The profiles and tensile strength on straight roots of plants withstand transient tensile injured after self-repair.

Plants roots are severely injured during the process of withstanding transient tensile, and the injured roots can self-repair. We investigated the change law of the growth characteristics and tensile strength on straight roots withstand transient tensile injured after self-repair. The survival rate of two kinds of injured plants roots was between 60 and 89%. The test roots after self-repaired, the tensile strength reduction rate of Hippophae rhamnoides L. roots was greater than that of Salix psammophila roots. The tensile force was positively related to the power function of root diameter, the tensile strength was negatively related to the root diameter in a power function. The tensile strength of straight roots under small injured force showed an increasing trend, but the straight roots under the large injured force showed the opposite result. The survival rate of rough roots was greater than that of fine roots. The large injured force was not conducive to the repair and force again of the straight roots of two kinds of plants. The reduction rate of tensile strength after repaired with small force was less than that of large force. The self-repair ability of fine roots was weaker than that of rough roots.

Population dynamics of Hippophae rhamnoides shrub in response of sea-level rise and insect outbreaks.

The coastal vegetation of islands is expected to be affected by future sea-level rise and other anthropogenic impacts. The biodiverse coastal vegetation on the eastern part of the Dutch Wadden Island of Ameland has experienced land subsidence caused by gas extraction since 1986. This subsidence mimics future sea-level rising through increased flooding and raising groundwater levels. We studied the effects of this relative sea-level rise and other environmental factors (i.e. insect outbreaks, temperature and precipitation) on the population dynamics (i.e. cover and age structure and annual growth) of the shrub sea-buckthorn (Hippophae rhamnoides L.) in young (formed after 1950) and old (formed before 1950) dune areas over a period of 56 years (1959-2015). We found an increase in sea-buckthorn cover in the young dune areas since 1959, while over time the population in the old dunes decreased due to successional replacement by other species. With the increasing age of the young dunes, we found also a decrease in sea-buckthorn after 2009. However the sharp decrease indicated that other environmental factors were also involved. The most important determinant of annual shrub growth appeared to be five outbreaks of the brown-tail moth (Euproctis chrysorrhoea L.), in the last decade. Relative sea-level rise caused more frequent flooding and reduced growth at lower elevations due to inundation or soil water saturation. This study clearly indicates that sea-buckthorn is affected by relative sea-level rise, but that other ecological events better explain its variation in growth. Although shrub distribution and growth can be monitored with robust methods, future predictions of vegetation dynamics are complicated by unpredictable extreme events caused by (a)biotic stressors such as insect outbreaks.

Diversity in sea buckthorn (Hippophae rhamnoides L.) accessions with different origins based on morphological characteristics, oil traits, and microsatellite markers.

Sea buckthorn (Hippophae rhamnoides) is an ecologically and economically important species. Here, we assessed the diversity of 78 accessions cultivated in northern China using 8 agronomic characteristics, oil traits (including oil content and fatty acid composition) in seeds and fruit pulp, and SSR markers at 23 loci. The 78 accessions included 52 from ssp. mongolica, 6 from ssp. sinensis, and 20 hybrids. To assess the phenotypic diversity of these accessions, 8 agronomic fruit traits were recorded and analyzed using principal component analysis (PCA). The first two PCs accounted for approximately 78% of the variation among accessions. The oil contents were higher in pulp (3.46-38.56%) than in seeds (3.88-8.82%), especially in ssp. mongolica accessions. The polyunsaturated fatty acid (PUFA) ratio was slightly lower in the seed oil of hybrids (76.06%) than that of in ssp. mongolica (77.66%) and higher than that of in ssp. sinensis (72.22%). The monounsaturated fatty acid (MUFA) ratio in the pulp oil of ssp. sinensis (57.00%) was highest, and that in ssp. mongolica (51.00%) was equal to the ratio in the hybrids (51.20%). Using canonical correspondence analysis (CCA), we examined the correlation between agronomic traits and oil characteristics in pulp and seeds. Oil traits in pulp from different origins were correlated with morphological groupings (r = 0.8725, p = 0.0000). To assess the genotypic diversity, 23 SSR markers (including 17 loci previously reported) were used among the 78 accessions with 59 polymorphic amplified fragments obtained and an average PIC value of 0.2845. All accessions were classified into two groups based on the UPGMA method. The accessions of ssp. sinensis and ssp. mongolica were genetically distant. The hybrid accessions were close to ssp. mongolica accessions. The 8 agronomic traits, oil characteristics in seed and pulp oils, and 23 SSR markers successfully distinguished the 78 accessions. These results will be valuable for cultivar identification and genetic diversity analysis in cultivated sea buckthorn.

Untargeted metabolic fingerprinting reveals impact of growth stage and location on composition of sea buckthorn (Hippophaë rhamnoides) leaves.

Sea buckthorn (Hippophaë rhamnoides) is increasingly cultivated to produce raw materials for food and nutraceuticals. There is little knowledge on composition of sea buckthorn leaves (SBLs) and the key factors influencing the composition. This research aims to unravel the metabolic profile of SBLs and the effects of cultivar, location and stage of growth, and climatic conditions on the metabolic profile of SBLs. Leaves of two sea buckthorn cultivars grown in the south and north of Finland during two consecutive growth seasons were studied using untargeted nuclear magnetic resonance (NMR) metabolomics. The highest variance in the metabolic profile was linked to the growth stage, wherein leaves from the first 7 weeks of harvest were characterized with higher abundance of polyphenols, while relatively higher abundance of carbohydrates and sugars was observed in the later weeks. The growth location attributed for the second highest variation, wherein the north-south comparison identified fatty acids and sugars as discriminatory metabolites, and the potential association of metabolome to natural abiotic stressors was revealed. An inverse correlation between carbohydrate/sugar content as well as fatty acids of higher carbon chain length with the temperature variables was evident. The supervised chemometric models with high sensitivity and specificity classified and predicted the samples based on growth stage and location, and cultivar. Nontargeted NMR-metabolomics revealed the metabolic profile of SBLs and their variation associated with various biotic and abiotic factors. Cultivar and growth stage are key factors to consider when harvesting SBLs for use in food and nutraceuticals. PRACTICAL APPLICATION: Globally, sea buckthorn cultivation has been rapidly increasing due to the known health-promoting benefits of the berries and leaves of the plant. The current research obtained new comprehensive information on the compositional profile of sea buckthorn leaves as well as the impact of major contributory factors, such as cultivars, the advancement of growth stage, geographical location, and weather parameters. The findings of this research provide new knowledge and guidance for plant breeding, cultivation and commercial utilization of sea buckthorn leaves as raw materials for food, feed, and nutraceuticals.

RNA-seq data reveals a coordinated regulation mechanism of multigenes involved in the high accumulation of palmitoleic acid and oil in sea buckthorn berry pulp.

BACKGROUND: Sea buckthorn is a woody oil crop in which palmitoleic acid (C16:1n7, an omega-7 fatty acid (FA)) contributes approximately 40% of the total FA content in berry pulp (non-seed tissue). However, the molecular mechanisms contributing to the high accumulation of C16:1n7 in developing sea buckthorn berry pulp (SBP) remain poorly understood. RESULTS: We identified 1737 unigenes associated with lipid metabolism through RNA-sequencing analysis of the four developmental stages of berry pulp in two sea buckthorn lines, 'Za56' and 'TF2-36'; 139 differentially expressed genes were detected between the different berry pulp developmental stages in the two lines. Analyses of the FA composition showed that the C16:1n7 contents were significantly higher in line 'Za56' than in line 'TF2-36' in the mid-late developmental stages of SBP. Additionally, qRT-PCR analyses of 15 genes involved in FA and triacylglycerol (TAG) biosynthesis in both lines revealed that delta9-ACP-desaturase (ACP-Δ9D) competed with 3-ketoacyl-ACP-synthase II (KASII) for the substrate C16:0-ACP and that ACP-Δ9D and delta9-CoA-desaturase (CoA-Δ9D) gene expression positively correlated with C16:1n7 content; KASII and fatty acid elongation 1 (FAE1) gene expression positively correlated with C18:0 content in developing SBP. Specifically, the abundance of ACP-Δ9D and CoA-Δ9D transcripts in line 'Za56', which had a higher C16:1n7 content than line 'TF2-36', suggests that these two genes play an important role in C16:1n7 biosynthesis. Furthermore, the high expressions of the glycerol-3-phosphate dehydrogenase (GPD1) gene and the WRINKLED1 (WRI1) transcription factor contributed to increased biosynthesis of TAG precursor and FAs, respectively, in the early developmental stages of SBP, and the high expression of the diacylglycerol O-acyltransferase 1 (DGAT1) gene increased TAG assembly in the later developmental stages of SBP. Overall, we concluded that increased ACP-Δ9D and CoA-Δ9D levels coupled with decreased KASII and FAE1 activity is a critical event for high C16:1n7 accumulation and that the coordinated high expression of WRI1, GPD1, and DGAT1 genes resulted in high oil accumulation in SBP. CONCLUSION: Our results provide a scientific basis for understanding the mechanism of high C16:1n7 accumulation in berry pulp (non-seed tissue) and are valuable to the genetic breeding programme for achieving a high quality and yield of SBP oil.

Unusual isovalerylated flavonoids from the fruit of sea buckthorn (Elaeagnus rhamnoides) grown in Sokólka, Poland.

Eight undescribed isorhamnetin glycosides, acylated with isovaleric acid were isolated from the fruit of sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson). Structures of the purified compounds were determined using one and two-dimensional NMR spectroscopy, mass spectrometry and chemical methods. In addition, the cytotoxic activity of the phenolic-rich fraction of sea buckthorn fruit and its major flavonoids against colon cell lines, HT-29, HCT-116 and Caco-2, was determined. While the phenolic fraction was moderately active against HT-29 and HCT-116, all investigated purified flavonoids showed significantly weaker activity. This is most probably the first report about isorhamnetin glycosides acylated with isovaleric acid.

Tandem Mass Tag Based Quantitative Proteomics of Developing Sea Buckthorn Berries Reveals Candidate Proteins Related to Lipid Metabolism.

Sea buckthorn ( Hippophae L.) is an economically important shrub or small tree distributed in Eurasia. Most of its well-recognized medicinal and nutraceutical products are derived from its berry oil, which is rich in monounsaturated omega-7 (C16:1) fatty acid and polyunsaturated omega-6 (C18:2) and omega-3 (C18:3) fatty acids. In this study, tandem mass tags (TMT)-based quantitative analysis was used to investigate protein profiles of lipid metabolism in sea buckthorn berries harvested 30, 50, and 70 days after flowering. In total, 8626 proteins were identified, 6170 of which were quantified. Deep analysis results for the proteins identified and related pathways revealed initial fatty acid accumulation during whole-berry development. The abundance of most key enzymes involved in fatty acid and triacylglycerol (TAG) biosynthesis peaked at 50 days after flowering, but TAG synthesis through the PDAT (phospholipid: diacylglycerol acyltransferase) pathway mostly occurred early in berry development. In addition, the patterns of proteins involved in lipid metabolism were confirmed by combined quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and parallel reaction monitoring analyses. Our data on the proteomic spectrum of sea buckthorn berries provide a scientific basic for understanding lipid metabolism and related pathways in the developing berries.

Occurrence of subdioecy and scarcity of gender-specific markers reveal an ongoing transition to dioecy in Himalayan seabuckthorn (Hippophae rhamnoides ssp. turkestanica).

Dioecy and the dynamics of its evolution are intensely investigated aspects of plant reproduction. Seabuckthorn (Hippophae rhamnoides ssp. turkestanica) is an alpine shrub growing wild in certain parts of western Himalaya. The previous studies have reported heteromorphic sex chromosomes in the species and yet marker-based studies indicate high similarity between the male and female genomes. Lack of information on sexual system in the species has further complicated the situation. A systematic study was thus undertaken to understand the sexual system in seabuckthorn and to discern the extent of similarity/dissimilarity between the male and female genomes by generating a large number of markers using amplified fragment length polymorphism and representational difference analysis. Floral biology and regular monitoring of species revealed the presence of polygamomonoecious (PGM) plants in most populations at a low percentage (~2-4%). PGM plants showed low pollen production and overall low fertility, suggesting a monoecy-paradioecy pathway at function. The results of the marker study demonstrated that there are limited differences between male and female genomes and these differences were not uniform across the populations in the Leh-Ladakh region, especially when the geographical distance increases. Results also suggest that a dynamic partitioning of genomes is operational between the two genders of seabuckthorn and differences are not homogenized across the populations. Both reproductive biology-based and DNA marker-based studies indicate that genders have separated recently. The present study proposes seabuckthorn as a promising model system to study evolution of dioecy and sex determination.

ISSR markers for gender identification and genetic diagnosis of Hippophae rhamnoides ssp. turkestanica growing at high altitudes in Ladakh region (Jammu and Kashmir).

Hippophae rhamnoides L. ssp. turkestanica (Elaeagnaceae) is a predominantly dioecious and wind-pollinated medicinal plant species. The mature fruits of the species possess antioxidative, anti-inflammatory, antimicrobial, anticancerous, and antistimulatory properties that are believed to improve the immune system. The identification of male and female plants in H. rhamnoides ssp. turkestanica is quite difficult until flowering which usually takes 3-4 years or more. A sex-linked marker can be helpful in establishing the orchards through identification of genders at an early stage of development. Therefore, we studied the genetic diversity of populations in Ladakh with the aim to identify a gender-specific marker using ISSR markers. Fifty-eight ISSR primers were used to characterize the genome of H. rhamnoides ssp. turkestanica, of which eight primers generated 12 sex-specific fragments specific to one or more populations. The ISSR primer (P-45) produced a fragment which faithfully segregates all the males from the female plants across all the three valleys surveyed. This male-specific locus was converted into a SCAR. Forward and reverse primers designed from this fragment amplified a 750-bp sequence in males only, thus specifying it as an informative male-specific sex-linked marker. This SCAR marker was further validated for its capability to differentiate gender on an additional collection of plants, representing three geographically isolated valleys (Nubra, Suru, and Indus) from Ladakh region of India. The results confirmed sex-linked specificity of the marker suggesting that this conserved sequence at the Y chromosome is well preserved through the populations in Ladakh region. At present, there are no reliable markers which can differentiate male from female plants across all the three valleys of Ladakh region at an early stage of plant development. It is therefore envisaged that the developed SCAR marker shall provide a reliable molecular tool for early identification of the sex in this commercial crop. The genetic diversity of populations as surveyed by ISSR primers revealed 85.71 % polymorphism at the population level. The dendrogram obtained divided the genotypes into three different clusters, and the distribution of male and female genotypes in all the clusters was random. The Nei's genetic similarity index was in the range of 0.63-0.96.

Effects of latitude and weather conditions on proanthocyanidins in berries of Finnish wild and cultivated sea buckthorn (Hippophaë rhamnoides L. ssp. rhamnoides).

Sea buckthorn (Hippophaë rhamnoides ssp. rhamnoides) of varieties 'Terhi' and 'Tytti' and one of wild origin were cultivated in southern and northern Finland, harvested during 2007-2013. Proanthocyanidins (PAs) were analyzed with HILIC UPLC-ESI-MS. The southern and northern samples were separated in the partial least squares discriminant analysis model (four factors, R(2) 0.75, Q(2) 0.70). The total PAs were more abundant in berries from the north (610-970mg/100gDW) than in those from the south (340-450mg/100gDW) (p<0.05). In northern Finland, the length of the growth season as well as the temperature sum and radiation sum of the growth season until harvest were negatively correlated with the total PAs in all the samples but positively with PA oligomers in 'Tytti' and 'Terhi'. In southern Finland no respective correlations were seen. 'Terhi' and 'Tytti' had different trends in the content of total PA and oligomers in overripe stages.

[Difference of anti-fracture mechanical characteristics between lateral-root branches and adjacent upper straight roots of four plant species in vigorous growth period].

Taking four plant species, Caragana korshinskii, Salix psammophila, Hippophae rhamnides and Artemisia sphaerocephala, which were 3-4 years old and in vigorous growth period, as test materials, the anti-fracture forces of lateral-root branches and adjacent upper straight roots were measured with the self-made fixture and the instrument of TY 8000. The lateral-root branches were vital and the diameters were 1-4 mm. The results showed that the anti-fracture force and anti-fracture strength of lateral-root branches were lesser than those of the adjacent upper straight roots even though the average diameter of lateral-root branches was greater. The ratios of anti-fracture strength of lateral-root branches to the adjacent upper straight roots were 71.5% for C. korshinskii, 62.9% for S. psammophila, 45.4% for H. rhamnides and 35.4% for A. sphaerocephala. For the four plants, the anti-fracture force positively correlated with the diameter in a power function, while the anti-fracture strength negatively correlated with diameter in a power function. The anti-fracture strengths of lateral-root branches and adjacent upper straight roots for the four species followed the sequence of C. korshinskii (33.66 and 47.06 MPa) > S. psammophila (17.31 and 27.54 MPa) > H. rhamnides (3.97 and 8.75 MPa) > A. sphaerphala (2.18 and 6.15 MPa).

Sea Buckthorn (Hippophaë rhamnoides ssp. rhamnoides) Berries in Nordic Environment: Compositional Response to Latitude and Weather Conditions.

Flavonol glycosides (FGs) in sea buckthorn (Hippophaë rhamnoides ssp. rhamnoides) berries of varieties 'Tytti' and 'Terhi', cultivated in northern Finland (68°02' N) for six years and southern Finland (60°23' N) for seven years, were investigated and compared by HPLC-DAD-ESI-MS/MS. The average total content of 23 identified glycosides of isorhamnetin and quercetin was 103 ± 23 and 110 ± 21 mg/100 g fresh berries in 'Terhi' and 'Tytti', respectively. The total contents of FGs, flavonol diglycosides, and triglycosides in both varieties were higher in the north than in the south, whereas total flavonol monoglycoside content behaved vice versa (p < 0.05). Among the 89 weather variables studied, the sum of the daily mean temperatures that are 5 °C or higher from the start of growth season until the day of harvest was the most important variable which associated negatively with the accumulation of FGs in berries. Such influence was much stronger in berries from the north than from the south.

Flavonol glycosides in berries of two major subspecies of sea buckthorn (Hippophaë rhamnoides L.) and influence of growth sites.

Flavonol glycosides of wild sea buckthorn (Hippophaë rhamnoides ssp. sinensis) berries from China and cultivated berries (H. rhamnoides ssp. mongolica) from Finland and Canada were identified and quantified. Twenty-six flavonol glycosides were found with isorhamnetin and quercetin as the major aglycones. The contents of flavonol glycosides ranged 23-250 mg/100 g fresh berries and were significantly higher in the berries of ssp. sinensis than in those of ssp. mongolica. Among the cultivars of ssp. mongolica, the berries of 'Oranzhevaya' had the lowest (23 mg/100 g) content, and those of 'Prevoshodnaya' the highest content of flavonol glycosides (80 mg/100 g). Within the ssp. mongolica, the samples from Kittilä (Northern Finland) had higher levels of most flavonol glycosides than those from Turku (Southern Finland) and Québec. Among the ssp. sinensis berries of different growth sites, increasing trends were detected in the contents of most of the compounds as the altitude increased and as the latitude decreased. The wild berries (ssp. sinensis) from Sichuan had remarkably high contents and unique profiles of flavonol glycosides.

Metabolite profiling and expression analysis of flavonoid, vitamin C and tocopherol biosynthesis genes in the antioxidant-rich sea buckthorn (Hippophae rhamnoides L.).

In this study, phenolic compounds were analyzed in developing berries of four Canadian grown sea buckthorn (Hippophae rhamnoides L.) cultivars ('RC-4', 'E6590', 'Chuyskaya' and 'Golden Rain') and in leaves of two of these cultivars. Among phenolic acids, p-coumaric acid was the highest in berries, while gallic acid was predominant in leaves. In the flavonoid class of compounds, myricetin/rutin, kaempferol, quercetin and isorhamnetin were detected in berries and leaves. Berries of the 'RC-4' cultivar had approximately ⩾ 2-fold higher levels of myricetin and quercetin at 17.5mg and 17.2 mg/100 g FW, respectively, than the other cultivars. The flavonoid content in leaves was considerably more than in berries with rutin and quercetin levels up to 135 mg and 105 mg/100 g FW, respectively. Orthologs of 15 flavonoid biosynthesis pathway genes were identified within the transcriptome of sea buckthorn mature seeds. Semi-quantitative RT-PCR analysis of these genes in developing berries indicated relatively higher expression of genes such as CHS, F3'H, DFR and LDOX in the 'RC-4' cultivar than in the 'Chuyskaya' cultivar. Vitamin C levels in ripened berries of the Canadian cultivars were on the high end of the concentration range reported for most other sea buckthorn cultivars. Orthologs of genes involved in vitamins C and E biosynthesis were also identified, expanding the genomic resources for this nutritionally important plant.

Sex-Biased Temporal Gene Expression in Male and Female Floral Buds of Seabuckthorn (Hippophae rhamnoides).

Seabuckthorn is an economically important dioecious plant in which mechanism of sex determination is unknown. The study was conducted to identify seabuckthorn homologous genes involved in floral development which may have role in sex determination. Forty four putative Genes involved in sex determination (GISD) reported in model plants were shortlisted from literature survey, and twenty nine seabuckthorn homologous sequences were identified from available seabuckthorn genomic resources. Of these, 21 genes were found to differentially express in either male or female flower bud stages. HrCRY2 was significantly expressed in female flower buds only while HrCO had significant expression in male flowers only. Among the three male and female floral development stages (FDS), male stage II had significant expression of most of the GISD. Information on these sex-specific expressed genes will help in elucidating sex determination mechanism in seabuckthorn.

Effect of monospecific and mixed sea-buckthorn (Hippophae rhamnoides) plantations on the structure and activity of soil microbial communities.

This study aims to evaluate the effect of different afforestation models on soil microbial composition in the Loess Plateau in China. In particular, we determined soil physicochemical properties, enzyme activities, and microbial community structures in the top 0 cm to 10 cm soil underneath a pure Hippophae rhamnoides (SS) stand and three mixed stands, namely, H. rhamnoides and Robinia pseucdoacacia (SC), H. rhamnoides and Pinus tabulaeformis (SY), and H. rhamnoides and Platycladus orientalis (SB). Results showed that total organic carbon (TOC), total nitrogen, and ammonium (NH4(+)) contents were higher in SY and SB than in SS. The total microbial biomass, bacterial biomass, and Gram+ biomass of the three mixed stands were significantly higher than those of the pure stand. However, no significant difference was found in fungal biomass. Correlation analysis suggested that soil microbial communities are significantly and positively correlated with some chemical parameters of soil, such as TOC, total phosphorus, total potassium, available phosphorus, NH4(+) content, nitrate content (NH3(-)), and the enzyme activities of urease, peroxidase, and phosphatase. Principal component analysis showed that the microbial community structures of SB and SS could clearly be discriminated from each other and from the others, whereas SY and SC were similar. In conclusion, tree species indirectly but significantly affect soil microbial communities and enzyme activities through soil physicochemical properties. In addition, mixing P. tabulaeformis or P. orientalis in H. rhamnoides plantations is a suitable afforestation model in the Loess Plateau, because of significant positive effects on soil nutrient conditions, microbial community, and enzyme activities over pure plantations.

¹H NMR spectroscopy reveals the effect of genotype and growth conditions on composition of sea buckthorn (Hippophaë rhamnoides L.) berries.

¹H NMR spectroscopy and multivariate data analysis were applied to the metabolic profiling and discrimination of wild sea buckthorn (Hippophaë rhamnoides L.) berries from different locations in Finland (subspecies (ssp.) rhamnoides) and China (ssp. sinensis). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) showed discrimination of the two subspecies and different growth sites. The discrimination of ssp. rhamnoides was mainly associated with typically higher temperature, radiation and humidity and lower precipitation in the south, yielding higher levels of O-ethyl ß-d-glucopyranoside and d-glucose, and lower levels of malic, quinic and ascorbic acids. Significant metabolic differences (p<0.05) in genetically identical berries were observed between latitudes 60° and 67° north in Finland. High altitudes (> 2,000 m) correlated with greater levels of malic and ascorbic acids in ssp. sinensis. The NMR metabolomics approach applied here is effective for identification of metabolites, geographical origin and subspecies of sea buckthorn berries.

[Response of sloping water erosion to rainfall and micro-earth pattern in the loess hilly area].

Severe water erosion in the key loess hilly area is affected by the coupling role of rainfall and earth surface features. In this study, rainfall simulation techniques at the micro-plot scale (1.2 m x 1.2 m; 2 m x 1.2 m) was used as the basic measures, the relations between rainfall depth, intensity and runoff-erosion under different plant morphology features as well as micro-landscape positions were quantified and analyzed. Several key findings were captured. Firstly, rainfall depth and intensity both affected water erosion significantly, while the role of the rainfall intensity was more important than that of the depth. Secondly, a strong negative correlation was found between the antecedent soil moisture content and the generation timing of surface runoff, while water erosion had a positive relation with the antecedent soil moisture. Thirdly, different plant morphology and micro-landscape positions of shrub plant (seabuckthorn) played different roles leading to different rates of surface runoff and soil erosion. Dominated by a rainfall intensity ranging from 50 to 60 mm x h(-1), runoff coefficient in those micro-plots covered by seabuckthorn was about 5%-8%, and changed into 25%, 45% and 63% in grassland-plots, bared plots covered by biological-crust and bared plots without any coverage, respectively. Fourthly, the specific landscape position of seabuckthorn in the plots was also found to play a key role in affecting water erosion processes, and seabuckthorn at the lower landscape position, rather than the upper and middle position, played a better buffering role in reducing runoff and soil loss.

Fatty acid composition of developing sea buckthorn (Hippophae rhamnoides L.) berry and the transcriptome of the mature seed.

BACKGROUND: Sea buckthorn (Hippophae rhamnoides L.) is a hardy, fruit-producing plant known historically for its medicinal and nutraceutical properties. The most recognized product of sea buckthorn is its fruit oil, composed of seed oil that is rich in essential fatty acids, linoleic (18:2 ω-6) and α-linolenic (18:3 ω-3) acids, and pulp oil that contains high levels of monounsaturated palmitoleic acid (16:1 ω-7). Sea buckthorn is fast gaining popularity as a source of functional food and nutraceuticals, but currently has few genomic resources; therefore, we explored the fatty acid composition of Canadian-grown cultivars (ssp. mongolica) and the sea buckthorn seed transcriptome using the 454 GS FLX sequencing technology. RESULTS: GC-MS profiling of fatty acids in seeds and pulp of berries indicated that the seed oil contained linoleic and α-linolenic acids at 33-36% and 30-36%, respectively, while the pulp oil contained palmitoleic acid at 32-42%. 454 sequencing of sea buckthorn cDNA collections from mature seeds yielded 500,392 sequence reads, which identified 89,141 putative unigenes represented by 37,482 contigs and 51,659 singletons. Functional annotation by Gene Ontology and computational prediction of metabolic pathways indicated that primary metabolism (protein>nucleic acid>carbohydrate>lipid) and fatty acid and lipid biosynthesis pathways were highly represented categories. Sea buckthorn sequences related to fatty acid biosynthesis genes in Arabidopsis were identified, and a subset of these was examined for transcript expression at four developing stages of the berry. CONCLUSION: This study provides the first comprehensive genomic resources represented by expressed sequences for sea buckthorn, and demonstrates that the seed oil of Canadian-grown sea buckthorn cultivars contains high levels of linoleic acid and α-linolenic acid in a close to 1:1 ratio, which is beneficial for human health. These data provide the foundation for further studies on sea buckthorn oil, the enzymes involved in its biosynthesis, and the genes involved in the general hardiness of sea buckthorn against environmental conditions.

Effects of genotype, latitude, and weather conditions on the composition of sugars, sugar alcohols, fruit acids, and ascorbic acid in sea buckthorn (Hippophaë rhamnoides ssp. mongolica) berry juice.

Sea buckthorn berries (Hippophaë rhamnoides ssp. mongolica) of nine varieties were collected from three growth locations in five inconsecutive years (n = 152) to study the compositional differences of sugars, sugar alcohols, fruit acids, and ascorbic acid in berries of different genotypes. Fructose and glucose (major sugars) were highest in Chuiskaya and Vitaminaya among the varieties studied, respectively. Malic acid and quinic acid (major acids) were highest in Pertsik and Vitaminaya, respectively. Ascorbic acid was highest in Oranzhevaya and lowest in Vitaminaya. Berry samples of nine varieties collected from two growth locations in five years (n = 124) were combined to study the effects of latitude and weather conditions on the composition of H. rhamnoides ssp. mongolica. Sea buckthorn berries grown at lower latitude had higher levels of total sugar and sugar/acid ratio and a lower level of total acid and were supposed to have better sensory properties than those grown at higher latitude. Glucose, quinic acid, and ascorbic acid were hardly influenced by weather conditions. The other components showed various correlations with temperature, radiation, precipitation, and humidity variables. In addition, fructose, sucrose, and myo-inositol correlated positively with each other and showed negative correlation with malic acid on the basis of all the samples studied (n = 152).