Cultivar Differences Research Articles

Elucidating differences in phenolic profile between tef (Eragrostis tef) varieties using multivariate analyses

AbstractBackground and objectivesTef (Eragrostis tef) is a cereal grain endemic to Ethiopia commonly consumed as injera, a fermented, pancake‐like bread. Tef is milled whole, retaining free, conjugated, and bound phenolic compounds that are concentrated in the bran and may differentially influence metabolism when consumed. Tef cultivars are classified by color into white and brown, an indication that they may differ in their phenolic content. This work aimed to analyze the effect of cultivar on the phenolic profile of tef grain (Eragrostis tef) while controlling for location and growing season.FindingsThe free, conjugated, and bound phenolic profiles of six tef cultivars, grown in the same season and location (Bishoftu a.k.a. Debrezeit, Ethiopia), and two grown in Idaho, USA, were characterized by high‐performance liquid chromatography with UV/Vis detection (HPLC–DAD). Subsequent uni‐ and multivariate statistical analyses, including principal component analysis (PCA) and multiple factor analysis (MFA), showed that brown and white tef cultivars can be differentiated by their free and bound phenolic fractions (free total phenolic content range = 0.12–0.19 μg/g defatted tef flour (DTF); bound total phenolic content range = 0.80–1.12 μg/g DTF). The most abundant phenolic compound in the bound fraction was ferulic acid, with the white‐colored DZ‐Cr‐384 (Kuncho) cultivar showing the highest bound ferulic acid content (280.73 μg/g DTF).ConclusionsThere are differences between the phenolic compounds of white and brown tef, likely due to differences in cultivars and growing conditions as well as extraction methods in addition to variety. Even when total phenolic content did not differ between varieties, the specific phenolic composition differed between cultivars. Therefore, when choosing tef varieties for use in in vitro or in vivo studies, it is important to consider that even the same cultivar may differ in phenolic content depending on factors such as growing location, storage time, and age.Significance and noveltyComprehensive sample preparation is required to obtain a complete picture of differences in health‐promoting phenolic compounds in whole grains such as tef.

Nitrogen Metabolism at Tillering Stage Differently Affects the Grain Yield and Grain Protein Content in Two Durum Wheat Cultivars

Soil nitrogen abundance, as well as nitrogen use efficiency (NUE), significantly affect the crop yield and grain protein content (GPC). Depending on the genotype, a negative correlation between the yield and GPC can occur. The aim of the study was to assess the agronomic performance, and to explore physiological pathways for the efficient use of N fertilizer for two durum wheat cultivars, “Aureo” and “Vespucci”. After fertilization, the nitrogen content and values of some of the agronomic parameters and yield-related traits increased in both cultivars; nevertheless, a simultaneous rise in both the yield and GPC occurred only in Aureo. The biochemical parameters, analyzed at tillering, confirm the genotypic specificity of nitrogen use. In Vespucci’s roots, the nitrogen supply did not affect the nitrate reductase (NR), but greatly increased the amino acids and proteins, suggesting that ammonium is preferentially assimilated. In Aureo, nitrate is in part assimilated by the roots, as suggested by the ammonium increase and NR enhancement. In the leaves of both cultivars, organic nitrogen significantly increased after fertilization; however, the rise in amino acids, as well as in NR activity, was higher in Aureo than in Vespucci. These results indicate that the different nitrogen use, and in particular the diverse NR behavior, at tillering, are in part responsible of the cultivar differences in grain yield and GPC.

Combine observational data and modelling to quantify cultivar differences of soybean

Abstract This paper combines the analysis of soybean growth data with modelling to quantify cultivar differences and to evaluate the ability of the APSIM-Soybean model for simulation of soybean biomass and grain yield. Crop data include main developmental stages, leaf area index (LAI), above ground biomass, grain yield and grain number of 72 soybean cultivars in China. We derived the parameters controlling soybean flowering and maturity time in the lack of data from contrasting environments, then tested APSIM to simulate LAI, biomass and grain yield. Our results show that once phenology is correctly simulated, APSIM was able to capture the LAI and biomass growth dynamics of multiple cultivars and across different years. Our data showed a strong correlation of grain yield with grain number, but not with grain size. Future model improvement could include the simulation of grain setting (grain number and grain filling rate) and their difference between cultivars so that yield difference can be simulated. Further scenario modelling demonstrated that APSIM also captured the genotype by environment interactions as they impact on yield. The derived parameters for 72 soybean cultivars provide the first data set in APSIM for improved modelling of soybean genotypes in China and beyond, adding to the current APSIM validation database of soybean. This also formed the basis for future modelling of intercropping systems with soybean, e.g. maize/soybean intercropping.

High throughput procedure utilising chlorophyll fluorescence imaging to phenotype dynamic photosynthesis and photoprotection in leaves under controlled gaseous conditions

BackgroundAs yields of major crops such as wheat (T. aestivum) have begun to plateau in recent years, there is growing pressure to efficiently phenotype large populations for traits associated with genetic advancement in yield. Photosynthesis encompasses a range of steady state and dynamic traits that are key targets for raising Radiation Use Efficiency (RUE), biomass production and grain yield in crops. Traditional methodologies to assess the full range of responses of photosynthesis, such a leaf gas exchange, are slow and limited to one leaf (or part of a leaf) per instrument. Due to constraints imposed by time, equipment and plant size, photosynthetic data is often collected at one or two phenological stages and in response to limited environmental conditions.ResultsHere we describe a high throughput procedure utilising chlorophyll fluorescence imaging to phenotype dynamic photosynthesis and photoprotection in excised leaves under controlled gaseous conditions. When measured throughout the day, no significant differences (P > 0.081) were observed between the responses of excised and intact leaves. Using excised leaves, the response of three cultivars of T. aestivum to a user—defined dynamic lighting regime was examined. Cultivar specific differences were observed for maximum PSII efficiency (Fv′/Fm′—P < 0.01) and PSII operating efficiency (Fq′/Fm′—P = 0.04) under both low and high light. In addition, the rate of induction and relaxation of non-photochemical quenching (NPQ) was also cultivar specific. A specialised imaging chamber was designed and built in-house to maintain gaseous conditions around excised leaf sections. The purpose of this is to manipulate electron sinks such as photorespiration. The stability of carbon dioxide (CO2) and oxygen (O2) was monitored inside the chambers and found to be within ± 4.5% and ± 1% of the mean respectively. To test the chamber, T. aestivum ‘Pavon76’ leaf sections were measured under at 20 and 200 mmol mol−1 O2 and ambient [CO2] during a light response curve. The Fv′/Fm′was significantly higher (P < 0.05) under low [O2] for the majority of light intensities while values of NPQ and the proportion of open PSII reaction centers (qP) were significantly lower under > 130 μmol m−2 s−1 photosynthetic photon flux density (PPFD).ConclusionsHere we demonstrate the development of a high-throughput (> 500 samples day−1) method for phenotyping photosynthetic and photo-protective parameters in a dynamic light environment. The technique exploits chlorophyll fluorescence imaging in a specifically designed chamber, enabling controlled gaseous environment around leaf sections. In addition, we have demonstrated that leaf sections do not different from intact plant material even > 3 h after sampling, thus enabling transportation of material of interest from the field to this laboratory based platform. The methodologies described here allow rapid, custom screening of field material for variation in photosynthetic processes.

Waxing and cultivar affect Salmonella enterica persistence on cucumber (Cucumis sativus L.) fruit

A dearth of knowledge exists on the pathogen-commodity association of Salmonella enterica on cucumber, despite cucumbers being implicated in multiple salmonellosis outbreaks in recent years in the U.S. Data are lacking on cultivar susceptibility to Salmonella colonization in relation to heterogeneity in fruit surface morphology. Further, fruit waxing is a common practice in wholesale cucumber to preserve the water content of fruit and prolong shelf-life, but its impact on epiphytic microbiota is not well studied. This study investigated the survival of Salmonella Newport and S. Javiana on the surface of six cucumber cultivars of varying surface morphology and the effect of fruit waxing on the persistence of S. Newport. S. Newport and S. Javiana were spot inoculated onto fruit of cultivars ‘Marketmore 97’, ‘Patio Snacker’ and ‘Corinto’ (varieties with trichomes or spines), and ‘Bella’, ‘Pepinex’ and ‘Summer Dance’ (glabrous or smooth varieties). Cucumbers were held at room temperature for 24 h before inoculated sections of exocarp were excised for enteropathogen enumeration. S. Javiana persisted at higher populations than S. Newport (1.0 and 1.5 log CFU g−1 exocarp decline, respectively) after 24 h (P < 0.05). Fruit waxing lessened S. Newport population decline after 24 h on all cultivars tested (P < 0.01). While there was a ~2 log CFU g−1 exocarp decline in populations on unwaxed cucumbers, the reduction on waxed cucumbers was ~1 log CFU g−1 exocarp. A cultivar effect was also observed; ‘Summer Dance’ supported consistently higher and ‘Corinto’ and ‘Marketmore 97’ (though for S. Javiana only) consistently lower Salmonella levels. Cultivars with trichomes were associated with lower populations than glabrous cultivars (P < 0.05). Our data showed that Salmonella persistence on fruit differed for the two serotypes tested and that cultivar differences play a role in determining cucumber surface favourability for pathogen colonization. Additionally, fruit waxing may elevate the risk of Salmonella persistence on cucumber.

Growth analysis of sweet potato cultivars using the float system greenhouse

Alternative use for float system in a greenhouse is being studied in Brazil for sweet potato crop. This study aimed at investigating the viability of the use of expanded 128-cell polystyrene trays for the production of sweet potato plantlets in a greenhouse float system. ‘Beauregard’, ‘Brazlândia Branca’, ‘Brazlândia Rosada’, ‘Brazlândia Roxa’, ‘Coquinho’ and ‘Princesa’ cultivars were tested, and vine cuttings without roots with one or two unfolded leaves. The experimental design was completely randomized using six sweet potato cultivars and two types of vine cuttings, single node cutting (with one unfolded leaf) and double node cutting (with two unfolded leaves). The number of sweet-potato vine cuttings with leaves and roots, leaf area, leaf and root weights of plantlets were recorded. In addition, the survival rate in the field and stems, and tuberous roots productivity were evaluated. Overall, survival of transplants (presence of leaves and/or roots) with two nodes was higher than those with one node, and significant differences between cultivars (p<0.01) were observed. Leaf area statistical analyses indicated significant differences of cultivars regarding to the vine cutting types. Statistical leaf weight analyses indicated significant differences of cultivars regarding vine cuttings type, except for ‘Beauregard’. Root weight statistical analyses indicated significant differences of cultivars regarding vine cuttings type, except for cultivars ‘Beauregard’, ‘Brazlândia Branca’ and ‘Coquinho’.

Evaluation of different soilless media on growth, quality, and yield of cucumber (Cucumis sativus L.) grown under greenhouse conditions

This experiment was conducted during spring growing season of 2018 at Jordan University of Science and Technology (JUST) campus in northern Jordan 32.4950° N, 35.9912° E. The aim of the study was to evaluate the effect of different soilless media such as T: Tuff 100%; TP: Tuff + Perlite 50% each; TPS: Tuff + Perlite + Sawdust 33% each; and TS: Tuff + Sawdust 50% each on some of morphological, physiological and biochemical characteristics related to the quality and quantity of seedless and baby cucumber cultivars. The experimental design was split plot with factorial arrangements and four replications. The measurements related to plant morphology: height, shoot and root length, shoot root fresh and dry weight, number of leaves and flowers, fruit quality: total yield, weight, diameter, hardness, length and numbers per plant. Fruit total soluble solids, the potential of hydrogen pH and electrical conductivity EC of fruit juice, leaf chlorophyll content, leaf relative water content and fruit water content, fruit and shoot biochemical content minerals, organic matters, fats, fibers, and proteins were also measured. The results indicated significant differences in both cucumber cultivars with respect to all parameters studied. Finally, this study concluded that using TS media for seedless cultivar is the best successful growing soilless media as well as the cheapest compared to other solid media used. On the other hand, using TP media for baby cultivar was the superior growing soilless media that was not expensive compared to other universal media. In addition, the TPS media showed minimum growth and low yield in both cucumber cultivars.

Susceptibility of apple fruits (Malus x domestica Borkh.) to the postharvest pathogen Colletotrichum fioriniae: cultivar differences and correlation with fruit ripening characteristics

Colletotrichum spp. infections are an increasing threat to the fruit production industry worldwide, as a postharvest disease. Gaining knowledge on the susceptibility of apple fruit cultivars to Colletotrichum species is essential for specific breeding programs aiming to decrease the disease susceptibility of commercial apple cultivars. We investigated fruit susceptibility of nine apple cultivars at harvest and after storage, and studied the relationship of the susceptibility with fruit ripening characteristics. An accurate artificial inoculation technique, by wounding and injecting the spore suspension, was used to consistently follow-up the relative susceptibility symptoms of fruits. The nine apple cultivars studied, cvs. Pinova, Nicoter, Nicogreen, Golden Delicious, Gala, Elstar, Jonathan, Idared and Topaz, showed clear differences in susceptibility to C. fioriniae, main species causing problems in Europe, based on lesion expansion growth rate data. Cultivar Nicoter and Nicogreen were evaluated as less susceptible cultivars, while cv. Golden Delicious and cv. Pinova were classified as high susceptible cultivars. After three months of storage all fruit cultivars showed a higher susceptibility than at harvest. We further explored the link between fruit ripening characteristics and postharvest pathogen developments. Results showed significant higher Brix, ethylene production and respiration and significantly lower firmness and titratable acids after storage, with the extent of these changes being cultivar dependent. The ripening parameters respiration and Brix had a positive and the firmness a negative correlation with the lesion expansion growth rate of C. fioriniae after artificial wound inoculations. These experiments help to give a better insight in the susceptibility of different cultivars. Moreover, our data support the hypothesis that the extent of the necrotrophic fungal development depends on the fruit ripening stage.

Biofortification of wheat cultivars with selenium

ABSTRACTBiofortification experiments with three winter wheat cultivars treated with sodium selenate through foliar- and soil-fertilisation were conducted at two locations in Croatia and Serbia in two consecutive years to increase the selenium (Se) concentration in bread-making wheat grain. The treatments were: (a) 5 g ha−1 Se foliar-, (b) 10 g ha−1 Se foliar- and (c) 10 g ha−1 Se in soil surface-application and they were compared with (d) control. Both Se foliar- and soil-fertilisation increased the Se concentration in grains from 2.6- to 4.6-fold. The concentration in grain was highest with Se foliar-fertilisation of 10 g ha−1 and it was increased by 29–32 µg Se kg−1 dry weight for each gram of Se applied per ha. The wheat cultivars differed in grain yield and Se uptake (g ha−1 Se). However, on average, there were no differences between wheat cultivars with respect to Se grain concentrations. Agronomic use efficiency (by grain) was significantly higher for Se foliar- (19%) than for soil-fertilisation (13%). It can be concluded that agronomic biofortification of winter wheat can be effective in increasing Se grain concentration, where the efficiency depends on the rate of Se applied, application method and local environmental conditions rather than on cultivar differences.

Cultivar differences in electrical and mechanical property changes and tolerance in apples due to high hydrostatic pressure treatment

Mass, volume, electrical and mechanical properties of four apple cultivars after high hydrostatic pressure (HHP) treatment were investigated. Volume changes were greater than those of mass after HHP treatment. Electric properties were measured by electrical impedance spectroscopy, and their frequency dependences were analyzed using the Cole-Cole plot and cell-based electrical circuit model (modified Hayden model). The analyzed electric parameters showed differences among the cultivars, indicating cell membrane damage after HHP treatment. HHP treatment also affected the mechanical properties such as breaking stress and strain, indicating changes in cell structure. However, the mechanical properties after HHP treatment of ‘Shinanogold’ and ‘Fuji’ fruit were retained to a greater extent than those of ‘Jonathan’ and ‘Jonagold’ despite cell membrane destruction. This study is the first to reveal cultivar differences in the physical property changes after HHP treatment and their tolerances to treatment.

An analysis of the physiological impacts on life history traits of peanut (Arachis hypogaea L.) related to seed maturity

ABSTRACT Peanut is an important oilseed crop and legume species, with more than 1.9 M tons produced annually in the U.S. Being indeterminate, peanut continually flowers and sets pods throughout the growing season, leading to the potential harvest of both mature and immature pods. To quantify the physiological impacts of peanut seed maturity, a two-year field study was conducted to elucidate the difference in canopy structure and reproductive characteristics, including flower production, yield, and grade between seed obtained from immature and mature seed of two commercial peanut cultivars: TUFRunner™ ‘727’ and FloRun™ ‘107’. Data indicated that seed from the yellow class of pods have lower vigor and overall plant development and performance; further, plants developed from immature seed never achieved a level of performance comparable to that of the mature brown/black pod classes. There were differences between cultivars in the severity of the impact of immaturity, with larger detrimental effects on immature TUFRunner™ ‘727’, which exhibited reduced emergence. Despite these cultivar differences, this study illustrated that mature seed performs better in a field setting than immature seed. These results are critically important to disproving the ‘catch-up' assumption: seed maturity not only has an impact on emergence, but on subsequent life history and performance traits through the remainder of the season.

Estimating canopy gap fraction and diffuse light interception in 3D maize canopy using hierarchical hemispheres

Studying the detailed organization of plant canopy structure allows a better understanding of functional processes in functional-structural plant models (FSPM). Canopy gap fraction (CGF) is an important indicator describing the canopy structure and affects the way plants capture light to perform photosynthesis, especially the interception of diffuse light. Though efforts have been made to improve the accuracy and efficiency of CGF measurement and estimation, current technologies are usually position limited. Thus, this work developed new virtual methods for computing CGF and diffuse light interception in the 3D space of plant canopies. Five hierarchical hemispheres, containing 15, 40, 360, 1,440, and 5760 triangle patches, respectively, were constructed by applying Sqrt-3 and Butterfly subdivision schemes on an original icosahedron. Compared with traditional hemisphere division strategies using solid angles or crossed arcs of latitude and longitude, the proposed hierarchical hemispheres provide more resolution choices for different accuracy demands. Most of the patches on the hemispheres are regular triangles with similar sizes, which improves the CGF and diffuse light calculation accuracy using the Turtle model. Acceleration mechanism was built when calculating the detection of plant facets in the canopy using the tree relationship between adjacent hemispheres. Two geometric models and six maize canopy geometric models with cultivar and density differences were constructed using measured data to validate the approach. The maximum CGF error was 1.39% for the two geometric models. The average error of the four derived CGFs from hemisphere photographs was 4.23%. The diffuse light distribution correlation coefficients R2 were 0.96, 0.98, and 0.90 for three different canopy densities. Our algorithm provides multi-scale hemisphere choices for CGF and diffuse light interception simulation. The study also paves the way for further investigation into plant canopy structure analysis and simulation of light dynamics in plant canopies.

Consistent Differences in Field Leaf Water-Use Efficiency among Soybean Cultivars.

High intrinsic water-use efficiency (WUEi), the ratio of leaf photosynthesis to stomatal conductance, may be a useful trait in adapting crops to water-limited environments. In soybean, cultivar differences in stomatal response to vapor pressure deficit have not consistently translated into differences in WUEi in the field. In this study, six cultivars of soybeans previously shown to differ in WUEi in indoor experiments were grown in the field in Beltsville, Maryland, and tested for mid-day WUEi on nine clear days during the mid-seasons of two years. Measurement dates were chosen for diverse temperatures, and air temperatures ranged from 21 to 34 °C on the different dates. Air saturation deficits for water vapor ranged from 0.9 to 2.2 kPa. Corrected carbon isotope delta values for 13C (CID) were determined on mature, upper canopy leaves harvested during early pod filling each year. WUEi differed among cultivars in both years and the differences were consistent across measurement dates. Correlations between mean WUEi and CID were not significant in either year. It is concluded that consistent cultivar differences in WUEi exist in these soybean cultivars under field conditions, but that carbon isotope ratios may not be useful in identifying them because of cultivar differences in mesophyll conductance.

Determinants of Shoot Biomass Production in Mulberry: Combined Selection with Leaf Morphological and Physiological Traits.

Physiological and morphological traits have a considerable impact on the biomass production of fast-growing trees. To compare cultivar difference in shoot biomass and investigate its relationships with leaf functional traits in mulberry, agronomic traits and 20 physiological and morphological attributes of 3-year-old mulberry trees from eight cultivars growing in a common garden were analyzed. The cultivars Xiang7920, Yu711, and Yunsang2 had higher shoot fresh biomass (SFB), which was closely associated with their rapid leaf expansion rate, large leaf area, and high stable carbon isotope composition (δ13C). Conversely, the cultivars 7307, Husang32, Wupu, Yunguo1, and Liaolu11 were less productive, and this was primarily the result of slower leaf expansion and smaller leaf size. Growth performance was negatively correlated with leaf δ13C and positively correlated with the total nitrogen concentration, indicating that a compromise exists in mulberry between water use efficiency (WUE) (low δ13C) and high nitrogen consumption for rapid growth. Several morphological traits, including the maximum leaf area (LAmax), leaf width and length, petiole width and length, leaf number per shoot, and final shoot height were correlated with SFB. The physiological traits that were also influential factors of shoot biomass were the leaf δ13C, the total nitrogen concentration, and the water content. Among the studied leaf traits, LAmax, leaf δ13C, and concentrations of chlorophyll a and b were identified as the most representative predictor variables for SFB, accounting for 73% of the variability in SFB. In conclusion, a combination of LAmax, leaf δ13C, and chlorophyll should be considered in selection programs for high-yield mulberry cultivars.

Cultivar differences in lipoxygenase activity affect volatile compound formation in dough from wheat mill stream flour

Flavor, an important aspect of wheat (Triticum aestivum) dough products, forms during preparation and is affected by the generation of volatile compounds. These compounds are produced mainly by the oxidation of unsaturated fatty acids by lipoxygenase (LOX). Here, we analyzed the volatile compounds emitted from dough made from wheat mill stream flour to clarify the cultivar differences in LOX distribution and its effect on the formation of volatile compounds. LOX activity increased with ash content, and the rate of increase was significantly higher for Norin 61 than for other wheat cultivars. The volatile compound profiles were analyzed by principal component analysis, with almost all volatile compounds correlated to ash content. The volatile compounds in some Norin 61 streams, however, were more characteristic of the outer layer of wheat kernels than those in the other cultivars. Since the ash content among cultivars was similar, the characteristic volatile compound profiles of Norin 61 were presumed to be caused by higher LOX activity in this cultivar. In conclusion, the characteristic volatile compound profiles in each cultivar are due to the differences of LOX activity.

In Vitro Quantitative Resistance Components in Wheat Plants to Fusarium Head Blight

Background: In vitro tools have proved to be very useful in identifying quantitative resistance in wheat to Fusarium Head Blight (FHB) infection. However, there is a need to understand how the different in vitro and in planta tests correlate to describe the level of wheat resistance to FHB infection. Objective and Methods: We evaluated the correlation between in vitro symptom assessment using nine quantitative resistance criteria and in planta disease severity for Type II resistance assessment using a set of 16 FHB isolates across two widely grown Syrian wheat cultivars: Cham1 (durum) and Cham6 (bread). Results: Cultivar differences after inoculation with fungal isolates in seedlings and adult plants relative to the controls were detected. There were significant differences in the resistance of two wheat cultivars as measured by adult FHB resistance, Latent Period (LP) of detached leaf inoculation and standardized Area Under Disease Progress Curve (AUDPCstandard) of modified Petri-dish inoculation. Correlation coefficients between FHB severity and the two in vitro components LP and AUDPCstandard were significant (r=0.545 with p&lt;0.05, and r=0.659 with p&lt;0.01, respectively). No significant differences in the resistance of Cham6 and Cham1 were indicated for the other seven in vitro components: incubation period and lesion length of detached leaf inoculation, germination rate reduction and coleoptile length reduction of modified Petri-dish inoculation and lesion length of clip-dipping inoculation and percentage of infected seedlings of foliar-spraying and pin-point inoculations. Results from these seven components were not correlated with adult FHB resistance. Longer latent period and less AUDPCstandard were related to greater FHB disease-type II resistance. Conclusion: LP and AUDPCstandard are indicators of mechanisms of resistance occurring in the whole plant during FHB infection. Therefore, the idea of using in vitro components is based on their predictive ability of in planta adult FHB resistance.

Soil properties and cultivars determine heavy metal accumulation in rice grain and cultivars respond differently to Cd stress.

Field and pot experiments were conducted to evaluate the factors affecting heavy metal (HM) accumulation in rice grain and subsequently to explore their cultivar difference when exposed to Cd. Forty-seven paired soil and rice cultivar samples were collected from Jiangxi province, China. The contents of Cd, Cu, Zn, Pb, Cr, and Ni in soils and grains were determined. It showed that among these metals, Cr and Cd were the dominant contaminants in samples from the test areas, with 100.0% and 59.6% of all grain samples exceeding the maximum permissible concentration. Random forest analysis showed that soil pH, soil organic matter (SOM), Fe fraction and cultivar were four most important factors affecting HMs accumulation in grain. Based on bioconcentration factors, two cultivars with high Cd (HCd) accumulation ability and two cultivars with low Cd (LCd) accumulation ability in rice grain were chosen to explore their physiological and growth responses when exposed to 0, 50, 100 and 1000μmolL-1 Cd. The results showed that the Cd phytotoxicity is Cd level- and cultivar-dependent. The height and weight decreased, while Cd accumulation increased in shoot and root for the four rice cultivars with the increasing of Cd content. The HCd cultivars showed less membrane damage, higher superoxide dismutase (SOD) activity and higher Cd accumulation than that of LCd cultivars. In conclusion, heavy metal accumulation in rice grain is soil property- and cultivar-dependent. And different rice cultivars respond differently to Cd stress.

Host Selection Behavior of the Green Peach Aphid, Myzus persicae, in Response to Volatile Organic Compounds and Nitrogen Contents of Cabbage Cultivars.

Plants emit volatile organic compounds (VOCs) in response to herbivore attack. VOCs emitted from the Chinese cabbage cultivars in response to the damage by the green peach aphid, Myzus persicae, were unknown. Using a solid-phase microextraction-based headspace collection method, we investigated and compared the emissions of VOCs from seven Chinese cabbage cultivars (Qibao, Qingan 80, Lvlong, Yuanbao, Qingan 70, Jinlv, and Lvqiu 66) in response to M. persicae attack. Our results showed that the VOCs emitted from the cultivars Qingan 80 and Yuanbao differed significantly from the other cultivars in response to the attraction of wingless M. persicae. Most importantly, out of the 27 detected compounds, α-caryophyllene was detected only in Qingan 80 and Qibao, but not in the other five cultivars. Among the compounds detected, 2 monoterpene and 12 terpenes were predominant in all cabbage cultivars. Furthermore, the wingless M. persicae showed preference to Qingan 80 while it had the highest nitrogen content among the tested cultivars. Moreover, we found a remarkable relationship among M. persicae attraction, plant nitrogen content, and total volatile emissions. Nitrogen content of the plants has a significant impact on volatile emission and preference behavior of M. persicae. Our results indicate that the wingless M. persicae were efficient in their interspecific host selection with an ability to distinguish plant cultivar differences by leaf nitrogen content. This study will be helpful in understanding aphid host selection, and sets a stage to further study the attractant-based integrated aphid management programs.

Anti-diabetes activity of Kombucha prepared from different snake fruit cultivars

PurposeThis paper aims to study the anti-diabetes activity of the Kombucha prepared from different snake fruit cultivars.Design/methodology/approachThe juices of snake fruits of Suwaru, Madura, Pondoh and Bali cultivars were fermented for 14 days. Anti-diabetes activity of the products was analyzed. Twenty-four male albino Wistar rats were used and randomly divided into six experimental groups, i.e. four groups of the diabetic rats treated with the Kombucha, plus the normal group and diabetic control group. The Kombucha were orally administered to the streptozotocin induced-diabetic rats at 5 mL/kg body weight per day during the 28-day experiment. The fasting plasma glucose (FPG), oxidative stress indices (superoxide dismutase [SOD] activity and Malondialdehyde [MDA] level) and lipid profile of the blood plasma were measured. The pancreas was used for immunohistochemical study and β-cells quantification. Data were analysed by ANOVA followed by Fisher test using Minitab version 16.0.FindingsFPG of the diabetic rats treated with the Kombucha (110.3-189.3 mg/dL) was significantly lower (p= 0.000) than the diabetic control group (413.3 mg/dL). Those were in line with the number of pancreatic β-cells of 42.1 in diabetic rats that lower (p= 006) than those in treated the diabetic rats (61.2-73.5). The treated diabetic rats had lower oxidative stress (SOD activity: 20.9-44.6 unit/100 µL withp= 0.000; MDA level: 0.37-0.48 ng/100 µL withp= 0.000) than those in the diabetic rats (SOD activity: 18.7 unit/100µL; MDA level: 0.84 ng/100 µL). The treated diabetic rats also showed better lipid profile than those in the diabetic control rats. There were cultivar differences, and the Suwaru and Madura snake fruit Kombucha demonstrated the most potential for diabetes management.Originality/valueThis is the first study on in vivo anti-diabetes activity of snake fruit Kombucha prepared from different snake fruit cultivars.

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.