Increased Stem Height Research Articles

Within-tree variation regarding ultrasonic velocity, wood density and compressive strength of the eucalypt hybrid (Eucalyptus urophylla × E. pellita)

ABSTRACT A variation study of the ultrasonic velocity (Vu ), wood density (AD), and compressive strength (CS) within trees (longitudinal and radial) of the eucalypt hybrid uropellita (Eucalyptus urophylla × E. pellita) was carried out for the first time. Vu was measured in pith-to-bark strips collected from six stem height levels (0.5, 1.5, 2.5, 3.5, 4.5, and 5.5 m above the ground) in the longitudinal axis using air-coupled ultrasonic techniques, and AD and CS were measured for small clear specimens obtained from these strips. In general, Vu increased outwards from the pith with increasing stem height. The overall mean values of Vu , AD, and CS were 2872 m/s, 0.50 g/cm3, and 41.40 MPa, respectively. Within the stem, the radial position was highly significant (P < 0.001) for all traits, whereas the longitudinal variation was significant only for Vu but its contribution was small (approximately 9% of the total variation). Vu and AD had significant (P < 0.05) positive linear correlations with CS in both the radial position and combined radial positions. The best prediction of CS was obtained when Vu and AD were used together by calculating the dynamic modulus of elasticity (Ed ).

Application of Rice Straw Compost and NPK Fertilizer to Increase The Growth of Kale Land (Ipomoea reptans poir)

Kale land can grow well in various environmental conditions. Fertilization is one way that can be done to increase the growth of Ipomoea reptans poir using both organic and inorganic fertilizers. Research on the application of rice straw compost and NPK fertilizer to increase the size of stems and leaves of Ipomoea reptans poir has been completed in 2023. This research aims to analyze: (1) the effectiveness of using NPK fertilizer on the size of stems and leaves of Ipomoea reptans poir, 2) the effectiveness of using rice straw compost on the size of stems and leaves of Ipomoea reptans poir, (3) the effectiveness of the combination of using rice straw compost and NPK fertilizer on the size of stems and leaves of Ipomoea reptans poir. Two factorial design was applied in this research. The results were obtained: (1) the application of rice straw compost was significantly effective in increasing stem height, leaf length and leaf width but could not increase the rate of increase in the number of kale land leaves, (2) NPK fertilizer treatment had a real effect on increasing the overall growth parameters observed, (3) ) the combined application of rice straw compost and NPK fertilizer did not have a significant effect on leaf width, number of leaves, leaf length and stem height of kale land.

Analysis of Purple Eggplant Growth After Vermicompost and NPK Fertilizer Treatment

Eggplant growth rate is determined by genetic and environmental factors. Environmental factors that affect eggplant growth include the availability of nutrients on agricultural land. Research on analysis of purple eggplant growth after vermicompost and NPK fertilizer treatment was carried out from March to July 2023. This study aims to analyze the effect of the application of vermicompost on the growth of purple eggplant. The application of NPK fertilizer on the growth of purple eggplant. The interaction effect of vermicompost and NPK fertilizer treatment on purple eggplant growth. Growth parameter data were analyzed using the F test. The results showed that: Vermicompost application increased stem height, total leaves and leaf length but did not increase leaf width and stem diameter of purple eggplant. The application of NPK fertilizer was effective in increasing stem height, total leaves, leaf length, leaf width and stem diameter of purple eggplant. The interaction of vermicompost treatment and NPK fertilizer was not effective in increasing all measured growth parameters.

PIF4 enhances the expression of SAUR genes to promote growth in response to nitrate

Nitrate supply is fundamental to support shoot growth and crop performance, but the associated increase in stem height exacerbates the risks of lodging and yield losses. Despite their significance for agriculture, the mechanisms involved in the promotion of stem growth by nitrate remain poorly understood. Here, we show that the elongation of the hypocotyl of Arabidopsis thaliana, used as a model, responds rapidly and persistently to upshifts in nitrate concentration, rather than to the nitrate level itself. The response occurred even in shoots dissected from their roots and required NITRATE TRANSPORTER 1.1 (NRT1.1) in the phosphorylated state (but not NRT1.1 nitrate transport capacity) and NIN-LIKE PROTEIN 7 (NLP7). Nitrate increased PHYTOCHROME INTERACTING FACTOR 4 (PIF4) nuclear abundance by posttranscriptional mechanisms that depended on NRT1.1 and phytochrome B. In response to nitrate, PIF4 enhanced the expression of numerous SMALL AUXIN-UP RNA (SAUR) genes in the hypocotyl. The growth response to nitrate required PIF4, positive and negative regulators of its activity, including AUXIN RESPONSE FACTORs, and SAURs. PIF4 integrates cues from the soil (nitrate) and aerial (shade) environments adjusting plant stature to facilitate access to light.

The Root Collar Diameter Growth Reveals a Strong Relationship with the Height Growth of Juvenile Scots Pine Trees from Seeds Differentiated by Spectrometric Feature

This study is intended for forest owners considering options to increase the efficiency of the production of forest seedlings in automated nurseries. In the short rotation technology of the Scots pine (Pinus sylvestris L.), the production of seedlings was integrated in the process of grading seeds by spectrometric features, followed by the fall outplanting of containerized seedlings to a restorable post-pyrogenic site. There are studies of the spectrometric effect grading viable seeds, but a negligible amount of testing has been conducted on the seedling’s field performance from these seeds. It was very important for us to evaluate the morphogenesis of juvenile Scots pine trees in relation to the change in morphological features—increase in root collar diameter (RCD-increment) and increase in stem height (SH-increment)—in the second and third growing season from the field outplanting. To determine the nature of the interaction between independent (RCD increase), dependent (SH-increment), and categorical (seed spectrometric categories and timespans) variables, a regression analysis was performed using the R statistical software. All coefficients of the linear models are statistically significant at the 1% significance level, and all are positively associated with an increase in seedling height. On average, a RCD increment by 0.1 cm causes a SH-increment by 0.72 ± 0.16 cm (p = 9.779 × 10−6). In addition, in 2020, compared to 2019, the SH-increment was 5.46 ± 0.37 cm (p &lt; 0.001). The seeds’ differentiation into spectrometric categories is strongly correlated with the stem height increment (p &lt; 0.001). Thus, in order to improve the plant propagation protocol, it seems advisable to first condition the seeds in accordance with the spectrometric feature, and to then apply a coating (by pelleting or encapsulating) in order to improve the storage and seeding conditions. For a medium-term assessment of the short rotation technology with an integrated seed spectrometric grading in the future, the morphogenesis of Scots pine trees at 5, 7 and 10 growing seasons from the seedlings field outplanting is controlled.

Tree stems are a net source of CH4 and N2O in a hemiboreal drained peatland forest during the winter period

Nutrient-rich northern peatlands are often drained to enhance forest productivity, turning peatland soils into sinks of methane (CH4) and sources of nitrous oxide (N2O). However, further attention is needed on CH4 and N2O dynamics during the winter period to fully understand the spatio-temporal variability of fluxes. Besides soil, tree stems can also emit CH4 and N2O. However, stem contribution is not considered in most biogeochemical models. We determined the temporal dynamics of winter-time CH4 and N2O fluxes in a drained peatland forest by simultaneously measuring stem and soil fluxes and exploring the relationships between gas fluxes and soil environmental parameters. During sampling (October 2020–May 2021), gas samples from Downy Birch (Betula pubescens) and Norway Spruce (Picea abies) trees were collected from different tree heights using manual static chambers and analysed using gas chromatography. Soil CH4 and N2O concentrations were measured using an automated dynamic soil chamber system. Tree stems were a net source of CH4 and N2O during the winter period. The origin of stem CH4 emissions was unclear, as stem and soil CH4 fluxes had opposite flux directions, and the irregular vertical stem flux profile did not indicate a connection between stem and soil fluxes. Stem N2O emissions may have originated from the soil, as emissions decreased with increasing stem height and were driven by soil N2O emissions and environmental parameters. Soil was a net sink for CH4, largely determined by changes in soil temperature. Soil N2O dynamics were characterised by hot moments—short periods of high emissions related to changes in soil water content. Tree stem emissions offset the soil CH4 sink by 14% and added 2% to forest floor N2O emissions. Therefore, CH4 and N2O budgets that do not incorporate stem emissions can overestimate the sink strength or underestimate the total emissions of the ecosystem.

Growth promotion potential ofBacillusspp. isolates on two tomato (Solanum lycopersicumL.) varieties in the West region of Cameroon

AbstractInoculation of plants with plant growth-promoting bacteria (PGPB) is an ecological approach to improve plants growth and yield. The objective of this study was to screen native PGPBs in tomato root rhizosphere and evaluate their performance in germination and growth of seedlings in the greenhouse in the western region of Cameroon. Isolates were selected based on their ability to solubilize phosphate, produce indole-3-acetic acid, and improve seed germination and seedling growth under laboratory conditions. Following this screening, eight bacteria were selected (S1, S4, S13, S14, S16, B9, B11, and B15) to assess their performance on seedling growth in greenhouse. Seeds of two tomato varieties (one improved, Raja, and the local one, Foolewouh) were used in this study. The experiment was performed in sterilized and non-sterilized soils. Phylogenetic analysis of the 16S rRNA sequence showed that these bacteria belong to the genusBacillus, includingB. thuringiensis,B. cereus,B. pacificus, andB. aerius. The bacterial performance depended on the variety and conditions of soil treatment. Isolates improved seed germination (up to 31.93%) and seeding strength (up to 78.59%)in vitro. In greenhouse, inoculation with PGPB significantly increased stem height, root length, and weight of fresh and dry stems and roots. Raja variety was more sensitive to bacteria and performed better than the Foolewouh variety. Bacterial isolates on sterilized soil allowed to better seedling growth compared to non-sterilized soil. The study showed thatB. thuringiensis(strain B9),B. pacificus(strain B11), andBacillussp. (strain B15) can be used as inoculant formulations to improve seedling growth of tomato plant.

Recovery of salt marsh vegetation after ice-rafting

Sediment transport on salt marsh platforms is usually brought about through storm events and high tides. At high latitudes, ice-rafting is a secondary mechanism for sediment transport, redistributing sediment from tidal flats, channels, and ponds to marshland. In January 2018, winter storm Grayson hit the North Atlantic coast, producing a large storm surge and a significant decrease in temperature. The Great Marsh in Plum Island Sound, Massachusetts, USA, experienced an unprecedented sediment deposition due to ice-rafting, burying marsh vegetation. Plant vegetation recovery was investigated in 17 sediment patches, dominated by Spartina patens, Distichlis spicata, Juncus gerardi, and S. alterniflora. The analysis was carried out considering the number of stems and stem height for each vegetation species. D. spicata firstly occupied bare patches, while S. patens, once smothered by sediment, regrew slowly. The number of stems of S. patens inside the sediment patches recovered, on average, after 2 growing seasons. The number of J. gerardi stems was not significantly affected by ice-rafted sediment deposition. S. alterniflora dynamics were different depending on physical and edaphic conditions. At some locations, S. alterniflora did not recover after sediment deposition. The deposition of the sediment layer had a positive effect on vegetation vigor, increasing stem height and maintaining high stem density. The results suggest a beneficial effect of sediment deposition not only for marsh accretion, but also for marsh vegetation growth, both of which are fundamental for marsh restoration.

Changes in White-Tailed Deer Browsing Selection of Hardwood Tree Species with Increasing Stem Height

To forage optimally, deer select individual plants highest in limiting nutrients, while avoiding individuals that are high in anti-herbivore defenses. For some woody species, deer may selectively browse on larger stems, which can provide a larger amount of younger, more nutritious tissue per individual. However, in some species, larger stems may possess increased levels of anti-herbivore defenses, ultimately discouraging deer from browsing on these larger individuals. We examined differences in the proportion of twigs and stems (individual seedlings/saplings/trees) browsed across three height classes for four species: blue ash (Fraxinus quadrangulata Michx,), white ash (F. americana L.), sassafras (Sassafras albidium Nutt.), and sugar maple (Acer saccharum L.), across multiple sites in central Indiana. Overall, we found that taller stems had a higher likelihood of being browsed, but smaller stems were browsed more heavily. We also found that sugar maple twigs and stems were most likely to be browsed, while sassafras twigs and white ash twigs and stems were least likely to be browsed. Our results indicate that under intense browsing pressure, preference should be given to smaller stems for protection, and that stands with greater vertical stratification of palatable species are more resilient to the effects of deer browsing.

Effect of Radiation Quality and Relative Humidity on Intumescence Injury and Growth of Tomato Seedlings

Intumescence is a physiological disorder that affects some tomato (Solanum lycopersicum) cultivars grown in environments lacking ultraviolet radiation. Both far-red (FR) radiation and blue light have been shown to help mitigate this disorder. Thus, the objectives of this study were to characterize and compare intumescence injury and growth of various tomato cultivars propagated under different radiation qualities (Expt. 1) and to evaluate plant responses to the interactive effect of radiation quality and relative humidity (RH) (Expt. 2). Seedlings of six cultivars in Expt. 1 were grown under broad band white light (W), W and blue with (WBFR) or without (WB) FR radiation, and blue and red light with FR radiation (BRFR). Seedlings of four cultivars in Expt. 2 were grown under W or WBFR and a low (≈50%) or high (≈95%) RH. In both experiments, seedlings were grown under a daily light integral of ≈13 mol·m‒2·d‒1 (200 ± 4 μmol·m‒2·s‒1 for 18 h·d−1). FR radiation was provided using 20 ± 2 μmol·m−2·s−1 delivered throughout the entire photoperiod or at the end-of-day (EOD) in Expts. 1 or 2, respectively. Intumescence was generally suppressed when seedlings in Expt. 1 were grown under BRFR and WBFR, which also corresponded with the general response to stomatal conductance (gs). In contrast, seedlings grown under W had the highest incidence of intumescence, ranging from 23% to 69% across cultivars. The high blue photon flux (PF) ratio in WB was not effective at suppressing intumescence injury without FR radiation, although incidence and severity were lower compared with W. In Expt. 2, intumescence incidence was generally lower in seedlings grown under WBFR, and RH had small effects on intumescence. In both experiments, younger leaves were relatively less affected by intumescence, suggesting that a developmental factor is associated with the disorder. As expected, providing FR radiation resulted in a general increase in stem height across cultivars and in both experiments. The high RH provided in Expt. 2 also resulted in an increase in stem height. However, seedlings under low RH produced larger leaves, lower specific leaf area, and more shoot dry mass than those under high RH. Overall, our findings show that applying FR radiation helps suppress intumescence, but strategies are needed to minimize issues with excessive stem elongation.

Uji Pemberian Dosis Pupuk Daun terhadap Pertumbuhan dan Hasil Tanaman Tebu (Saccharum officinarum L.) Terbakar

Sugar production has decreased due to the fertilization method. One solution is to apply the proper dose of fertilization. The purpose of this study was to determine the application of various doses of foliar fertilizer on the growth and yield of the JR 01 variety at the age of 7 months burned in Gresik Regency. This study used a Randomized Block Design with one factor, namely P0 (control), P1 (cow urine fertilizer 20 ml/liter), P2 (cow urine fertilizer 40 ml/liter), P3 (cow urine fertilizer 60 ml/liter), P4 (Petrovita fertilizer 3 ml/liter), P5 (Petrovita fertilizer 6 ml/liter), and P6 (Petrovita fertilizer 9 ml/liter). Each was repeated four times so that there were 28 experimental units with observation variables, including growth variables (increase in stem height, stem diameter, number of stems, number of segments, number of tillers) and yield variables (Brix, yield, weight per cane stalk (g plant-1) and weight per cane stalk (t ha-1). Observational data were then analyzed using analysis of variance (ANOVA). If there was a significant difference, proceed with the Least Significant Difference test (LSD) 5% and correlation test. In the growth variable, the highest significant differences were between ages 44, 46, and 48 weeks after planting (WAP) and the use of cow urine fertilizer on the variable number of tillers. While in the yield variable, there was the highest significant difference at the age of 44 WAP using petrovita fertilizer on the Brix and yield variables. There was a significant correlation with a very strong and unidirectional relationship between the growth and yield variables. Effective treatment in increasing growth in the number of tillers, namely P2 (cow urine fertilizer 40 ml/liter), effective therapy in increasing Brix yield, and the yield is P5 (Petrovita fertilizer 6 ml/liter).

Identifying Sources and Oxidation of Methane in Standing Dead Trees in Freshwater Forested Wetlands

Wetlands are large sources of methane (CH4), therefore it is vital to understand the pathways, mechanisms, and sources to anticipate future positive feedbacks to climate change. Plant mediated transport of CH4 from sediment-borne gases is thought to be a major contributor in wetland ecosystems, though few studies have measured standing dead trees (snags). Snags are expected to become more common across the southeastern coast as marshes migrate into freshwater forested wetlands. In this study, our goal was to distinguish the main sources of CH4 being emitted from snags, that is, from soil or in situ origin. The δ2H and δ13C stable isotopic composition from various sources was sampled for source determination. We measured CH4 in various components: emissions from snag stem sides and the soil-atmosphere interface; and concentrations from snag trunk airspace at various heights from ground level (30, 60, and 120 cm), and soil porewater. Potential CH4 production and oxidation in tree cores from two heights (60 and 120 cm) was also measured to examine the potential for CH4 generation or oxidation in stems. We found that CH4 concentrations inside snags (∼10–200 ppm) were 2–50 times higher than atmospheric levels, and generally decreased with increasing stem height. The stable isotopes δ13C and δ2H showed an enrichment from porewater to soils and snag stems. δ13C enrichment of CH4 in snag stems suggests that CH4 is being oxidized as it moves through snags. The tree core vial incubations showed that very few cores produced small amounts of CH4 under anaerobic conditions (n = 5 out of 50), and very few cores oxidized CH4 under more aerobic conditions (n = 5 out of 50). It is possible that a small amount of CH4 is produced in-situ within the heartwood, but it is likely this depends on the density, porosity, and aeration of snags (degree of decay). Our results highlight that high concentrations of CH4 can persist within the heartwood of snags long after initial decay, and that CH4 emitted from snags is largely derived from deep wetland soils and oxidized during transport (via diffusion) throughout the stem of snags.

Effect of climate warming on seedling growth and biomass accumulation of Acacia modesta and Olea ferruginea in a subtropical scrub forest of Pakistan

ABSTRACT This study investigated the short-term impacts of projected climate warming on two dominant tree species of the Hayat-ul-Mir subtropical scrub forest of Pakistan. Seedlings of Acacia modesta and Olea ferruginea were exposed to ambient (To) and warming temperature (To + 2.3°C and To + 4.5°C) with control (M15%) and elevated (M20%) soil moisture in plant growth chamber for 90 days. To + 4.5°C induced detrimental effects on both species inhibiting seed germination and reducing their growth rate, biomass accumulation and allocation, however promoted development of root nodules (12 ± 4,0 nodules/root) in A. modesta. To + 2.3°C with M20% was beneficial for O. ferruginea with significant increase in stem height (4.8 ± 1.4 cm), elongated roots (31.2 ± 3.4 cm), branch development (9 ± 1.7), biomass accumulation (8.69 ± 0.4 g) and higher foliar nutrient concentration but for A. modesta it only promoted root elongation (16.5 ± 1.3 cm) and biomass accumulation in stem (1.05 ± 0.1 g) and foliage (0.08 ± 0.001 g). A. modesta grew better under To with significantly high germination and survival rate. A future 2.3°C warming could be ecologically significant to induce shifts in the structure and function of the Hayat-ul-Mir forest.

The effectiveness of Ryzoboft and Ryzohumin microbiological preparations use for beans biometric indicators (Faba bona Medic)

The use of biological preparations based on nodule bacteria and complexes containing, except rhizobia, biologically active substances is a cost-effective and environmentally sound element of legumminous cultivation technologies. The study aimed to establish the influence of pre-sowing treatment of seeds with microbiological preparations Ryzoboft and Ryzohumin according to the indicators of growth processes (Faba bona Medic) of Khorostkivskyi variety beans in the conditions of Western Forest-Steppe of Ukraine. The research was conducted during 2018–2020 in the felds of agrobiolaboratory of Ternopil National University named after Volodymyr Hnatiuk. During the vegetation period, the height of the stem was measured, the number of leaves on the plant was counted, and the raw and dry weight of the aboveground organs and the root system were determined. It was established that microbiological preparations Ryzoboft and Ryzohumin affect the growth processes of beans against the background of spontaneous inoculation by local populations of nodule bacteria. The increase in stem height of the experimental plants in comparison with the control of pre-sowing treatment of seeds with Ryzohumin at the beginning of flowering was 13,9 %, during flowering –14,1 %, and in the green bean phase – 9,0 %. Pre-sowing inoculation with Ryzoboft signifcantly increased the height of the bean stalk only in the green bean phase – 11,8 %. During flowering of beans with the use of the Ryzohumin signifcantly increased the number of leaves on the plant – by 25,7 % compared to the control. In the green bean phase, both studied preparations signifcantly influenced the process of leaf formation. There was a signifcant effect on the foliage of plants of the Ryzohumin, compared with Ryzoboft during the study period. Statistically signifcant increase in the indicators of raw and dry mass of aboveground organs of beans in the green bean phase under the influence of Ryzoboft and Ryzohumin was revealed. During flowering in the conditions of pre-sowing treatment of seeds with Ryzohumin, a signifcant increase in the raw mass of the root system was found. The obtained results indicate the prospects of further studies of production processes of bean plants under the influence of microbiological preparations Ryzoboft and Ryzohumin. Key words: beans, inoculation, Ryzoboft, Ryzohumin, vegetation period, biometric indicators.

Irrigation of wheat with select hydraulic fracturing chemicals: Evaluating plant uptake and growth impacts.

Oilfield flowback and produced water (FPW) is a waste stream that may offer an alternative source of water for multiple beneficial uses. One practice gaining interest in several semi-arid states is the reuse of FPW for agricultural irrigation. However, it is unknown if the reuse of FPW on edible crops could increase health risks from ingestion of exposed food, or impact crop growth. A greenhouse experiment was conducted using wheat (Triticum aestivum) to investigate the uptake potential of select hydraulic fracturing additives known to be associated with health risks. The selected chemicals included acrylamide, didecyldimethylammonium chloride (DDAC), diethanolamine, and tetramethylammonium chloride (TMAC). Mature wheat grain was extracted and analyzed by liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ) to quantify chemical uptake. Plant development observations were also documented to evaluate impacts of the chemicals on crop yield. Analytical results indicated that TMAC and diethanolamine had significantly higher uptake into both wheat grain and stems than control plants which were not exposed to the four chemicals under investigation. Acrylamide was measured in statistically higher concentrations in the stems only, while DDAC was not detected in grain or stems. Growth impacts included lodging in treated wheat plants due to increased stem height and grain weight, potentially resulting from increased nitrogen application. While analytical results show that uptake of select hydraulic fracturing chemicals in wheat grain and stems is measurable, reuse of FPW for irrigation in real world scenarios would likely result in less uptake because water would be subject to natural degradation, and often treatment and dilution practices. Nonetheless, based on the outstanding data gaps associated with this research topic, chemical specific treatment and regulatory safeguards are still recommended.

Evaluation of bioformulation of Enterobacter sp. UPMSSB7 and mycorrhizae with silicon for white root rot disease suppression and growth promotion of rubber seedlings inoculated with Rigidoporus microporus

White root rot (WRR) disease, caused by Rigidoporus microporus, is one of the major constraints causing the economic loss to rubber plantation worldwide including in Malaysia. This glasshouse study was conducted to evaluate the efficacy of a peat-based bioformulation of Enterobacter sp. UPMSSB7 and an arbuscular mycorrhizal fungus (AMF, Glomus mosseae) with silicon (Si) for WRR suppression and plant growth promotion of rubber seedlings. Results revealed that the tested bioformulation significantly (P < 0.0001) reduced the disease compared to positive control while, was not significantly different than the propiconazole, a triazole fungicide. The lower values of disease incidence, disease severity of foliar and root rot symptoms, area under disease progress curve, pathogen colonization and higher value of disease reduction were recorded in both bioformulation and the triazole fungicide treated seedlings than positive control treatment 24 weeks after inoculation with R. microporus. Results indicated that pathogen-inoculated seedlings treated with bioformulation had significantly (P < 0.0001) increased stem height, girth size, chlorophyll content, leaf area, shoot and root dry weight, total root length, root volume and root surface area (103.8 cm, 8.08 mm, 56.62 SPAD value, 3534.8 cm2, 37.04 g and 36.76 g, 1617.7 cm, 24.15 cm3 and 402.97 cm2, respectively) as compared to fungicide and control treatments. The tested bioformulation also significantly (P < 0.0001) increased silicon content in root and shoot (18.56 g kg−1 and 27.61 g kg−1, respectively) as well as leaf nutrient (N, P, K and Ca) contents (3.89%, 0.19%, 1.06% and 0.57%, respectively) as compared to the triazole fungicide and control treatments. The population of Enterobacter sp. (1.1 × 108 cfu g−1 soil) recorded in pathogen-inoculated seedlings treated with bioformulation was not significantly different than non-inoculated seedlings treated with bioformulation. AMF spore density and root colonization were recorded higher in bioformulation treated seedlings with or without pathogen inoculation than the triazole fungicide and control treatments. From this study, it was concluded that the peat-based bioformulation of Enterobacter sp. and an AMF (Glomus mosseae) with Si could be a potential approach to suppress WRR and improve growth of rubber seedlings.

Genome-wide identification and expression profiling of the YUCCA gene family in Malus domestica

The plant hormone auxin is essential for plant growth and development. YUCCA proteins catalyse the rate-limiting step for endogenous auxin biosynthesis. In this study, we isolated 20 MdYUCCA genes from apple genome. MdYUCCA6a, MdYUCCA8a, and MdYUCCA10a were expressed in most organs and could support whole plant basal auxin synthesis. MdYUCCA4a, MdYUCCA10b, and MdYUCCA11a expression indicated roles for these genes in auxin biosynthesis in vegetative organs. MdYUCCA2b, MdYUCCA11b, and MdYUCCA11d were mainly expressed in flower organs. High temperature induced the expression of MdYUCCA4a, MdYUCCA6a, MdYUCCA8a, and MdYUCCA10a, and down-regulated the expression of MdYUCCA2b and MdYUCCA6b. Dual-luciferase assay indicated that MdPIF4 could trans-activate the MdYUCCA8a promoter. Overexpression of MdYUCCA8a increased IAA content, increased stem height, enhanced apical dominance, and led to silique malformation. These results provide a foundation for further investigation of the biological functions of apple MdYUCCAs.

Underwater oblique shock wave reflection from submerged hydraulic structures

This paper investigates the effect of obliquity on impulse imparted to the hydraulic structures by an underwater shock wave. In this regard, the oblique shock reflection phenomenon due to a planar shock wave impingement on an inclined rigid surface is numerically modeled. Results from simulations are presented in this manuscript for different shock strengths and angles of structure obliquity. The study reveals that impulse transmitted to the structure due to oblique shock reflection is lower than that of normal incidence. In specific regimes of structure obliquity to incident shock direction, the formation of Mach-stem is observed, i.e., triple point configuration at a certain distance from the structure. Inside these regimes, the stem height decreases with the increase in structure obliquity and vice versa. Locus of the triple point has a direct implication on the magnitude of transmitted impulse, which reduces with the increase in stem height, i.e., more the locus of the triple point is away from the structure, less is the transmitted impulse. Results presented in this manuscript may help in understanding the physics of shock reflections from submerged hydraulic structures and subsequently framing mitigation strategies.

Seed germination, growth and chlorophyll a fluorescence in young plants of Allophylus edulis in different periods of flooding

The distribution of woody species in flooded environments depends on the duration of stress as well as seed germination strategies and plant morphophysiological adaptations. Allophylus edulis is a tree that occurs in temporarily or permanently flooded areas in several countries of South America. In this paper, we evaluate seed germination, growth parameters, photosynthetic pigment contents and chlorophyll a fluorescence in young plants to understand the tolerance of the specie to flood events. The evaluations were performed in non-flooded (NFL) and flooded (FL) plants in a temporal scale that included short (up to 30 days) and long (up to 90 days) flood periods. A short flooding (15 days) may favor germination but maintaining stress for 60 days makes the seeds unviable. Although 71.4% of the FL plants survived up to 90 days of flooding, injuries such as chlorosis and foliar abscission appeared. An increase in stem height and diameter was only observed in NFL plants; whereas, FL plants showed a growth inhibition. At 90 days, NFL and FL plants presented total dry mass of 18.35 ± 1.57 g and 1.93 ± 0.62 g, respectively. The photosynthetic performance indexes indicated acclimatization of the plants on the third day of flooding, but the stress induced a progressive decline in the parameters, signaling damages to the photosystem II. Both seeds and young plants of A. edulis tolerate short periods of flooding, but prolonged floods make the seeds unfeasible and damages the photosynthetic apparatus, leading to death of the plants.

Altering potato isoprenoid metabolism increases biomass and induces early flowering

Isoprenoids constitute the largest class of plant natural products and have diverse biological functions including in plant growth and development. In potato (Solanum tuberosum), the regulatory mechanism underlying the biosynthesis of isoprenoids through the mevalonate pathway is unclear. We assessed the role of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) homologs in potato development and in the metabolic regulation of isoprenoid biosynthesis by generating transgenic lines with down-regulated expression (RNAi-hmgr) or overexpression (OE) of one (StHMGR1 or StHMGR3) or two genes, HMGR and farnesyl diphosphate synthase (FPS; StHMGR1/StFPS1 or StHMGR3/StFPS1). Levels of sterols, steroidal glycoalkaloids (SGAs), and plastidial isoprenoids were elevated in the OE-HMGR1, OE-HMGR1/FPS1, and OE-HMGR3/FPS1 lines, and these plants exhibited early flowering, increased stem height, increased biomass, and increased total tuber weight. However, OE-HMGR3 lines showed dwarfism and had the highest sterol amounts, but without an increase in SGA levels, supporting a rate-limiting role for HMGR3 in the accumulation of sterols. Potato RNAi-hmgr lines showed inhibited growth and reduced cytosolic isoprenoid levels. We also determined the relative importance of transcriptional control at regulatory points of isoprenoid precursor biosynthesis by assessing gene-metabolite correlations. These findings provide novel insights into specific end-products of the sterol pathway and could be important for crop yield and bioenergy crops.