Winter Type Research Articles

Winter‐type oilseed pennycress crop staging guide

AbstractOilseed pennycress (Thalspi arvense L.) is a crop that has undergone domestication for use as a new oilseed option in parts of the United States for use in biofuel and livestock feed production but does not yet have management resources such as a growth staging guide. Winter types of this crop may have utility in existing summer annual rotations throughout much of the U.S. Midwest by growing during the fall/winter fallow period. This guide contains an adaptation of the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH)‐staging method used in other oilseeds and integrates management considerations and key physiological development stages for this new crop. The implementation of substages within a predominant phase of growth in this guide is more reflective of the Feekes growth staging system for small grains with which U.S. Midwest producers commonly use. Utilization of a common staging system for winter‐type pennycress will help with development of future management guides and pesticide labeling practices and will help connect producers and consultants to ensure management practices are employed at the appropriate growth stages.

A Study on Personal Fashion Color Choices in Manicures and Pedicures

Purpose: The purpose of this study was to offer useful information for improving women’s beauty self-images by analyzing personal color choices in women’s fashions and determining the correlation between color matching and personal fashion color choices in manicures and pedicures.Methods: The research subjects included 32 women aged 20–50 years who lived in capital area and whose personal color fashion choices were determined. The data were analyzed with frequency analysis, a χ<sup>2</sup>-test, and a one-way ANOVA using SPSS WIN 25.0.Results: Considering the personal color choices, they were high in “summer types” for L* values of skin, high in “winter types” for L* values of hands and feet, and high in “fall types” for values a* and b* of skin, hands, and feet. Also, with regard to matching tones for hands and feet, the personal color choices were mostly “spring types” with warm spring-type tones, summer types with cool summer-type tones, “fall types” with warm fall-type tones, and “winter types” with cool winter-type tones.Conclusion: The results of this study suggested the matched tones for hands and feet are similar to the personal color fashion choices. These findings support a theoretical basis for harmonious color matching when choosing colors in manicure and pedicure nail art. The findings of this study may assist with beauty styling and self-images of women in this fashion era.

Cold Conditioned: Discovery of Novel Alleles for Low-Temperature Tolerance in the Vavilov Barley Collection.

Climate changes leading to higher summer temperatures can adversely affect cool season crops like spring barley. In the Upper Midwest region of the United States, one option for escaping this stress factor is to plant winter or facultative type cultivars in the autumn and then harvest in early summer before the onset of high-temperature stress. However, the major challenge in breeding such cultivars is incorporating sufficient winter hardiness to survive the extremely low temperatures that commonly occur in this production region. To broaden the genetic base for winter hardiness in the University of Minnesota breeding program, 2,214 accessions from the N. I. Vavilov Institute of Plant Industry (VIR) were evaluated for winter survival (WS) in St. Paul, Minnesota. From this field trial, 267 (>12%) accessions survived [designated as the VIR-low-temperature tolerant (LTT) panel] and were subsequently evaluated for WS across six northern and central Great Plains states. The VIR-LTT panel was genotyped with the Illumina 9K SNP chip, and then a genome-wide association study was performed on seven WS datasets. Twelve significant associations for WS were identified, including the previously reported frost resistance gene FR-H2 as well as several novel ones. Multi-allelic haplotype analysis revealed the most favorable alleles for WS in the VIR-LTT panel as well as another recently studied panel (CAP-LTT). Seventy-eight accessions from the VIR-LTT panel exhibited a high and consistent level of WS and select ones are being used in winter barley breeding programs in the United States and in a multiparent population.

Infestation and Seasonal Fluctuation of Gamasid Mites (Parasitiformes: Gamasida) on Indochinese Forest Rat, Rattus andamanensis (Rodentia: Muridae) in Southern Yunnan of China.

Simple SummaryGamasid mites are a large group of arthropods and some of them are ectoparasites on the body surface of rodents and some other small mammals. Some species of ectoparasitic gamasid mites are associated with the transmission of some zoonotic diseases such as rickettsialpox and hemorrhagic fever with renal syndrome (HFRS). Based on a 12-month consecutive investigation at Jingha village in southern Yunnan of China from April 2016 to March 2017, the present paper studied the infestation and seasonal fluctuation of gamasid mites on the Indochinese forest rat, Rattus andamanensis, the most dominant species of rodent at the investigated site. The temperature and rainfall are two key factors that influence the seasonal fluctuation of the mites.A 12-month consecutive investigation was made at Jingha village in southern Yunnan of southwest China from April 2016 to March 2017. A total of 2053 Indochinese forest rats (Rattus andamanensis Blyth, 1860) were captured and examined, which account for 84.69% (2053/2424) of all the animal hosts (rodents and other small mammals) at the investigation site. And 39.82% (13,531/33,980) of gamasid mites were identified from the body surface of R. andamanensis and they belong to 41 species, 10 genera, 3 subfamilies and 2 families. Of the 41 species of gamasid mites identified from R. andamanensis, Laelaps nuttalli Hirst, 1915 and Laelaps echidninus Berlese, 1887 were the most dominant with 70.63% and 20.67% of constituent ratios respectively. In monthly fluctuations of all the gamasid mites on R. andamanensis, the constituent ratio (Cr) and overall infestation mean abundance (MA) of the mites in 12 months showed two obvious peaks in January (winter season) and June (summer season). However, the two dominant mite species, L. nuttalli and L. echidninus, showed different patterns of seasonal fluctuations. Laelaps nuttalli occurred throughout the year, and its Cr and MA showed two prominent peaks in winter season (December and January) and summer season (June), which belongs to the summer-winter type of seasonal fluctuation. Laelaps echidninus also occurred on R. andamanensis throughout the year, but its Cr and MA showed only one peak in winter season (December and January), which belongs to the winter type of seasonal fluctuation. A negative correlation existed between two climatic factors (temperature and rainfall) and the infestations (Cr, prevalence PM and MA) of two dominant mite species (L. nuttalli and L. echidninus) on R. andamanensis (p < 0.05). Temperature and rainfall are considered to be two key factors that influence the seasonal fluctuations of the mites on the studied rat species.

Comparative analyses of changes in the ice cover of the Tatar Strait in relation to 1961-1990 and 1991-2020 climate normals

Current warming in the Northern Hemisphere has encompassed not only the surface atmosphere, but also manifested itself in a change in the state of the sea ice cover, as an integral part of the climate system. One of the indicators of the warming was a reduction in ice cover observed in the water area of the Far Eastern seas since the late 1980s. The prospective areas of hydrocarbon deposits discovered in the Tatar Strait, as well as the existing needs for the transportation of hydrocarbons along the shipping routes in the strait, led to the emerging interest in researching the ice regime of the Sea of Japan in the modern climatic era. The proposed paper analyses the changes in ice cover of the Tatar Strait in relation to 1961–1990 and 1991–2020 climate normals. The regularities of the long-term variability of ice cover within non-overlapping 30-year periods were revealed. The analysis of the dynamics of ice cover anomalies, calculated for each normal separately, was carried out. An assessment of the distribution of winter types in the periods under study was carried out. The characteristic features of variations in the intra-seasonal course of ice cover and the dates of the onset of ice phases in different types of winters were identified.

Trends of genetic changes uncovered by Env- and Eigen-GWAS in wheat and barley

Key messageVariety age and population structure detect novel QTL for yield and adaptation in wheat and barley without the need to phenotype.The process of crop breeding over the last century has delivered new varieties with increased genetic gains, resulting in higher crop performance and yield. However, in many cases, the alleles and genomic regions underpinning this success remain unknown. This is partly due to the difficulty of generating sufficient phenotypic data on large numbers of historical varieties to enable such analyses. Here we demonstrate the ability to circumvent such bottlenecks by identifying genomic regions selected over 100 years of crop breeding using age of a variety as a surrogate for yield. Rather than collecting phenotype data, we deployed ‘environmental genome-wide association scans’ (EnvGWAS) based on variety age in two of the world’s most important crops, wheat and barley, and detected strong signals of selection across both genomes. EnvGWAS identified 16 genomic regions in barley and 10 in wheat with contrasting patterns between spring and winter types of the two crops. To further examine changes in genome structure, we used the genomic relationship matrix of the genotypic data to derive eigenvectors for analysis in EigenGWAS. This detected seven major chromosomal introgressions that contributed to adaptation in wheat. EigenGWAS and EnvGWAS based on variety age avoid costly phenotyping and facilitate the identification of genomic tracts that have been under selection during breeding. Our results demonstrate the potential of using historical cultivar collections coupled with genomic data to identify chromosomal regions under selection and may help guide future plant breeding strategies to maximise the rate of genetic gain and adaptation.

Comprehensive speed breeding: a high-throughput and rapid generation system for long-day crops.

Breeding cycle time largely determines the efficiency of crop genetic improvement. To accelerate the generation progress, Watson et al. (2018) proposed a concept of 'speed breeding (SB)' by extending the photoperiod and increasing the light intensity during plant growth. However, there have been few reports on the successful application of SB in semi-winter and winter long-day crops. Here, we propose a comprehensive speed breeding (CSB) system for the rapid generation and high-throughput culture of long-day crops, which can accomplish 4.5 generations for both semi-winter canola and winter wheat per year. With the aid of extra far-red light, three and 5.5 generations can be accomplished for the typical winter and semi-winter type canola. CSB also exhibits high efficiency in spring type canola, and can achieve up to 6.5 and 5.5 generations with or without extra far-red light, respectively. This strategy is expected to greatly accelerate gene pyramiding of superior alleles, screening of recombinants for QTL mapping and functional genomics research by rapid purification of multiple mutated alleles.

WHEAT SEED (TRITICUM AESTIVUM L.) RADIOCARBON CONCENTRATION OVER THE LAST 75 YEARS

ABSTRACTHere we report radiocarbon measurements made on wheat seed tissue (Triticum aestivum L.; winter or spring type growth habit), from the seed archive of the IPK Gatersleben, Sachsen-Anhalt, Germany, which was harvested between 1946 and 2020. The results give an overview of 75 years of radiocarbon concentration evolution in agricultural plant products. The wheat tissue radiocarbon concentrations follow known pre- and post-bomb radiocarbon records, such as the atmospheric Jungfraujoch, Schauinsland, and NH1 datasets. Based on a Northern Hemisphere growing period from April to July, the Gatersleben seed tissue radiocarbon concentration indicates incorporation of fossil carbon of about 1% with respect to the high alpine, clean-air CO2 of the Jungfraujoch station between 1987 and 2019. We propose to use the pre- and post-bomb radiocarbon record of Gatersleben wheat as a reference in forensic investigations, such as the age estimation of paper by analyzing starch used in paper manufacture. Additionally, an advantage of the record reported here lies in its extensibility by adding new analyses from future harvests.

Early-Season Mapping of Winter Crops Using Sentinel-2 Optical Imagery

Sentinel-2 imagery is an unprecedented data source with high spatial, spectral and temporal resolution in addition to free access. The objective of this paper was to evaluate the potential of using Sentinel-2 data to map winter crops in the early growth stage. Analysis of three winter crop types—winter garlic, winter canola and winter wheat—was carried out in two agricultural regions of China. We analysed the spectral characteristics and vegetation index profiles of these crops in the early growth stage and other land cover types based on Sentinel-2 images. A decision tree classification model was built to distinguish the crops based on these data. The results demonstrate that winter garlic and winter wheat can be distinguished four months before harvest, while winter canola can be distinguished two months before harvest. The overall classification accuracy was 96.62% with a kappa coefficient of 0.95. Therefore, Sentinel-2 images can be used to accurately identify these winter crops in the early growth stage, making them an important data source in the field of agricultural remote sensing.

Kanolada (Brassica napus L.) Farklı Ekim Zamanı, Çeşit ve Tohumluk Miktarının Verim ve Kalite Özelliklerine Etkisi

This study was carried out to determine the effect of different sowing dates and seeding rate on seed yield, oil and protein contents of seed in two rapeseed cultivars in the field of experiment and application of Aydin Adnan Menderes University Faculty of Agriculture during 2014/2015 and 2015/2016. The experiment was the split-split-plot design with 4 replications. The sowing dates, cultivars and seeding rates were arranged to main, sub and sub-sub plots, respectively. This experiment was conducted applying two sowing dates (early and late), two winter type cultivars (NK Petrol and NK Caravel) and five seeding rates (3, 5, 7, 9 and 11 kg ha-1). The early sowing date and 7.0 kg ha-1 seeding rate given the highest seed yield for both cultivars based on two-year results. The interaction between sowing dates and cultivars for crude oil rate was significant, and the highest crude oil rate was recorded in NK Petrol cultivar (43.34 - 43.54%) at the first sowing date in both years. Non-significant protein content for all factors and interactions varied from 19.10% to 23.72%. Finally, it was recommended the earliest possible sowing with 7.0 kg ha-1 seeding rate for seed yield and quality in winter rapeseed growing. Moreover, it was recommended that NK Petrol for early sowing dates and NK Caravel for late sowing dates should be used as a cultivar.

ActiPso: definition of activity types for psoriatic disease: A novel marker for an advanced disease classification.

Assessment of psoriasis is exclusively done measuring severity using somatic scores such as the psoriasis area and severity index or patient-reported outcomes such as the dermatology life quality index. There is no established tool to measure a patient's individual psoriasis activity over time. Development of a new tool to classify psoriasis activity types. Open patient interviews were performed and adapted in several steps and by using different groups of patients. Wording of the tool's axis and description how to use it was optimized with the input of patients. The final ActiPso tool was used in a prospective study in psoriasis patients. Four activity types could be identified describing psoriasis intensity (e.g. severity, itch, pain) over one typical year and an event/trigger type describing flares. In the study in 586 psoriasis patients of the 536 patients eligible for analysis 40.9% self-classified as type 1 ('stable'), 22.6% as type 2 ('unstable'), 30.6% as type 3 ('winter type') and 6.0% as type 4 ('summer type'), respectively. Flares of psoriasis as identified by the event/trigger type were reported in 36.1% of patients with activity type 1, 67.8% with type 2, 73.8% of type 3 and 59.4% of type 4, respectively. Interviewed patients were able to describe their course of psoriatic disease and to name potential triggering factors. By doing so, activity types of psoriasis were defined for the first time and the importance of events/triggers for flares described and integrated into ActiPso types as a basis for advanced patient-centric management. A limitation of ActiPso is that in regions with no seasonal variations types 3 and 4 may not apply.

How sowing date affects development and performance of safflower through climate variables

AbstractSafflower (Carthamus tinctorius L.) has unrealized potential as an alternative crop in many semiarid regions including central Argentina. Our objective was to relate how temperature and precipitation conditions with fall (5 June 2012 and 23 Apr. 2013) and winter sowing (13 Aug. 2012 and 20 Aug. 2013) affected phenology, yield, yield components, and oil percent in four winter and eight spring‐type safflower accessions in the semiarid region of central Argentina. Fall sowing was associated with lower temperatures, higher precipitation, lower heat/moisture stress indices and precipitation deficits than winter sowing. Rosette period lasted 55 d longer, and stem elongation to anthesis period 30 d longer in fall than in winter sowing. However, anthesis was advanced only few days in fall sowing and duration of postanthesis development was comparable between sowing regimes and years. Fall sowing plants averaged 3,252 filled grains m–2 and a grain yield of 109.8 g m–2, whereas winter sowing plants averaged 1,443 filled grains m–2 and a grain yield of 49.3 g m–2. Grain yield was 35% higher in winter than in spring‐type accessions, but winter types had lower oil percent (22.0%) than spring‐types (33.3%). In the semiarid region of central Argentina, we recommend fall sowing as it extended the growing season in terms of days preanthesis and presented favorable climatic conditions for safflower development.

Combining Protein Content and Grain Yield by Genetic Dissection in Bread Wheat under Low-Input Management.

The simultaneous improvement of protein content (PC) and grain yield (GY) in bread wheat (Triticum aestivum L.) under low-input management enables the development of resource-use efficient varieties that combine high grain yield potential with desirable end-use quality. However, the complex mechanisms of genotype, management, and growing season, and the negative correlation between PC and GY complicate the simultaneous improvement of PC and GY under low-input management. To identify favorable genotypes for PC and GY under low-input management, this study used 209 wheat varieties, including strong gluten, medium-strong gluten, medium gluten, weak gluten, winter, semi-winter, weak-spring, and spring types, which has been promoted from the 1980s to the 2010s. Allelic genotyping, performed using kompetitive allele-specific polymerase chain reaction (KASP) technology, found 69 types of GY-PC allelic combinations in the tested materials. Field trials were conducted with two growing season treatments (2018–2019 and 2019–2020) and two management treatments (conventional management and low-input management). Multi-environment analysis of variance showed that genotype, management, and growing season had extremely substantial effects on wheat GY and PC, respectively, and the interaction of management × growing season also had extremely significant effects on wheat GY. According to the three-sigma rule of the normal distribution, the GY of wheat varieties Liangxing 66 and Xinmai 18 were stable among the top 15.87% of all tested materials with high GY, and their PC reached mean levels under low-input management, but also stably expressed high GY and high PC under conventional management, which represents a great development potential. These varieties can be used as cultivars of interest for breeding because TaSus1-7A, TaSus1-7B, TaGW2-6A, and TaGW2-6B, which are related to GY, and Glu-B3, which is related to PC, carry favorable alleles, among which Hap-1/2, the allele of TaSus1-7A, and Glu-B3b/d/g/i, the allele of Glu-B3, can be stably expressed. Our results may be used to facilitate the development of high-yielding and high-quality wheat varieties under low-input management, which is critical for sustainable food and nutrition security.

A 598-bp InDel Variation in the Promoter Region of Bna.SOC1.A05 Is Predominantly Present in Winter Type Rapeseeds.

During rapeseed domestication and breeding, genetic diversity allowed to adapt it to different eco-geographical regions and to shape its useful traits. Structural variations (SVs), including presence/absence variations (PAVs), are thought to play a major role in the genetic diversity and phenotypic plasticity of rapeseed. In this study, we detected a 598-bp PAV within the promoter region of an Arabidopsis ortholog of a major flowering time gene and a downstream target of FLC, SOC1, which is one of the first genes that are upregulated in rapeseed during vernalization. Further analysis showed that the insertion is present predominantly in winter types while absent in spring types. The 589-bp sequence is present only in the A sub-genome indicating that it originated from Brassica rapa. Since the genomic region around Bna.SOC1.A05 showed a strong reduction in nucleotide diversity, the insertion might represent a larger selected sweep for rapeseed adaptation. Cis-element analysis showed that the insertion contains an ACGTG box, which is the strongest binding motif for the HY5 transcription factor in Arabidopsis. In addition, expression analyses showed that mRNA levels of Bna.SOC1.A05 were lower in accessions carrying the insertion compared to the ones that had no insertion.

Winter Wheat Adaptation to Climate Change in Turkey

Climate change scenarios reveal that Turkey’s wheat production area is under the combined effects of heat and drought stresses. The adverse effects of climate change have just begun to be experienced in Turkey’s spring and the winter wheat zones. However, climate change is likely to affect the winter wheat zone more severely. Fortunately, there is a fast, repeatable, reliable and relatively affordable way to predict climate change effects on winter wheat (e.g., testing winter wheat in the spring wheat zone). For this purpose, 36 wheat genotypes in total, consisting of 14 spring and 22 winter types, were tested under the field conditions of the Southeastern Anatolia Region, a representative of the spring wheat zone of Turkey, during the two cropping seasons (2017–2018 and 2019–2020). Simultaneous heat (&gt;30 °C) and drought (&lt;40 mm) stresses occurring in May and June during both growing seasons caused drastic losses in winter wheat grain yield and its components. Declines in plant characteristics of winter wheat genotypes, compared to those of spring wheat genotypes using as a control treatment, were determined as follows: 46.3% in grain yield, 23.7% in harvest index, 30.5% in grains per spike and 19.4% in thousand kernel weight, whereas an increase of 282.2% in spike sterility occurred. On the other hand, no substantial changes were observed in plant height (10 cm longer than that of spring wheat) and on days to heading (25 days more than that of spring wheat) of winter wheat genotypes. In general, taller winter wheat genotypes tended to lodge. Meanwhile, it became impossible to avoid the combined effects of heat and drought stresses during anthesis and grain filling periods because the time to heading of winter wheat genotypes could not be shortened significantly. In conclusion, our research findings showed that many winter wheat genotypes would not successfully adapt to climate change. It was determined that specific plant characteristics such as vernalization requirement, photoperiod sensitivity, long phenological duration (lack of earliness per se) and vulnerability to diseases prevailing in the spring wheat zone, made winter wheat difficult to adapt to climate change. The most important strategic step that can be taken to overcome these challenges is that Turkey’s wheat breeding program objectives should be harmonized with the climate change scenarios.

A novel deletion in FLOWERING LOCUS T modulates flowering time in winter oilseed rape

Key messageA novel structural variant was discovered in the FLOWERING LOCUS T orthologue BnaFT.A02 by long-read sequencing. Nested association mapping in an elite winter oilseed rape population revealed that this 288 bp deletion associates with early flowering, putatively by modification of binding-sites for important flowering regulation genes.Perfect timing of flowering is crucial for optimal pollination and high seed yield. Extensive previous studies of flowering behavior in Brassica napus (canola, rapeseed) identified mutations in key flowering regulators which differentiate winter, semi-winter and spring ecotypes. However, because these are generally fixed in locally adapted genotypes, they have only limited relevance for fine adjustment of flowering time in elite cultivar gene pools. In crosses between ecotypes, the ecotype-specific major-effect mutations mask minor-effect loci of interest for breeding. Here, we investigated flowering time in a multiparental mapping population derived from seven elite winter oilseed rape cultivars which are fixed for major-effect mutations separating winter-type rapeseed from other ecotypes. Association mapping revealed eight genomic regions on chromosomes A02, C02 and C03 associating with fine modulation of flowering time. Long-read genomic resequencing of the seven parental lines identified seven structural variants coinciding with candidate genes for flowering time within chromosome regions associated with flowering time. Segregation patterns for these variants in the elite multiparental population and a diversity set of winter types using locus-specific assays revealed significant associations with flowering time for three deletions on chromosome A02. One of these was a previously undescribed 288 bp deletion within the second intron of FLOWERING LOCUS T on chromosome A02, emphasizing the advantage of long-read sequencing for detection of structural variants in this size range. Detailed analysis revealed the impact of this specific deletion on flowering-time modulation under extreme environments and varying day lengths in elite, winter-type oilseed rape.

Changes in Chemical Composition and Accumulation of Cryoprotectants as the Adaptation of Anholocyclic Aphid Cinara tujafilina to Overwintering

One of the consequences of climate change is the expansion of insects’ ranges. Colonization of new habitats forces insects to adapt to new conditions, such as low temperatures in winter. Cinara tujafilina is a thermophilic anholocyclic aphid species, which reproduce exclusively parthenogenetic throughout the year, including winter. On the areas where the populations of C. tujafilina had expanded, it demonstrated its adaptation for surviving colder winters. Based on analyses of changes in body chemical composition using Fourier transform infrared (FTIR) and changes in cryoprotectant content using high performance liquid chromatography (HPLC), we showed how aphid C. tujafilina adapted to overwintering as an active stage. In the FTIR spectrum of the winter type of C. tujafilina, higher peak values originating from the carbohydrates, proteins and lipids, were observed. Glucose, trehalose, mannitol, myo-inositol and glycerol were identified in the aphid body in winter as main putative cryoprotectants to increase the insects’ tolerance to cold. The complex sugar-polyol cryoprotectant system facilitates aphids’ survival in unfavorable low temperatures.

Total FLC transcript dynamics from divergent paralogue expression explains flowering diversity in Brassica napus.

Summary Flowering time is a key adaptive and agronomic trait. In Arabidopsis, natural variation in expression levels of the floral repressor FLOWERING LOCUS C (FLC) leads to differences in vernalization. In Brassica napus there are nine copies of FLC. Here, we study how these multiple FLC paralogues determine vernalization requirement as a system.We collected transcriptome time series for Brassica napus spring, winter, semi‐winter, and Siberian kale crop types. Modelling was used to link FLC expression dynamics to floral response following vernalization.We show that relaxed selection pressure has allowed expression of FLC paralogues to diverge, resulting in variation of FLC expression during cold treatment between paralogues and accessions. We find that total FLC expression dynamics best explains differences in cold requirement between cultivars, rather than expression of specific FLC paralogues.The combination of multiple FLC paralogues with different expression dynamics leads to rich behaviour in response to cold and a wide range of vernalization requirements in B. napus. We find evidence for different strategies to determine the response to cold in existing winter rapeseed accessions.

Is Drought Stress Tolerance Affected by Biotypes and Seed Size in the Emerging Oilseed Crop Camelina?

One of the main advantages of camelina (Camelina sativa (L.) Crantz) is its wide environmental adaptability and extreme drought tolerance. The availability of both winter and spring camelina biotypes, characterized by different seed sizes, raises the question about possible differences in their response to drought stress at the emergence stage. To address this, a germination test was set up in controlled conditions, comparing six winter and six spring genotypes with differing seed sizes (ranging from 1.83 to 0.88 g/1000-seeds) under increasing levels of osmotic stress (0, −0.4, −0.8, −1.2, −1.4, −1.6 MPa) using polyethylene glycol (PEG). Camelina withstands mild level of osmotic stress (−0.4 MPa) without significant decrease in germination. Even at −1.2 MPa after 10 d, it still had 75% germination. Significant differences in germination were observed between biotypes, where spring biotypes performed better than winter ones. Shoot and radicle lengths were significantly diminished by imposed osmotic stress, but shoot growth seemed more impacted. In general, spring biotypes had longer shoots and radicles than winter ones. Seed size played a role in the response of camelina to drought, but it depended on biotype and stress level imposed. In particular large seeded spring types had the highest germination percentage and resulted less impaired by osmotic stress, otherwise among the tested winter types the small seeded ones were the best performing. The presented data could be useful for breeding purposes for selecting the appropriate camelina type for sowing in drought-prone regions.

The transition to flowering in winter rapeseed during vernalization.

Flowering time is a major determinant of adaptation, fitness and yield in the allopolyploid species rapeseed (Brassica napus). Despite being a close relative to Arabidopsis thaliana, little is known about the timing of floral transition and the genes that govern this process. Winter, semi-winter and spring type plants have important life history characteristics that differ in vernalization requirements for flowering and are important for growing rapeseed in different regions of the world. In this study, we investigated the timing of vernalization-driven floral transition in winter rapeseed and the effect of photoperiod and developmental age on flowering time and vernalization responsiveness. Microscopy and whole transcriptome analyses at the shoot apical meristems of plants grown under controlled conditions showed that floral transition is initiated within few weeks of vernalization. Certain Bna.SOC1 and Bna.SPL5 homeologs were among the induced genes, suggesting that they are regulating the timing of cold-induced floral transition. Moreover, the flowering response of plants with shorter pre-vernalization period correlated with a delayed expression of Bna.SOC1 and Bna.SPL5 genes. In essence, this study presents a detailed analysis of vernalization-driven floral transition and the aspects of juvenility and dormancy and their effect on flowering time in rapeseed.