Responses of Super Rice (Oryza sativa L.) to Different Planting Methods for Grain Yield and Nitrogen-Use Efficiency in the Single Cropping Season

To break the yield ceiling of rice production, a super rice project was developed in 1996 to breed rice varieties with super high yield. A two-year experiment was conducted to evaluate yield and nitrogen (N)-use response of super rice to different planting methods in the single cropping season. A total of 17 rice varieties, including 13 super rice and four non-super checks (CK), were grown under three N levels [0 (N0), 150 (N150), and 225 (N225) kg ha⁻¹] and two planting methods [transplanting (TP) and direct-seeding in wet conditions (WDS)]. Grain yield under WDS (7.69 t ha⁻¹) was generally lower than TP (8.58 t ha⁻¹). However, grain yield under different planting methods was affected by N rates as well as variety groups. In both years, there was no difference in grain yield between super and CK varieties at N150, irrespective of planting methods. However, grain yield difference was dramatic in japonica groups at N225, that is, there was an 11.3% and 14.1% average increase in super rice than in CK varieties in WDS and TP, respectively. This suggests that high N input contributes to narrowing the yield gap in super rice varieties, which also indicates that super rice was bred for high fertility conditions. In the japonica group, more N was accumulated in super rice than in CK at N225, but no difference was found between super and CK varieties at N0 and N150. Similar results were also found for N agronomic efficiency. The results suggest that super rice varieties have an advantage for N-use efficiency when high N is applied. The response of super rice was greater under TP than under WDS. The results suggest that the need to further improve agronomic and other management practices to achieve high yield and N-use efficiency for super rice varieties in WDS.     

The Influence of Two Lithium Forms on the Growth, l-Ascorbic Acid Content and Lithium Accumulation in Lettuce Plants

Lithium (Li) is a trace element that is essential in the human diet due to its importance for health and proper functioning of an organism. However, the biological activity of this metal in crop plants, which are the primary dietary sources of Li, is still poorly understood. The aim of the presented study was to comparatively analyse two Li chemical forms on the growth, as well as the l-ascorbic acid content, the Li accumulation and translocation in butterhead lettuce (Lactuca sativa L. var. capitata) cv. Justyna. The plants were grown in a nutrient solution enriched with Li in the form of LiCl or LiOH at the following concentrations: 0, 2.5, 20, 50 or 100 mg?Li?dm^?3. The obtained results indicate that the presence of Li⁺ ions in the root environment reduced the yield of edible parts of the lettuce if the Li concentration in a nutrient solution had reached 20 mg?Li?dm^?3. However, a yield reduction under these conditions was found to be significant only for LiOH. In plants exposed to 50 mg?Li?dm^?3, both shoot and root fresh weights (FW) significantly decreased, regardless of the supplied Li chemical form. On the other hand, under the lowest LiOH dose, a significant increase in the root FW was noted, suggesting beneficial effects of Li on the growth of lettuce plants. However, applied Li concentrations and forms did not affect the l-ascorbic acid content in the lettuce leaves. Regardless of which Li form was used, Li accumulated mainly in the root tissues. An exception was the higher concentration of this metal in the shoots than in the roots of plants supplied with 100 mg?Li?dm^?3 in LiCl, and there were almost the same Li concentrations in both examined organs of plants supplied with 100 mg?Li?dm^?3 in LiOH. The effectiveness of Li translocation from roots to shoots rose with increasing Li concentrations in the growth medium, and this suggests a relatively ready translocation of this metal throughout the plant. Moreover, these results suggest that Li toxicity in lettuce plants is related to a high accumulation of this element in the root and shoot tissues, causing a drastic reduction in the yield, in the presence either of LiCl or LiOH, but not affecting the l-ascorbic acid accumulation in the leaves.     

Rates of Leaf and Tiller Production in Young Spaced Perennial Ryegrass Plants in Relation to Soil Temperature and Solar Radiation

In an experiment designed to investigate the rate of leaf appearanceand tiller production in young spaced plants of three clonesof perennial ryegrass grown in the field, it was found thatthe rate of leaf appearance per tiller increased linearly withmean soil temperature up to approx. 14 °C. The rate of productionof tillers in relation to the rate of leaf appearance (sitefilling) appeared to be virtually independent of weather conditions.In plants which were adequately established, but still relativelysmall, site filling was equal to or exceeded the theoreticalsteady state; all the tiller buds which were being formed weredeveloping into visible tillers. Thus the relative rate of tillerproduction was controlled by the rate of leaf appearance. Inlarger plants site filling was less complete, and site redundancieswere probably caused by within-plant competition for light atthe tiller bases. Lolium perenne L., perennial ryegrass, tillering, leaf production, solar radiation, soil temperature     

Cytopathology of Anthers and Pollen From Lettuce Plants Infected by Lettuce Mosaic Virus

Thin sections of mature anthers and pollen grains from three lettuce (Lactuca sativa) plants infected with lettuce mosaic potyvirus (LMV) were studied by immunogold labelling. Labelled LMV particles were present externally on the exine of pollen grains from all plants, but were observed internally in the pollen grains from only one plant. Within mature pollen grains the virus particles were associated with the cytoplasmic bundle inclusions typical of infection by potyviruses. The tapetal plasmodium and the epidermal and endothecial layers of mature anthers from all infected plants also contained labelled virus particles, together with pinwheel and bundle inclusions.     

Salicylic Acid Increases Photosynthesis of Drought Grown Mustard Plants Effectively with Sufficient-N via Regulation of Ethylene,Abscisic Acid,and Nitrogen-Use Efficiency

Journal of Plant Growth Regulation - An essential approach to reduce drought in plants is to maximize the use of most limited available resources. The increase in water-use efficiency (WUE) is...     

Forms of Silicon in Medicinal Plants

The contents of three forms of silicon (organic, soluble mineral, and polymeric) were determined in leaves of 21 medicinal plants. At a total content of silicon of 0.74 to 3.59%, the organic, soluble mineral, and polymeric forms accounted for 0.51–1.91%, 0.05–0.51%, and 0.1–1.21%, respectively. An analysis of silicon in the condensed polyphenol fraction was performed for the first time revealing the presence of a covalently bound form in amounts of 0.1 to 0.2% of the total silicon content in the leaves. These results are of interest for food or medical applications of the plants studied.     

Content of Oxalate in Actinidia Deliciosa Plants Grown in Nutrient Solutions with Different Nitrogen Forms

Kiwifruit plants (Actinidia deliciosa cv. Hayward) were grown in Hoagland nutrient solution with calcium nitrate, potassium nitrate, ammonium nitrate or ammonium chloride as the nitrogen source. Plants grown in the solution with nitrate nitrogen displayed a higher oxalate content, greater shoot length and leaf area, and higher content of ascorbic acid and NO₃ ^– ions in the leaves. Plants grown in the solution with ammonium nitrate, and particularly with ammonium chloride, showed low oxalate content, low content of ascorbic acid and NO₃ ^–, high content of Cl^– and Na⁺, low shoot length and leaf area. Oxalate formation appeared to be connected with the assimulation of nitrate, more precisely with nitrate reduction, while ammonium nitrogen assimilation did not induce the synthesis of oxalic acid.     

花期减少施钙量对不同钙效率番茄果实钙形态和含量的影响

花期降低施钙量后,钙低效番茄品种L-402果实中钙含量显著降低,高效品种江蔬一号降低不显著,镁含量显著增加,钾含量有增加趋势。果实底端的钙含量高于顶端,降低施钙量后果实水溶性钙含量和比例显著提高,果胶酸钙含量和比例降低,磷酸钙含量也降低。钙低效品种L-402水溶性钙含量的增加,以及果胶酸钙和磷酸钙的降低程度,都大于高效品种江蔬一号,且降钙后果实顶端的革酸钙含量和比例增加。     

Nitrogen-Use Efficiency,Nitrous Oxide Emissions,and Cereal Production in Brazil: Current Trends and Forecasts

The agriculture sector has historically been a major source of greenhouse gas (GHG) emissions into the atmosphere. Although the use of synthetic fertilizers is one of the most common widespread agricultural practices, over-fertilization can lead to negative economic and environmental consequences, such as high production costs, depletion of energy resources, and increased GHG emissions. Here, we provide an analysis to understand the evolution of cereal production and consumption of nitrogen (N) fertilizers in Brazil and to correlate N use efficiency (NUE) with economic and environmental losses as N₂O emissions. Our results show that the increased consumption of N fertilizers is associated with a large decrease in NUE in recent years. The CO₂ eq. of N₂O emissions originating from N fertilization for cereal production were approximately 12 times higher in 2011 than in 1970, indicating that the inefficient use of N fertilizers is directly related to environmental losses. The projected N fertilizer forecasts are 2.09 and 2.37 million ton for 2015 and 2023, respectively. An increase of 0.02% per year in the projected NUE was predicted for the same time period. However, decreases in the projected CO₂ eq. emissions for future years were not predicted. In a hypothetical scenario, a 2.39% increase in cereal NUE would lead to $ 21 million savings in N fertilizer costs. Thus, increases in NUE rates would lead not only to agronomic and environmental benefits but also to economic improvement.     

Zearalenone-Like Substance in Winter Plants and Its Relation to Vernalization

It was found that there is a zearalenone-like substance in the growing points of vernalized wheat seedlings and carrot plants. The content of this substance synchronously increased with the depth of vernalization. It was separated by thin layer chromatography. Its UV spectrum was similar to that of zearalenone. It is believed that this substance may be one of the important endogenous substances which control the vernalization of winter plants.     

Boron in Relation to Membrane Function in Higher Plants

The capacity for absorption of phosphate was shown to be reducedin Zea mays and Vicia faba suffering from boron deficiency;addition of 10^–5 M boron rapidly restored this capacity.Root tips of normal plants also responded to the addition ofboron during a short pretreatment period prior to the determinationof phosphate absorption. Comparable effects of boron on theabsorption of chloride and rubidium ions were also demonstratedin Zea mays. Specific inhibition of ion uptake by auxins maybe relevant to the mechanism of the impaired ion transport seenduring boron deficiency. The KCl-stimulated adenosine triphosphatase (ATPase) of theroots of Zea mays was also studied, with a view to examiningthe effect of boron deficiency on the activity of the enzyme.Boron-deficient roots had a reduced ATPase activity which couldbe rapidly restored by the addition of 10^–4 M H₃BO₃ 1h before extraction of the enzyme. The results suggest that the activity of specific membrane componentscan be directly influenced by boron. Possible mechanisms wherebythis control is exercised include direct interaction of boronwith polyhydroxy components of the membrane and the elevationof endogenous levels of auxins. The evidence presented stronglysupports the view that boron plays an essential role in theregulation of the functions of higher plant membranes and thatthe ATPase is a possible component of the transplant process.     

Rates of Respiration and of Increase in Structural Dry Matter in Young Wheat, Ryegrass and Maize Plants in Relation to Temperature, to Water Stress and to Their Sugar Content

A method to determine the rate of conversion of reserve materialsinto structural dry matter in living, whole plants is presented.It is based on a brief measurement of plant respiration. Therate of increase in structural dry matter and of decrease ofreserve materials is calculated by subtracting the maintenancerespiration component from the total respiration. The remainder,the growth respiration rate, is multiplied by a factor thatis derived from the biochemical composition of the structuraldry matter formed. This method is applied to determine the relations of the rateof conversion of reserve material into structural dry matterto temperature, water stress and the level of reserve carbohydratesin plants of three species. The weakest part of the method is in the determination of therate of maintenance respiration. Consequences of different assumptionsconcerning the rate of adjustment of this respiration componentto modified environmental conditions are discussed. Lolium perenne L, Triticum aestivum L, Zea mays L, ryegrass, wheat, maize, respiration, maintenance respiration, water stress, sugar content, structured dry matter     

Aminotransferase Activity in Relation to Floral Differentiation in Wheat Plants

The present investigation was carried out to study the transamination reaction in relation to floral differentiation in wheat (cv. NP 876) under three photoperiodic conditions. Three selected aminotransferases namely glutamic-glyoxylate, glutamic-pyruvate, and alanine-glyoxylate were studied in the top young leaves at various growth and developmental stages. The activity of all the three systems increased progressively during the vegetative phase till the plants produced reproductive buds. When flower primordia started differentiating, there was a sharp decrease in the aminotransferase activity followed by an increase during anthesis period. Photoperiodic treatments clearly show that even when the vegetative period of the plant is shortened considerably by long day or extended by short day, the aminotransferase activity remains closely associated with different developmental processes.     

Ontogeny of Different Life Forms of Plants and Specific Features of Age and Spatial Structure of Their Populations

Materials have been generalized that were accumulated in population-ontogenetic studies of plants and leading features of the ontogeny of plants have been noted that determine specific structural features of their populations. The described patterns allowed the authors to develop simulation models of plant population dynamics. The results of simulation are provided, and they are compared to the empirical data. Problems have been considered that concern the influence of specific features of development of different plant biomorphs on the genetic structure of populations and biocoenotic processes.     

植物细胞程序死亡的机理及其与发育的关系

细胞程序死亡（ＰＣＤ）是在植物体发育过程中普遍存在的,在发育的特定阶段发生的自然的细胞死亡过程,这一死亡过程是由某些特定基因编码的“死亡程序”控制的。ＰＣＤ的细胞分化的最后阶段。细胞分化的临界期就牌死亡程序执行中的某个阶段。ＰＣＤ包含启动期和清除期三个阶段,其间ＣＡＳＰＡＳＥ家族起着重要作用。ＰＣＤ在细胞和组织的平衡、特化,以及组织分化、器官建成和对病原体的反应等植物发育过程中起着重要作用。ＰＣＤ     

The Occurence of delta-Tocopherylquinone in Higher Plants and Its Relation to Senescence

delta-Tocopherylquinone (deltaTQ) content was determined in tobacco and yellow maple leaves, green ivy leaves and cactus tissues. It was found that the concentration of delta-TQ was highest in mature or senescent tissues, such as white tobacco leaves (0.02 mumole/g dry wt) while its detection was uncertain in young, green leaves from the apex of tobacco plants. Fractionation by centrifugation of senescent tobacco leaves showed that the osmiophilic globule fraction was enriched in delta-TQ. Electron microscope studies of young, mature and senescent tobacco tissues showed progressive changes in the size and number of osmiophilic globules. After chloroplast breakdown in senescent tobacco leaves, these globules became the predominant constituents of the organelle. delta-TQ which is associated with osmiophilic globules may play a role in the development of plants, particularly during senescence.     

植物细胞程序死亡的机理及其与发育的关系

细胞程序死亡（PCD）是在植物体发育过程中普遍存在的,在发育的特定阶段发生的自然的细胞死亡过程,这一死亡过程是由某些特定基因编码的“死亡程序”控制的。PCD是细胞分化的最后阶段。细胞分化的临界期就处于死亡程序执行中的某个阶段。PCD包含启动期、效应期和清除期三个阶段,其间caspase家族起着重要作用。PCD在细胞和组织的平衡、特化,以及组织分化、器官建成和对病原体的反应等植物发育过程中起着重要作用。PCD中的形态学变化和生物化学变化都有着严格的时序性。植物的PCD和动物的PCD有许多共性,包括细胞形态和DNA降解等变化。也有一些不同,植物PCD的产物既可被其它细胞吸收利用;也可用于构建自身的次生细胞壁。