Light Deprivation Research Articles

Study on the application of LED lighting in seedling production of some chryanthemum varieties in Hanoi

Chrysanthemum is a high commercial value plant, which is accounted for a large proportion of the total export of cut flowers in Vietnam. Therefore, the demand for seedling plants is very high. As a short-day plant, chrysanthemum requires supplemental lighting during the 2nd propagation stage in the autumn-winter period. This study aimed to evaluate the applicability of energy-saving LED lights to replace traditional lights in the propagation of some chrysanthemum varieties in Hanoi. The results show that the B3R7 660 nm LED (450 nm blue LED and 660 nm red LED combined in the ratio 7:3) was the most suitable for the 2nd propagation process in the greenhouse of 3 varieties (Pha le Chrysanthemum indicumyellow, Kim cuong C. morifolium cv Kim Cuong and Farm C. morifolium Hibiki). Plants grown under this LED light had a higher shoot multiplication efficiency than those under compact lamps (67.91, 18.47, and 26.89% respectively for Pha le, Kim cuong and Farm). Besides, the quality of seedlings is equivalent to chrysanthemums grown under compact lights. The power-saving efficiency when using LED light was approximate lower 55.21% compared to compact lamps.

Экзогенная регуляция фенотипического проявления признака фотопериодической чувствительности у сои

Soybean is a photoperiodically highly sensitive, short-day plant. There are practically no genes and gene complexes of photoperiodic neutrality in the soybean gene pool. This greatly limits the optimal day lengths and latitudinal ranges of cultivation of the vast majority of soybean varieties. Therefore, the task of neutralizing the negative impact of suboptimal, first of all, shortened day lengths on soybeans is of global importance. The purpose of these studies was to study the possibility of exogenous neutralization of photoperiodic sensitivity of soybeans by using gibberellin solutions on vegetative plants in order to prolong the period of their vegetative growth, the formation of additional nodes of beans and seeds, providing an increase in yield against the background of suboptimal, shortened day lengths. The research was carried out in 2019–2022 at the V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK), Krasnodar, on soybean varieties Puma, Barguzin, Vita and Slavia. Based on the theory of hormonal regulation of flowering by M.H. Chil-akhyan we developed a method for exogenous regu-lation of a genetically determined trait of high photoperiodic sensitivity of soybeans to shortened day lengths. The most sensitive to exogenous regulation of photoperiodic sensitivity stage of soybean ontogeny – the 4th trifoliate leaf (ontogeny stage V4) was established by treating plants with a solution of gibberellin. The most active concentration of gibberellin aqueous solutions was determined – 0.003%, the application of which to soybean leaves, at the stage of ontogenesis V4, causes prolongation of vegetative plant growth, formation of additional nodes, beans and seeds. Exogenous phytohormonal prolongation of vegetative growth increases the yield of photoperiodically sensitive soybean varieties when they are grown under conditions of shortened day lengths, including in second summer crops after harvesting winter crops.

Dark cities or cities of light? – sunlight amenity preservation at whole-city scale using a spatio-temporal decision support approach

Public open spaces are fundamentally important for the health and well-being of citizens in densely populated cities. If not carefully planned, high-density urban development can overshadow adjacent open spaces, resulting in poor quality, dark and oppressive winter conditions. Current planning control approaches for protecting light amenity in cities are often limited to simple overshadowing impact diagrams (e.g. shadows cast on the equinox at 9 a.m., 12 p.m. and 3 p.m.). In cities transitioning from low to higher density, comprising more complex urban forms and more extreme seasonal light amenity dynamics, these static approaches are insufficient. This paper outlines the development of a spatio-temporal design decision support system for analysing and protecting the light amenity of public open spaces, applied to a capital city in Australia. The system described has two parts: Firstly, to assess the overshadowing of existing public open spaces and identify those in need of protection (Part A), and secondly to generate planning restrictions to protect designated open spaces from future deprivation of light (Part B). For Part A, we use a graphics processing unit accelerated aggregate-shadow (15 minute increments) calculation applied to a detailed city-wide 3D model generated from billions of points of aerial survey (LiDAR) data. For Part B, we use a reversed solar ray casting approach we call the ‘Subtracto-Sun’ which allows a user to specify a time range (e.g. 9 a.m.–4 p.m.) for multiple days of the year and subsequent generation of 3D maximum building height development envelopes. The output of this system was used by the local government to inform a proposed planning policy amendment for the City of Melbourne. The findings illustrate the potential for urban professionals to use the system to rapidly assess shadow impacts for existing and proposed, contextually accurate, large, complex urban environments with high levels of geometric and temporal details. The presented results are significant in that we develop and apply our spatio-temporal decision-support approach to a local government area, successfully informing planning height restriction decisions to protect daylight amenity of public open spaces in need of protection. Our method for setting development height restrictions allows for higher density to be achieved, while not increasing the overshadowing of critical open space infrastructure during designated times.

Effects of Acute Gamma Irradiation on the Morphology of Stevia rebaudiana

Stevia is a short-day plant with constant day length less than 12 hours in Malaysia cause to generate flower early. The shorter vegetative period, resulting in low content of steviol glycosides compound. Cultivation of stevia in Malaysia is a challenge due to lack of suitable variety. The response to gamma irradiation varies among plant species and affected by the irradiation dose. The method applied was acute gamma irradiation with six doses (50, 100, 250, 300, 400 and 500 Gy) to investigate the effect of radiation. The LD50 value was at 182 Gy. The number of days for seed to germinate was varied in all treatments and none of the seedlings survived at 400 Gy and 500 Gy of irradiation. The plant height recorded the highest in treatment 50 Gy (142.0±1.98). Meanwhile, for other parameters such as the number of leaves, the number of branches, leaf width and leaf length were decreased as the dose increases. Overall, our findings suggest that low doses of radiation (below 325 Gy) is the suitable dose to study the improvement of stevia by acute gamma irradiation.

Light deprivation as a herbicide?

Light deprivation as a herbicide?

Flowering Habit and Photoperiodic Flowering Response of Stevia (Stevia rebaudiana Bertoni) in the Philippines

Stevia is a perennial shrub commercially cultivated for the sweet-tasting compounds known as steviol glycosides (SVglys). SVglys are extracted from the green leaves, thus maintenance of vegetative growth is critical in stevia production. This study described the flowering habit and response of potted stevia plants to different photoperiods under Philippine conditions. Photoperiodic treatments (10, 11, 12, 13, and 14 h) were provided using light chambers. Stevia has both terminal and axillary flowering habits. It has five white florets enclosed in a capitulum and exhibits an opposite branching pattern. Results showed that stevia is a facultative short-day plant with a critical daylength of about 12 h. Earlier and more profuse flowering was observed in plants exposed to photoperiods less than 12 h. Earliest flowering response was in 10 h photoperiod which occurred 10 d after light treatment, while flowering time was extended to 23 d in the 14 h photoperiod. Plants subjected to the 10 h photoperiod had the largest number of flowers (34 flower clusters or capitula), while the most number of leaves (37 leaves) was recorded in the longest photoperiod treatment. The study also established that stevia under a 10 h photoperiod requires 10 inductive cycles to induce flowering. Photoperiod was found to have significant positive correlations with the number of nodes and flowering time.

Decoding Gene Expression Signatures Underlying Vegetative to Inflorescence Meristem Transition in the Common Bean

The tropical common bean (Phaseolus vulgaris L.) is an obligatory short-day plant that requires relaxation of the photoperiod to induce flowering. Similar to other crops, photoperiod-induced floral initiation depends on the differentiation and maintenance of meristems. In this study, the global changes in transcript expression profiles were analyzed in two meristematic tissues corresponding to the vegetative and inflorescence meristems of two genotypes with different sensitivities to photoperiods. A total of 3396 differentially expressed genes (DEGs) were identified, and 1271 and 1533 were found to be up-regulated and down-regulated, respectively, whereas 592 genes showed discordant expression patterns between both genotypes. Arabidopsis homologues of DEGs were identified, and most of them were not previously involved in Arabidopsis floral transition, suggesting an evolutionary divergence of the transcriptional regulatory networks of the flowering process of both species. However, some genes belonging to the photoperiod and flower development pathways with evolutionarily conserved transcriptional profiles have been found. In addition, the flower meristem identity genes APETALA1 and LEAFY, as well as CONSTANS-LIKE 5, were identified as markers to distinguish between the vegetative and reproductive stages. Our data also indicated that the down-regulation of the photoperiodic genes seems to be directly associated with promoting floral transition under inductive short-day lengths. These findings provide valuable insight into the molecular factors that underlie meristematic development and contribute to understanding the photoperiod adaptation in the common bean.

Genome-wide characterization of PEBPgene family in Perilla frutescens and PfFT1 promotes flowering time in Arabidopsis thaliana.

Phosphatidylethanolamine-binding proteins (PEBP) family plays important roles in regulating plant flowering time and morphogenesis. However, geneme-wide identification and functional analysis of PEBP genes in the rigorous short-day plant Perilla frutescens (PfPEBP) have not been studied. In this study, 10 PfPEBP were identified and divided into three subfamilies based on their phylogenetic relationships: FT-like, TFL1-like and MFT-like. Gene structure analysis showed that all PfPEBP genes contain 4 exons and 3 introns. Motifs DPDxP and GIHR essential for anion-binding activity are highly conserved in PfPEBP. A large number of light-responsive elements were detected in promoter regions of PfPEBP. Gene expression of PfFT1 exhibited a diurnal rhythm. It was highly expressed in leaves under the short-day photoperiod, but higher in flowers and seeds under the long-day photoperiod. Overexpression of PfFT1 in Arabidopsis thaliana not only promoted early flowering of Col-0 or Ler, but also rescued the late flowering phenotype of ft-1 mutant. We concluded that PfFT1 promotes early flowering by regulating the expression of flowering-related genes AtAP1, AtLFY, AtFUL and AtSOC1. In conclusion, our results provided valuable information for elucidating the functions of PfPEBP in P. frutescens and shed light on the promoting effect of PfFT1 on flowering.

The extended day length promotes earlier flowering of bermudagrass.

Day length is a very critical environmental factor affecting plant growth and development. The extension of light application time has been shown to promote flowering in the long-day plant and to shorten breeding time in some crops. However, previous research on the regulation of bermudagrass flowering by light application time is scarce. Therefore, this study investigated the effect of day length on the growth and flowering of bermudagrass by prolonging the light application time in a controlled greenhouse. Three different light application times were set up in the experiment: 22/2 h (22 hours light/2 hours dark), 18/6 h (18 hours light/6 hours dark), 14/10 h (14 hours light/10 hours dark). Results showed that extending the light application time not only promoted the growth of bermudagrass (plant height, fresh weight, dry weight) but also its nutrient uptake (nitrogen (N) and phosphorous (P) content). In addition, daily light integrals were different when flowering under different light application times. Most importantly, under the 22/2 h condition, flowering time was successfully reduced to 44 days for common bermudagrass (Cynodon dactylon [L.] pers) genotype A12359 and 36 days for African bermudagrass (Cynodon transvaalensis Burtt-Davy) genotype ABD11. This study demonstrated a successful method of bermudagrass flowering earlier than usual time by manipulating light application time which may provide useful insights for bermudagrass breeding.

Bifunctional regulators of photoperiodic flowering in short day plant rice.

Photoperiod is acknowledged as a crucial environmental factor for plant flowering. According to different responses to photoperiod, plants were divided into short-day plants (SDPs), long-day plants (LDPs), and day-neutral plants (DNPs). The day length measurement system of SDPs is different from LDPs. Many SDPs, such as rice, have a critical threshold for day length (CDL) and can even detect changes of 15 minutes for flowering decisions. Over the last 20 years, molecular mechanisms of flowering time in SDP rice and LDP Arabidopsis have gradually clarified, which offers a chance to elucidate the differences in day length measurement between the two types of plants. In Arabidopsis, CO is a pivotal hub in integrating numerous internal and external signals for inducing photoperiodic flowering. By contrast, Hd1 in rice, the homolog of CO, promotes and prevents flowering under SD and LD, respectively. Subsequently, numerous dual function regulators, such as phytochromes, Ghd7, DHT8, OsPRR37, OsGI, OsLHY, and OsELF3, were gradually identified. This review assesses the relationship among these regulators and a proposed regulatory framework for the reversible mechanism, which will deepen our understanding of the CDL regulation mechanism and the negative response to photoperiod between SDPs and LDPs.

Delayed flowering due to ‘cold memory’ is regulated by suppression of FLOWERING LOCUS T-like 3 gene in chrysanthemums

ABSTRACT Chrysanthemum (Chrysanthemum morifolium) is a short-day (SD) plant native to the temperate zone. SD and warm conditions suitable for flowering occur in both spring and autumn. When chrysanthemum plants are exposed to prolonged low temperatures, they are unable to induce flowering for a time afterwards. Therefore, chrysanthemums do not flower in spring, because they are in a state of internal suppression of flowering due to low temperatures in winter (i.e., ’cold memory’). To elucidate the mechanism of the floral suppression by cold memory, we analysed the expression of FLOWERING LOCUS T-like 3 (CsFTL3), which encodes a floral promoter in the wild C. seticuspe. SD induced CsFTL3 upregulation and flowering in untreated plants, but this induction was suppressed in plants with 12-weeks’ cold treatment. Cold memory had little effect on flowering in CsFTL3-overexpressing plants. These results indicate that cold memory suppresses flowering by repressing CsFTL3. This prevents floral induction under SD in spring, and is one of the factors that determines the autumn-flowering nature of chrysanthemum.

Nutrient enrichment alters risk assessment in Giant clams

AbstractMany species exhibit state‐dependent risk assessment. Photosynthetic giant clams (e.g. Tridacna maxima) retract their mantles and close their shells as an anti‐predator response. Although being open allows clams to photosynthesize or siphon‐feed, staying open increases vulnerability to predation. Prior studies indicate that giant clam risk assessment is state‐dependent. Hiding time differs based on body condition, shown by the light deprivation of clams for varying amounts of time. Nutrient enrichment has been shown to impact giant clam growth and photophysiology through their symbiotic zooxanthellae (Symbiodinium sp.). Although previous work by Hayes et al. (2021) examined risk assessment in light‐deprived giant clams, nutrient enrichment and its potential effects on giant clam risk assessment are unstudied. Here, we tested whether nutrient enrichment would alter risk assessment of giant clams by conducting two experiments that quantified hiding time for nutrient‐enhanced clams and two control treatments following an experimentally induced mantle closure: one with a singular simulated predator probe per trial and then with repeated simulated predator probes in the same trial. In our single predation probe experiment, nutrient‐enriched clams significantly increased their hiding time over multiple days. Nutrient‐enrichment did not, however, modify their response to repeated probes. Overall, our results support that nutrient enrichment modulates clam risk assessment. This indicates support for prior state‐dependent risk assessment literature, suggesting nutrient enriched clams will take less risks to forage. This is in direct contrast to results found by Hayes et al. (2021) that suggested that energetically depleted clams were taking less risks to forage, warranting additional research into the mechanisms behind clam energetics and behaviour.

Advancing understanding of oat phenology for crop adaptation.

Oat (Avena sativa) is an annual cereal grown for forage, fodder and grain. Seasonal flowering behaviour, or phenology, is a key contributor to the success of oat as a crop. As a species, oat is a vernalization-responsive long-day plant that flowers after winter as days lengthen in spring. Variation in both vernalization and daylength requirements broadens adaptation of oat and has been used to breed modern cultivars with seasonal flowering behaviours suited to different regions, sowing dates and farming practices. This review examines the importance of variation in oat phenology for crop adaptation. Strategies to advance understanding of the genetic basis of oat phenology are then outlined. These include the potential to transfer knowledge from related temperate cereals, particularly wheat (Triticum aestivum) and barley (Hordeum vulgare), to provide insights into the potential molecular basis of variation in oat phenology. Approaches that use emerging genomic resources to directly investigate the molecular basis of oat phenology are also described, including application of high-resolution genome-wide diversity surveys to map genes linked to variation in flowering behaviour. The need to resolve the contribution of individual phenology genes to crop performance by developing oat genetic resources, such as near-isogenic lines, is emphasised. Finally, ways that deeper knowledge of oat phenology can be applied to breed improved varieties and to inform on-farm decision-making are outlined.

Callus Production and Analysis of Isoflavonoids and Some Terpenes from Bituminaria bituminosa

Background: Bituminaria bituminosa is a long-day plant. The plant has a high pastoral value and palatability. It is grazed by cattle, goats and sheep. Leaves and stems contain four furanocoumarins’ psoralen, angelicin, xanthotoxin and bergapten. The seed is covered by the fruit. Germination was not observed in beaked fruits. A cut with a scalpel can increase the germination rate. According to the literature there are not enough studies about the culture media and convenient conditions. Methods: In our study, we tried six medium for callus production with different hormone concentrations including 2,4-D, BAP and kinetin. In this study, a protocol for callus induction and analysis of isoflavonoids and terpenes of Bituminaria bituminosa has been developed. Result: Maximum callus induction frequency was observed on Murashige and Skoog (MS) medium supplemented with 0.75 mg/L 2,4-D + 2.5 mg/L kinetin in young primary leaves. 0.75 mg/L 2,4-D+2.5 mg/L kinetin medium is more successful in the production ofses of flavonoids that can be produced in vitro and is more successful in producing phenols. In terpene production, it is seen that 1.25 mg/L 2,4-D+3.5 mg/L BAP, which is the best callus producing medium containing BAP, is the most successful medium among all tested mediums.

Domestication-associated PHYTOCHROME C is a flowering time repressor and a key factor determining Setaria as a short-day plant.

Phytochromes play vital roles in the regulation of flowering time, but little is known in Panicoideae species, especially the C4 model Setaria. Here, genomic variations of PHYTOCHROME C (PHYC) between wild and cultivated Setaria gene pools were analysed and three SiphyC mutants were identified. The function of SiPHYC was verified by CRISPR-Cas9 approach and transcriptome sequencing. Furthermore, efficiency of indoor cultivation of SiphyC mutants were systematically evaluated. An extreme purified selection of PHYC was detected in wild to cultivated domestication process of Setaria. SiphyC mutants and knockout transgenic plants showed an early heading date and a loss of response to short-day photoperiod. Furthermore, variable expression of SiFTa, SiMADS14 and SiMADS15 might be responsible for promoting flowering of SiphyC mutants. Moreover, SiphyC mutant was four times that of the indoor plot ratio of wild-type and produced over 200 seeds within 45 d per individual. Our results suggest that domestication-associated SiPHYC repressed flowering and determined Setaria as a short-day plant, and SiphyC mutants possess the potential for creating efficient indoor cultivation system suitable for research on Setaria as a model, and either for maize or sorghum as well.

Too Dense or Not Too Dense: Higher Planting Density Reduces Cannabinoid Uniformity but Increases Yield/Area in Drug-Type Medical Cannabis.

A major challenge for utilizing cannabis for modern medicine is the spatial variability of cannabinoids in the plant, which entail differences in medical potency. Since secondary metabolism is affected by environmental conditions, a key trigger for the variability in secondary metabolites throughout the plant is variation in local micro-climates. We have, therefore, hypothesized that plant density, which is well-known to alter micro-climate in the canopy, affects spatial standardization, and concentrations of cannabinoids in cannabis plants. Canopy density is affected by shoot architecture and by plant spacing, and we have therefore evaluated the interplay between plant architecture and plant density on the standardization of the cannabinoid profile in the plant. Four plant architecture modulation treatments were employed on a drug-type medicinal cannabis cultivar, under a density of 1 or 2 plants/m2. The plants were cultivated in a naturally lit greenhouse with photoperiodic light supplementation. Analysis of cannabinoid concentrations at five locations throughout the plant was used to evaluate treatment effects on chemical uniformity. The results revealed an effect of plant density on cannabinoid standardization, as well as an interaction between plant density and plant architecture on the standardization of cannabinoids, thus supporting the hypothesis. Increasing planting density from 1 to 2 plants/m2 reduced inflorescence yield/plant, but increased yield quantity per area by 28–44% in most plant architecture treatments. The chemical response to plant density and architecture modulation was cannabinoid-specific. Concentrations of cannabinoids in axillary inflorescences from the bottom of the plants were up to 90% lower than in the apical inflorescence at the top of the plant, considerably reducing plant uniformity. Concentrations of all detected cannabinoids in these inflorescences were lower at the higher density plants; however, cannabinoid yield per cultivation area was not affected by neither architecture nor density treatments. Cannabigerolic acid (CBGA) was the cannabinoid least affected by spatial location in the plant. The morpho-physiological response of the plants to high density involved enhanced leaf drying at the bottom of the plants, increased plant elongation, and reduced cannabinoid concentrations, suggesting an involvement of chronic light deprivation at the bottom of the plants. Therefore, most importantly, under high density growth, architectural modulating treatments that facilitate increased light penetration to the bottom of the plant such as “Defoliation”, or that eliminated inflorescences development at the bottom of the plant such as removal of branches from the lower parts of the plant, increased chemical standardization. This study revealed the importance of plant density and architecture for chemical quality and standardization in drug-type medical cannabis.

Photomorphogenesis and content of carbohydrates in the axial organs of field pean seedlings under the influence of selective light

Background: Light is a multifaceted exogenous factor that plays an important role in plant growth and development. The spectral composition of light is determinative for the regulation of photomorphogenetic processes in plants. Nowadays plants have several groups of photoreceptors that include receptors of red (RL) and far red light (FRL) — phytochromes; receptors of UV-A, blue (BL) and green (GL) light — cryptochromes, phototropins, proteins of the ZEITLUPE family, as well as the UV-B receptor — UVR8 protein. One of the possible mechanisms that realize an activation of photoreceptor systems in the plant may be concerned with carbohydrate metabolism. The research of morphogenetic reactions of seedlings under the action of selective light irradiation by activating photoreceptor systems is important for understanding the mechanisms of regulation of the program of plant organism`s ontogenesis. The aim of this study was to investigate the effect of selective light of different spectrum: RL (660 nm), GL (530 nm) and BL (450 nm) on growth reactions, morphogenesis and content of soluble carbohydrate in axial organs of seedlings of long-day plants. Materials and methods: 10-day etiolated seedlings of pea Maecenat variety were used for experiments. Activation of photoreceptor systems by red (RL, 660nm), green (GL, 530nm) and blue (BL, 450nm) light was performed for 5 days for 30 minutes using LED matrices. The growth reaction, morphogenesis and the content of soluble mono- and oligosugars in the axial organs of seedlings were analyzed. Results: The axial organs of seedlings differ in their response to irradiation with selective light. The root system is more sensitive to the action of selective light than the shoot of the seedlings of the long-day plants of the pea Maecenat variety. Activation of photoreceptor systems stimulates growth processes, activates the processes of photomorphogenesis and the biosynthesis of oligosugars de novo, most likely sucrose. Among the spectra of selective light, the maximum stimulating effect is shown by irradiation of the GL (530 nm) in the reactions of the aboveground part and roots. RL (660 nm) and BL (450 nm) show opposite effects: RL initiates a photomorphogenetic program of shoot part, and BL has a greater effect on photomorphogenesis of root system. Conclusions: Different levels of growth, morphogenetic processes and changes in the content of soluble carbohydrates are probably related to the ability of photoreceptor systems to activate the realization of different ways of photomorphogenesis in the axial organs of seedlings under the influence of selective light of a certain spectrum.

Developmental light deprivation transiently reduces the expression of vGluT2 and GluN2B in the rat ventral suprachiasmatic nucleus.

The suprachiasmatic nucleus (SCN) is the most important circadian clock in mammals. The SCN synchronizes to environmental light via the retinohypothalamic tract (RHT), which is an axon cluster derived from melanopsin-expressing intrinsic photosensitive retinal ganglion cells. Investigations on the development of the nonimage-forming pathway and the RHT are scarce. Previous studies imply that light stimulation during postnatal development is not needed to make the RHT functional at adult stages. Here, we examined the effects of light deprivation (i.e., constant darkness (DD) rearing) during postnatal development on the expression in the ventral SCN of two crucial proteins for the synchronization of circadian rhythms to light: the presynaptic vesicular glutamate transporter type 2 (vGluT2) and the GluN2B subunit of the postsynaptic NMDA receptor. We found that animals submitted to DD conditions exhibited a transitory reduction in the expression of vGluT2 (at P12-19) and of GluN2B (at P7-9) that was compensated at older stages. These findings support the hypothesis that visual stimulation during early ages is not decisive for normal development of the RHT-SCN pathway.

Identification and mapping of major-effect flowering time loci Autoflower1 and Early1 in Cannabis sativa L.

Flowering time is an important trait for all major market classes of hemp (Cannabis sativa), affecting yields and quality of grain, fiber, and cannabinoids. C. sativa is usually considered a short-day plant, flowering once night length reaches a critical threshold. Variations in flowering time within and across cultivars in outdoor grown populations have been previously identified, likely corresponding to genetic differences in this critical night length. Further, some C. sativa are photoperiod insensitive, colloquially referred to as “autoflowering.” This trait has anecdotally been described as a simple recessive trait with major impacts on phenology and yield. In this work, the locus responsible for the “autoflower” trait (Autoflower1), as well as a major-effect flowering time locus, Early1, were mapped using bulked segregant analysis. Breeder-friendly high-throughput molecular marker assays were subsequently developed for both loci. Also detailed are the flowering responses of diverse cultivars grown in continuous light and the result of crossing two photoperiod insensitive cultivars of differing pedigree.

Prolonged Light Deprivation Modulates the Age-Related Changes in α-Tocopherol Level in Rats

Prolonged Light Deprivation Modulates the Age-Related Changes in α-Tocopherol Level in Rats