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Shoot growth, phonological period of flowering and fruiting, overwintering, fruit character and quality of 9 introduced Syzygiums arnarangense varieties (lines) were analyzed and compared for continuous 4 years and shoot growth, tree growth and fruiting habit were investigated to discuss adaptability of Syzygiums arnarangense in south subtropical climatic region of GuizhouProvince and to select suitable S'yzygiums arnarangense varieties (lines) with good quality and strong cold resistance for popularization and application of Syzygiums arnarangense in Southern Guizhou and other regions with the similar ecological conditions. The results showed that Heizhenzhu, Feidan and Daye varieties are of fast-growing, early maturity, stable yield, strong cold resistance and good quality in the introduction cultivation test in Southern Guizhou. [ABSTRACT FROM AUTHOR]

ABSTRACT Two-phase pomace represents an important environmental problem in Mediterranean areas. With its high organic content, direct application of two-phase pomace in the field is recommended to improve soil organic carbon levels and fertility. However, this does not consider any antagonistic effects that this application might have on root proliferation and biomass partitioning. We studied the effects of untreated two-phase pomace on properties of growth substrate, and on shoot and root growth and biomass allocation of potted olive plantlets. A pot experiment was carried out in a greenhouse over 90 days, with five levels of two-phase pomace and using two olive cultivars. The effects on shoot growth, leaf pigment content and maximum quantum efficiency of photosystem II ( ΦPSII) were assessed each month. After 90 days, the shoot and root biomass of the olive plants was quantified, along with total organic matter, and carbon, nitrogen and polyphenol contents of the growth substrate and shoots, and the fine root nutritional status. Two-phase pomace increased the total organic matter, total nitrogen and polyphenol contents of the growth substrate. It significantly altered biomass partitioning in the olive plantlets, with reduced shoot dry mass and leaf area, and new shoot formation. It also increased fine and total root dry mass for all two-phase pomace levels except 40%. There were no significant differences in leaf pigment content and ΦPSII across the treatment levels. Therefore, application of untreated two-phase pomace at more than 4% induces a severe imbalance in olive plantlet biomass partitioning, and shoot and root growth. [ABSTRACT FROM AUTHOR]

Current methods of in-house plant phenotyping are providing a powerful new tool for plant biology studies. The self-constructed and commercial platforms established in the last few years, employ non-destructive methods and measurements on a large and high-throughput scale. The platforms offer to certain extent, automated measurements, using either simple single sensor analysis, or advanced integrative simultaneous analysis by multiple sensors. However, due to the complexity of the approaches used, it is not always clear what such forms of plant phenotyping can offer the potential end-user, i.e. plant biologist. This review focuses on imaging methods used in the phenotyping of plant shoots including a brief survey of the sensors used. To open up this topic to a broader audience, we provide here a simple introduction to the principles of automated non-destructive analysis, namely RGB, chlorophyll fluorescence, thermal and hyperspectral imaging. We further on present an overview on how and to which extent, the automated integrative in-house phenotyping platforms have been used recently to study the responses of plants to various changing environments. [ABSTRACT FROM AUTHOR]

Even though the repetitive and decentralized nature of plant organogenesis confers a large plasticity to plants, their architecture is highly organized throughout ontogeny and at different scales. Growth, branching and flowering constitute the main processes leading to plant architectures and are key determinants of plant productivity, whatever the target product (biomass, flowers, seeds or fruits). Their genetic and genomic study is thus of great interest for breeding purpose. However, progresses have been limited by many constraints resulting from the large size and long-live of trees and therefore the difficult to assess phenotypes on large numbers of individuals for exploring both the genetic effect or genetic by environment interaction. Despite these limitations, significant advances have been recently obtained in quantitative genetics studies performed on architectural traits in forest and fruit trees, and on the physiological and molecular comprehension of mechanisms underlying plant architectural edification. Moreover, tools and methods for describing plant architectures and for exploring genetic and molecular controls have been improved, leading to new perspectives in terms of high-throughput genotyping, phenotyping and genomic studies. In this chapter, we review the genetic, physiological and molecular analyses that have been performed in the last years on tree architecture, with a particular focus on advances realized on tree crops. [ABSTRACT FROM AUTHOR]

Background: Recently emerging approaches to high-throughput plant phenotyping have discovered their importance as tools in unravelling the complex questions of plant growth, development and response to the environment, both in basic and applied science. High-throughput methods have been also used to study plant responses to various types of biotic and abiotic stresses (drought, heat, salinity, nutrient-starving, UV light) but only rarely to cold tolerance. Results: We present here an experimental procedure of integrative high-throughput in-house phenotyping of plant shoots employing automated simultaneous analyses of shoot biomass and photosystem II efficiency to study the cold tolerance of pea (Pisum sativum L.). For this purpose, we developed new software for automatic RGB image analysis, evaluated various parameters of chlorophyll fluorescence obtained from kinetic chlorophyll fluorescence imaging, and performed an experiment in which the growth and photosynthetic activity of two different pea cultivars were followed during cold acclimation. The data obtained from the automated RGB imaging were validated through correlation of pixel based shoot area with measurement of the shoot fresh weight. Further, data obtained from automated chlorophyll fluorescence imaging analysis were compared with chlorophyll fluorescence parameters measured by a non-imaging chlorophyll fluorometer. In both cases, high correlation was obtained, confirming the reliability of the procedure described. Conclusions: This study of the response of two pea cultivars to cold stress confirmed that our procedure may have important application, not only for selection of cold-sensitive/tolerant varieties of pea, but also for studies of plant cold-response strategies in general. The approach, provides a very broad tool for the morphological and physiological selection of parameters which correspond to shoot growth and the efficiency of photosystem II, and is thus applicable in studies of various plant species and crops. [ABSTRACT FROM AUTHOR]

The influence of red and blue light wavelengths was tested to improve the initial in vitro multiplication of apple (Malus X domestica) rootstock cultivars Budagovsky 9 (B.9), Geneva 30 (G.30), and Geneva 41 (G.41). Single-node segments were established in semisolid Murashige and Skoog media and then transferred to proliferation media and cultured 40 days under white, red, or blue light irradiance. In a second experiment, G.30 was cultured under red, blue, or white light with and without gibberellic acid (GA3). The three rootstocks responded similarly under w hite light in terms of shoot number, length of the longest shoot, and the number of elongated shoots. Red light increased the number of shoots, length of the longest shoot, and the number of elongated shoots of B.9 and G.30 when compared with white or blue light. Red light increased the number of elongated B.9 and G.30 shoots to five per explant compared with one per explant under white light. In contrast, shoot growth of G.41 showed no difference under the three light quality treatments, and the number of elongated shoots per explant was less than one. When compared with an absence of GA3 a concentration of GA3 at 0.5 mg⋅L-1 promoted in vitro shoot growth of G.30 under red and blue light. [ABSTRACT FROM AUTHOR]

Brassinosteroid activity controls plant growth and development, often in a seemingly opposing or complex manner. Differential impact of the hormone and its signalling components, acting both as promoters and inhibitors of organ growth, is exemplified by meristem differentiation and cell expansion in above- and below-ground organs. Complex brassinosteroid-based control of stomata count and lateral root development has also been demonstrated. Here, mechanisms underlying these phenotypic outputs are examined. Among these, studies uncovering core brassinosteroid signalling components, which integrate with distinct peptide, hormone, and environmental pathways, are reviewed. Finally, the differential spatiotemporal context of brassinosteroid activity within the organ, as an important determinant of controlled growth, is discussed. [ABSTRACT FROM AUTHOR]

The aim of this work was to examine the compatibility of different rootstocks with various wine grape varieties. In the first trial, Vitis vinifera L. cvs. Furmint, Regent, Riesling, Sauvignon Blanc, and Welschriesling were grafted onto Börner, 5BB and SO4 rootstocks. In the second trial Welschriesling was grafted on 12 rootstocks. Their growth during the first year in the vineyard was measured. As an index of compatibility, the percentage of first grade grafted vines as well as dry weight of mature shoots (canes) and roots was determined. After the grafts went through the first phase of healing often called callusing (2–3 weeks of moist warm conditions), the differences in callus formation were greater between years than among rootstocks, which were the most obvious with Furmint as a scion. No good callus formation occurred when cane (rootstock, scion) maturity is not adequate. Such was the case in 2005, there were 24% fewer grafts with fully developed callus than those in 2006. The dry weight of roots was higher on 5BB than on Börner and SO4. Börner rootstock had fewer roots, and the roots were thinner. Welschriesling had good compatibility with all rootstocks (the average grafts success was 67%), but that of 5BB, G251, and G103 (above 80%) was greater than the average. The G103 rootstock had the highest dry weight of roots. Shoot growth in vineyards was above the average with 5BB, SO4, Binova, Börner, and M V rootstocks. All Georgikon rootstocks had a lower cane dry weight per vine than the others. [ABSTRACT FROM AUTHOR]

A better understanding of crop growth and nutrient uptake responses to the depth of fertilizer banded-placement in the soil is needed if growth and nutrient uptake responses are to be maximized. A two-year field study covering two rape seasons (2010–2011 and 2011–2012) was conducted to examine the effect of banded-placement of N–P–K fertilizer at various depths on growth, nutrient uptake and yield of oilseed rape ( Brassica napus L.). The results showed that fertilization at 10 cm and 15 cm soil depth produced greater taproot length and dry weight than fertilization at 0 cm and 5 cm. 0 cm and 5 cm deep fertilization significantly increased the lateral root distribution at 0–5 cm soil depth, while 10 cm and 15 cm deep fertilization induced more lateral root proliferation at 5–15 cm soil depth. At 36 days after sowing (DAS), 5 cm deep fertilization produced better aboveground growth and nutrient uptake than 10 cm and 15 cm deep fertilization. However, reversed results were observed after 36 DAS. 10 cm and 15 cm deep fertilization produced more rapeseed than 0 cm and 5 cm deep fertilization, moreover, the yield difference was more significant in drought season (2010–2011) than in relatively normal season (2011–2012). In summary, these results preliminarily suggest that both 10 cm and 15 cm are relatively proper fertilizer placement depth when the practice of banding fertilizer is used in oilseed rape production. But from the viewpoint of diminishing the production cost, 10 cm deep fertilization should be recommended in actual farming. Because 15 cm deep fertilization may require higher mechanical power input, and thus resulting in higher cost of production. [ABSTRACT FROM AUTHOR]

There has been a dramatic recent increase in the understanding of the mechanisms by which plants detect their neighbors, 1 including by touch, 2 reflected light, 3 volatile organic chemicals, and root exudates. 4,5 The importance of root exudates remains ill-defined because of confounding experimental variables 6,7 and difficulties disentangling neighbor detection in shoot and roots. 8–10 There is evidence that root exudates allow distinction between kin and non-kin neighbors, 11–13 but identification of specific exudates that function in neighbor detection and/or kin recognition remain elusive. 1 Strigolactones (SLs), which are exuded into the soil in significant quantities in flowering plants to promote recruitment of arbuscular mycorrhizal fungi (AMF), 14 seem intuitive candidates to act as plant-plant signals, since they also act as hormones in plants, 15–17 with dramatic effects on shoot growth 18,19 and milder effects on root development. 20 Here, using pea, we test whether SLs act as either cues or signals for neighbor detection. We show that peas detect neighbors early in the life cycle through their root systems, resulting in strong changes in shoot biomass and branching, and that this requires SL biosynthesis. We demonstrate that uptake and detection of SLs exuded by neighboring plants are needed for this early neighbor detection, and that plants that cannot exude SLs are outcompeted by neighboring plants and fail to adjust growth to their soil volume. We conclude that plants both exude SLs as signals to modulate neighbor growth and detect environmental SLs as a cue for neighbor presence; collectively, this allows plants to proactively adjust their shoot growth according to neighbor density. • Pea plants detect neighbors through their root systems early in life • Strigolactone exudation by neighbors is needed for this response • Strigolactone exudation mutants are outcompeted by their neighbors • Environmental strigolactones thus act as cue for neighbor presence Wheeldon et al. show that pea plants change shoot growth in response to strigolactones exuded by neighboring plant roots. They show that plants that cannot exude strigolactones are outcompeted by neighbors and conclude that environmental strigolactones therefore act as a cue for neighbor presence in plants. [ABSTRACT FROM AUTHOR]

Reduced glutathione (GSH) is an abundant low molecular weight plant thiol. It fulfils multiple functions in plant biology, many of which remain poorly characterised. A phenomics approach was therefore used to investigate the effects of glutathione homeostasis on growth and stress tolerance in Arabidopsis thaliana. Rosette leaf area was compared in mutants that are either defective in GSH synthesis (cad2, pad2 and rax1) or the export of γ-glutamyl cysteine and GSH from the chloroplast (clt) and in wild type plants under standard growth conditions and following exposure to a range of abiotic stress treatments, including oxidative stress, water stress and high salt. In the absence of stress, the GSH synthesis mutants had a significantly lower leaf area than the wild type. Conversely, the clt mutant has a greater leaf area and a significantly reduced lateral root density than the wild type. These findings demonstrate that cellular glutathione homeostasis exerts an influence on root architecture and on rosette area. An impaired capacity to synthesise GSH or a specific depletion of the cytosolic GSH pool did not adversely affect leaf area in plants exposed to short term abiotic stress. However, the negative effects of long term exposure to oxidative stress and high salt on leaf area were less marked in the GSH synthesis mutants than the wild type. These findings demonstrate the importance of cellular glutathione homeostasis in the regulation of plant growth under optimal and stress conditions.

Stem or trunk girdling is a technique used in physiological studies and in horticultural practice for interrupting carbon flow through the phloem to other parts of the plant without influencing water flow in the xylem. Trunk girdling in peaches is practiced primarily to stimulate fruit growth but it also tends to decrease shoot vigour for a period of time after girdling. Water flow through the trunk or branches of peach trees is thought to be primarily dependent on the most recently formed ring of xylem and vegetative growth is closely related to stem water potential and stem hydraulic conductance. The aim of the present work was to determine whether vigour reduction due to girdling was correlated with a reduction in midday stem water potential during the period of time between girdling and the subsequent healing of stem tissue. 'Springcrest' peach trees were girdled on two different dates. Fruit yield and size, water sprout growth, proleptic shoot growth and stem water potential were measured. Early and late girdled trees yielded larger fruits and fewer and shorter water sprouts in comparison with control trees. Midday stem water potential declined significantly after girdling and gradually recovered until the time of fruit harvest. These results suggest that the vigour reduction of girdled trees is related to a decrease of midday stem water potential caused by girdling. Early tree girdling increased the reduction in midday stem water potential and shoot growth compared with the later girdling treatment. These results point out that even though girdling only removes bark and phloem tissue it can apparently affect water flow in xylem. Trunk girdling (horticultural practice used to increase fruit size) reduces vegetative shoot growth although there appears to be higher availability of carbohydrates above the girdle in girdled trees. This research indicates that early spring scaffold girdling decreased stem water potential above the girdle suggesting that early spring girdling not only influences phloem flow (that is interrupted by girdling) but also decreases xylem flow. The decreased stem water potentials appear to be directly related to reductions in vegetative shoot growth and explain why early spring girdling reduces shoot growth. It is hypothesized that early spring girdling affects xylem flow because the girdling process interrupts cambial activity and the production of new xylem however girdling may also influence root activity. [ABSTRACT FROM AUTHOR]

Plant growth regulators, such as hormones and their respective biosynthesis inhibitors, are effective tools to elucidate the physiological function of phytohormones in plants. A problem of chemical treatments, however, is the potential for interaction of the active compound with the growth media substrate. We studied the interaction and efficacy of propiconazole, a potent and specific inhibitor of brassinosteroid biosynthesis, with common soilless greenhouse growth media for rice, sorghum, and maize. Many of the tested growth media interacted with propiconazole reducing its efficacy up to a hundred fold. To determine the molecular interaction of inhibitors with media substrates, Fourier Transform Infrared Spectroscopy and sorption isotherm analysis was applied. While mica clay substrates absorbed up to 1.3 mg of propiconazole per g substrate, calcined clays bound up to 12 mg of propiconazole per g substrate. The efficacy of the gibberellic acid biosynthesis inhibitor, uniconazole, and the most active brassinosteroid, brassinolide, was impacted similarly by the respective substrates. Conversely, gibberellic acid showed no distinct growth response in different media. Our results suggest that the reduction in efficacy of propiconazole, uniconazole, and brassinolide in bioassays when grown in calcined clay is caused by hydrophobic interactions between the plant growth regulators and the growth media. This was further confirmed by experiments using methanol-water solvent mixes with higher hydrophobicity values, which reduce the interaction of propiconazole and calcined clay. [ABSTRACT FROM AUTHOR]

Background: Plant responses to phytohormone stimuli are the most important biological features for plants to survive in a complex environment. Cytokinin regulates growth and nutrient homeostasis, such as the phosphate (Pi) starvation response and Pi uptake in plants. However, the mechanisms underlying how cytokinin participates in Pi uptake and Pi signaling are largely unknown. In this study, we found that OsARF16 is required for the cytokinin response and is involved in the negative regulation of Pi uptake and Pi signaling by cytokinin. Principal Findings: The mutant osarf16 showed an obvious resistance to exogenous cytokinin treatment and the expression level of the OsARF16 gene was considerably up-regulated by cytokinin. Cytokinin (6-BA) application suppressed Pi uptake and the Pi starvation response in wild-type Nipponbare (NIP) and all these responses were compromised in the osarf16 mutant. Our data showed that cytokinin inhibits the transport of Pi from the roots to the shoots and that OsARF16 is involved in this process. The Pi content in the osarf16 mutant was much higher than in NIP under 6-BA treatment. The expressions of PHOSPHATE TRANSPORTER1 (PHT1) genes, phosphate (Pi) starvation-induced (PSI) genes and purple PAPase genes were higher in the osarf16 mutant than in NIP under cytokinin treatment. Conclusion: Our results revealed a new biological function for OsARF16 in the cytokinin-mediated inhibition of Pi uptake and Pi signaling in rice. [ABSTRACT FROM AUTHOR]

Light limitation caused by dense vegetation is one of the greatest threats to plant survival in natural environments. Plants detect such neighboring vegetation as a reduction in the red to far-red ratio (R:FR) of the incoming light. The low R:FR signal, perceived by phytochromes, initiates a set of responses collectively known as the shade avoidance syndrome, intended to reduce the degree of current or future shade from neighbors by overtopping such competitors or inducing flowering to ensure seed production. At the seedling stage these responses include increased hypocotyl elongation. We have systematically analyzed the Arabidopsis seedling response and the contribution of phyA and phyB to perception of decreased R:FR, at three different levels of photosynthetically active radiation. Our results show that the shade avoidance syndrome, induced by phyB deactivation, is gradually antagonized by phyA, operating through the so-called FR-High Irradiance Response, in response to high FR levels in a range that simulates plant canopy shade. The data indicate that the R:FR signal distinguishes between the presence of proximal, but non-shading, neighbors and direct foliar shade, via a intrafamily photosensory attenuation mechanism that acts to suppress excessive reversion toward skotomorphogenic development under prolonged direct vegetation shade. [ABSTRACT FROM AUTHOR]

Human alterations of landscapes often lead to colonization of ecosystems by new species, which may alter ecosystem structure and function. Understanding canopy changes is important for management of gradually changing ecosystems. Here, we develop a model that both explains and predicts the rate at which colonizing nativePinus halepensis form an upper forest canopy in native shrublands. We surveyed allometric properties of 602 pine trees, distributed throughout environmental gradients in the Mediterranean region of Israel, where native oak scrublands are being invaded by pines and converting to forests. We developed maximum likelihood models for growth and height of trees in different habitats. Growth fit a log-normal model as a function of height and height fit a power function in relation to age. Precipitation had the strongest impact on both height and shoot growth. The differences in height and growth among trees growing in different soil types and grazing regimes were relatively small, but statistically significant, and could be attributed to direct inhibition or indirect facilitation. In general, pines form an overstory in almost all colonized shrublands, converting them to forests, but the rate of canopy development varies across environmental gradients. [ABSTRACT FROM AUTHOR]

The genetic diversity of plants has traditionally been employed to improve crop plants to suit human needs, and in the future feed the increasing population and protect crops from environmental stresses and climate change. Genome-wide sequencing is a reality and can be used to make association to crop traits to be utilized by high-throughput marker based selection methods. This study describes a strategy of using next generation sequencing (NGS) data from the rice genome to make comparisons to the high-quality reference genome, identify functional polymorphisms within genes that might result in function changes and be used to study correlations to traits and employed in genetic mapping. We analyzed the NGS data of Oryza sativa ssp indica cv. G4 covering 241 Mb with ∼20X coverage and compared to the reference genome of Oryza sativa ssp. japonica to describe the genome-wide distribution of gene-based single nucleotide polymorphisms (SNPs). The analysis shows that the 63% covered genome consists of 1.6 million SNPs with 6.9 SNPs/Kb, and including 80,146 insertions and 92,655 deletions (INDELs) genome-wide. There are a total of 1,139,801 intergenic SNPs, 295,136 SNPs in intronic/non-coding regions, 195,098 in coding regions, 23,242 SNPs at the five-prime (5′) UTR regions and 22,686 SNPs at the three-prime (3′) UTR region. SNP variation was found in 40,761 gene loci, which include 75,262 synonymous and 119,836 non-synonymous changes, and functional reading frame changes through 3,886 inducing STOP-codon (isSNP) and 729 preventing STOP-codon (psSNP) variation. There are quickly evolving 194 high SNP hotspot genes (>100 SNPs/gene), and 1,513 out of 2,458 transcription factors displaying 2,294 non-synonymous SNPs that can be a major source of phenotypic diversity within the species. All data is searchable at . We envision that this strategy will be useful for the identification of genes for crop traits and molecular breeding of rice cultivars. [ABSTRACT FROM AUTHOR]

Improved drought tolerance is always a highly desired trait for agricultural plants. Significantly increased drought tolerance in Arabidopsis thaliana (Columbia-0) has been achieved in our work through the suppression of ESKMO1 (ESK1) gene expression with small-interfering RNA (siRNA) and overexpression of CBF genes with constitutive gene expression. ESK1 has been identified as a gene linked to normal development of the plant vascular system, which is assumed directly related to plant drought response. By using siRNA that specifically targets ESK1, the gene expression has been reduced and drought tolerance of the plant has been enhanced dramatically in the work. However, the plant response to external abscisic acid application has not been changed. ICE1, CBF1, and CBF3 are genes involved in a well-characterized plant stress response pathway, overexpression of them in the plant has demonstrated capable to increase drought tolerance. By overexpression of these genes combining together with suppression of ESK1 gene, the significant increase of plant drought tolerance has been achieved in comparison to single gene manipulation, although the effect is not in an additive way. Accompanying the increase of drought tolerance via suppression of ESK1 gene expression, the negative effect has been observed in seeds yield of transgenic plants in normal watering conditions comparing with wide type plant. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet) is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S. italica to different levels of inorganic phosphate (Pi) and to colonisation with the arbuscular mycorrhizal fungus Funneliformis mosseae (syn. Glomus mosseae) were studied. Phosphate is taken up from the environment by the PHT1 family of plant phosphate transporters, which have been well characterized in several plant species. Bioinformatic analysis identified 12 members of the PHT1 gene family (SiPHT1;1-1;12) in S. italica, and RT and qPCR analysis showed that most of these transporters displayed specific expression patterns with respect to tissue, phosphate status and arbuscular mycorrhizal colonisation. SiPHT1;2 was found to be expressed in all tissues and in all growth conditions tested. In contrast, expression of SiPHT1;4 was induced in roots after 15 days growth in hydroponic medium of low Pi concentration. Expression of SiPHT1;8 and SiPHT1;9 in roots was selectively induced by colonisation with F. mosseae. SiPHT1;3 and SiPHT1;4 were found to be predominantly expressed in leaf and root tissues respectively. Several other transporters were expressed in shoots and leaves during growth in low Pi concentrations. This study will form the basis for the further characterization of these transporters, with the long term goal of improving the phosphate use efficiency of foxtail millet. [ABSTRACT FROM AUTHOR]

Background: Strigolactones are a new class of plant hormones that play a key role in regulating shoot branching. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathway. In the model plant Arabidopsis, MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3 and MAX4 are four founding members of strigolactone pathway genes. However, little is known about the strigolactone pathway genes in the woody perennial plants. Methodology/Principal Finding: Here we report the identification of MAX homologues in the woody model plant Populus trichocarpa. We identified the sequence homologues for each MAX protein in P. trichocarpa. Gene expression analysis revealed that Populus MAX paralogous genes are differentially expressed across various tissues and organs. Furthermore, we showed that Populus MAX genes could complement or partially complement the shoot branching phenotypes of the corresponding Arabidopsis max mutants. Conclusion/Significance: This study provides genetic evidence that strigolactone pathway genes are likely conserved in the woody perennial plants and lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants. [ABSTRACT FROM AUTHOR]

This study investigated bud burst and onset and cessation of radial growth (i.e., secondary xylem cell production by cambium) along an altitudinal gradient (1,600-2,800 m a.s.l.) in central Japan, to examine whether timing of the three phenological events are controlled by thermal conditions alone, irrespective of altitude. Measurement was done at biweekly intervals during 3 years (2006-2008) for four subalpine tree species at their upper and lower distribution limits, except for bud burst in 2006. Although bud burst and onset of radial growth were later at higher altitudes in the combined data of the four species, cessation of radial growth occurred in mid-August, irrespective of altitude. Coefficients of variation of timing of the phenological events decreased in the order bud burst, onset of radial growth, and cessation of radial growth in combined data of the four species. Growing degree days (GDD) for bud burst did not differ greatly along the altitudinal gradient for each species. However, GDD for the onset of radial growth was lower at higher altitude. This study suggests that the effects of thermal conditions on the phenological events along the altitudinal gradient might decrease in the order bud burst, onset of radial growth and cessation of radial growth. Probably not only temperature, but also other factors such as day length, may affect onset and cessation of radial growth. However, further research is necessary to examine the altitudinal differences in timing of the phenological events more accurately, by measurements at shorter time intervals than the biweekly intervals of this study. [ABSTRACT FROM AUTHOR]

Background: Strigolactones are a new class of plant hormones that play a key role in regulating shoot branching. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathway. In the model plant Arabidopsis, MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3 and MAX4 are four founding members of strigolactone pathway genes. However, little is known about the strigolactone pathway genes in the woody perennial plants. Methodology/Principal Finding: Here we report the identification of MAX homologues in the woody model plant Populus trichocarpa. We identified the sequence homologues for each MAX protein in P. trichocarpa. Gene expression analysis revealed that Populus MAX paralogous genes are differentially expressed across various tissues and organs. Furthermore, we showed that Populus MAX genes could complement or partially complement the shoot branching phenotypes of the corresponding Arabidopsis max mutants. Conclusion/Significance: This study provides genetic evidence that strigolactone pathway genes are likely conserved in the woody perennial plants and lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants. [ABSTRACT FROM AUTHOR]

Highlights: [•] The blue net restrained the vine vigor. [•] The red and the gray nets stimulated vegetative growth. [•] The photo-selective netting affected the growth model of kiwifruit vines. [•] Photo-selective netting provides a multi-benefit solution for kiwifruit growers. [Copyright &y& Elsevier]

Global warming can have substantial impacts on the phenological and growth patterns of alpine and Arctic species, resulting in shifts in plant community composition and ecosystem dynamics. We evaluated the effects of a six-year experimental soil warming treatment (+4°C, 2007–2012) on the phenology and growth of three co-dominant dwarf shrub species growing in the understory of Larix decidua and Pinus uncinata at treeline in the Swiss Alps. We monitored vegetative and reproductive phenology of Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum throughout the early growing season of 2012 and, following a major harvest at peak season, we measured the biomass of above-ground ramet fractions. For all six years of soil warming we measured annual shoot growth of the three species and analyzed ramet age and xylem ring width of V. myrtillus. Our results show that phenology of the three species was more influenced by snowmelt timing, and also by plot tree species (Larix or Pinus) in the case of V. myrtillus, than by soil warming. However, the warming treatment led to increased V. myrtillus total above-ground ramet biomass (+36% in 2012), especially new shoot biomass (+63% in 2012), as well as increased new shoot increment length and xylem ring width (+22% and +41%, respectively; average for 2007–2012). These results indicate enhanced overall growth of V. myrtillus under soil warming that was sustained over six years and was not caused by an extended growing period in early summer. In contrast, E. hermaphroditum only showed a positive shoot growth response to warming in 2011 (+21%), and V. gaultherioides showed no significant growth response. Our results indicate that V. myrtillus might have a competitive advantage over the less responsive co-occurring dwarf shrub species under future global warming. [ABSTRACT FROM AUTHOR]

Previous studies have reported that a purified sedimentary humic acid (PHA) was able to increase the concentration of nitric oxide (NO), indole-acetic acid (IAA) and ethylene in cucumber roots. Here, we investigated if these effects are functionally related to the ability of PHA to improve shoot growth. The effect of specific inhibitors of NO, IAA and ethylene functionality and signaling on PHA-induced shoot growth was studied. Likewise, the effect of these inhibitors on the synthesis and activity of the phytoregulators concerned by PHA action in cucumber roots was also explored. The results show that shoot growth promoted by PHA is due to an increase of IAA concentration in the root through both a NO-dependent and a NO-independent pathway. In addition, the increased ethylene production in the root is regulated by an IAA-dependent pathway. Finally, results also showed that the increase of ABA concentration in the root is regulated through both IAA- and ethylene-dependent pathways. In summary, the shoot growth promoting action of PHA involves a complex hormonal network. On one hand, the PHA action is functionally linked to increments in NO and IAA concentration in roots. And on the other hand, PHA action also increases ethylene and ABA root concentration mediated by NO-IAA dependent pathways. [ABSTRACT FROM AUTHOR]

Nous avons étudié pendant 3 ans, en serre et en plein champ, l'effet sur la vigne (cépage Merlot) d'applications foliaires de 9 produits commerciaux associant à une fraction minérale divers constituants organiques, et conseillés pour stimuler la végétation et améliorer la récolte. Nous nous sommes intéressés à la croissance des rameaux et à la production (coulure, rendement, teneur en sucre des moûts). Dans nos conditions expérimentales, ces produits ont peu modifié, et de façon aléatoire, les paramètres mesurés. L'intérêt de l'utilisation de telles substances dans la pratique viticole reste donc à démontrer.

In the production of single-stemmed roses in a closed system, it is necessary to identify the optimal ranges of ions in the nutrient solution in order to determine the optimal management practices for the crop. This study was conducted to determine the optimal levels of Ca and Mg in the nutrient solution for optimization of nutrition of single-stemmed roses grown in a closed aeroponic system. Single-stemmed roses were grown in the nutrient solution with 7 different levels each of Ca (0, 10, 40, 80, 120, 160, and 200 mg·L) and Mg (0, 10, 20, 40, 80, 120, and 160 mg·L) for four weeks after transplanting. A sharp pH change was observed in the treatments with low levels of Ca and Mg during the first and second weeks after transplanting, and there was a stable variation in EC in a range of 1.3-1.8 dS·m in the treatments of 40-120 mg·L Ca and 10-80 mg·L Mg. Contents of Ca and K contents in leaf tissue were significantly decreased by increasing Mg level in the nutrient solution. Although there was an increase in the fresh weight and stem length under higher levels of Ca and Mg, plant growth did not increase as compared to the treatments of 120 mg·L Ca and 80 mg·L Mg. Photosynthetic rate in the leaves of flowering shoots was the greatest in the range of 80-120 mg·L Ca, and the stomatal conductance and transpiration rate had a tendency to increase along with the increase of Ca concentration up to 120 mg·L before distinct decrease at Ca level greater than 160 mg·L. In Mg treatments, photosynthetic responses showed maximum values at around 40-80 mg·L, and began to decrease at level greater than 80 mg·L. Photosynthetic water use efficiency (WUE) was lower in leaves of the treatments of 160 and 200 mg·L Ca, and 0 and 160 mg·L Mg. Chlorophyll content in five-leaflet leaves as influenced by Mg level tended to increase continuously up to 80 mg·L, showing a positive correlation with Mg content in the leaves. Content of anthocyanin in five-leaflet leaves was higher in the treatments with low Mg levels (0 and 10 mg·L). Considering the nutrient and water absorption patterns, and growth characteristics of single-stemmed roses with different solution Ca and Mg levels, 80-120 mg·L Ca and 30-80 mg·L Mg seem to be appropriate for the optimization of plant nutrition in a closed production system. [ABSTRACT FROM AUTHOR]

The article discusses a study on how the date and method of transplanting 3 urban species of Isfahan, Iran, namely the eldarica pine, white mulberry and smoothleaf elm, can improve their survival and establishment as well as landscape performance in arid climate. The species were planted in early winter, early spring and in late spring. It indicates which species survived the best in each of these seasons, suggesting species-specific response for post-transplant establishment in arid climate.

The article presents a study that investigated how five nursery production methods affect root systems and post-transplant shoot growth. It also examined the effect of root structure on the trees' response to various production methods as well as the effect of the conditions at the site where the trees were transplanted. The experiments were conducted on sweet cherry and red oak. It showed that the sweet cherry was more responsive to production methods in transplanting than the red oak.

The relationship between the cycle of flush development and temperature is not well described for Tahitian lime, or citrus species in general. We pruned trees over 16 months in the humid subtropics of northern New South Wales (NSW), and monitored post-pruning flush development over two cycles, in terms of flush commencement and flowering. We also recorded temperatures over this period. The time from pruning to the emergence of the first post-pruning flush was correlated with mean daily temperature, with emergence being slower at cooler temperatures. Emergence times ranged from 11 to 39 days. The time between the commencement of the first and second flushes was also correlated with mean daily temperature, with slower development of the first flush at cooler temperatures. The duration of the first flush varied from 41 to 128 days. There was more flowering on the first than the second flush (16% of shoots versus 3%). There was no flowering on flushes that commenced in the warmer months, from November to March. The temperature threshold for flowering appeared to be at a mean daily temperature of ~20°C. Regressions between flush development and temperature were used to estimate the effects of climate warming from 1963-1971 to 2003-2011, using long-term temperature records. The warming decreased bud emergence time by 1.6 days in winter and 1 day in summer; and reduced the time from the first to the second flush by 11.8 days in winter and 9.2 days in summer. The results for Tahitian lime were similar to those for other recurrent flushing trees. Tahitian lime grows by repeated flushes. We show that the timing of successive flushes depends on the weather in much the same way that it does for other recurrent flushing trees, with more frequent flushing in the warmer months in a humid, subtropical environment. We also show that the likelihood of a flush flowering depends on the timing of flush development, with no flowers on flushes that develop in the warmest months. [ABSTRACT FROM AUTHOR]

In the present study phenological activities such as leaf and shoot growth, leaf pool size and leaf fall were observed for 3 years (March 2007-March 2010) in 19 tree species (13 evergreen and 6 deciduous species) in a wet tropical forest in Assam, India. The study area receives total annual average rainfall of 2,318 mm of which most rain fall (>70 %) occurs during June-September. Both the plant groups varied significantly on most of the shoot and leaf phenology parameters. In general, growth in deciduous species initiated before the evergreen species and showed a rapid shoot growth, leaf recruitment and leaf expansion compared to evergreen species. Leaf recruitment period was significantly different between evergreen (4.2 months) and deciduous species (6.8 months). Shoot elongation rate was also significantly different for evergreen and deciduous species (0.09 vs. 0.14 cm day shoot). Leaf number per shoot was greater for deciduous species than for evergreen species (34 vs. 16 leaves). The average leaf life span of evergreen species (328 ± 32 days) was significantly greater than that of deciduous species (205 ± 16 days). The leaf fall in deciduous species was concentrated during the winter season (Nov-Feb), whereas evergreens retained their leaves until the next growing season. Although the climate of the study area supports evergreen forests, the strategies of the deciduous species such as faster leaf recruitment rate, longer leaf recruitment time, faster shoot elongation rate during favorable growing season and short leaf life span perhaps allows them to coexist with evergreen species that have the liberty to photosynthesize round the year. Variations in phenological strategies perhaps help to reduce the competition among evergreen and deciduous species for resources in these forests and enable the coexistence of both the groups. [ABSTRACT FROM AUTHOR]

Neotropical savannas ('cerrados') of Central Brazil are characterized by the coexistence of a large diversity of tree species with divergent phenological behaviors, which reflect a great diversity in growth strategies. In the present study time behavior and quantitative aspects of shoot growth, shoot mortality, and leaf longevity and production were analyzed in 12 woody species of contrasting leaf phenology, adopting a functional group approach where 12 species were categorized into three functional groups: evergreen, decidous and brevideciduous, according to their leaf phenology. Shoot growth and leaf production were seasonal for the three functional groups, differing in their time of occurrence, but being concentrated during the last months of the dry season. Shoot growth differed between evergreens and deciduous, as well leaf production. Evergreens had higher rates of shoot growth, produced a higher number of leaves and had longer leaf longevity (around 500 days against 300 days in deciduous and brevideciduous). Leaf longevity was associated with patterns of leaf production when accounting for all phenological groups studied. It was possible to identify different patterns of aerial growth in savanna phenological groups, providing evidence of great functional variability amongst the groups studied. [ABSTRACT FROM AUTHOR]

Abstract: Chemical thinning of young apple (Malus domestica, Borkh.) fruit has become standard agricultural practice worldwide. The general understanding about the mode of action of thinning substances is, however, still very limited. Benzyladenine (BA), one of the most promising newer thinning chemicals has been chosen as an example to study its “mode of action”. The following aspects were investigated: (1) the site of action, (2) effects on seed number and development, (3) fruit and vegetative growth, (4) photosynthesis and (5) polar indoleacetic acid transport (IAAPAT). When BA was applied at 100mgL−1 on three apple cultivars on whole trees or leaves-only, thinning effects were comparable to or even stronger than hand thinning. BA applied only on fruit showed insignificant thinning. At June drop the weight of abscising fruit was comparable or even higher when treated with BA. Growth of remaining fruit was not affected until harvest when only fruit were treated. However, when leaves-only or whole trees were treated remaining fruit showed a decreased fruit growth initially but surpassed control fruit thereafter. No direct correlations were found between thinning efficacy and seed number, shoot growth, photosynthesis and by indirect conclusion, assimilate allocation. Thus, these assessments provided no clear explanation for a possible mode of action of BA. Remarkably, a decrease in IAAPAT of lateral fruit was opposed to an increase in IAAPAT of bourse shoot tips after BA application. This was only observed when leaves/shoot tips but not fruit only were treated. Assuming a correlative IAA transport autoinhibition (ATA) of fruit by the IAAPAT of shoots, particularly of bourse shoot tips, may explain fruit abscission and the mode of action of BA applications in apple. The latter aspects are discussed in more detail. [Copyright &y& Elsevier]