Soluble sugar drives plant leaf turgor, restricts plant growth, and regulates plant hydraulic capacity of Haloxylon ammodendron to different groundwater level

Anthropogenic withdraw of groundwater and climatic drought results in the decline of groundwater depth that, in turn, severely limits the water availability for phreatophytic vegetation in arid regions. In this study, a small xeric, phreatophytic tree Haloxylon ammodendron (C.A. Mey.) was investigated to understand the influence of depth to groundwater (DGW) on hydraulic traits and on the trade-off between drought tolerance and leaf area increment. A suite of traits including leaf water potential, pressure–volume (P–V) curves, Huber value, assimilation branch growth, and osmotic regulation substance were measured across five sites with DGW ranges from 3.45 to 15.91 m. Our results indicate that H. ammodendron was subject to greater water stress with increasing DGW, as indicated by decreased predawn (Ψpd) & midday (Ψmd) branch water potential. We also found that growth rate declined as Huber value increased with increasing DGW in the early growing season (EGS). Solute sugar, as a major osmotic substance, drives decreases in osmotic potential at full turgor, and thus constrains assimilation branch growth with increasing DGW in EGS. Therefore, osmotic adjustment accompanied with water potential regulation (Ψpd－Ψmd) and plasticity of Huber value allows this phreatophyte to absorb water from deeper soil layers and tolerate drought. However, these adaptive adjustments cannot fully compensate for nonoptimal water conditions as growth rate continued to decrease as DGW increased in EGS and even became negative in the late growing season (LGS) at almost all sites. Our results provide an insight into how H. ammodendron responds and adapts to changes DGW in a region experiencing hydrological and climatic drought. Greater depth of groundwater had a significant effect on H. ammodendron and may have similar effects for other non-riparian phreatophytic plants in arid regions.

Dependence of size and weight indices of European spruce tree branches on their phytocoenotic state

Изучение структуры кроны является важным элементом как экологических, так и лесоводственных исследований. Интенсивное лесовыращивание подразумевает проведение регулярных рубок ухода, а также выполнение многоприемной обрезки ветвей для получения высококачественной бессучковой древесины. При этом производительность работ связана с количественными параметрами кроны: числом живых и сухих ветвей в мутовке, диаметрами ветвей, количеством мутовок и др. В результате исследований, проведенных в искусственных древостоях ели, были изучены количественно-весовые параметры крон у деревьев разных классов роста. Установлено, что интенсивность роста ветвей, а также процесс очистки ствола от сучьев в значительной степени зависят от фитоценотического положения деревьев. The study of crown structure is an important element of both ecological and silvicultural research. Intensive reforestation involves regular thinning and multi-stage pruning for getting high quality knot-free timber. At the same time, the productivity ofthe work is related to the quantitative parameters of the crown: the number of living and dry branches in a whorl, branch diameters, the number of whorls, etc. As a result of studies carried out in artificial stands of spruce of different ages, the quantitative and weight parameters of crowns in trees of different growth classes were established. It was also found that the intensity of branch growth, as well as the process of clearing the trunk from branches, largely depend on the phytocenotic position of trees.

Stimulasi Pertumbuhan Kina Belum Menghasilkan (TBM) dengan Aplikasi Konsentrasi BAP Setelah Fase Pembentukan Batang

Cinchona is plantation commodity that useful as medicine material. Productivity of cinchona is influenced by growth phase on young plant. For increasing the productivy of cinchona should be applied stem shaping and combine with growth regulator. This research aims to get the precise concentration of growth regulator for young cinchona after stem shaping. The experiment was observed at Ciparanje field station of Agriculture Faculty, Padjadjaran University, Jatinangor. It used randomized block design with 6 treatments and 4 replications (3 plants for each plot). The treatments were 6 levels of BAP (0 ppm, 30ppm, 60ppm, 90 ppm, 120ppm and 150 ppm). The result showed that BAP level had significant effect for growing of young cinchona. 30 ppm of BAP influenced branch growth meanwhile 90 ppm and 150 ppm had significant effect on leaves number and stem diameter was influenced by all of BAP concentrations.

The interplay between irrigation and fruiting on branch growth and mortality, gas exchange and water relations of coffee trees

The overall coordination between gas exchanges and plant hydraulics may be affected by soil water availability and source-to-sink relationships. Here we evaluated how branch growth and mortality, leaf gas exchange and metabolism are affected in coffee (Coffea arabica L.) trees by drought and fruiting. Field-grown plants were irrigated or not, and maintained with full or no fruit load. Under mild water deficit, irrigation per se did not significantly impact growth but markedly reduced branch mortality in fruiting trees, despite similar leaf assimilate pools and water status. Fruiting increased net photosynthetic rate in parallel with an enhanced stomatal conductance, particularly in irrigated plants. Mesophyll conductance and maximum RuBisCO carboxylation rate remained unchanged across treatments. The increased stomatal conductance in fruiting trees over nonfruiting ones was unrelated to internal CO2 concentration, foliar abscisic acid (ABA) levels or differential ABA sensitivity. However, stomatal conductance was associated with higher stomatal density, lower stomatal sensitivity to vapor pressure deficit, and higher leaf hydraulic conductance and capacitance. Increased leaf transpiration rate in fruiting trees was supported by coordinated alterations in plant hydraulics, which explained the maintenance of plant water status. Finally, by preventing branch mortality, irrigation can mitigate biennial production fluctuations and improve the sustainability of coffee plantations.

Vegetative development of vine rootstock cultivars in brazilian cerrado conditions

In the State of Goiás, studies related to the vine's responses to the region's edaphoclimaticconditions are scarce. Therefore, the objective of this work was to evaluate the growth of three vine rootstock cultivars, IAC 572 'Jales', IAC313 'Tropical' and IAC766 'Campinas', in the region of Goiânia, GO, after drastic pruning for uniformity. To evaluate the growth of rootstocks, the experiment was carried out in random blocks, in a double factorial scheme (3x7), with five replications, each repetition formed by a plant. The first factor consisted of three rootstocks: IAC313 ‘Tropical’, IAC572 ‘Jales’ and IAC766 ‘Campinas’. The plants were evaluated after 45 days after a drastic uniformization pruning, totaling seven evaluations (45, 60, 75, 90, 105, 120, 135 days after pruning), this being the second factor. The diameter of the main branch at the height of grafting (80 cm) and length of the main branch were evaluated. With the data on the diameter and length of the main branch, the absolute growth rate in diameter and length was calculated.The IAC572 'Jales' rootstock cultivar has greater vigor for branch growth, being 69% and 47.3% longer in length, and 49.8% and 18.8% longer in diameter than the IACrootstock. IAC 313 'Tropical' 'and' IAC766 'Campinas', respectively. The IAC766 ‘Campinas’ rootstock cultivar, although it has low vigor in branch growth, presents satisfactory development.

Gravity-Sensing Tissues for Gravitropism Are Required for “Anti-Gravitropic” Phenotypes of lzy Multiple Mutants in Arabidopsis

Plant posture is controlled by various environmental cues, such as light, temperature, and gravity. The overall architecture is determined by the growth angles of lateral organs, such as roots and branches. The branch growth angle affected by gravity is known as the gravitropic setpoint angle (GSA), and it has been proposed that the GSA is determined by balancing two opposing growth components: gravitropism and anti-gravitropic offset (AGO). The molecular mechanisms underlying gravitropism have been studied extensively, but little is known about the nature of the AGO. Recent studies reported the importance of LAZY1-LIKE (LZY) family genes in the signaling process for gravitropism, such that loss-of-function mutants of LZY family genes resulted in reversed gravitropism, which we term it here as the “anti-gravitropic” phenotype. We assume that this peculiar phenotype manifests as the AGO due to the loss of gravitropism, we characterized the “anti-gravitropic” phenotype of Arabidopsis lzy multiple mutant genetically and physiologically. Our genetic interaction analyses strongly suggested that gravity-sensing cells are required for the “anti-gravitropic” phenotype in roots and lateral branches. We also show that starch-filled amyloplasts play a significant role in the “anti-gravitropic” phenotype, especially in the root of the lzy multiple mutant.