Short Shoots Research Articles

GA-sensitive Rht13 gene improves root architecture and osmotic stress tolerance in bread wheat

The root architecture, more seminal roots, and Deeper roots help the plants to uptake the resources from the deeper soil layer to ensure better growth. The Gibberellic acid-sensitive (GA-sensitive) Rht genes are well known for increasing drought tolerance in wheat. Much work has been performed on the effect of these genes on the plant agronomic traits and little work has been done on the effect of Rht genes on seminal roots and root architecture. This study was designed to evaluate 200 wheat genotypes under normal and osmotic stress. The genotypes were sown in the solution culture and laid under CRD factorial arrangement with three replications and two factors i.e., genotypes and treatments viz. normal and osmotic stress (20% PEG-6000) applied one week after germination. The data was recorded for the root traits. Results demonstrated that out of 200 genotypes, the GA-sensitive Rht13 gene was amplified in 21 genotypes with a fragment length of 1089 bp. In comparison, the GA-insensitive Rht1 gene was amplified in 24 genotypes with a band size of 228 bp. From 200 wheat genotypes, 122 genotypes produced 5 seminal roots, 4 genotypes 4 seminal roots, and 74 genotypes 3 seminal roots. The genotypes G-3 (EBW11TALL#1/WESTONIA-Rht5//QUAIU#1), G-6 (EBW01TALL#1/SILVERSTAR-Rht13B//ROLF07) and G-8 (EBW01TALL#1/SILVERSTAR-Rht13B//NAVJ07) produced 5 seminal roots and have longer coleoptile (> 4.0 cm), root (> 11.0 cm) and shoot (> 17 cm) under normal and osmotic stress. Furthermore, Ujala 16, Galaxy-13, and Fareed-06 produced 3 seminal roots and have short coleoptile (< 3 cm), root (< 9.0 cm) and shoot (< 10.0 cm). These results showed that the genotypes showing the presence of GA-sensitive Rht genes produced a greater number of seminal roots, increased root/shoot growth, and osmotic stress tolerance compared to the genotypes having GA-insensitive Rht genes. Thus, the Rht13 gene improved the root architecture which will help to uptake the nutrients from deeper soil layers. Utilization of Rht13 in wheat breeding has the potential to improve osmotic stress tolerance in wheat.

EVALUATION OF THE MORPHOBIOLOGICAL AND PRODUCTIVE INDICATORS OF CHAYOTE (Sechium edule L) IN THE REGION OF MYZEQE, LIBOFSHË, FIER

Prickly potato - Chayote (Sechium edule L) is an exotic plant that grows and is cultivated in Costa Rica. It has been brought to Albania since 2004 and has been studied several times in different areas, mainly in the warm zone. It is a plant that has many synonyms and uses. Sometimes it is called prickly eggplant or prickly gourd and in some places it is called Kayota. The fruit grows above the ground and the plant develops as a pergola with long shoots. The fruit is used cooked in different forms: fried, dish, and or casserole. The leaves are used to make various pies and it is very tasty, especially when cooked with milk. The fruits are planted in March by placing them in the soil and covering them with 5-8 cm. During the vegetation, measurements of biometric and productive indicators were made: Number of shoots/plant, length of shoots/plant (sum), longest shoot, shortest shoot, number of leaves/plant, leaf color, flower color, the shape of the leaf, the shape of the tuber, the color of the skin of the tuber, the color of the tuber pulp, the placement of the buds on the tuber, yield/plant (kg/plant), number of tubers/plant, average tuber weight (kg), the weight of the largest tuber (kg), the weight of the smallest tuber (kg), yield kv/ha. The fruits were chemically analyzed to determine the main chemical indicators: the content of starch and the most important chemical elements.

Cultivar ideotype for intensive olive orchards: plant vigor, biomass partitioning, tree architecture and fruiting characteristics

In order to achieve higher and earlier yield, modern olive orchards are increasingly intensified, with tree densities up to &amp;gt; 1500 trees hectare-1. With increasing tree densities, individual-tree canopy volume must be proportionally reduced. Not all cultivars are adaptable to high and very high orchard densities, because of excessive vigor and/or insufficient bearing when the canopy is pruned to a small volume. However, what makes an olive cultivar suitable for intensive and super intensive orchards is not clear. Recently, few studies have addressed this topic, suggesting that tree architecture and early bearing are essential traits. Yet, what architectural and productive features are important, how they work and whether they are interrelated remains elusive. This review summarizes and interprets the literature on olive, as well as the more abundant literature available for other fruit species, aiming to provide a comprehensive knowledge framework for understanding how tree architectural characteristics, plant vigor, and fruiting vary across olive genotypes, and how they are interconnected. It is concluded that, among the architectural characteristics, greater branching and smaller diameters of woody structures are particularly important features for cultivar suitability to intensive and super intensive olive orchards. Greater branching allows to produce more fruiting sites in the small volume of canopy allowed in these systems. It also reduces investments in woody structures, liberating resources for fruiting. Additional resources are liberated with smaller structure diameters. Greater branching also increases resources by increasing biomass partitioning into leaves (i.e. the photosynthetic organs), relative to wood. Since yield is affected by the competition for resources with vegetative growth, reducing resource investments in woody structures and/or increasing resource directly, increases yield. Yield, in turn, depresses vegetative growth, reducing vigor and the need for pruning. High yields also produce short shoots which have relatively greater investments in leaf mass and area, and lower in the woody stem, making them more suitable than long shoots to support concurrent fruit growth. This single framework of interpretation of how the different architectural and fruiting characteristics work and interact with one-another, will provide guidance for cultivar selection and breeding for intensive and super intensive olive orchards.

A successful method to restore seagrass habitats in coastal areas affected by consecutive natural events.

Seagrass meadows, known for providing essential ecosystem services like supporting fishing, coastline protection from erosion, and acting as carbon sinks to mitigate climate change effects, are facing severe degradation. The current deteriorating state can be attributed to the combination of anthropogenic activities, biological factors (i.e., invasive species), and natural forces (i.e., hurricanes). Indeed, the global seagrass cover is diminishing at an alarming mean rate of 7% annually, jeopardizing the health of these vital ecosystems. However, in the Island Municipality of Culebra, Puerto Rico, losses are occurring at a faster pace. For instance, hurricanes have caused over 10% of cover seagrass losses, and the natural recovery of seagrasses across Culebra's coast has been slow due to the low growth rates of native seagrasses (Thalassia testudinum and Syringodium filiforme) and the invasion of the invasive species Halophila stipulacea. Restoration programs are, thus, necessary to revitalize the native seagrass communities and associated fauna while limiting the spread of the invasive species. Here, we present the results of a seagrass meadow restoration project carried out in Punta Melones (PTM), Culebra, Puerto Rico, in response to the impact of Hurricanes Irma and María during 2017. The restoration technique used was planting propagation units (PUs), each with an area of 900 cm2 of native seagrasses Thalassia testudinum and Syringodium filiforme, planted at a depth between 3.5 and 4.5 m. A total of 688 PUs were planted between August 2021 and August 2023, and a sub-sample of 88 PUs was monitored between August 2021 and April 2023. PUs showed over 95% of the seagrass survived, with Hurricane Fiona causing most of the mortalities potentially due to PUs burial by sediment movement and uplifting by wave energy. The surface area of the planting units increased by approximately 200% (i.e., 2,459 cm2), while seagrass shoot density increased by 168% (i.e., 126 shoots by PU). Additionally, flowering and fruiting were observed in multiple planting units, indicating 1) that the action taken did not adversely affect the PUs units and 2) that the project was successful in revitalizing seagrass populations. The seagrass restoration project achieved remarkable success, primarily attributed to the substantial volume of each PUs. Likely this high volume played a crucial role in facilitating the connection among roots, shoots, and microfauna while providing a higher number of undamaged and active rhizome meristems and short shoots. These factors collectively contributed to the enhanced growth and survivorship of the PUs, ultimately leading to the favorable outcome observed in the seagrass restoration project.

ANALISIS RANCANGAN PERBAIKAN DESIGN MOLD DENGAN MENGGUNAKAN METODE TAGUCHI DI PT X

PT X Indonesia is one of the Korean Foreign Manufacturing Companies (PMA) that produce injection molding. December 2022 PT X Indonesia received customer complaints from PT. Y because of defects in products such as: gas burn, white spot, weld line, bending, short shoot, bubbles, flashing, silver, wrong color, and contamination. Flashing is a type of defect that the largest number of ratios reaches 10% while the defect restriction of the customer is 2% so the company and the authors choose the theme of improvement in 2018 is the improvement of molding design to reduce flashing defects in plastic products. The method used in the proposed improvement of molding design is the taguchi method by making 4 point suggestion that is the level 1 slot dimension: Hight 70mm taper 15 °, level 2: Hight 70mm taper 10 °, level 3: High 70mm taper 5 °; insert level 1 dimension: 70mm taper insert 1 °, level 2: 70mm taper deepness insert 2 °, level 3: 70mm taper deepth insert 3 °; clamping tolerance force level 1: + 5%, level 2: + 8%, level 3: + 10% and parting line line length 1: 10mm, level 2: 20mm, level 3: 30mm. The proposed best molding design improvements are in Slast dimensions: Hight 70 mm taper 15 °, Insert: 70mm taper deepness 2 °, clamping force tolerance + 10%, Parting Line Length: 30mm. The smallest flashing flaw was found to be 0.1% in confirmatory experimental conditions, much smaller than the specified target defects of 2%. Cost reduction cost obtained by PT ART Mold Indonesia with the proposed repair on Molding design that is Rp 115.600.000,00 per 1 molding. The cost savings incurred by customers of PT ART Mold Indonesia is worth Rp 784.080.000,00 per year

Inducing mutation and ascertaining lethal dosage of in vitro cultures of banana cv. Ney Poovan to ethyl methane sulfonate

In vitro mutation breeding in vegetatively propagated crops like banana offers a benefit in screening for beneficial variants in plant cells or cultured tissues. An attempt was made to induce mutants and determine the lethal dose, as it is the prerequisite to optimize the concentration and duration of the mutagen used to recover a larger population in mutation research. Shoot tip cultures were treated for 2 and 4 h at six different EMS concentrations ranging from 80 mM to 160 mM, whereas proliferating multiple shoots were exposed for 30 and 60 min at six different EMS concentrations ranging from 8 mM to 40 mM. Survival percentage, shoot length, and number of shoots reduced linearly and significantly as concentration and duration increased in both shoot tips and proliferating multiple buds. The probit curve-based analysis of mortality of treated explants revealed that the LD50 was 155.83 mM for 2 h and 113.72 mM for 4 h, respectively for shoot tip cultures, whereas for proliferating multiple buds, the LD50 value was adjusted to 39.11 mM for 30 min and 30.41 mM for 60 min. 160 mM EMS for 4 h resulted in a shorter shoot, a longer rooting duration, a lesser number of roots, and decreased root development. In proliferating multiple shoots, the smallest shoot, longest rooting duration, least number of roots, and shortest root were observed in 40 mM EMS for 60 min. Similar reductions in growth parameters were observed in proliferating multiple shoots at higher exposure to EMS for a longer duration.

Changes in the Shoot Apical Meristem with Decrease in Illumination within the Crown of &lt;i&gt;Pseudotsuga menziesii&lt;/i&gt; (Pinaceae) Introduced in St. Petersburg

Abstract—In Pseudotsuga menziesii Mirb. Franco introduced in St. Petersburg, the changes in the apical meristem morphogenesis during the formation of a short bud shoot with covering scales and meristematic primordium of shoot with needles, under the decrease in illumination within the crown were studied. Terminal 1–4-year-old shoots of the third-order branches in the lower part of the crown with a relative light availability (RLA) in the range of 23.9–18.3% perform full annual cycle of morphogenesis of the shoot apical meristem. Before each stage of morphogenesis, the apical meristem performs independent volume growth associated with the formation of mother groups of phytomer cells of covering scales and needles in the peripheral meristem. With RLA reducing to 15.1–15.4%, in terminal 5–6-year-old shoots over the growing season, the apical meristem performs only formation of a short bud shoot with covering scales and stops volume growth. This is because in the vascular bundles of the stele of the short bud stem, the sieve cells of the phloem are not formed, and the xylem part is poorly developed. The direct contact of the apex with the stele of the bud stem is blocked by procambium bundles, since their cells are differentiated and crystalline cellulose is accumulated in the cell walls. The cell walls of the bark parenchyma of the short bud stem contains significantly less birefringent inclusions, and only single small resin receptacles.

Shift in the Light Quality of Night Interruption Affects Flowering and Morphogenesis of Petunia hybrida.

Petunia hybrida Hort. "Easy Wave Pink", a qualitative long-day plant (LDP), was investigated to study the effects of the night interruption light (NIL) provided by light-emitting diodes (LEDs) quality shifting on the morphogenesis, blooming, and transcription of photoreceptor genes. Plants were grown in a closed-type plant factory employing white (W) LEDs at an intensity of 180 μmol·m-2·s-1 PPFD provided for short day (SD, 10 h light, 14 h dark), long day (LD, 16 h light, 8 h dark), or SD with 4 h night interruption (NI) with LEDs at an intensity of 10 μmol·m-2·s-1 PPFD. The NIL quality was shifted from one light spectrum to another after the first 2 h of NI. Light treatments consisting of all possible pairings of W, far-red (Fr), red (R), and blue (B) light were tested. The SD and LD were referenced as the control, while 12 NI treatments involved altering LED NIL qualities, as follows: from R to B (NI-RB), from B to R (NI-BR), from Fr to R (NI-FrR), from R to Fr (NI-RFr), from Fr to B (NI-FrB), from B to Fr (NI-BFr), from B to W (NI-BW), from W to B (NI-WB), from W to Fr (NI-WFr), from Fr to W (NI-FrW), from W to R (NI-WR), and from R to W (NI-RW). The NI-RFr resulted in the longest shoots, while the NI-WR and NI-RW resulted in the shortest shoots. NI-WR, NI-RW, NI-BW, NI-WB, NI-RFr, NI-RB, NI-BR, and LD all exhibited flowering. High-level expressions of photoreceptor genes were confirmed in the NI-RFr, NI-FrR, NI-BFr, NI-RW, and NI-WR treatments. Morphogenesis and blooming were both impacted by the photoperiod. The first NIL had no effects on the flowering or the morphogenesis, but the second NIL had a profound impact on both.

Effect of spring nitrogen fertilization on bearing and branching behaviors of young apple trees.

The total aboveground biomass production, nutritional status, bearing and branching behaviors of the central leader and one year old shoots of young apple trees have been analyzed. The shoots were further characterized according to the length, shoot demography, and the production of terminal and lateral flowers. All the characteristics are described in connection with nitrogen supply and cultivar. Nitrogen represents one of the major macronutrients involved in the growth and development of the fruit trees. The understanding of the effect of nitrogen supply for flower bud formation can be further improved by detailed analyses of tree architecture. While the biomass production was cultivar specific, the trees within particular cultivar were characterized by almost similar growth with respect to the nitrogen supply. Cultivar ´Rubinola´ exhibited similar branching pattern, but higher vigor than ´Topaz´. As a result of higher apical dominance, ´Rubinola´ produced higher proportion of long shoots, but a lower quality of short shoots than ´Topaz´. Consequently, cultivar ´Rubinola´ produced only few terminal flowers on short shoots and lateral flowers dominantly in the distal zone, while ´Topaz´ was characterized by intensive terminal flowering, but the lateral flowers were more abundant in the median zone. Even a lower dose of spring nitrogen improved the flower bud formation on both terminal and lateral positions extending the flowering zone on one-year-old shoots. This further changed the branching and bearing behavior of the apple trees, which particularly allows to optimize their fertilization management. However, this effect appears to be further regulated by mechanism connected with apical dominance.

Hydraulic and Economical Traits in Short- and Long-Shoot Leaves of Ginkgo biloba Males and Females

Ginkgo biloba is a dioecious heterophyllous tree species with two leaf types. Short shoots always bear many leaves, which are undivided or slightly bilobed, but long-shoot leaves are smaller and are deeply divided into two or more lobes. To clarify the functional difference between the two leaf types, we investigated the morphology, anatomy, gas exchange, and hydraulic traits of the two leaf types in male and female trees. Our results showed that long-shoot leaves possessed a lower specific leaf area (SLA), higher leaf thickness, gas exchange rates, and average tracheid number than short-shoot leaves. When compared to short-shoot leaves, long-shoot leaves in male trees had higher leaf hydraulic conductance (Kleaf) and leaf water potential of 50% loss in Kleaf (leaf P50), while female trees exhibited relatively higher Kleaf. When comparing sexual differences, male trees possessed higher leaf thickness, leaf dissection index, vein density (VD), and predawn leaf water potential and lower SLA, tracheid number, and midday leaf water potential, while no significant difference in leaf P50 was observed between the two sexes. Male trees exhibited greater leaf gas exchange rates, which were tightly associated with other functional traits, such as VD and Kleaf. We found strong shoot-based and sex-related heterogeneities in the leaf hydrology, anatomy, and economy of Ginkgo biloba. Moreover, male ginkgoes may perform better due to their greater leaf hydraulic efficiency and gas exchange rates.

Triacylglycerol lipase a10 (SlTGLa10) gene negatively regulates cold tolerance, vegetative and reproductive growth in tomato

Triacylglycerol (TAG) Lipases (TGLs) are the main enzymes involved in triacylglycerol catabolism. TGLs hydrolyze long-chain fatty acid triglycerides, which are involved in plant development and abiotic stress responses. Cold stress severely affects the yield of tomato plants; however, the mechanisms are not clear. Here, we show that Triacylglycerol Lipase a10 (SlTGLa10) negatively regulates cold tolerance and growth in tomato. Compared to wild-type (WT) plants, SlTGLa10 overexpression (OE) plants showed increased sensitivity to cold stress associated with higher levels of malondialdehyde, ion leakage and lipid peroxidation, lower activities of antioxidant enzymes, and reduced expression of several cold-responsive genes (SlCBF1, SlDRCi7, etc.) while the SlTGLa10 knockdown (KD) plants were moderately more cold-tolerant than WT. Expression of lipid transport and metabolism-related genes, and the TAG contents and composition were differentially affected in the OE and KD plants. The OE plants exhibited lighter seed weight, inhibited seed germination, shorter shoots and smaller fruits than WT plants, whereas KD plants showed the opposite phenotypes (heavier seeds, improved seed germination, longer shoots and larger fruits compared to the WT plants). Although our data indicated that SlMYB16 might not bind to conventional MYB-recognition sites in the promoter region of SlTGLa10, the transcript levels of SlTGLa10 were reduced in tomato plants overexpressing SlMYB16. The results suggest that SlMYB16 may function as a negative factor for the transcription of SlTGLa10. Overall, our work emphasizes the importance of SlTGLa10 for cold tolerance and growth and development in tomato and can provide a straightforward breeding strategy to develop crops that are cold-resistant and high-yielding.

If self-shading is so bad, why is there so much? Short shoots reconcile costs and benefits.

If trees minimize self-shading, new foliage in shaded parts of the crown should remain minimal. However, many species have abundant foliage on short shoots inside their crown. In this paper, we test the hypothesis that short shoots allow trees to densify their foliage in self-shaded parts of the crown thanks to reduced costs. Using 30 woody species in Mediterranean and tropical biomes, we estimated the contribution of short shoots to total plant foliage, calculated their costs relative to long shoots including wood cost and used 3D plant simulations calibrated with field measurements to quantify their light interception, self-shading and yield. In species with short shoots, leaves on short shoots account for the majority of leaf area. The reduced cost of short stems enables the production of leaf area with 36% less biomass. Simulations show that although short shoots are more self-shaded, they benefit the plant because they cost less. Lastly, the morphological properties of short shoots have major implications for whole plant architecture. Taken together, our results question the validity of only assessing leaf costs to understand leaf economics and call for more integrated observations at the crown scale to understand light capture strategies in woody plants.

Variable leaf shape on short and long shoots: an elliptic Fourier analysis of Prunus microcarpa C.A.Mey

Variable leaf shape on short and long shoots: an elliptic Fourier analysis of Prunus microcarpa C.A.Mey

Growth Characteristics of Five Plum Varieties on Six Different Rootstocks Grown in Containers at Different Irrigation Levels

In contrast to other European countries, the nurseries in Hungary mainly use Myrobalan seedlings as rootstock for plum trees; no experience with other rootstocks is available yet. The aim of our research was to gather experience and recommend rootstocks to growers that are adapted to the climatic conditions and can be used in high-density intensive orchards. In the experiment, six rootstocks (Myrobalan seedlings, ‘St. Julien GF655/2’, ‘St. Julien A’, ‘Fereley’, ‘Wangenheim’ and ‘WaVit’) and five varieties (‘Topper’, ‘Toptaste’, ‘Topfive’, ‘Čačanska lepotica’ and ‘Jojo’) were tested. The experimental plantation was established in Kecskemét, in the lowland region of Hungary, which is characterised by low humus content and dry climatic conditions. The trees received two different irrigation doses from 2012 onwards, one for each half of the trees (six trees) of a combination. The first irrigation dose was 2 L and the second was 4 L per hour. Trees with the highest trunk cross-sectional area (TCSA) and canopy volume were ‘Topper’, ‘Toptaste’ and ‘Topfive’ on the ‘Fereley’ rootstock, but this rootstock showed lower survival, with only 33–50% of trees surviving the 2× dose irrigation. The average TCSA values of the rootstocks showed that ‘Wangenheim’ and ‘WaVit’ rootstocks resulted in too poor growth. In contrast, the Myrobalan seedling (Sdlg) and ‘St. Julien GF655/2’ provided strong growth to the trees based on the TCSA and canopy volume data. The results of the analysis of shoot growth showed that irrigation did not significantly affect shoot length, except for ‘Jojo’. The plum trees developed fruit trees typical of the cultivars after fruiting, with little influence of the rootstocks. ‘Topper’ and ‘Čačanska lepotica’ were dominated by bunched and bunched shoots, while ‘Topfive’ was dominated by short shoots and ‘Toptaste’ developed the highest proportion of long shoots.

Middle-Late Jurassic fossils from Northeast China confirm the affiliation of Umaltolepis seed-bearing structures and Pseudotorellia leaves

Umaltolepis seed-bearing structures and Pseudotorellia leaves were considered to be produced by the same plant according to their consistent association in the same bed and similarities in cuticular structures. Here we describe new fossils of Umaltolepis and Pseudotorellia based on well-preserved materials from the Middle-Late Jurassic Daohugou Bed in eastern Inner Mongolia, Northeast China. Umaltolepis zhoui sp. nov. is an umbrella-like, four-lobed cupule that was borne on a stalk at the tip of a short shoot. The stalk is cylindrical, with a prominent cup-like flange situated at the tip of the stalk and below the cupule. The short shoot bears growth cycles consisting of alternating pseudo-whorled bud scales and abscission scars. The cupule lobes are resinous, having sparse, longitudinally oriented stomata. Pseudotorellia zhoui sp. nov. is established based on a two-order leafy shoot and isolated leaves. The ultimate short shoot bears terminal clustered strap-shaped leaves, and alternating pseudo-whorled bud scales and abscission scars on surface. Leaves have acute apex, cuneate base; each bearing 4 to 8 longitudinal parallel veins. Abaxial cuticle has sparse, longitudinally to leaf margin oriented stomata which are arranged in 1–3 discontinuous files in the stomatal bands. The co-occurrence of U. zhoui and P. zhoui in the Daohugou Bed and their similarities in cuticular structures and morphology of attached short shoots further confirm that Umaltolepis and Pseudotorellia are produced by the same plant. These fossils also provide new evidence for a close relationship between the Mesozoic Umaltolepis-Pseudotorellia plant and living Ginkgo.

Plant sizes and shapes above and belowground and their interactions with climate.

Summary Although the above and belowground sizes and shapes of plants strongly influence plant competition, community structure, and plant–environment interactions, plant sizes and shapes remain poorly characterized across climate regimes. We investigated relationships among shoot and root system size and climate.We assembled and analyzed, to our knowledge, the largest global database describing the maximum rooting depth, lateral spread, and shoot size of terrestrial plants – more than doubling the Root Systems of Individual Plants database to 5647 observations.Water availability and growth form greatly influence shoot size, and rooting depth is primarily influenced by temperature seasonality. Shoot size is the strongest predictor of lateral spread, with root system diameter being two times wider than shoot width on average for woody plants.Shoot size covaries strongly with rooting system size; however, the geometries of plants differ considerably across climates, with woody plants in more arid climates having shorter shoots, but deeper, narrower root systems. Additionally, estimates of the depth and lateral spread of plant root systems are likely underestimated at the global scale.

The planting of licorice increased soil microbial diversity and affected the growth and development of apple trees

ABSTRACT Grass cultivation is an important soil management practice for improving orchard soil quality. A suitable grass variety can enhance the soil microenvironment and increase fruit yield and quality. In the arid regions of northwestern China, licorice is often planted between apple trees. To clarify the effects of licorice on the soil microenvironment and apple tree growth and development,apple trees and licorice were grown in a root limiter under the following three treatment conditions: apple alone (A), intercropping of apple and licorice (AL), and licorice alone (L). Several soil properties (e.g., salt, soil organic matter, nitrogen, phosphorus, and potassium contents) were analyzed. Additionally, soil microbial communities were characterized via the high-throughput sequencing of bacterial and fungal rRNA gene markers. Apple tree growth and development indices were also determined.The soil organic matter, total and available nitrogen, and the available phosphorus contents were significantly higher in the L treatment soil than in the original soil or the A and AL treatment soils. The compositions of the dominant bacteria and fungi were similar among treatments. Soil bacterial and fungal richness and diversity were greater for the L and AL treatments than for the A treatment. At the phylum level, the characteristic bacteria for the A and L treatments were Gemmatimonadetes and Chloroflexi species, respectively. Some soil properties, including soil organic matter, available N, available P, and available K contents, were significantly correlated with bacterial and fungal taxa. Furthermore, the apple tree growth and development indices trunk diameter, crown size, 1-year-old branch length, and the proportion of short shoots were respectively 25.66%, 21.70%, 28.23%, and 20.78% lower for the AL treatment than for the A treatment.Cultivating licorice alone or intercropping with apple trees can increase or maintain the soil organic matter, total and available nitrogen, and available phosphorus contents as well as the microbial composition and abundance. However, intercropping with licorice will restrict fruit tree growth and development (e.g., proportion of short shoots and the trunk diameter).

Natural Variation in the Control of Flowering and Shoot Architecture in Diploid Fragaria Species.

In perennial fruit and berry crops of the Rosaceae family, flower initiation occurs in late summer or autumn after downregulation of a strong repressor TERMINAL FLOWER1 (TFL1), and flowering and fruiting takes place the following growing season. Rosaceous fruit trees typically form two types of axillary shoots, short flower-bearing shoots called spurs and long shoots that are, respectively, analogous to branch crowns and stolons in strawberry. However, regulation of flowering and shoot architecture differs between species, and environmental and endogenous controlling mechanisms have just started to emerge. In woodland strawberry (Fragaria vesca L.), long days maintain vegetative meristems and promote stolon formation by activating TFL1 and GIBBERELLIN 20-OXIDASE4 (GA20ox4), respectively, while silencing of these factors by short days and cool temperatures induces flowering and branch crown formation. We characterized flowering responses of 14 accessions of seven diploid Fragaria species native to diverse habitats in the northern hemisphere and selected two species with contrasting environmental responses, Fragaria bucharica Losinsk. and Fragaria nilgerrensis Schlecht. ex J. Gay for detailed studies together with Fragaria vesca. Similar to F. vesca, short days at 18°C promoted flowering in F. bucharica, and the species was induced to flower regardless of photoperiod at 11°C after silencing of TFL1. F. nilgerrensis maintained higher TFL1 expression level and likely required cooler temperatures or longer exposure to inductive treatments to flower. We also found that high expression of GA20ox4 was associated with stolon formation in all three species, and its downregulation by short days and cool temperature coincided with branch crown formation in F. vesca and F. nilgerrensis, although the latter did not flower. F. bucharica, in contrast, rarely formed branch crowns, regardless of flowering or GA20ox4 expression level. Our findings highlighted diploid Fragaria species as rich sources of genetic variation controlling flowering and plant architecture, with potential applications in breeding of Rosaceous crops.

Molecular evidence to the day length in regulating the short shoot phenomenon during summer in roses (Rosa sp.)

ABSTRACT The short shoot phenomenon is an important phenotype underlying the economic value of roses – node number can directly affect shoot length. To elucidate the molecular mechanism of how day length affects shoot length, the effect of 8, 10, and 12 h day lengths on node number were studied. The number of nodes between the 8 and 12 h treatment groups significantly differed. Node development in the 12 h treatment group occurred significantly earlier than that in the 8 and 10 h treatment groups and the number of nodes reached a maximum on the third day. Using RNA-seq analysis, we identified candidate genes that regulated shoot length; these were involved in the abscisic acid synthesis pathway and auxin signal transduction and synthesis pathways. Furthermore, the abscisic acid content in the shoot tip decreased with an increasing day length, while the auxin content increased with day length.

Exhibition Review: Niki de Saint Phalle: Structures for Life

Exhibition Review: <i>Niki de Saint Phalle: Structures for Life</i>