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Yellowhorn ( Bunge) has been widely planted for biodiesel production in China, but has frequently shown poor field performance. Container-grown yellowhorn seedlings originating from three Chinese provenances, Wengniute Qi (WQ), Alukeerqin Qi (AQ), and Shanxian (SX), were fertilized with slow-release fertilizer (SRF) at 40, 80, 120, 160 or 200 mg N seedling. Tree growth, survival and nutrient content were measured after one yearâs growth in a greenhouse followed by two years in a field site. Plants from AQ and SX tended to have higher stem and root P contents in the nursery. Higher rates of SRF increased root N, and stem and root P contents. After one year in the nursery, there were a number of interactions between provenance and SRF for plant growth responses and nutrient content in the nursery, however after two years of additional growth in the field, plants from the different provenances generally responded similarly to applied SRF in the nursery, with few interactions. Final plant height was approximately 10% lower in trees from provenance SX but was not affected by application of SRF. Conversely, final trunk diameter and stem and root biomass were unaffected by provenance but increased with higher rates of applied SRF. Our results indicate that application of SRF may be a useful tool to nutrient load yellowhorn in the nursery and facilitate transplanting performance in the field. Overall, optimal nursery and field performance of yellowhorn were observed in provenance AQ at 120â200 mg N seedling SRF. We suggest that growers consider a wider range of yellowhorn provenances and SRF rates (above 200 mg N seedling) to yield even better growth response.Xanthoceras sorbifoliumâ1â1â1

Although controlled release fertilizer (CRF) with single and multiple-layer coatings are extensively used in tree seedlings, studies that compare the impact of CRF type and application rate on seedling growth, nutrient storage, and, most importantly, outplanting performance, are lacking. In the current study, container-grown Carr. (Chinese pine) seedlings were fertilized with commercial CRF with either one or multiple coating layers with equivalent formulation and longevity, at six rates ranging from 40 to 240 mg N seedling. Seedlings were sampled for dry mass, non-structural carbohydrate (NSC) content, and mineral nutrient status at the end of the growing season in the nursery, and subsequently outplanted for one season. Compared to Chinese pine seedlings fertilized with single-layer CRF treatments, seedlings treated with multiple-layer CRF had higher starch concentrations but reduced dry mass and N, P, K concentrations in the nursery, and reduced diameter growth in the field. Fertilization rates of 80 and 120 mg N seedling generally yielded maximal plant dry mass and mineral nutrient content. Field survival peaked at 80 mg N seedling. Seedling growth, soluble sugar content, and starch concentration in the nursery and survival in the field consistently decreased at rates of 200 and 240 mg N seedling. In our study, optimal nursery and field performance of were observed using single layer CRF at 80 mg N seedling (3.3 g CRF l media).Pinus tabulaeformisâ1â1â1â1P. tabulaeformisâ1â1

Optimum fertilization levels are often determined solely from nursery growth responses. However, it is the performance of the seedling on the outplanting site that is the most important. For species seedlings, little information is known about the field performance of plants cultured with different nutrient rates, especially with exponential fertilization. In this study, Chinese pine ( Carr.) seedlings grown in 187 ml containers were fertilized exponentially in 6 treatments ranging from 10 to 120 mg N seedling for 25 weeks before outplanting. Dry mass and N content were measured at planting. Survival and field growth were monitored for two growing seasons. In the nursery, our data showed no difference in dry mass among the 40, 80, 100, and 120 mg N seedling fertilizer treatments; collectively, these treatments were significantly greater than at 10 and 20 mg N seedling treatments. Seedling N content was greatest for the 100 and 120 mg N seedling rates. These data suggested that nursery optimum N fertilization rate was no less than 100 mg N seedling. Outplanting height and root-collar diameter growth characteristics were not significantly different after two years, whereas maximum mean survival was best for seedlings nursery-fertilized at 80 mg N seedling. In consideration of both nursery and field performance metrics, our data suggest that exponentially fertilizing Chinese pine seedlings at 80 mg N seedling maximizes both nursery biomass accumulation and outplanting survival.Pinus Pinus tabulaeformisâ1â1â1â1â1â1â1

Thinning alters litter quality and microclimate under forests. Both of these two changes after thinning induce alterations of litter decomposition rates and nutrient cycling. However, a possible interaction between these two changes remains unclear. We placed two types of litter (LN, low N concentration litter; HN, high N concentration litter) in a Chinese pine ( Carrière) plantation under four thinning treatments to test the impacts of litter quality, thinning or their combination on decomposition rate and N cycling. In our study, N was accumulated to approach an underlying critical acid-unhydrolyzable residue to nitrogen ratio (approximately 57â69) in litter. Moreover, an interaction between litter quality and thinning on decomposition rates, N accumulation and net release did exist. On one hand, one year decomposition rate of LN was elevated after thinning while that of HN remained the same or even lower (under light thinning); N accumulation of LN declined with light thinning and was restored with the increase of thinning intensity whereas that of HN did not decline with thinning and increased under heavy thinning; Net N release from LN was only found in light and heavy thinning while that from HN was found in all treatments, moreover net N release from LN and HN were both elevated under heavy thinning. On the other hand, HN decomposed faster, accumulated less and released more N than LN did under all treatments. Generally, high N concentration in litter and high-intensity thinning can lead to rapid litter decomposition and N cycling in coniferous plantations.Pinus tabulaeformis

Nursery response of evergreen trees to fall fertilization has been studied widely, but little attention has been given to deciduous trees. Bareroot Olga Bay larch (Larix olgensis Henry) seedlings were fertilized in the nursery with urea at four rates (0, 30, 60, 90 kg N ha), with half of each rate applied on two dates (September 16 and October 1, 2009). The seedlings were excavated for evaluation on October 15. In the unfertilized (control) treatment, root and shoot dry mass increased by 100% and 57% respectively, while N concentration in the roots and shoots increased by 43% and 40% during the 30 day period. This indicated that substantial biomass growth during this period did not lead to internal nutrient dilution. Root dry mass increased when fall fertilization rates were ⥠60 kg N ha. Fall fertilization increased N concentrations in root tissue by 48â73%. Compared with the control, shoot tissues of fall fertilized seedlings had slightly higher N concentration and content and significantly higher frost hardiness.â1â1

A progressive decline in tree growth may be induced by global warming, affecting tree health and eventually resulting in death, particularly for trees growing in rocky mountainous regions where seasonal droughts have become more pronounced. However, tree growth dynamics in areas experiencing pronounced climate change have received little attention. In this study, a total of 100 (10 m × 10 m) grid plots were investigated in planted forests of Chinese cork oak (Quercus variabilis Blume), which were established in the 1960s and 1970s in a rocky mountainous area near Beijing, northern China. Furthermore, the radial growth of Q. variabilis (a total of 843 trees sampled from the dominant [D], co-dominant [CD], and suppressed [S] crown classes) was analyzed using retrospective dendrochronology and generalized additive models. The effects of meteorological changes between 1962 and 2020 on radial growth across the three crown classes were examined using correlation analysis. The results indicated that the growth of Q. variabilis initially increased and then decreased after 2010 at the regional level, and these trends varied according to crown class. The radial growth of the D trees responded more positively to an increase in temperature and drought severity index (<0 for dry and >0 for wet conditions) compared with that of the CD and S trees. The growth of the D and CD trees continuously increased under higher temperatures during the rainy seasons (June to September); however, the increases were higher for D than for CD trees. In contrast, the radial growth of S trees declined. We confirmed the historical effects of rising temperatures on tree growth and health, which are linked to water availability. Our data suggested that Q. variabilis trees will be considerably affected by intensified droughts. This study furthers our knowledge regarding the impact of climate change on tree and forest growth and provides management strategies for afforestation projects in rocky mountainous areas that are facing climate change. [ABSTRACT FROM AUTHOR]

Summary: Hydrolyzable tannins (HTs), predominant polyphenols in oaks, are widely used in grape wine aging, feed additives, and human healthcare. However, the limited availability of a high‐quality reference genome of oaks greatly hampered the recognition of the mechanism of HT biosynthesis. Here, high‐quality reference genomes of three Asian oak species (Quercus variabilis, Quercus aliena, and Quercus dentata) that have different HT contents were generated.Multi‐omics studies were carried out to identify key genes regulating HT biosynthesis. In vitro enzyme activity assay was also conducted. Dual‐luciferase and yeast one‐hybrid assays were used to reveal the transcriptional regulation.Our results revealed that β‐glucogallin was a biochemical marker for HT production in the cupules of the three Asian oaks. UGT84A13 was confirmed as the key enzyme for β‐glucogallin biosynthesis. The differential expression of UGT84A13, rather than enzyme activity, was the main reason for different β‐glucogallin and HT accumulation. Notably, sequence variations in UGT84A13 promoters led to different trans‐activating activities of WRKY32/59, explaining the different expression patterns of UGT84A13 among the three species.Our findings provide three high‐quality new reference genomes for oak trees and give new insights into different transcriptional regulation for understanding β‐glucogallin and HT biosynthesis in closely related oak species. [ABSTRACT FROM AUTHOR]

Chinese cork oak (Quercus variabilis Blume) is a widespread tree species with high economic and ecological values. Chinese cork oak exhibits epicotyl dormancy, causing emergence heterogeneity and affecting the quality of seedling cultivation. Gibberellic acid-stimulated transcript (GAST) is a plant-specific protein family that plays a crucial regulatory role in plant growth, development, and seed germination. However, their evolution in Chinese cork oak and roles in epicotyl dormancy are still unclear. Here, a genome-wide identification of the GAST gene family was conducted in Chinese cork oak. Ten QvGAST genes were identified, and nine of them were expressed in seed. The physicochemical properties and promoter cis-acting elements of the selected Chinese cork oak GAST family genes indicated that the cis-acting elements in the GAST promoter are involved in plant development, hormone response, and stress response. Germinated seeds were subjected to gibberellins (GAs), abscisic acid (ABA), and fluridone treatments to show their response during epicotyl dormancy release. Significant changes in the expression of certain QvGAST genes were observed under different hormone treatments. QvGAST1, QvGAST2, QvGAST3, and QvGAST6 exhibited upregulation in response to gibberellin. QvGAST2 was markedly upregulated during the release of epicotyl dormancy in response to GA. These findings suggested that QvGAST2 might play an important role in epicotyl dormancy release. This study provides a basis for further analysis of the mechanisms underlying the alleviation of epicotyl dormancy in Chinese cork oak by QvGASTs genes. [ABSTRACT FROM AUTHOR]

It is hypothesized that 'hydraulic vulnerability segmentation' (the vulnerability of expendable organs is higher compared to the vulnerability of nonexpendable organs) can enhance the drought‐tolerance of trees. However, prediction of positive segmentation (leaf minus branch) did not gain undisputed support in field observations. Further, the main organs of trees (leaf/trunk/root) are vital to test the hypothesis at the individual level. Unfortunately, most verifications of the hypothesis focus on the hydraulic vulnerabilities between leaves and terminal branches of mature trees. In this study, we grew three deciduous oak (Quercus mongolica, Q. variabilis and Q. aliena) seedlings (6 months old), and measured the hydraulic vulnerabilities of leaves (by rehydration method), main stems and main roots (by bench dehydration method). The sensitivity of stomata to water potential was obtained by monitoring the stomata conductance response to drought stress. The xylem anatomy of main stem and main root was also measured. It was found that the leaves of all three oak species exhibited greater vulnerability than the main stems and main roots. The leaf‐stem segmentation was more pronounced than the stem‐root one, and the stem‐root in Q. aliena even showed a reversed segmentation. Further, we found that higher stomatal sensitivity was associated with higher P50,leaf (water potential at 50% loss of leaf hydraulic conductivity), and narrower segmentation between leaf and the most embolism‐resistant organ. Collectively, our results support the 'hydraulic vulnerability segmentation' hypothesis at the individual level, and highlight the importance of stomatal regulation in hydraulic vulnerability segmentation. [ABSTRACT FROM AUTHOR]

Shoot dieback is an important survival strategy in juvenile Quercus spp. However, it is unknown how nursery practices can influence the regulatory mechanisms of shoot dieback after planting. Furthermore, there is scarce information about the interactive effects between container depth and nursery fertilization on field seedling performance, and in combination with field weed control. Here, Quercus variabilis seedlings were cultivated the first year in with two container depths (25 cm, D40; 36 cm, D60) and with two nitrogen-loading levels (25, N25; 100 mg seedling−1, N100) in the nursery, and the following year, they were out-planted with/without weed elimination. We evaluated first year seedlings' functional traits after nursery culture (plant and root morphology and nutritional status) and second year field performance (survival, shoot dieback, growth and nutrient increments), and their relationship. Independently of nursery culture, weed management was an irreplaceable practice to optimize seedling field performance. Seedlings grown in deep containers (D60) showed enhanced field growth and nutrient acquisition and reduced shoot dieback. Fertilization increased N and K loading (content and concentration) in the nursery, but showed no effect in the field. Low quality seedlings (low fertilization and normal container) maintained high survival rates at the expense of increasing shoot dieback rate. Thus, field survival did not differ among seedlings with differing nursery practices. Together, deep container and high N fertilization, increased plant nutritional reserves (content) and improved root system development, consequently, mitigating field shoot dieback. Under our experimental conditions, improved seedling quality by the use of deep container (D60) was sufficient to optimize field seedling performance without weed competition. However, both, deep container and nitrogen loading (D60-N100) were the best nursery practices to optimize seedling success without weed control in the field. Our study highlights that shoot dieback is a paramount trade-off strategy between growth and survival, which should be considered as an important indicator for further evaluating seedling field performance. [ABSTRACT FROM AUTHOR]

To investigate the impact of topiramate versus flunarizine on the non-headache symptoms (NHS) of migraine, and to observe the changes of dopamine (DA) and prolactin (PRL) before and after prophylactic treatment. Sixty-six episodic migraine patients were enrolled and randomized 1:1 to receive either flunarizine or topiramate treatment. Clinical characteristics and NHS associated with migraine were investigated before and after prophylactic treatment. The DA and PRL levels were also determined before and after prophylactic treatment. The NHS of migraine in the two groups were significantly better after treatment than before treatment in premonitory phase (PP), headache phase (HP), and resolution phase (RP). The NHS in the two groups had no significant difference in PP, HP, and RP before and after treatment. In the flunarizine group, the PRL content after treatment was significantly higher than that before treatment (t = –4.097, p < 0.001), but the DA content was decreased slightly compared with that before treatment (t = 1.909, p = 0.066). There was no significant difference in PRL content (t = 1.099, p = 0.280) and DA content (t = 1.556, p = 0.130) in topiramate group before and after treatment. The two classical prophylactic drugs of migraine were significantly effective in treating the NHS of migraine, but there was no significant difference between the two drugs. The DA-PRL axis may be involved in the underlying mechanism of the flunarizine treatment for the NHS of migraine. [ABSTRACT FROM AUTHOR]