Mineral Nutrient Concentrations Research Articles

QTL mapping for micronutrients concentration and yield component traits in a hexaploid wheat mapping population

Bread wheat is a major staple cereal provides more than 20% of dietary energy and protein supply to global population. However, with increasing population growth, the problem of nutritional deficiencies is increasingly affecting the health of resource people with predominantly cereal-based diet. Therefore, the development of wheat genotypes with micronutrient-dense grains along with high-yield potential is one of the major priorities of wheat biofortification program at CIMMYT. We conducted a QTL mapping study using a recombinant inbred line (RIL) population derived from a cross between a Chinese parental line with highGZnC and a Mexican commercial bread wheat cultivar Roelfs F2007 to identify QTLs that could potentially be integrated in mineral nutrient concentrations and agronomic-related traits breeding. We evaluated 200 RIL lines for mineral nutrient concentrations and agronomic-related traits over two years. A total of 60 QTLs were detected, of which 10 QTLs for GZnC, 9 for GFeC, 5 for GPC and 36 for agronomic-related traits. Moreover, a total of 55 promising candidate genes were identified from the list of associated markers for GFeC and GZnC using the recently annotated wheat genome sequence. We identified the promising genomic regions with high mineral nutrient concentrations and acceptable yield potential, which are good resource for further use in wheat biofortification breeding programs.

Organically grown outdoor tomato: fruit mineral nutrients and plant infection by Phytophthora infestans

Tomato fruits are characterized by a good nutritional profile, including sugars and bioactive compounds such as carotenoids, phenolic compounds, ascorbic acid, and mineral nutrients. The objective of this study was to determine the mineral nutrient content of 28 tomato genotypes from field trials from the Organic Outdoor Tomato Project. Outdoor production as a very resource-efficient production method is limited by infections with Phytophthora infestans in the research area. The relationship between mineral nutrients and fruit infection with P. infestans was estimated. Experiments were carried out in 2004 and 2005 at two locations in Central Germany. Tomato fruits from diverse genetic backgrounds differed significantly in mineral nutrients and dry matter content. For Ca, Fe, Zn, and Mn, higher maximum contents were found than those in past experiments. Low genotypic effects were observed for Fe and Zn. Environmental conditions induced variation in the mineral status of tomato genotypes. All traits but the Mn content interacted significantly with the environment. Outdoor tomatoes can contribute significantly to human diets. The observed significant differences between genotypes for almost all investigated traits allow improving organic tomato production and breeding.

The impacts of season and livestock management strategy on the quality of diets selected by goats and sheep in the semi-arid rangelands of Namaqualand, South Africa

Access to good-quality forages is one of the major limitations to livestock production in semi-arid pastoral systems. This study aimed to determine whether there are differences in the nutritional quality of diets selected by herded and free-ranging goat and sheep flocks utilising Namaqualand Granite Renosterveld vegetation during the wet and dry seasons. Plant samples collected along the grazing routes of livestock were dried and analysed for their fibre, condensed tannin, total phenolic and mineral nutrient contents. The study showed that a large variety of forages were on offer and livestock groups selected different diets of which some were different to the total diet on offer. In general, significant deficiencies in phosphate, protein and energy in the diets selected by herded and free-ranging goats and sheep were observed in both wet and dry season. The quality of the diets selected by herded and free-ranging livestock was also found to be different from each other, with herded livestock generally selecting more nutrient-dense diets. Herding, therefore, allows livestock to access better-quality forage in the Namaqualand Granite Renosterveld rangeland, where it is generally poor.

Response of alfalfa and sugar beet to field dodder (Cuscuta campestris Yunck.) parasitism: a physiological and anatomical approach

The physiological and anatomical impact of field dodder (Cuscuta campestris Yunck.) on alfalfa and sugar beet was examined under controlled conditions. The following parameters were checked: physiological — content of pigments (chlorophyll a, chlorophyll b, and carotenoids) and mineral nutrients: nitrogen, phosphorus, potassium, and percent of organic and mineral nutrients; and anatomical — thickness of the epidermis and cortex, diameter of the stem and central cylinder of alfalfa plants, diameter of tracheids and phloem cells, area of xylem and phloem, and hydraulic conductance of petiole bundles in petiole vascular bundles of sugar beet plants. Leaf parameters were also measured on both host plants: thickness of upper and underside leaf epidermis, thickness of palisade, spongy and mesophyll tissue, and diameter of vascular bundle cells. Pigments content and anatomical parameters were measured 7, 14, 21, 28, 35, and 42 d after infestation (DAI), while mineral nutrient contents were determined 20 and 40 DAI. Field dodder caused a significant reduction in pigments content in infested alfalfa (15%–68%) and sugar beet plants (1%–54%). The results obtained in this study confirmed that this parasitic flowering plant has a strong effect on most anatomical parameters of the stem and leaf of alfalfa and leaf and petiole of sugar beet. Also, it was revealed that field dodder increased the contents of N, P2O5, K2O, and organic nutrients in infested alfalfa plants, while infested sugar beet plants had higher contents of N and organic nutrients compared with non-infested plants.

Nitric oxide alters nitrogen metabolism and PIN gene expressions by playing protective role in arsenic challenged Brassica juncea L.

Plants have ability to adapt themselves through altering their growth process. In the present study, we examined exogenous application of nitric oxide (NO) on nitrogen metabolism and auxin (PIN) gene expression, and its possible role in alleviation of arsenic (As) toxicity in Brassica juncea seedlings. Seven days old hydroponically grown B. juncea seedlings were exposed to AsIII (150 μM), Sodium nitroprusside (NO donor, 100 μM), AsIII + SNP and control (without metal)for 48 h. Experimental results revealed that AsIII stress: enhanced the level of nitrite, NiR activity, NO3− and NH4+content as well as NADH-GOGAT activity; but GDH level decreased; enhanced content of amino acids; upregulated gene expression level of N metabolism and downregulated polar auxin transporter genes (PIN); inhibited plant growth and morphological parameters; increased MDA, H2O2, cysteine, proline content, enzymatic antioxidants (SOD, CAT, APX; GSH, TT, NPT); and decreased nutrient content. AsIII + SNP combination reduced the accumulation of As; improved growth; chlorophyll, protein and mineral nutrient content by scavenging ROS generation; maintained amino acids content; downregulated expression of N metabolism genes and upregulated expression of auxin transporter (PIN) genes . Additional biochemical data depicts reduction in the level of nitrogen related enzymatic activities, and other stress related parameters. Overall, this study provides an integrated view that exogenous SNP (NO donor) supplementation alleviated the inhibitory role of AsIII in B. juncea seedlings by altering nutrients, amino acids and auxin redistribution via expression of nitrogen and PIN gene profiling.

Characterization of deficiency symptoms and mineral nutrient content in Acmella oleracea cultivated under macronutrient and boron omissions

Acmella oleracea occurs in the Amazon forest and is widely consumed in regional cuisine and folk medicine. Many studies concerning its active principles are available, but few studies have been carried out regarding mineral nutrition. The aim of this study was to characterize deficiencies symptoms and nutritional content in Acmella oleracea. The experimental design applied was a randomized block with four replications. After blooming, following treatments were applied: complete solution, absence of Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, and Boron. After harvesting, growth and nutrient content of inflorescences, new leaves, old leaves, and stems were assessed. The absence of aforementioned nutrients allowed for characterization of visual deficiency symptoms. The first observed symptom was absence of Nitrogen. The accumulation of macronutrients in inflorescences followed the order N > K > Ca > P > S > Mg, in new leaves, N > K > Ca > S>Mg > P, in old leaves, K > N > Ca > Mg > S > P, and in stems K > N > Ca > Mg > P > S. The greatest growth restrictions were observed in nitrogen and calcium absence treatments.

YUNHAN LEI, The Linsly School, Wheeling, WV, 26003. Pre-germination inoculation with 11 species of endomycorrhizal fungi slightly improves early growth of lettuce (Lactuca sativa) seeds but not that of radish (Raphanus raphanistrum) or beans (Phaseolus vulgaris).

Mycorrhizal associations of fungi with established and mature plant roots are well-known to benefit the plant. Mycorrhizal fungi, by penetrating into plant’s root cells and increasing their surface area, improve a plant’s absorption of water and mineral nutrients. In return, the fungi absorb carbohydrates from the plant. Less well known are the effects mycorrhizal fungi have on germination and early root growth. Tiny orchid seeds contain low quantities of nutrients and need early contact with mycorrhizal fungi for germination success. This study asks whether inoculation of lettuce, radish and bean seeds improves seed germination or seedling growth, and whether any effect is seed size dependent. Ten groups of seeds of lettuce, radish and beans were treated with a powder consisting of 11 different species of endomycorrizal fungi while ten seeds for each species served as controls. Seeds were placed in plastic petri dishes lined with paper toweling and provided equal amounts of distilled water. All six groups had 100% germination rates, except for 90% germination in the mycorrhizal fungi radish group. In comparing mycorrhizal fungi treatment groups to the control, average root length in lettuce increased by 12% (p=0.15, t-test), but only by 8% (p=0.71, t-test) in radish and 5% (p=0.91, t-test) in beans. Only the effect on lettuce seeds approached statistical significance. A larger trial with more seeds growing longer might yield significant results. Since mycorrhizal fungi treated seeds absorbed water faster and left drier paper toweling, seed coat proteins may be triggered to absorb water faster, aiding germination.

Path Analysis in Cowpea Reveals Protein Accumulation Dependency of Mineral Nutrients Accumulation

This work aimed at evaluating the effects of the nutrients on the protein content of cowpea grains. The trial was carried out in completely randomized design, in the Instituto Federal do Ceará (Federal Institute of Ceará), Limoeiro do Norte, Ceará State, Brazil, between October and November 2018. Grains of 10 cowpea cultivars were evaluated about its mineral nutrient phosphorus, potassium, calcium, magnesium, sulfur, chlorine, iron, zinc, copper, manganese, boron, sodium and protein contents. The seeds of the cultivars were obtained from the farmers market in three municipalities of the Ceará State, Brazil, in the crop year 2017. The components of variances within and between families were computed by analysis of variance, and the genetic variance and correlation were therefrom estimated. The statistical analyses of variance, Pearson’s correlation and Path analysis were carried out. The protein content broad sense heritability was 60.47%, and the other cowpea traits evaluated had high broad heritability values, ranging from 49.91% (sulfur content) to 99.69% (zinc content). No mineral nutrient content presented any genotype correlation with protein content, that is, no gene function is related to mineral nutrients and protein accumulation. Potassium (0.44), chlorine (0.38) and calcium (0.35) presented the higher path coefficients in protein of cowpea accumulation but are still weak indices (<0.50) to be indicated for screening. In screening cowpea cultivars for protein content, potassium and related traits are not the most important but present some degree of dependency with protein accumulation in the grains, resulting from path effects.

Improvement of mineral nutrient content of tomato through selection of cultivars and soil fertility

Depleted soil fertility and high-yielding cultivars have been associated with low nutrient contents in vegetables. This study explored if elemental nutrient concentrations in tomato (Lycopersicon esculentum Mill.) can be increased through selection of cultivars and nutritional regimes. Cultivars with different phenotypes of heirloom and modern origins were studied in field experiments in two years. Chemical fertilizer (10-10-10), compost, and an organic fertility regime of soybean meal, bone meal, and potassium sulfate were assessed for their effects on growth and composition of fruits of the cultivars. Differences in nutrient concentrations between modern or heirloom cultivars or among fertility treatments were small or non-significant. Differences among individual cultivars for each element were large with some cultivars having nearly twice the concentrations of nutrients of others and with considerable uniformity in cultivar rankings among the elements. This work suggests that cultivars can be selected for production of nutrient-dense tomatoes.

Effects of copper treatment on mineral nutrient absorption and cell ultrastructure of spinach seedlings.

The accumulation of heavy metals in soil has serious influence on plant growth and ecosystem balance. It is of great importance to explore the mechanism of plant tolerance to heavy me-tals. Although spinach is supposed to have strong Cu tolerance, the effects of Cu on mineral element absorption and cell ultrastructure are still unclear. In this study, the growth of spinach seedlings, the absorption of mineral elements and the ultrastructure of leaf cells were examined in a pot experiment. The results showed that Cu2+ accumulation in the root of spinach seedling was less than that in the shoot when CuSO4 concentration was 100 mg·L-1, with root growth being increased and shoot growth being slightly decreased. When copper concentration continued to increase, the growth parameters continuously declined. When the CuSO4 concentrations were less than 400 mg·L-1, the foliar N, K, Ca, Mg and Fe concentrations of spinach seedling increased, and that of P decreased. The concentrations of N, P and K in roots went down and that of Ca, Mg and Fe went up. All organelles in leaf cells were clearly visible. The basal granule layer was arranged orderly, and the inner and outer membranes of chloroplasts were intact. When the CuSO4 concentrations exceeded 600 mg·L-1, foliar N concentration increased while that of P, K, Ca, Mg and Fe decreased. The concentrations of N, P, K, Ca, Mg and Fe in roots declined. The cell ultrastructure of spinach seedlings substantially changed with the increases of CuSO4 treated concentrations. The chloroplast in leaf cells became rounder, the chloroplast membrane became thinner, the stroma and basal granule layer became less, and the layer accumulation height decreased. The nucleus was broken up and small black spots were found in vacuoles and cell walls, which might be attributed to the enhancement of intracellular swelling pressure caused by high accumulation of Cu2+. In conclusion, low concentration of CuSO4 had little negative effect on the life activities of spinach seedlings, and the high concentrations of CuSO4 did not terminate their growth, indicating that spinach seedlings had strong copper resistance.

“Wild barley serves as a source for biofortification of barley grains”

The continuing growth of the human population creates an inevitable necessity for higher crop yields, which are mandatory for the supply with adequate amounts of food. However, increasing grain yield may lead to a reduction of grain quality, such as a decline in protein and mineral nutrient concentrations causing the so-called hidden hunger. To assess the interdependence between quantity and quality and to evaluate the biofortification potential of wild barley, we conducted field studies, examining the interplay between plant development, yield, and nutrient concentrations, using HEB-YIELD, a subset of the wild barley nested association mapping population HEB-25. A huge variation of nutrient concentration in grains was obtained, since we identified lines with a more than 50% higher grain protein, iron, and zinc concentration in comparison to the recurrent parent ‘Barke’. We observed a negative relationship between grain yield and nutritional value in barley, indicated by predominantly negative correlations between yield and nutrient concentrations. Analyzing the genetic control of nutrient concentration in mature grains indicated that numerous genomic regions determine the final nutritional value of grains and wild alleles were frequently associated with higher nutrient concentrations. The targeted introgression of wild barley alleles may enable biofortification in future barley breeding.

Sources and concentrations of silicon modulate the physiological and anatomical responses of Aechmea blanchetiana (Bromeliaceae) during in vitro culture

The use of silicon (Si) has been shown to be a good alternative to improve the growth and content of photosynthetic pigments of plants propagated in vitro. So far, it is not well understood how the sources and concentrations of Si can affect the root and leaf anatomy as well as the functioning of the photosynthetic apparatus of these plants. The aim was to assess the physiological and anatomical responses of Aechmea blanchetiana plants in function of sources and concentrations of Si during in vitro culture. Side shoots of plants previously established in vitro were excised and transferred to a culture medium containing CaSiO3 or Na2SiO3 in four concentrations (0, 7, 14 or 21 µM). After culture for 90 days, the chlorophyll a fluorescence transient, root and leaf anatomy, contents of photosynthetic pigments and mineral nutrients as well as growth were analyzed. Plants grown in medium supplemented with Na2SiO3 presented characteristics of salt stress, such as smaller stomata, higher potassium content and lower number of active reaction centers (RC/CSM). On the other hand, plants cultured with 7 and 14 µM CaSiO3 had an increase in photosynthetic pigment content and performance of photosynthetic apparatus, verified by the performance indexes (PI(ABS) and PI(TOTAL)). The employment of concentrations equal to or higher than 21 µM Si, independent of Si source, caused toxicity symptoms in the plants. The use of CaSiO3 had a positive effect on the concentration interval between 7 and 14 µM by improving physiological and anatomical quality of A. blanchetiana plants. Silicon source and concentration can affect the physiological responses of Aechmea blanchetiana during in vitro culture. This study highlights that CaSiO3 increases the photosynthetic pigment content and photosynthetic apparatus performance.

Chemical and isotopic markers detect water deficit and its influence on nutrient allocation in Phaseolus vulgaris.

The impact of drought on plant growth and yield has been widely studied and is considered a major limitation to crops reaching yield potential. Less known is the impact of water deficit on the nutritional quality of the resulting yield. This study characterised the impact of water deficit on carbon assimilation, modelled water use efficiency from carbon isotope discrimination and analysed the concentration of mineral nutrients, amino acids and sugars in leaf, phloem and pod pools collected from Phaseolus vulgaris L. (common bean) grown in a controlled environment. Water deficit led to an isohydric response, impacting on carbon isotope abundance in all tissues though not translating to any significant treatment differences in water use efficiency or nutrient content in tissues over the course of plant development. The results obtained in this study demonstrate that nutrient content of P. vulgaris yield was not impacted by the availability of water. The absence of significant changes in the nutrient content of individual seeds highlights the plasticity of developing reproductive tissue to changes in whole plant water availability.

Influence of Tomato Plant Mycorrhization on Nitrogen Metabolism, Growth and Fructification on P-Limited Soil

The application of mycorrhizal fungi in agricultural soils as bio-fertilizers is going to be established as an agronomic practice for enhancing crop nutrients acquisition and production. In this work, the effects of tomato root colonization by arbuscular mycorrhizal fungus Glomus mosseae, on nitrogen metabolism, fructification and environmental sustainability without P soil fertilization have been studied. At the harvesting fruit stage, the mycorrhizal (M) plants present a significantly higher concentration of mineral nutrients and organic nitrogen compounds. In particular, GLU, GLN, ASP and ASN have risen about 35% more than non-mycorrhizal (NM) plants. Tomato root mycorrhization improved nitrogen metabolism in plants, too by increasing the nitrate reductase and the glutamine synthetase enzymatic activity. Moreover, mycorrhization affects many aspects of vegetative and reproductive growth. In particular, the fruit production turns from inoculated (M) plants into non-inoculated (NM) plants, rising up to 50%.

Evaluation of concentration of heavy metals in animal rearing system

Animal manure is one of the diffusion routes of heavy metals and metalloids into the environment, where the soil can accumulate them. Heavy metals and metalloids can then be released into groundwater sources, be absorbed by crops, and enter the food chain with negative effects for human and animal health. The aim of this study was to evaluate the concentration of heavy metals and mineral nutrients from modern animal rearing systems in order to develop effective strategies to increase the sustainability. Samples of feed (n = 24: n = 16 from swine, n = 8 from cattle), faeces (n = 120: n = 80 from swine, n = 40 from cattle) and water (n = 8), were collected from eight typical intensive swine and cattle farms located in northern Italy. All samples were analysed for the humidity and the principal components. The samples were also dried, mineralised, and analysed by ICP-MS to detect the following elements: Na, Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, and Pb. The swine diets represented the highest amounts of Zn and Cu, with an average concentration for the finishing and weaning phases of Zn: 1737.9 ± 301.3; 821.7 ± 301.3; Cu: 133.8 ± 11.6; 160.1 ± 11.6 mg/kg as fed, respectively. The faecal content reflected the heavy metal composition from feed. The average content of cattle diets of Zn and Cu did not result higher than the maximum permitted levels. We observed that the swine manure represented the sources of Zn and Cu output into the environment. The Zn and Cu content should be monitored strictly in line with agroecology principles.HighlightsEvaluation of the role of zinc and copper in animal production.Increase the sustainability of farms.Consider the feed as major route of HMs in livestock.

Effect of fruit thinning on nut characteristics and leaf mineral nutrient concentration in walnut (Juglans regia) cv. Xiangling

The experiment was conducted to find out the effect of fruit thinning in walnut (Juglans regia L.) ` final nut number, nut weight, kernel rate, nuts mineral nutrients concentration and mineral nutrients concentration within leaves during growing season of 2014 and 2015 at Baoking in Hubai, China. The fruit thinning affected nut uniformity more than final nut number, weight and kernel rate. Fruit thinning showed non-significant effect on macro nutrient (N, P and K) concentrations within kernel, but had significant effect on micronutrient (Fe, Zn and B) concentration. With more fruits been retained, N, K, Fe, B and Zn concentrations within leaves increased significantly during the fruit developing. Thus, fruit thinning management for early-bearing commercial orchard could obtain more commercially valuable nuts and reduce mineral nutrients consuming.

Effect of rootstock-scion interaction on petiole nutrient content, bud break, and yield of three commercial grape cultivars

An experiment was conducted to study the influence different rootstocks (1103 P, SO4 and Dog ridge) on petiole nutrient content (%), bud break (days) and fruit yield (kg ha−1) of commercial grape varieties (Thompson Seedless, Flame Seedless and Kishmish Chorni). The study revealed that there was often rootstock, scion and rootstock x scion interaction effect on mineral nutrient content, yield components and yield. In general, across scion cultivars higher petiole N content was recorded with Dogridge rootstock at full bloom, while the pronounced effect on increasing petiole K content was recorded with Dogridge at bud differentiation stage. Considerable effect in increasing phosphorus (P) content was recorded with 1103 P which was comparable to own rooted vines during both the stages. Across rootstocks, Thompson Seedless cultivar recorded higher nitrogen (N) and P and Kishmish Chorni recorded higher potassium (K) content. Early bud break was observed with 1103P and own rooted vines among rootstocks and with Kishmish Chorni among cultivars. Yield per vine was higher in Thompson Seedless on own root which was on par with Kishmish Chorni on Dogridge which recorded comparable yields with 1103 P and own rooted vines. Irrespective of the scion varieties, higher bunch weight was recorded on Dogridge.

The effects of magnetic treatment of irrigation water on seedling growth, photosynthetic capacity and nutrient contents of Populus × euramericana ‘Neva’ under NaCl stress

The use of saline water in irrigation is cause for concern due to the reduced availability of fresh water resources for agroforestry in some regions; however, salinity can negatively affect plant populations, such as Populus. Here, magnetic techniques were employed to investigate their effects on improving salinity tolerance in Populus. Irrigation experiments were performed with Populus applying magnetized water (MW) and non-magnetized water (NMW), and seedling growth and development in 1-year-old potted seedlings of Populus × euramericana ‘Neva’ were evaluated under saline conditions. A magnetic treatment device with a low-intensity magnetic field was used for the management of irrigation water. Two average salinity levels, 0 and 4.0 g L−1 of NaCl, were used with MW and NMW, yielding four treatments of irrigation water. The experiments were performed according to a single-factor randomized block design. Seedling growth; the biomass of leaves, roots and stems; photosynthetic parameters and nutrient contents were measured. The results showed that, compared with the non-magnetic treatment (NMT), magnetic treatment (MT) led to improvements in seedling height, basal diameter, leaf area and biomass of leaves and roots (but not stem biomass). Net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and water use efficiency were increased in MT, whereas both transpiration rate and stomatal limiting value were decreased in MT compared with those in NMT. In addition, MT promoted root development, as evidenced by improvements in the length, surface area, mean diameter, volume and tips of the roots. The microelement contents analyses indicated that MT led to higher contents of Fe, Zn and Cu in leaves and roots and a lower content of Mn. MT led to increased contents of C and P and an increased C/N ratio in leaves but a decreased N content; in the roots, the C content and the ratios of C/N and C/P were increased. These results indicated that irrigation with MW appeared to promote seedling growth, root development, photosynthesis and mineral nutrient contents. The properties of saline water were improved by MT, indicating that MT-treated saline water can be used for irrigation.

Physiological responses of Pedunculate oak (Quercus robur L.) to Corythucha arcuata (Say, 1832) attack

The spread and occurrence of the oak lace bug Corythucha arcuata out of its natural distribution area across European and Asian countries has been reported during the past decades. The ecological and economic significance of oak stands and the vulnerability of plants to various abiotic and/or biotic factors requires in-depth knowledge of plant-pest interaction. The present study examined the influence of C. arcuata feeding on the photosynthetic characteristics and gas-exchange parameters, mineral nutrient concentrations and defense mechanisms (the activities of some antioxidant enzymes) of leaves of pedunculate oak. The rate of photosynthesis, transpiration and stomatal conductance were lowered by 58.84, 21.66 and 35.71%, respectively, in comparison to non-infested plants. The concentrations of photosynthetic pigments and activities of antioxidant enzymes, catalase and ascorbate peroxidase, were affected by the presence of C. arcuata. To our knowledge this is the first paper providing a report on the physiological responses of Quercus robur plants exposed to C. arcuata infestation. Understanding the impact of pests, such as the invasive species C. arcuata on physiological processes and vitality of young plants and plant responses, could provide a foundation for efficient preservation of oak forests endangered by the oak lace bug.

The contrasting leaf functional traits between a karst forest and a nearby non-karst forest in south-west China.

Karst and non-karst forests occur in the same region in south-west China, but the soil water and mineral nutrients availability are different between the forests. Our hypothesis was that the leaves of karst trees would be better adapted to dry, nutrient-poor conditions than those of trees in a nearby non-karst forest. We compared the gas exchange, anatomical characteristics and mineral nutrient concentrations in leaves from 21 tree species in a tropical karst forest and 19 species in a nearby non-karst forest in south-west China. We found that the leaves of karst trees had higher P concentrations, photosynthetic capacity and water use efficiency, and greater adaxial and abaxial epidermis thickness than leaves of non-karst forest trees. Evergreen and deciduous trees differed more significantly in leaf functional traits in the karst forest than in the non-karst forest. The leaf palisade:spongy mesophyll thickness ratio was positively correlated with stomatal conductance and negatively correlated with photosynthetic water use efficiency in the karst forest but not in the non-karst forest. Our findings indicate that karst forest trees are more conservative in water use, whereas soil P deficiency could be a major limiting factor for the growth of non-karst forest trees.