Ertragsstruktur alter und neuer Winterweizensorten unter dem Aspekt der Einlagerung und Remobilisation von Fruktanen im Weizenhalm

Yield components in old and new german winter wheat varieties with respect to the storage and remobilization of fructan in the wheat stem
Yield components and changes in carbohydrate content of four old german winter wheat varieties, bred before 1950, were compared with six new varieties over two years in field trials. In both years the old varieties built up more biomass than the new varieties. In the latter a better harvest-index (0,56) as compared to the old varieties (0,43) was obtained, resulting in higher grain yields for the new varieties. Changes in water-soluble carbohydrate (WSC) content were mainly due to variations in fructan content. Maximum of fructan content was mostly reached at the stage of early milk ripeness. In the new varieties a faster and more complete remobilization of fructan occurred; especially in the year with the short grainfilling period.     

The Relationship Between Yield and Fructan Exo-Hydrolases Activity in Two Drought Resistant Wheat Cultivars Grown Under Different Fertilizer and Tillage Treatments

Using two drought resistant wheat (Triticum aestivum L.) cultivars, ‘Changwu134’ and ‘Changhan58,’ a field experiment was conducted in ChangWu Agro-ecological Experiment Station on China's Loess Plateau during 2008 and 2009 to compare the effects of different fertilizer and tillage treatments on the fructan contents as well as fructan exo-hydrolase (FEH) activity in relation to wheat yield. We found that ‘Changhan58’ had greater yield and fructan content in the penultimate internode and higher FEH activity than did ‘Changwu134.’ For ‘Changhan58.’ applying 195 kg·ha^?1(120 +75) N plus 45000 kg·ha^?1 of pig manure and 120 kg·ha^?1 phosphate under conservation tillage produced the highest yield (6769 ka/ha), fructan content in penultimate internode, water use efficiency (WUE), as well as FEH activity among the fertilizer and tillage treatments. Therefore, routine soil management for wheat should focus on combined use of manures and inorganic fertilizer to enhance the amount and transportation efficiency of WSC and ultimately ensure greater yield.     

全生育期菊芋不同器官果聚糖积累分配特征研究

以“青芋2号”和“青芋3号”菊芋为试材,研究了整个生长周期内菊芋不同器官中以果聚糖为主的碳水化合物含量变化动态特征以及在各器官的分配情况.结果表明:苗期叶、茎中果聚糖含量和总量增加迅速,主要贮存在叶中;植株迅速生长期和块茎形成期叶、茎中果聚糖含量呈起伏变化;全株果聚糖积累总量呈持续上升趋势,主要贮存在叶和茎中;开花期叶、茎中的果聚糖含量和积累总量先后达到全生育期的最高值,并完成果聚糖从叶片向茎的转运;块茎内含量稳定,积累总量增加缓慢;果聚糖主要贮存在茎内;块茎膨大期,全株的果聚糖积累量增加缓慢,以植株内部转运为主,果聚糖开始迅速从茎向块茎分配,到生育期末,全株果聚糖70％分配到块茎.     

Drought tolerance in four-day-old seedlings of a drought-sensitive cultivar of wheat

Four-day-old seedlings of spring wheat (Triticum aestivum L. cv. Marvdasht) can tolerate severe dehydration and recover after re-watering. In order to clarify tolerance mechanism, in a completely randomized design, the seedlings were exposed to drought by complete water cessation for 10 and 20 days, followed by re-watering for 3 and 7 days. Upon dehydration, the activity of α-amylase increased whereas growth parameters; photosynthetic pigments; and the activities of lipoxygenase, indole acetic acid (IAA) oxidase, and ascorbate peroxidase (APX) decreased. The activity of APX and the expression of its gene, however, increased after re-watering. Prolonged dehydration was also accompanied by increase in sucrose, soluble proteins, fructans, and certain amino acids, e.g. proline, glutamine, and valine. The results indicated that during dehydration, 4-day-old wheat seedlings shifted their energy expenditure from basal metabolism to withstand water deficiency via lowering the activity of membrane-damaging enzymes and enhancing the production of osmoprotectants.     

Autumn growth and cold hardening of winter wheat under simulated climate change

Abstract

Plant responses to elevated CO₂ are governed by temperature, and at low temperatures the beneficial effects of CO₂ may be lost. To document the responses of winter cereals grown under cold conditions at northern latitudes, autumn growth of winter wheat exposed to ambient and elevated levels of temperature (+2.5°C), CO₂ (+150 µmol mol^?1), and shade (?30%) was studied in open-top chambers under low light and at low temperatures. Throughout the experiment, temperature dominated plant responses, while the effects of CO₂ were marginal, except for a positive effect on root biomass. Increased temperature resulted in increased leaf area, total biomass, total root biomass, total stem biomass, and number of tillers, but also a lower content of total sugars and a weaker tolerance to frost. The loss of frost tolerance was related to the larger size of plants grown at elevated temperature. The 30% light reduction under shading did not affect the growth, sugar content, or frost tolerance of winter wheat. At the low temperatures found at high latitudes during autumn, the atmospheric CO₂ increase is unlikely to enhance autumn growth of winter wheat to any significant extent, while a temperature increase may have important and major effects on its development and growth.     

弱光对冬小麦茎中果聚糖代谢的影响

以耐弱光性不同的冬小麦品种‘扬麦158’(耐弱光品种)和‘扬麦11’(不耐弱光品种)为材料,研究了拔节至成熟期遮光对小麦籽粒淀粉积累量、茎中花前贮存果聚糖转运以及果聚糖代谢关键酶活性的影响。结果表明:拔节至成熟期遮光降低了小麦茎中花前贮存果聚糖的转运量,提高了贮存果聚糖对小麦淀粉产量的贡献率。遮光降低了小麦灌浆前中期茎中蔗糖∶蔗糖果糖基转移酶(SST)和果聚糖∶果聚糖果糖基转移酶(FFT)活性,不利于果聚糖积累,从而导致茎中可溶性碳水化合物积累量下降。遮光条件下灌浆中后期小麦茎中果聚糖外水解酶(FEH)活性下降,分解果聚糖向外转运的能力降低,故向籽粒中转运的量下降,最终导致小麦籽粒淀粉积累量显著降低。遮光33%时小麦籽粒淀粉积累量的下降幅度大于遮光22%,且‘扬麦11’的下降幅度大于‘扬麦158’。     

面包小麦干物质,组织氮和果糖动态累积

研究了面包小麦各组织器官干物质、组织氮和组织果糖的动态分布。结果表明 ,叶片和茎秆分别是组织氮和组织果糖的重要贮存器官和后期籽粒灌浆营养物质的主要供给源     

Fructan,sucrose and related enzyme activities are preserved in timothy (Phleum pratense L.) during wilting

Timothy (Phleum pratense L.) is an important forage grass used for pasture, hay and silage in regions with cool and humid growth seasons. Harvesting conditions could reduce its nutritive value, particularly with extended wilting periods. To understand how daytime or night‐time wilting influences the nutritive value of timothy, this study investigated the metabolism of non‐structural carbohydrates, including fructan and starch, together with total soluble protein and amino acid patterns in timothy plants harvested at two maturity stages (heading and anthesis) and wilted under controlled conditions for 24 h at two temperatures (15°C, 20°C) and two light regimes (darkness, light) by simulating different wilting management practices. Correlation analysis with the whole dataset showed that soluble protein, glucose and starch contents declined in plant tissues concomitantly with water loss, while amino acid, sucrose and fructose contents increased. Transient increase in amino acid content suggests that the decrease in protein content was due to proteolysis during wilting. Sucrose and fructose contents generally increased in plant tissues harvested at anthesis and wilted in light whereas they were unaffected in plants wilted in darkness. Fructan content remained stable. Fructan exohydrolase (FEH) and soluble acid invertase (INV) activities were well preserved during the first 12 h of wilting and might facilitate the fermentation process at the beginning of ensiling by supplying fructose from fructans and hexoses from sucrose to the fermentive bacteria.