification to germinate. Temperatures during the germination trial significantly influenced seed germinability. Twenty-three species (54%) germinated to higher percentages at intermediate temperatures (20 to 30°C) similar to the maximum temperatures of the rainiest months, when germination in the field is high. Thirteen species (30%) also germinated at a higher temperature (40°C). Seven species (16%) germinated best at low temperatures (5 to 10°C). Our results suggest that cold stratification is an efficient and easy treatment to apply prior to sowing seeds in the field for restoration.

Abscisic acid (ABA) is a major phytohormone affecting seed dormancy and germination in plants. ABA is synthesized mainly through the C40 carotenoid pathway. In the ABA biosynthesis pathway, 9-cis-epoxycarotenoid dioxygenase (NCED) is a key rate-limiting enzyme that regulates the accumulation and content of ABA. However, the role of the NCED gene in perennial plants with complex seed dormancy remains largely unknown. Here, we cloned two differentially expressed paralogs of herbaceous peony NCED genes, named PlNCED1 and PlNCED2, and further identified their involvement in seed dormancy from perennial herbaceous peony experiencing complex double seed dormancy. The deduced PlNCED amino acid sequences had high sequence homology with NCED sequences from other plants and contained the typical conserved RPE65 domain of the NCED family. Phylogenetic analysis showed that PlNCED1 and PlNCED2 have a close relationship with PoNCED in Paeonia ostii and VvNCED6 in Vitis vinifera, respectively. A subcellular localization assay demonstrated that the PlNCED1 protein resided within the nucleus, while the PlNCED2 protein was located in the cytoplasm, indicating their different roles in the biosynthesis of ABA. Furthermore, the content of endogenous ABA in transgenic calluses showed that PlNCEDs were positively correlated with ABA content. Both PlNCED transgenic Arabidopsis lines and the functional complementation of Arabidopsis NCED mutants found that PlNCEDs promoted seed dormancy and delayed seed germination. These results reveal that PlNCEDs participate in the seed dormancy of herbaceous peony by regulating the accumulation of endogenous ABA.

Caper is a perennial shrub that is widespread in the Mediterranean Basin. Although the fruits contain many seeds, they germinate slowly and with very low percentages, due to their nondeep physiological dormancy. The influence of the testa and endosperm, as well as the effect of applying gibberellic acid (GA3) solutions on seed germination to release its dormancy, are reported in this study. The mechanical resistance exerted by the testa and endosperm against radicle protrusion in mature caper seeds was measured. The best germination results were obtained with seeds devoid of testa wetted with water and with intact seeds wetted with a 500 mg L−1 GA3 solution, without statistical differences between them. The GA3 addition triggers an increase in both the content of endogenous gibberellins (GA) and the GA/abscisic acid ratio, increasing germination. Its germination consists of two temporally separated events: testa cracking and endosperm piercing. Testa cracking begins in the hilum-micropillar area; it involves a signal from the embryo, which GA can replace, possibly by increasing the growth potential of the embryo. After testa cracking, the radicle emerges through a hole in the micropylar endosperm. The puncture force necessary to pierce the micropylar endosperm decreased drastically during the first day of imbibition, remaining practically constant until testa cracking, decreasing afterwards, regardless of the addition or not of gibberellins.

Seed dormancy is an adaptive response of plants to environmental changes during long-term evolution. It plays an important role in plant survival and propagation. Acer cinnamomifolium, a plant species endemic to China, is an excellent garden and street tree species. However, dormancy and germination characteristics of A. cinnamomifolium seeds are not currently known. In the present paper, the mature seeds were used as experimental materials and we investigated the effect of temperature including alternating temperature, light, after-ripening, stratification and phytohormone on seed dormancy release and germination. After being incubated for 30 days, 0 to 10% of the seeds germinated in constant temperature (10, 15, 20, 25 and 30°C), while in alternating temperature regimes (20/10, 25/15 and 30/20°C), seed germination was < 35%. Dormancy release and germination of seeds can be increased by after-ripening, cold stratification and phytohormone treatments. We concluded that A. cinnamomifolium seeds have a non-deep physiological dormancy. Cold stratification at 4°C for 30 days and incubation thereafter at 20°C were found to be optimal for dormancy release and high seed germination.

Seed dormancy-break via cold stratification is of fundamental importance for plant adaptation to environmental conditions and response to climate change through timing germination, seedling emergence and consequently community dynamics. Although cold stratification requirements for dormancy break vary among species, it is not known if this variation is determined by the environmental conditions experienced by seeds or by differences among species. We determined the soil moisture content and duration of cold stratification required for seed dormancy-break of species from alpine and desert habitats (soil moisture content: 20 and 18 species from alpine and desert habitats, respectively; duration: 16 and 16 species from the alpine and desert, respectively), and examined the correlation between environmental conditions (soil moisture content and duration of cold stratification) required for dormancy-break and seed traits. Seed germination increased and then decreased as soil moisture content or duration of cold stratification increased. The optimal and critical soil moisture content for seed dormancy-break were higher for alpine species than desert species. A positive correlation between optimal soil moisture content and seed shape was found. However, the duration of cold stratification required for dormancy-break was not related to habitat, seed mass or seed shape. Our results suggest that soil moisture content rather than duration of cold stratification resulting from climate change could affect seed germination and consequently seedling emergence and establishment, especially for desert species.

GATA transcription factors have been reported to function in plant growth and development and during various biotic/abiotic stresses in Arabidopsis and rice. However, the functions of wheat GATAs, particularly in the regulation of seed dormancy and germination, remain unclear. Here, we identified 78 TaGATAs in wheat and divided them into five subfamilies. Sixty-four paralogous pairs and 52 orthologous pairs were obtained, and Ka/Ks ratios showed that the TaGATAs had undergone strong purifying election during the evolutionary process. Triplet analysis indicated that a high homologue retention rate could explain the large number of TaGATAs in wheat. Gene structure analysis revealed that most members of the same subfamily had similar structures, and subcellular localization prediction indicated that most TaGATAs were located in the nucleus. Gene ontology annotation results showed that most TaGATAs had molecular functions in DNA and zinc binding, and promoter analysis suggested that they may play important roles in growth, development, and biotic/abiotic stress response. We combined three microarray datasets with qRT-PCR expression data from wheat varieties of contrasting dormancy and pre-harvest sprouting resistance levels during imbibition in order to identify ten candidate genes (TaGATA17/-25/-34/-37/-40/-46/-48/-51/-72/-73) that may be involved in the regulation of seed dormancy and germination in wheat. These findings provide valuable information for further dissection of TaGATA functions in the regulation of seed dormancy and germination, thereby enabling the improvement of wheat pre-harvest sprouting resistance by gene pyramiding.

This review provides a revised and expanded word-formula system of whole-seed primary dormancy classification that integrates the scheme of Nikolaeva with that of Baskin and Baskin. Notable changes include the following. (1) The number of named tiers (layers) in the classification hierarchy is increased from three to seven. (2) Formulae are provided for the known kinds of dormancy. (3) Seven subclasses of class morphological dormancy are designated: ‘dust seeds’ of mycoheterotrophs, holoparasites and autotrophs; diaspores of palms; and seeds with cryptogeal germination are new to the system. (4) Level non-deep physiological dormancy (PD) has been divided into two sublevels, each containing three types, and Type 6 is new to the system. (5) Subclass epicotyl PD with two levels, each with three types, has been added to class PD. (6) Level deep (regular) PD is divided into two types. (7) The simple and complex levels of class morphophysiological dormancy (MPD) have been expanded to 12 subclasses, 24 levels and 16 types. (8) Level non-deep simple epicotyl MPD with four types is added to the system. (9) Level deep simple regular epicotyl MPD is divided into four types. (10) Level deep simple double MPD is divided into two types. (11) Seeds with a water-impermeable seed coat in which the embryo-haustorium grows after germination (Canna) has been added to the class combinational dormancy. The hierarchical division of primary seed dormancy into many distinct categories highlights its great diversity and complexity at the whole-seed level, which can be expressed most accurately by dormancy formulae.

The 14-3-3 proteins widely exist in almost all plant species. They specifically recognize and interact with phosphorylated target proteins, including protein kinases, phosphatases, transcription factors and functional proteins, offering an array of opportunities for 14-3-3s to participate in the signal transduction processes. 14-3-3s are multigene families and can form homo- and heterodimers, which confer functional specificity of 14-3-3 proteins. They are widely involved in regulating biochemical and cellular processes and plant growth and development, including cell elongation and division, seed germination, vegetative and reproductive growth, and seed dormancy. They mediate plant response to environmental stresses such as salt, alkaline, osmotic, drought, cold and other abiotic stresses, partially via hormone-related signalling pathways. Although many studies have reviewed the function of 14-3-3 proteins, recent research on plant 14-3-3s has achieved significant advances. Here, we provide a comprehensive overview of the fundamental properties of 14-3-3 proteins and systematically summarize and dissect the emerging advances in understanding the roles of 14-3-3s in plant growth and development and abiotic stress responses. Some ambiguous questions about the roles of 14-3-3s under environmental stresses are reviewed. Interesting questions related to plant 14-3-3 functions that remain to be elucidated are also discussed.

Variations in fruit size, color, and stripe pattern on fruit rinds have been noticed among individuals within Citrullus colocynthis (Cucurbitaceae) populations in the hyper-arid deserts of the UAE. The present study aimed at assessing variations in fruit and seed characters, germination behavior, and genetic diversity among 12 individuals (hereafter referred accessions) collected from one population. Results showed that the accessions differed in seed dormancy level and response to light and temperature of incubation. The overall germination ranged between 18.5% in accession number 9 and 56.6% for accession number 2. At lower temperatures (15/25 °C), little germination occurred in darkness but not in the light. Germination was significantly greater and faster (germination rate index was higher) at higher temperatures (25/35 °C) than moderate (20/30 °C) and lower temperatures. Germination was greater in light than darkness in almost all accessions at higher temperatures but not at moderate temperatures. Random amplified polymorphic DNA (RAPD) analysis showed polymorphism varied between 90 and 100%, with polymorphic information content values ranged from 0.28 to 0.37 with an average of 0.33. Few individuals showed high genetic similarities, while most of them had similarity coefficients less than 0.5. There were moderate to weak relationships between genetic similarities and germination behavior of the different accessions.

Wild oat is a herbicide resistance-prone global weed species that causes significant economic losses in dryland and horticultural agriculture. As a result, there has been a significant research effort to control this species. A major impediment to this research is the seed coat-mediated dormancy of wild oat, which requires a labor-intensive incision or puncturing of the seed coat to initiate seed germination. This study defines the most efficient settings of a mechanical thresher to overcome wild oat seed dormancy and then validates these settings using multiple populations collected from the Western Australian grain belt. We also compare the effects of rapid mechanical scarification and known germination stimulus tactics such as scarification with sulfuric acid (H2SO4), partial endosperm removal, sandpaper scarification of the seed coat, and immersion in sodium nitroprusside (NO donor SNP) solution on wild oat seedling growth rate. Threshing treatment of 1,500 rpm for 5 s provides equivalent germination compared with manually puncturing individual wild oat seeds, with no difference in seedling relative growth rate. The mechanical scarification of seeds using the thresher resulted in greater germination (66%) than H2SO4 scarification (0%), partial endosperm removal (10%), sandpaper seed coat scarification (25%), and exposure to NO donor SNP (34%). This study demonstrates that the physical dormancy of wild oat can be rapidly overcome using a commercially available mechanical thresher.

Underdeveloped (small) embryos embedded in abundant endosperm tissue, and thus having morphological dormancy (MD) or morphophysiological dormancy (MPD), are considered to be the ancestral state in seed dormancy evolution. This trait is retained in the Apiaceae family, which provides excellent model systems for investigating the underpinning mechanisms. We investigated Apium graveolens (celery) MD by combined innovative imaging and embryo growth assays with the quantification of hormone metabolism, as well as the analysis of hormone and cell-wall related gene expression. The integrated experimental results demonstrated that embryo growth occurred inside imbibed celery fruits in association with endosperm degradation, and that a critical embryo size was required for radicle emergence. The regulation of these processes depends on gene expression leading to gibberellin and indole-3- acetic acid (IAA) production by the embryo and on crosstalk between the fruit compartments. ABA degradation associated with distinct spatiotemporal patterns in ABA sensitivity control embryo growth, endosperm breakdown and radicle emergence. This complex interaction between gibberellins, IAA and ABA metabolism, and changes in the tissuespecific sensitivities to these hormones is distinct from non-MD seeds. We conclude that the embryo growth to reach the critical size and the associated endosperm breakdown inside MD fruits constitute a unique germination programme.

Summary High humidity during harvest season often causes pre‐harvest sprouting in barley (Hordeum vulgare). Prolonged grain dormancy prevents pre‐harvest sprouting; however, extended dormancy can interfere with malt production and uniform germination upon sowing. In this study, we used Cas9‐induced targeted mutagenesis to create single and double mutants in QTL FOR SEED DORMANCY 1 (Qsd1) and Qsd2 in the same genetic background. We performed germination assays in independent qsd1 and qsd2 single mutants, as well as in two double mutants, which revealed a strong repression of germination in the mutants. These results demonstrated that normal early grain germination requires both Qsd1 and Qsd2 function. However, germination of qsd1 was promoted by treatment with 3% hydrogen peroxide, supporting the notion that the mutants exhibit delayed germination. Likewise, exposure to cold temperatures largely alleviated the block of germination in the single and double mutants. Notably, qsd1 mutants partially suppress the long dormancy phenotype of qsd2, while qsd2 mutant grains failed to germinate in the light, but not in the dark. Consistent with the delay in germination, abscisic acid accumulated in all mutants relative to the wild type, but abscisic acid levels cannot maintain long‐term dormancy and only delay germination. Elucidation of mutant allele interactions, such as those shown in this study, are important for fine‐tuning traits that will lead to the design of grain dormancy through combinations of mutant alleles. Thus, these mutants will provide the necessary germplasm to study grain dormancy and germination in barley.

This study was conducted to elucidate the germination characteristics and dormancy types in Maianthemum dilatatum (A. W. Wood) A. Nelson and J. F. Macbr. M. dilatatum seeds were collected from the Nari Basin on Ulleungdo Island, South Korea and used in a water imbibition test; the seed weight increased by approximately 20% within 48 h. The embryo-to-seed ratio at the time of seed dispersal was 0.57 ± 0.03. When the seeds were incubated under light and dark conditions, they germinated under dark conditions, and the germination rate was higher at 25 °C than at 20 °C. However, the final germination rates under dark conditions were 27.4 ± 3.6 and 47.1 ± 7.6%, respectively. Under 4, 8, 12, and 16 weeks of cold stratification treatment, the highest germination rate of 83.6 ± 3.6% was observed at 25 °C at 12 weeks of cold stratification treatment, the germination start date was decreased by more than 10 d, and the mean germination time (MGT) was shortened from 50 d to 39 d. However, the germination rate, germination start date, and MGT did not differ significantly among the gibberellic acid hormone treatments. Therefore, it was evident that M. dilatatum demonstrated physiological dormancy (PD) that can broken by cold stratification treatment and dark conditions.

Climate warming may affect multiple aspects of plant life history, including important factors such as germination responses and the key trade-off between offspring size and number. As a case study to address these concepts, we used an alpine plant (waxy bluebell, Wahlenbergia ceracea; Campanulaceae) that shows plasticity to warming in seed traits and in which seed dormancy status regulates germination. We chose an alpine species because alpine environments are ecosystems particularly under threat by climate change. We conducted germination assays under cool and warm temperatures using seeds produced by individuals that were grown under historical (cooler) and future (warmer) temperature scenarios. We assessed the presence of a seed size versus number trade-off, and then examined the effects of seed number and size on germination percentage, the fractions of dormant and viable seeds, and germination velocity. Further, we examined whether warming during parental growth and during germination affected these relationships. We found evidence for a seed size versus number trade-off only under historical parental temperatures. Indeed, under future growth temperatures parental plants produced fewer and smaller seeds and there was no evidence of a trade-off. However, the reductions in both seed traits under warming did not affect germination, despite correlations of seed size and number with germination traits. Warming increased germination, particularly of larger seeds, but overall, it resulted in more than fourfold reductions in parental fitness. Synthesis. Our study shows the importance of growth conditions when evaluating the seed size versus number trade-off. Stressful conditions, such as warmer temperatures, can restrain the ability of plants to reach optimal investment in reproduction, masking the trade-off. By analysing responses across the whole life cycle, we show here an overall detrimental effect of warming, highlighting the potential risk of climate change for Wahlenbergia ceracea, and, potentially, for alpine plant communities more widely.

Vaccinium oldhamii Miq. is an edible berry; however, little is known about its seed dormancy-break and germination. Therefore, the aim of this study was to elucidate the seed-dormancy break and germination characteristics of V. oldhamii. The results showed that the length and width of the seeds of V. oldhamii were 2.4588 ± 0.0273 mm and 1.7028 ± 0.0248 mm, respectively, the filled percentage was 49.0 ± 3.0%, and the 1000-seed weight was 0.9453 g. Additionally, water imbibition test showed that the seed weight of V. oldhamii increased by more than 70% after 24 h, indicating the absence of physical dormancy. Embryo length measured at dispersal and just before germination did not differ significantly. There was no significant difference in E:S (Embryo:Seed) ratio in length at the time of seed dispersal (0.6780 ± 0.0258) and before germination (0.7370 ± 0.0469), indicating the absence of morphological dominance. Temperature treatments showed that the germination of the seed was 0, 6.0, 6.0, 20.0, and 0% under 15, 20, 25, 25/15, and 15/6 °C, respectively. However, treatment with 250 ppm of GA3 increased the germination of the seeds to 22.0, 36.0, 32.0, 40.0, and 1.0%, respectively. Additionally, treatment with 500 ppm of GA3 increased the germination to 34.6, 40.0, 40.0, 46.0 %, respectively. These results indicated that the seeds of V. oldhamii exhibited Nondeep physiological dormancy (Nondeep PD). Overall, the findings of this study showed that treatment with 500 ppm of GA3 at 25/15 °C can effectively break the dormancy of V. oldhamii seeds, which could facilitate further research on the species.

Seed dormancy is an important breeding trait for the development of certain types of peanut cultivars. Peanut cultivars with seed dormancy can inhibit preharvest sprouting in which the sprouting may increase susceptibility to preharvest aflatoxin contamination. The recombinant inbred line (RIL) mapping population derived from a cross of Tifrunner, a dormant Runner type, and GT-C20, a non-dormant Spanish type, were planted in the field for 2 years, and the freshly harvested seeds were used for seed dormancy tests at 7, 14, 21, and 28 days during germination. There were three RILs from 2-year tests with no dormancy (T48, T83, T160) and two lines with strong dormancy (T11, T163). This RIL population was genotyped using peanut SNP array ‘Axiom_Arachis’ 58 K, and two major seed dormancy QTLs were anchored on chromosome A04 and A05 with 43.16% and 51.61% of the phenotype variation explained (PVE), respectively. The QTL mapped on chromosome A05 had been anchored on a physical map interval of 98 kb (157.538–157.636 Mb) from which a possible candidate gene (Arahy.KB746A, ethylene-responsive transcription factor) was identified. Reference to the peanut physical map and flanking sequences, DNA markers can be developed for these two QTLs and used in marker-assisted breeding selection for seed dormancy in peanut.

Seed dormancy and germination are two distinct physiological processes in the life cycle of plants. Dormancy alleviation and the attendant transition to seed germination are critical developmental events that are regulated by endogenous and ambient cues. ROS, Ca2+ (and Ca2+-dependent) signals, and phytohormones, such as ABA and GA, are significant endogenous cues. On the other hand, temperature, light, and smoke-derived compounds are ambient cues that regulate the transition from seed dormancy to germination. An intricate balance in ABA and GA metabolism and their antagonistic hormonal interactions, in which ROS and Ca2+-dependent signals feature as signal initiators, integrators, or transducers, underpin the regulatory mechanisms that control dormancy alleviation and seed germination. Smoke-derived compounds are exogenous chemical cues with significant influences on seed dormancy and germination. They interact with several endogenous cues, including ROS and phytohormones, to control these processes. In this review, we summarize Ca2+ signaling in plants with a concise detail on Ca2+-dependent signals in the regulation of seed germination. We also discuss the cross talks between smoke-derived cues and Ca2+-dependent signals, phosphoinositide/phospholipase C pathway, and ROS signaling. Finally, we touch on current knowledge on the involvement of Ca2+-dependent signals in smoke cue-mediated ABA-GA hormonal interactions and provide some perspectives on how to advance the subject of Ca2+ signal involvement in the regulation of dormancy alleviation and seed germination by smoke-derived cues.

Poor germination and the length of time required for the growth of seedlings appropriate for planting in the farm affect the cultivation of medicinal plants such as yarrow (Achillea millefolium L)....

Temperature variation during seed set is an important modulator of seed dormancy and impacts the performance of crop seeds through effects on establishment rate. It remains unclear how changing temperature during maturation leads to dormancy and growth vigour differences in nondormant seedlings. Here we take advantage of the large seed size in Brassica oleracea to analyse effects of temperature on individual seed tissues. We show that warm temperature during seed maturation promotes seed germination, while removal of the endosperm from imbibed seeds abolishes temperature-driven effects on germination. We demonstrate that cool temperatures during early seed maturation lead to abscisic acid (ABA) retention specifically in the endosperm at desiccation. During this time temperature affects ABA dynamics in individual seed tissues and regulates ABA catabolism. We also show that warm-matured seeds preinduce a subset of germination-related programmes in the endosperm, whereas cold-matured seeds continue to store maturation-associated transcripts including DOG1 because of effects on mRNA degradation before quiescence, rather than because of the effect of temperature on transcription. We propose that effects of temperature on seed vigour are explained by endospermic ABA breakdown and the divergent relationships between temperature and mRNA breakdown and between temperature, seed moisture and the glass transition.

Germination is considered as one of the most crucial steps in a plant’s lifetime. The germination of Eryngium maritimum, a dune species located across all European coasts, has been extensively analysed in Northern populations, where it is considered a locally endangered species. However, less attention has been given to southern populations, where the knowledge about the germination of the species is very limited. The main objective of the present study was to analyse the effect of cold stratification in one Mediterranean and one Atlantic population of the species, as well as to compare the potential variation of seed dormancy among a latitudinal gradient in European populations based on current literature. Seeds collected from Mallorca (Mediterranean, Spain) and Asturias (Atlantic, Spain) were germinated at different temperatures and cold stratification periods ranging from 4 to 20 weeks. These results were merged with the results of previous studies to test the potential effect of latitude and climatic variables in germination. Although the optimal incubation temperature was 10 ºC, the highest final germination percentages (up to 96%) was obtained in both populations combining specific cold stratification periods (5 ºC) and constant incubation temperatures (15–20 ºC). Atlantic seeds needed longer cold stratification times to reach high germination percentages compared with Mediterranean seeds. Apart from the stratification response, significant differences in viability and in germination were observed between the Atlantic and the Mediterranean populations. Considering data from previous studies in the analysis, the results suggest that there is a potential effect of latitude in the ecological germination requirements, by which the higher the latitude, the longer the cold stratification period required to germinate, with a correlation with the mean annual temperature. These results suggests that two factors, modulation of dormancy relating to adaptative or maternal effects and viability, govern the germination of the species.

Background To adapt seasonal climate changes under natural environments, Polygonatum sibiricum seeds have a long period of epicotyl morphophysiological dormancy, which limits their wide-utilization in the large-scale plant progeny propagation. It has been proven that the controlled consecutive warm and cold temperature treatments can effectively break and shorten this seed dormancy status to promote its successful underdeveloped embryo growth, radicle emergence and shoot emergence. To uncover the molecular basis of seed dormancy release and seedling establishment, a SMRT full-length sequencing analysis and an Illumina sequencing-based comparison of P. sibiricum seed transcriptomes were combined to investigate transcriptional changes during warm and cold stratifications. Results A total of 87,251 unigenes, including 46,255 complete sequences, were obtained and 77,148 unigenes (88.42%) were annotated. Gene expression analyses at four stratification stages identified a total of 27,059 DEGs in six pairwise comparisons and revealed that more differentially expressed genes were altered at the Corm stage than at the other stages, especially Str_S and Eme. The expression of 475 hormone metabolism genes and 510 hormone signaling genes was modulated during P. sibiricum seed dormancy release and seedling emergence. One thousand eighteen transcription factors and five hundred nineteen transcription regulators were detected differentially expressed during stratification and germination especially at Corm and Str_S stages. Of 1246 seed dormancy/germination known DEGs, 378, 790, and 199 DEGs were associated with P. sibiricum MD release (Corm vs Seed), epicotyl dormancy release (Str_S vs Corm), and the seedling establishment after the MPD release (Eme vs Str_S). Conclusions A comparison with dormancy- and germination-related genes in Arabidopsis thaliana seeds revealed that genes related to multiple plant hormones, chromatin modifiers and remodelers, DNA methylation, mRNA degradation, endosperm weakening, and cell wall structures coordinately mediate P. sibiricum seed germination, epicotyl dormancy release, and seedling establishment. These results provided the first insights into molecular regulation of P. sibiricum seed epicotyl morphophysiological dormancy release and seedling emergence. They may form the foundation of future studies regarding gene interaction and the specific roles of individual tissues (endosperm, newly-formed corm) in P. sibiricum bulk seed dormancy.

Lolium perenne L. (perennial ryegrass) shows variable levels of seed physiological dormancy (PD), which depends on the genotype and environmental condition during seed development. To analyse the effect of field temperature and precipitation during seed filling on the PD, two cultivars were sown on five dates in 2014 and 2015. After harvest, the level of seed PD was 4–28%. High-temperature stress (>29°C) in the field during seed development, measured as heat stress units (HSUs), reduced seed PD (increased germination) at harvest. After 9 months of dry afterripening under laboratory conditions, mean dormant seed values were reduced from 15 ± 8 to 8 ± 7%. An increment in the seed PD level reduced seedling emergence in the field. Seed with 20% PD produced only 50% of field emergence, under optimal environmental conditions. Different vigour tests were conducted and each was compared with field emergence. The speed of germination, through the first count at 5 d of the standard germination test, and the shoot length at 10 d were better associated with the seedling establishment in the field. The HSU could be useful to establish a possible PD range in the seed of perennial ryegrass after the growing season. The development of models considering the HSU and other climatic parameters could motivate future studies.

An understanding of the seed dynamics of endangered plant species, such as Magnolia zenii Cheng, is important for successful conservation. This study examined the morphological, physiological and biochemical changes that occur in M. zenii Cheng during seed development to determine the appropriate harvest stage. The appearance of the seeds was influenced by the physiological and biochemical changes occurring during the developmental period, during which the colour of the fruits changed from green to red, while that of the seed changed from light brown to dark brown. There was a significant decrease in the seed moisture content from 90 to 120 days after flowering (DAF); however, there was no significant change from 135 to 165 DAF. The seeds from 135 DAF onwards showed developed cotyledonary embryos. The seed viability exceeded 95% from 135 DAF onwards; however, the germination percentage was 0, hypothesising that the seeds of M. zenii Cheng might exhibit physiological dormancy under certain conditions of this experiment. There was a significant increase in the fat, soluble sugar and soluble starch content of the seeds while approaching maturity. There were significant changes in malate dehydrogenase (MDH), glucose‐6‐phosphate dehydrogenase (G‐6‐PDH), 6‐phosphogluconate dehydrogenase (6‐PGDH) and β‐amylase activities in the seeds during the developmental period. At 135–165 DAF, the MDH activity remained stable, whereas that of 6‐PGDH reached its maximum, indicating that the seeds underwent vigorous metabolism. The findings of this study provide a theoretical basis for researching seed dormancy and seed harvest time.

Black cardamom (Amomum tsao-ko Crevost & Lemarié) is a spice plant of great commercial value in Vietnam, but with limited propagation ability. Its seeds are characterized by a thick and hard seed coat, a small endosperm, and a small embryo, which are the causes of the physical dormancy of the seeds and low germination. Attempts in this study to improve the germination rate and achieve uniform germination included mechanical scarification, immersion in hot or cold water, acid scarification, and the application of plant growth regulators. Although immersion of seeds in cold water and application of plant growth regulators (PGRs) (gibberellic acid (GA3) and 1-naphtaleneacetic acid (NAA)) showed positive effects on seed germination and subsequent seedling growth, mechanical scarification provided the highest germination rate of black cardamom seeds (68.0%) and significantly shortened germination time (53.7 days) compared to control (16.0% and 74.7 days). On the other hand, an efficient micropropagation protocol has been established using shoot tip explants derived from in-vitro-grown seedlings. Murashige and Skoog (MS) medium supplemented with 4.0 mg/L 6-benzylaminopurine (BAP) + 0.5 mg/L NAA proved to be most suitable for rapid multiplication and rooting, providing a mean of 5.4 shoots per explant, 6.8 cm shoot length, and 16.2 roots per explant after 7 weeks of culture. Well-rooted black cardamom plantlets have been successfully adapted to ex vitro conditions. “Fasco” bio-soil was more suitable for acclimatization, with a 48.9% survival rate, 23.3 cm plant length, and 5.7 leaves per plant after 3 months of planting. Improved germination and multiplication protocols can be used to improve propagation performances and to develop elite of black cardamom planting material.

PremiseUnderstanding recruitment processes of invasive species is central to conservation and management strategies. Iris pseudacorus, an emergent macrophyte, has established invasive populations across a broad global range, and reduces biodiversity in wetland ecosystems. Climate change is altering germination cues, yet studies on the invasion of wetland macrophytes often ignore germination ecology despite its importance to their establishment and spread.MethodsWe explored germination of seeds from invasive I. pseudacorus populations in California in response to seed coat presence or absence, and several environmental factors. Using experimental results in a thermal time model, we derived germination temperature thresholds.ResultsGermination of I. pseudacorus seeds did not require cold or warm stratification, and was not affected by seed coat presence or absence. Germination occurred in the dark, although germinability was two- to threefold times greater under light. At constant temperature, thermal time model estimates included 18.3 ± 1.8°C base germination temperature (Tb$({T}_{b}$ ); 28.2 ± 0.5°C optimal temperature (To$({T}_{o}$ ); and 41.0 ± 1.7°C ceiling temperature (Tc$({T}_{c}$ ). Seeds exposed to 36.0°C achieved over 10% germination, and embryos of ungerminated seeds presented 76% viability. Overall, germinability remained relatively low at constant temperatures (≤25%) but was close to 90% under alternating daily temperatures.ConclusionsExposure to diurnally fluctuating temperatures is essential for this species to achieve high germination rates. Our study reveals that I. pseudacorus has a broad germination niche supporting its establishment in a relatively wide range of environments, including at high temperatures more frequent with climate change.

Fruit and seed morphology interact with embryo physiology and environmental conditions to control seed germination timing. This interaction plays a pivotal role in ecosystems with narrow windows for seedling establishment, such as the Mediterranean mountains. In this study, we investigated the germination responses of the secondary capitula (disseminules) of Gundelia tournefortii from East Mediterranean mountain populations. When incubated at 15 °C, intact capitula did not reach 20% of final germination, with or without the addition in the germination substrate of GA3 (250 mg L−1), while extracted fruits reached 50% of germination, which increased to ca. 70% when treated with GA3. Cold stratification enhanced final germination of the capitula at 15 °C to ca. 65%, although almost half of the initially sown capitula germinated during the second month of stratification at 5 °C. During the stratification at 5 °C, peak puncture force needed to pierce the basal part of the capitula decreased linearly and capitula started germinating after one month, which corresponded to a peak puncture force of 0.41–0.35 N. These findings highlight the presence of mechanical and hormonal components of physiological seed dormancy. The morphology of the disseminules controls seed germination timing, by interacting with cold winter temperatures and starting seed germination only in early winter. These findings not only provide new insights on the reproduction from seeds of this plant, but by highlighting high germination of cold-stratified intact capitula, can also support plant propagation programmes for this key wild edible species, very important for food security and the livelihoods of local communities in the East Mediterranean region.

Cutin and suberin are lipid polyesters deposited in specific apoplastic compartments. Their fundamental roles in plant biology include controlling the movement of gases, water and solutes, and conferring pathogen resistance. Both cutin and suberin have been shown to be present in the Arabidopsis seed coat where they regulate seed dormancy and longevity. In this study, we use accelerated and natural ageing seed assays, glutathione redox potential measures, optical and transmission electron microscopy and gas chromatography-mass spectrometry to demonstrate that increasing the accumulation of lipid polyesters in the seed coat is the mechanism by which the AtHB25 transcription factor regulates seed permeability and longevity. Chromatin immunoprecipitation during seed maturation revealed that the lipid polyester biosynthetic gene long-chain acyl-CoA synthetase 2 (LACS2) is a direct AtHB25 binding target. Gene transfer of this transcription factor to wheat and tomato demonstrated the importance of apoplastic lipid polyesters for the maintenance of seed viability. Our work establishes AtHB25 as a trans-species regulator of seed longevity and has identified the deposition of apoplastic lipid barriers as a key parameter to improve seed longevity in multiple plant species.

Methods for diploid true potato seed (TPS) production and handing are crucial for inbred-hybrid potato breeding. This study determined the effects of mother plant nutrition on average TPS weight and germination kinetics as modeled by Gompertz curves. Additionally, it characterized germination of stratified TPS and TPS imbibed in water or gibberellic acid (GA3). Seeds were produced by three interspecific hybrids between diploid relatives of cultivated potato and diploid lines derived from cultivated potato. Effects of stratification on seed dormancy and germination rate were genotype-dependent. With one exception, GA3-treated seeds reached 50% germination as fast or faster than stratified seeds and seeds imbibed in water. Mother plant nutrition was varied by fertilizing with two nutrient solutions that differed in composition. Effects of fertilizer type on germination were modest, and 100-seed weight did not differ between fertilizer types. These findings support previous research showing that GA3 treatment effectively promotes robust TPS germination.

Fil: Longas, Maria de Las Mercedes. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Bahia Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina. Universidad Nacional del Sur. Departamento de Agronomia; Argentina

This article comments on: Fernández Farnocchia RB, Benech-Arnold RL, Mantese A, Batlla D. 2021. Optimization of timing of next-generation emergence in Amaranthus hybridus is determined via modulation of seed dormancy by the maternal environment. Journal of Experimental Botany 72, 4283–4297.

Temperature may regulate seed dormancy and germination and determine the geographical distribution of species. The present study investigated the thermal limits for seed germination of Polygonum ferrugineum (Polygonaceae), an aquatic emergent herb distributed throughout tropical and subtropical America. Seed germination responses to light and temperature were evaluated both before (control) and after stratification at 10, 15 and 20°C for 7, 14 and 28 d. Germination of control seeds was ~50% at 10 and 15°C, and they did not germinate from 20 to 30°C. The best stratification treatment was 7 d at 10°C, where seed germination was >76% in the dark for all temperatures, except at 30°C, and < 60% in light conditions. A thermal time approach was applied to the seed germination results. Base temperature (Tb) was 6.3°C for non-dormant seeds and optimal temperature (To) was 20.6°C, ceiling temperature (Tc () was 32.8°C, and thermal time requirement for 50% germination was 44.4°Cd. We concluded that a fraction of P. ferrugineum seeds is dormant, has a narrow thermal niche to germinate (10 and 15°C) and that cold stratification (10°C) alleviated dormancy and amplified the thermal range permissive for germination of the species. Consequently, P. ferrugineum is expected to occur in colder environments, for example, at high altitudes. Higher temperatures decrease the probabilities of alleviate dormancy and the ability of their seeds to germinate.

Seed dormancy and the formation of a soil seed bank is important plant regeneration strategies, especially if the environment is unpredictable. The present research explores how environmental factors control seed dormancy release, and how seed dormancy is related to the soil seed bank and regeneration of the perennial Aquilegia oxysepala. The effects of incubation temperature, light, cold and warm stratification, gibberellic acid (GA3) along with the germination phenology of A. oxysepala in the field were used to determine the type of seed dormancy. Seasonal change of seed dormancy was determined by regularly exhuming buried seeds and incubating them in laboratory conditions. A. oxysepala seeds has underdeveloped (small) embryos along with physiological dormancy at dispersal. With the increased amounts of cold stratification, the germination of A. oxysepala increased gradually. GA3 served as a substitute for cold stratification. Breaking of physiological dormancy under natural temperatures in the field occurred in winter, while growth of embryos and germination of seeds occurred in early spring. Viable seeds that had not germinated in early spring were induced into secondary dormancy by high soil temperatures. A. oxysepala provides one of a few examples of dormancy cycling in seeds with morphophysiological dormancy. Freshly matured seeds of A. oxysepala seeds have non-deep simple morphophysiological dormancy. The annual dormancy–non-dormancy cycle maintains the coordination between timing of seedling emergence with favorable seasons, thus increasing the survival chances of seedlings in environments with seasonal changes.

The timing of emergence of weed species has critical ecological and agronomical implications. In several species, emergence patterns largely depend on the level of dormancy of the seedbank, which is modulated by specific environmental factors. In addition, environmental conditions during seed maturation on the mother plant can have marked effects on the dormancy level at the time of seed dispersal. Hence, the maternal environment has been suggested to affect seedbank dormancy dynamics and subsequent emergence; however, this modulation has not been adequately examined under field conditions, and the mechanisms involved are only partly understood. Combining laboratory and field experiments with population-based models, we investigated how dormancy level and emergence in the field are affected by the sowing date and photoperiod experienced by the mother plant in Amaranthus hybridus, a troublesome weed worldwide. The results showed that an earlier sowing date and a longer photoperiod enhanced the level of dormancy by increasing the dormancy imposed by both the embryo and the seed coat. However, this did not affect the timing and extent of emergence in the field; on the contrary, the variations in dormancy level contributed to synchronizing the emergence of the next generation of plants with the time period that maximized population fitness. Our results largely correspond with effects previously observed in other species such as Polygonum aviculare and Arabidopsis, suggesting a common effect exists within different species.

Seed dormancy of cultivated rice was largely weakened during the progress of domestication. Correct timing and uniformity of seed germination are important for rapid seedling establishment and high-yield production. In the present study, we found that the heading-date gene Ghd7 acted as a negative regulator of germination. A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed germination. Further investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED genes. Moreover, elevated GA3 level was detected in seeds of ghd7 mutant during imbibition course, which was attributed to the induction of genes responsible for the synthesis pathways of bioactive GAs. Thus, Ghd7 inhibits seed germination by increasing the ABA/GA3 ratio. Besides revealing pleiotropic effects of Ghd7, our results indicate its role in linking seed germination to growth-phase transition in rice, which would enrich the theoretical basis for future breeding practices.

Pre-harvest sprouting (PHS) induced by the absence of seed dormancy causes a severe reduction in crop yield and flour quality. In this study, we isolated and characterized TaABI4, an ABA-responsive transcription factor that participates in regulating seed germination in wheat. Sequence analysis revealed that TaABI4 has three homologues, located on chromosomes 1A/1B/1D. TaABI4 contains a conserved AP2 domain, and AP2-associated, LRP and potential PEST motifs. Putative cis-acting regulatory elements (CE1-like box, W-box, ABRE elements and RY elements) were identified in the TaABI4 promoter region that showed high conservation in 17 wheat cultivars and wheat-related species. Expression profiling of TaABI4 indicated that it is a seed-specific gene accumulating during the middle stages of seed development. Transcript accumulation of TaABI4 in wheat cultivar Chuanmai 32 (CM32, PHS susceptible) was 5.07-fold and 1.39-fold higher than that in synthetic hexaploidy wheat SHW-L1 (PHS resistant) at 15 and 20 DPA, respectively. Six expression quantitative trait loci (eQTL) of TaABI4 on chromosomes 2A, 2D, 3B and 4A were characterized based on the accumulated transcripts of TaABI4 in SHW-L1 and CM32-derived recombinant inbred lines. These QTLs explained 10.7 to 46.1% of the trait variation with 4.53–10.59 of LOD scores, which contain genes that may affect the expression of TaABI4.

Himalayan yew (Taxus baccata subsp wallichiana) produces Taxol (an anticancer drug) and therefore is of commercial importance. Yew is slow growing, exhibits poor regeneration rate, low survival percentage and has long seed dormancy period low viability potential. Overexploitation of Taxus has forced scientist to think of alternative measures for growing Taxus without compromising with Taxol extraction from the plant. Hydroponics is a good method for growing plants and the same was targeted in our study. The design was to grow yew cuttings in Hoagland’s medium as nutrition medium for growing Taxus with auxin (NAA, IAA, and IBA) in 250 mg/l, 500 mg/l, 1000 mg/l, 2000 mg/l, and 5000 mg/l concentration supplemented in the medium for 16 weeks. The control plants died after 16 weeks but the auxin supplemented medium kept yew cuttings alive and resulted in increase in shoot length. On average, the yew cuttings gained an increase of more than 80 % in yew cuttings for 16 weeks. From the experiment, it was deduced that auxin in the range of 250–2000 mg/l enhances the shoot length better than higher concentration. It was seen from the comparative data between eight to 16 weeks that the percentage of increase in height of yew cutting at 5000 mg/l is 7 % for IBA, 17 % for IAA and 14 % for NAA, clearly depicting that IAA and NAA are better Auxins for eliciting growth of Yew in stress condition. This strategy can work for the conservation of Taxus baccata for its ex situ conservation.