Sequential Harvests Research Articles

Efficient sequential harvesting of solar light by heterogeneous hollow shells with hierarchical pores.

In nature, sequential harvesting of light widely exists in the old life entity, i.e. cyanobacteria, to maximize the light absorption and enhance the photosynthesis efficiency. Inspired by nature, we propose a brand new concept of temporally-spatially sequential harvesting of light in one single particle, which has purpose-designed heterogeneous hollow multi-shelled structures (HoMSs) with porous shells composed of nanoparticle subunits. Structurally, HoMSs consist of different band-gap materials outside-in, thus realizing the efficient harvesting of light with different wavelengths. Moreover, introducing oxygen vacancies into each nanoparticle subunit can also enhance the light absorption. With the benefit of sequential harvesting of light in HoMSs, the quantum efficiency at wavelength of 400 nm is enhanced by six times compared with the corresponding nanoparticles. Impressively, using these aforementioned materials as photocatalysts, highly efficient photocatalytic water splitting is realized, which cannot be achieved by using the nanoparticle counterparts. This new concept of temporally-spatially sequential harvesting of solar light paves the way for solving the ever-growing energy demand.

Microbiological and Nutritional Analysis of Lettuce Crops Grown on the International Space Station.

The ability to grow safe, fresh food to supplement packaged foods of astronauts in space has been an important goal for NASA. Food crops grown in space experience different environmental conditions than plants grown on Earth (e.g., reduced gravity, elevated radiation levels). To study the effects of space conditions, red romaine lettuce, Lactuca sativa cv ‘Outredgeous,’ plants were grown in Veggie plant growth chambers on the International Space Station (ISS) and compared with ground-grown plants. Multiple plantings were grown on ISS and harvested using either a single, final harvest, or sequential harvests in which several mature leaves were removed from the plants at weekly intervals. Ground controls were grown simultaneously with a 24–72 h delay using ISS environmental data. Food safety of the plants was determined by heterotrophic plate counts for bacteria and fungi, as well as isolate identification using samples taken from the leaves and roots. Molecular characterization was conducted using Next Generation Sequencing (NGS) to provide taxonomic composition and phylogenetic structure of the community. Leaves were also analyzed for elemental composition, as well as levels of phenolics, anthocyanins, and Oxygen Radical Absorbance Capacity (ORAC). Comparison of flight and ground tissues showed some differences in total counts for bacteria and yeast/molds (2.14 – 4.86 log10 CFU/g), while screening for select human pathogens yielded negative results. Bacterial and fungal isolate identification and community characterization indicated variation in the diversity of genera between leaf and root tissue with diversity being higher in root tissue, and included differences in the dominant genera. The only difference between ground and flight experiments was seen in the third experiment, VEG-03A, with significant differences in the genera from leaf tissue. Flight and ground tissue showed differences in Fe, K, Na, P, S, and Zn content and total phenolic levels, but no differences in anthocyanin and ORAC levels. This study indicated that leafy vegetable crops can produce safe, edible, fresh food to supplement to the astronauts’ diet, and provide baseline data for continual operation of the Veggie plant growth units on ISS.

Analysis of the process of green hemp stalks sequential harvesting

HEMP (Cannabis Sativa - Industrial Hemp) is the industrial plant with the highest use of all these plants in the industry, since nothing is thrown away from this plant. Hemp is the plant of which everything is used, and the products obtained are of a great diversity, from the common rope to the medicinal or cosmetic substances, textiles, automotive or construction materials. It is an unpretentious plant because, apart from the fact that it wants a neutral PH and soils without excess humidity, no maintenance work need to be done and no extra care should be given. The fibre hemp is harvested at the technical maturity when the male plants shed the last pollen grains, and the stalks have a greenish-yellow colour and the leaves fell on the ground. Production management is different for an exclusive fibre production. If we look for raw materials that meet the demands of different areas of the economy with the lowest costs, we must take into account the reactivation of the hemp culture at the level of Romania, because, as we mentioned above, hemp is the plant of which everything is capitalised, and the products obtained are of a great diversity. By applying the technology for processing the stalks in green, the obtained fibre can be used with special results in the strawberry culture at the mulching operation. The paper presents the Equipment for harvesting green hemp stalks ERCV, equipment that performs sequential harvesting of hemp stalks leaving them on the ground. At the same time, factors that influence the process of harvesting hemp stalks are presented: harvesters’ cutting devices, kinematic of the cutting blades, cutting speed, cutting angles of the cutting blades, the forces acting on the blade and the power required to drive the cutting devices.

Soil and foliar zinc biofortification of broccolini: effects on plant growth and mineral accumulation

Millions of people have Zn-deficient diets, so Zn-biofortified crops could prevent such deficiency. The aim of this study was to evaluate the use of agronomic Zn biofortification of broccolini – a new hybrid crop variety derived from a cross between kalian cabbage and broccoli. Plants were grown in pots using a Zn deficient soil. Four fertiliser treatments were tested: (1) control; (2) soil application of 5 mg ZnSO4•7H2O kg–1 soil; (3) foliar application at the early flowering stage of 0.5% (w/v) ZnSO4•7H2O; (4) combined soil and foliar treatments. Florets were harvested in four sequential harvests. There was a decrease in both growth and leaf composition of Zn, Ca, Fe and Mg. Soil Zn application increased floret production. There were increases in the Zn concentration stem+leaves and florets of 12- and 2.5-fold in foliar and soil+foliar treatments respectively. PA:Zn molar ratios decreased under both foliar and soil+foliar treatments. Boiling reduced Zn concentration by 40%, along with a decrease of other mineral nutrients. A soil+foliar treatment can increase both plant growth and Zn concentration in broccolini, and boiled 100 g portion of biofortified florets fertilised at rates in this study would deliver ~49 mg Zn, a 46% increase than in the non-biofortified broccolini.

Agronomic biofortification of leafy vegetables grown in an Oxisol, Alfisol and Vertisol with isotopically labelled selenium (77Se)

Selenium biofortification of crops is a proven technology for improving dietary nutrition. This study used isotopically labelled selenate (>99% enriched 77Se) to assess uptake and Se availability to two green vegetables, Brassica napus L (B. napus) and Amaranthus retroflexus L (A. retroflexus) grown in three contrasting Malawi soils: a Vertisol (calcareous), Alfisol (moderately acidic) and Oxisol (acidic). Plants were grown under glasshouse conditions (4 replicates; 6 kg soil per pot) following application of 77Se-enriched selenate at rates equivalent to 0, 10 and 20 g ha−1. Leaves were harvested at fortnightly intervals and the plants were then allowed to re-grow, to simulate cultivation practice. Leaf samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) for selenium isotopes (77Se and 78Se). The isotopic data were processed to quantify the contribution to plant Se concentration from the fertilizer and the soil. Both concentration and uptake of the fertilizer 77Se declined sharply with sequential harvests due to progressive fixation of 77Se in the soil rather than exhaustion (by uptake) of the Se applied. Initially the bioavailability of fertilizer Se was three orders of magnitude greater than the soil Se but this declined to the same order of magnitude by the end of the trial. Application of 77Se had no effect on uptake of soil-derived Se. There were marked differences between the three soils studied. The relative bio-availability of the fertilizer Se followed the sequence (Vertisol > Alfisol > Oxisol) but the two crops showed the same trend in decline of fertilizer Se uptake. Thus, fixation of selenium in the soils studied was sufficiently rapid that Se biofortification of green vegetables subject to several harvests would require multiple applications during the growing season.

Extraction, Storage Duration, and Storage Temperature Affect the Activity of Ascorbate Peroxidase, Glutathione Reductase, and Superoxide Dismutase in Rice Tissue.

In experimental plant science, research often faces large numbers of tissue samples resulting from sequential harvests of a larger number of genotypes and treatments combinations. Analyses of biological processes such as enzyme kinetics are often time-consuming or need specific sample preparation procedures before the actual measurements can be done. Time is thus often the critical factor and the possibility to store plant samples either as tissue or as extracts increases the available timeframe for analyses. Biological molecules such as enzymes often change their activities when stored and thus do not reflect the processes occurring in living tissue. We investigated the effect of different storage methods such as freeze-drying, freezing at −20 °C, and freezing at −80 °C on the activity of three enzymes known as antioxidants, namely ascorbate peroxidase, glutathione reductase, and superoxide dismutase from two rice varieties. Varieties differed in enzyme activity in extracts of fresh material from leaf blades, leaf sheaths, and roots. When subjected to different storage methods, there were no differences between varieties, but strong effects of the different storage methods on enzyme activities were found. The effects of the storage methods on enzyme activity strongly differed between extracts from stored tissue samples or extracts stored from freshly sampled material. We propose enzyme-specific storage methods and durations that allow for expanding the window for analyses in large experimental studies involving destructive samplings for enzyme kinetics.

Harvesting at the Right Time: Maturity and Its Effects on the Aromatic Characteristics of Cabernet Sauvignon Wine.

The aim of this paper was to investigate how maturity affects the aroma characteristics of Cabernet Sauvignon wine. A series of four Vitis vinifera cv. Cabernet Sauvignon wines were produced from grapes of different harvest dates. The berries of sequential harvest treatments showed an increase in total soluble solids and anthocyanin and a decrease in titratable acidity. Berry shriveling was observed as berry weight decreased. In the wines, anthocyanin, dry extract, alcoholic strength, and pH were enhanced with the sequential harvest, whereas polyphenol and tannin were decreased. The concentrations of volatile compounds in sequential harvests were found to be at higher levels. Isopentanol, phenylethyl alcohol, ethyl acetate, ethyl lactate, benzaldehyde, citronellol, and linalool significantly increased when harvest was delayed by one or two weeks. Through a principal component analysis, the volatile compounds and phenols characterizing each harvest date were clearly differentiated. These results suggest that sequential harvest may be an optional strategy for winemakers to produce high-quality wine.

Lipid-Extracted Algae as a Soil Amendment Can Increase Soil Salinization and Reduce Forage Growth

Algae as a biodiesel feedstock are more productive per unit area than traditional feedstock options, but currently algae production is not economical without high-value co-products. Lipid-extracted algae (LEA) may be useful as a soil amendment; however, research is needed to determine the feasibility and management strategies required. The objective was to determine salinity-associated effects of LEA as a soil amendment on a range of salt tolerant forages [foxtail millet (Setaria italica L.), pearl millet (Pennisetum glaucum L.), and a sorghum-sudangrass hybrid (Sorghum bicolor L. Moench)]. Forage seed were planted in columns containing sandy clay loam soil amended with the following: (1) control [nitrogen (N) and phosphorus (P) fertilizer added], (2) 1.5% LEA by weight, (3) 3.0% LEA, (4) 1.5% LEA + 1.5% wheat straw (WS), and (5) 1.5% WS (+N, +P). Seedling emergence and total herbage mass (HM) from sequential harvests was determined, along with forage mineral uptake. Soil pH and electrical conductivity (EC) were analyzed after the final harvest. Seedling emergence of pearl millet was negatively affected by LEA application, but not foxtail millet or sorghum-sudangrass. Pearl millet emergence was most reduced in 3.0% LEA treated soil, however, this treatment produced greater HM by the third harvest. Soil pH and EC were greater in 3.0% LEA-treated soil than the control and 1.5% WS treatment. Production of salt tolerant forages such as sorghum-sudangrass is possible in LEA-amended soil; however, with repeated applications soil salinity may reduce productivity and sustainability.

Cultivar Differences and Impact of Plant-Plant Competition on Temporal Patterns of Nitrogen and Biomass Accumulation.

Current niche models cannot explain multi-species plant coexistence in complex ecosystems. One overlooked explanatory factor is within-growing season temporal dynamism of resource capture by plants. However, the timing and rate of resource capture are themselves likely to be mediated by plant-plant competition. This study used Barley (Hordeum sp.) as a model species to examine the impacts of intra-specific competition, specifically inter- and intra-cultivar competition on the temporal dynamics of resource capture. Nitrogen and biomass accumulation of an early and late cultivar grown in isolation, inter- or intra- cultivar competition were investigated using sequential harvests. We did not find changes in the temporal dynamics of biomass accumulation in response to competition. However, peak nitrogen accumulation rate was significantly delayed for the late cultivar by 14.5 days and advanced in the early cultivar by 0.5 days when in intra-cultivar competition; there were no significant changes when in inter-cultivar competition. This may suggest a form of kin recognition as the target plants appeared to identify their neighbors and only responded temporally to intra-cultivar competition. The Relative Intensity Index found competition occurred in both the intra- and inter- cultivar mixtures, but a positive Land Equivalence Ratio value indicated complementarity in the inter-cultivar mixtures compared to intra-cultivar mixtures. The reason for this is unclear but may be due to the timing of the final harvest and may not be representative of the relationship between the competing plants. This study demonstrates neighbor-identity-specific changes in temporal dynamism in nutrient uptake. This contributes to our fundamental understanding of plant nutrient dynamics and plant-plant competition whilst having relevance to sustainable agriculture. Improved understanding of within-growing season temporal dynamism would also improve our understanding of coexistence in complex plant communities.

Management of Apple Maturity and Postharvest Storage Conditions to Increase Polyphenols in Cider

Hard cider production in the United States has increased dramatically during the past decade, but there is little information on how harvest and postharvest practices affect the chemistry of the resulting cider, including concentrations of organoleptically important flavanols. For 2 years we assessed fruit, juice, and cider from a total of five apple (Malus ×domestica Borkh.) cultivars in two experiments: sequential harvests and postharvest storage. Different cultivars were used in 2015 and 2016 with the exception of ‘Dabinett’, which was assessed in both years. There were no differences in polyphenol concentrations in cider made from fruit that was harvested on three separate occasions over a 4-week period in either 2015 or 2016. Fruit storage durations and temperatures had little influence on the chemistry when the experiment was conducted in 2015, but polyphenol concentration was greater after storage in the 2016 experiment. In 2016, total polyphenols in ‘Dabinett’ ciders were 51% greater after short-term storage at 10 °C and 67% greater after long-term storage at 1 °C than the control, which was not subjected to a storage treatment. In 2016, total polyphenols in ‘Binet Rouge’ ciders were 67% greater after short-term storage at 10 °C and 94% greater after long-term storage at 1 °C than the control. Although results varied among cultivars and harvest years, storing apples for longer periods of time and at warmer temperatures may be a strategy to increase polyphenol, particularly flavanol, concentrations in hard cider.

Functional group contributions to carbon fluxes in arctic-alpine ecosystems

ABSTRACTOngoing responses to climate change in arctic-alpine ecosystems, including the increasing dominance of deciduous shrubs, involve major shifts in plant functional group composition. Because rates of photosynthesis and respiration and their responses to temperature may vary among plant functional groups, a better understanding of their contributions to carbon fluxes will help improve predictions of how ecosystem changes will affect carbon source-sink relations in globally important tundra regions. We used a sequential harvest method to estimate growing season functional group contributions to net ecosystem exchange (NEE), ecosystem respiration (ER), and gross photosynthesis (GP) in alpine heath-, meadow-, and Salix-dominated shrub communities. We also partitioned ER into aboveground and belowground components in all three communities. Belowground efflux was the dominant component of ER in the heath and meadow communities (63 percent and 88 percent of ER, respectively) but contributed only approximately 40 percent of ER in the shrub community. The dominant functional group in each community contributed most to aboveground exchanges. Estimates for cryptogams were uncertain, but indicated a minor role for bryophytes and lichens in overall exchange. The results of our novel method of partitioning gas-exchange measurements suggest strong differences in the relative proportions of soil versus aboveground respiration and in the contributions of different functional groups in the net carbon exchange of three important arctic-alpine community types, with implications for changes in carbon dynamics as these systems respond to environmental change.

Bold to do — bald to be? Outcomes decades after harvesting the scalp in burned children

BackgroundThe scalp is the only hidden donor site for split thickness skin grafts. Nevertheless, it is underappreciated due to fear of iatrogenic scarring alopecia. Long-term data showing whether androgenetic hair loss can reveal previously hidden scarring alopecia is unavailable. We aimed to evaluate results and patient satisfaction up to 30years after skin harvest from the scalp. MethodsBurn patients, hospitalized between 1977 and 1987 at the University Children’s Hospital Zurich with scalp skin harvest and currently over 30years old, were studied. Medical records and patient satisfaction were analyzed, and a clinical scalp examination was performed. ResultsThirty-two patients (18 males, 14 females) with a current age of 34.13±3.42years participated. Mean follow-up time was 27.09±3.04years. Fifty-four scalp harvests were performed with 1.69±0.96 sequential harvests. Hair growth was considered normal in 97% patients. Androgenetic alopecia (AGA) type Norwood II–VI was seen in 11 patients. Scalp examination revealed 11 unknown likely harvest-related alopecias with a mean size of 0.7cm2. ConclusionsLong-term morbidity of scalp skin harvest and the risk of clinically significant alopecia is very low while patient satisfaction is high. AGA is unlikely to reveal harvest damage previously hidden by regrown hair.

Calibration and validation of the AquaCrop model for repeatedly harvested leafy vegetables grown under different irrigation regimes

Traditional leafy vegetables (TLVs’) are vegetables that were introduced in an area a long time ago, where they adapted to local conditions and became part of the local culture. In Sub-Saharan Africa, the use of TLVs’ as a nutrient dense alternative food source to combat micronutrient deficiency of rural resource-poor households (RRPHs), has gained attention in debates on food and nutrition security. However, TLVs’ are underutilised because of lack of information on their yield response to water and fertiliser. To better assess TLVs’ yield response to water stress, the AquaCrop model was calibrated (using 2013/14 data) and validated (using 2014/15 data) for three repeatedly harvested leafy vegetables [Amaranthus cruentus (Amaranth), Cleome gynandra (Spider flower), and Beta vulgaris (Swiss chard)] in Pretoria, South Africa. Experiments were conducted during two consecutive seasons, in which the selected leafy vegetables were subjected to two irrigation regimes; well-watered (I30) and severe water stress (I80). Measured parameters were canopy cover (CC), soil water content (SWC), aboveground biomass (AGB), actual evapotranspiration (ETa), and water productivity (WP). Statistical indicators [root mean square error (RMSE), RMSE-standard deviation ratio (RSR), R2, and relative deviation] showed good fit between measured and simulated (0.60 < R2 < 0.99, 0.94 < RMSE < 5.44, and 0.04 < RSR < 0.79) values for the well-watered treatment. However, the fit was not as good for the water-stressed treatment for CC, SWC, ETa and WP. Nevertheless, the model simulated the selected parameters satisfactorily. These results revealed that there was a clear difference between transpiration water productivity (WPTr) for C4 crops (Amaranth and Spider flower) and a C3 crop (Swiss chard); WPTr for the C4 crops ranged from 4.61 to 6.86 kg m−3, whereas for the C3 crop, WPTr ranged from 3.11 to 4.43 kg m−3. It is a challenge to simulate yield response of repeatedly harvested leafy vegetables because the model cannot run sequential harvests at one time; therefore, each harvest needs to be simulated separately, making it cumbersome. To design sustainable food production systems that are health-driven and inclusive of RRPHs, we recommend that more vegetables (including traditional vegetables) should be included in the model database, and that sequential harvesting be facilitated.

Phytoremediation potential of Leersia hexandra Swartz of copper contaminated soil and its enhancement by using agronomic management practices

The objective of this study was to discuss the phytoremediation potential of Leersia hexandra Swartz in Cu contaminated soil and its enhancement by agronomic management practices. The results showed that L. hexandra had a high extraction capacity for copper (Cu), and Cu concentration was found maximum in shoots (755.4 mg/kg), which is very close to the Cu-hyperaccumulators. Three successive harvests did not reduce the biomass and Cu level in shoots of L. hexandra (p > 0.05), indicating that sequential harvest was feasible for the increase of total biomass and Cu extraction amount. Fertilization could obviously increase the tissue dry weight, resulting in the total amount of extracted-Cu up to 52.3%. 3-Indole acetic acid (IAA) also significantly increased biomass, causing the efficiency of Cu phytoextraction up to 204.6%. These suggested that fertilization and IAA were effective for enhancing Cu phytoextraction by L. hexandra.

Cultured Pearl Surface Quality Profiling by the Shell Matrix Protein Gene Expression in the Biomineralised Pearl Sac Tissue of Pinctada margaritifera.

Nucleated pearls are produced by molluscs of the Pinctada genus through the biomineralisation activity of the pearl sac tissue within the recipient oyster. The pearl sac originates from graft tissue taken from the donor oyster mantle and its functioning is crucial in determining key factors that impact pearl quality surface characteristics. The specific role of related gene regulation during gem biogenesis was unknown, so we analysed the expression profiles of eight genes encoding nacreous (PIF, MSI60, PERL1) or prismatic (SHEM5, PRISM, ASP, SHEM9) shell matrix proteins or both (CALC1) in the pearl sac (N = 211) of Pinctada margaritifera during pearl biogenesis. The pearls and pearl sacs analysed were from a uniform experimental graft with sequential harvests at 3, 6 and 9months post-grafting. Quality traits of the corresponding pearls were recorded: surface defects, surface deposits and overall quality grade. Results showed that (1) the first 3months of culture seem crucial for pearl quality surface determination and (2) all the genes (SHEM5, PRISM, ASP, SHEM9) encoding proteins related to calcite layer formation were over-expressed in the pearl sacs that produced low pearl surface quality. Multivariate regression tree building clearly identified three genes implicated in pearl surface quality, SHEM9, ASP and PIF. SHEM9 and ASP were clearly implicated in low pearl quality, whereas PIF was implicated in high quality. Results could be used as biomarkers for genetic improvement of P. margaritifera pearl quality and constitute a novel perspective to understanding the molecular mechanism of pearl formation.

A comparative study of partial dealcoholisation versus early harvest: Effects on wine volatile and sensory profiles

Two Verdelho and Petit Verdot wines were produced from sequential harvests of grapes. The alcohol concentration of early harvest (EH) and late harvest (LH) wines were respectively 9% and 13.5% v/v for Verdelho, and 10.5% and 13% v/v for Petit Verdot. LH wines were dealcoholised to match the same alcohol level of EH samples using a combined reverse osmosis-evaporative perstraction process. In dealcoholised wines, there was a decrease in volatile compounds (esters particularly) compared to LH treatments. For both varieties, the sensory attribute ratings for overall aroma intensity and alcohol mouthfeel also decreased following dealcoholisation. Dealcoholised wines were distinctively different from both LH and EH wines even though these wines had similar alcohol level to EH wines. When dealcoholisation is considered for high-alcohol wines, it is important to consider that membrane effects can significantly change depending on the wine non-volatile matrix composition and the level of alcohol reduction required.

Mycorrhizal symbiosis induces plant carbon reallocation differently in C3 and C4 Panicum grasses

Although arbuscular mycorrhizal symbiosis is common in many plants with either C3 or C4 photosynthesis, it remains poorly understood whether photosynthesis type has any significant impact on carbon (C) fluxes in mycorrhizal plants. Thus, we compared mycorrhizal and non-mycorrhizal (NM) plants belonging to Panicum bisulcatum (C3) to its congeneric P. maximum (C4). Plants were or were not exposed to arbuscular mycorrhiza (AM) fungal inoculation and/or phosphorus (P) fertilization. Plants’ C budgets were assembled based on 13CO2 pulse-chase labelling and sequential harvesting. Mycorrhizal plants allocated on average 3.9% more recently fixed C belowground than did their NM counterparts. At low P, mycorrhizal C3-Panicum plants allocated less C to aboveground respiration as compared to their respective NM controls. In contrast, mycorrhizal C4-Panicum increased the rates of photosynthesis and allocated more C to aboveground respiration than the respective NM controls. At high P, the differences were less prominent. We demonstrated consistent differences in aboveground C allocation due to AM symbiosis formation in congeneric C3 and C4 grasses. Both grasses benefited from AM symbiosis in terms of improved P uptake (at least at low P). These results advocate a holistic (whole-plant) perspective in studying C fluxes in mycorrhizal plants.

Whole-plant mineral partitioning during the reproductive development of rice (Oryza sativa L.)

Minimal information exists on whole-plant dynamics of mineral flow. Understanding these phenomena in a model plant such as rice could help in the development of nutritionally enhanced cultivars. A whole-plant mineral accumulation study was performed in rice (cv. Kitaake), using sequential harvests during reproductive development panicle exertion, grain filling, and full maturity stages in order to characterize mineral accumulation in roots, non-flag leaves, flag leaves, stems/sheaths, and panicles. Partition quotient analysis showed that Fe, Zn, Cu and Ni are preferentially accumulated in roots; Mn and Mg are accumulated in leaves; Mo, Ca, and S in roots and leaves; and K in roots, leaves and stems/sheaths. Correlation analysis indicated that changes in the concentrations of mineral pairs Fe-Mn, K-S, Fe-Ni, Cu-Mg, Mn-Ni, S-Mo, Mn-Ca, and Mn-Mg throughout the reproductive development of rice were positively correlated in all four of the above ground organs evaluated, with Fe-Mn and K-S being positively correlated also in roots, which suggest that root-to-shoot transfer is not driven simply by concentrations in roots. These analyses will serve as a starting point for a more detailed examination of mineral transport and accumulation in rice plants.

Yield formation of Central-European winter wheat cultivars on a large scale perspective

Abstract Improvement of grain yield potential for winter wheat ( Triticum aestivum ) may become harder to achieve in the future because an increase of harvest index has been largely exploited by breeders. Therefore, it is of high interest to detect how the components of the yield equation GY = Q × LUE × HI ( GY : grain yield, Q : radiation interception, LUE : light use efficiency, HI : harvest index) contribute to the explanation of yield differences of modern high yielding wheat varieties. To gain more insight in the variability of the parameters in the above equation and their contribution to grain yield, a field experiment was carried out in two seasons using a set of 9 recent German winter wheat cultivars (among them a hybrid cultivar and its parent lines). Beneath combine harvest, sequential harvests by hand were conducted (4 in the growing season 2013–2014, 5 in the growing season 2014–2015) to ascertain the above-ground biomass, the leaf area index and the harvest index (at the final harvest). Non-destructive measurements with a plant canopy analyzer to measure leaf area indices and mean tilt angles were conducted 4 times in 2014 and 9 times in 2015. Light absorption was calculated based on interpolated values of leaf area indices and mean tilt angles. Light use efficiency was calculated based on the linear relationship between above-ground biomasses at hand harvests and the related quantities of absorbed radiation. For all parameters of yield formation besides light use efficiency ( P = 0.073) statistically significant differences regarding the cultivars can be observed. Our results suggest that grain yield of modern German cultivars can be explained to a similar extent by differences in harvest indices (adj. r 2 : 0.77) and total biomass accumulation (adj. r 2 : 0.61). Variation in biomass accumulation partly can be explained by light use efficiency differences and to a lesser extent by differences in radiation interception. Most of the differences in biomass accumulation result, however, from differences in the accumulation of biomass from mid flowering to the final yield which for methodological reasons could not be further dissected to effects of light use efficiency and radiation interception. This information gap was described by the introduced parameter late performance. Various combinations of high and low performance, regarding the parameters of yield formation, exist in the analyzed set of cultivars.

Half-sibling loblolly pine clones exhibited intraspecific variation, a G × E interaction, and differences in stable isotope composition in response to soil moisture availability

We examined the response of three loblolly pine half-sibling clones (hereafter referred to as Clone 1, 2, and 3) to soil moisture availability in a greenhouse study. Three soil moisture treatments were imposed. Two were constant soil moisture treatments at either high (−0.3MPa) or low (−1.5MPa) soil water potential. The third was an alternating wet-dry treatment that alternated between one week at high (−0.3MPa) and three weeks at low (−1.5MPa) soil water potential, which simulated several natural wetting-drying cycles. At intervals throughout the experiment we measured biomass accumulation (via sequential harvesting), change in height, pre-dawn needle water potential, afternoon needle water potential, dark respiration, and morning and afternoon gas exchange (photosynthesis, stomatal conductance, intercellular CO2, and transpiration). Carbon allocation to root and shoot biomass, stomatal density, and carbon isotope composition were measured at the end of the experiment.All clones accumulated more biomass in the high soil moisture treatment than in the low soil moisture treatment, but there was a genetic by environment (G×E) interaction: Clone 1 accumulated more biomass than the other clones in the low soil moisture treatment and less than the others in the high soil moisture treatment. Stable carbon isotope composition, which we interpreted as a time-integrated index of water use efficiency, was significantly higher (indicating greater water use efficiency) in Clone 2, compared to Clones 1 and 3 across all soil moisture treatments except in the wet-dry treatment, where Clone 1 and 3 were not significantly different. A strong negative correlation was found between stable carbon isotope composition and biomass accumulation. Gas exchange parameters and needle water potential were higher in the high soil moisture treatment compared to the other treatments across all clones. Morning measurements of gas exchange were higher in Clones 2 and 3 than in Clone 1 across all treatments. Stomatal density varied significantly among clones but not among treatments. These results demonstrated that closely related clones differed in their growth and physiological responses to moisture availability, suggesting that clonal variation could be used to breed for increased drought resistance or to identify drought resistant genotypes for selective deployment.