Impact of octenyl succinylated pearl millet (Pennisetum typhoides) starch addition as fat replacer on the rheological,textural and sensory characteristics of reduced‐fat yoghurt

The current study evaluated the impact of octenyl succinic anhydride (OSA)‐esterified pearl millet (Pennisetum typhoides) starch as a fat replacer (0.5, 1.0, 1.5 and 2.0%) on various characteristics of reduced‐fat yoghurt (1.5% fat). Firmness, flow point, storage and loss modulus increased with increasing levels of the OSA starch. The Herschel–Bulkley model was best fit for elucidating their pseudoplastic behaviour. Syneresis decreased considerably, whereas sensory acceptability improved with increasing OSA starch level. Owing to this reduced syneresis, improved structural strength and sensory acceptability, OSA‐esterified pearl millet starch functions as a fat replacer in reduced‐fat yoghurt.     

巨菌草沼渣制备液化多元醇及合成聚氨酯的研究

以巨菌草经厌氧沼气发酵后产生的沼渣为原料,在聚乙二醇(PEG400)和丙三醇的混合溶剂中进行液化制备液化多元醇。研究了液化条件对液化效果的影响。结果表明:巨菌草沼渣最佳液化条件为液化试剂PEG400/丙三醇(质量比)1.5:1、液化温度160℃、液化时间1.5h、液固比(质量比)2.9:1、催化剂浓硫酸用量为液化试剂质量5%。在此条件下,沼渣液化效果最好,制得的液化多元醇羟值为498mg/g,适用于聚氨酯硬质泡沫的生产。用液化多元醇部分代替聚醚多元醇制备聚氨酯材料,质量比为1:1时,所得材料性能最佳,密度和压缩强度分别为38.7kg/m³和0.21MPa。     

多沙粗沙区林草植被建设对径流影响初析

依据以往的研究成果,针对多沙粗沙区北部、中部和西南部的实际情况,采用综合分析和统计的方法,在确定林草植被蒸散耗水量基础上,应用与坡地蒸散耗水量相对比的方法,分析了林草植被建设对径流量的影响。结果表明:①对于灌木草地来说,整个多沙粗沙区都能够满足其对水分的需求,而乔木林地在北部区基本上不能满足其需要。②林草植被蒸散耗水量的区域分布,与最大可能蒸发量的分布大体相似,而与降水量分布呈相反趋势,呈现出由西北向东南部递减以及自西向东减少的趋势;北部较中部乔灌草植被分别约偏多8%、10%和17%,而西南部较中部乔灌林地和人工草地分别偏多3%左右和约6%。③从水资源的适应性来说,多沙粗沙区适应乔木生长的区域还是有一定的限制。     

Structure and digestibility of tissues in normal and brown midrib pearl millet (Pennisetum glaucum)

The tissues in leaf blades, midribs, sheaths and stems of normal (N), 5848, and two brown midrib (bmr) mutants, 5753 and 5778, of pearl millet (Pennisetum glaucum (L) R Br) were examined for structural characteristics related to digestibility. The anatomies of the various plant parts were not substantially different between N and bmr plants. The more rigid, lignified tissues such as vascular bundles in all plant parts and the rind of stems were not digested after incubation for 7 days in N or bmr plants, indicating that modifications in these tissues were not sufficient to affect biodegradation. Modifications in the digestible tissues resulted in faster and more extensive degradation in bmr plants, and these changes appear to be the most significant in relation to biodegradation. The parenchyma of midveins and stems, which occupies c 70 and 60% of the cross-sectional area of these respective parts, were the sites where modification in phenolics resulted in the greatest improvement in digestibility.     

Distribution of chemical constituents in the plant parts of six tropical-origin forage grasses at early anthesis

The distribution of chemical constituents in the plant parts of six tropical forage grasses at early anthesis was studied. The forage grasses were guinea grass Panicum maximum (Jacq.); angleton grass Dichanthium aristatum (Poir.); gamba grass Andropogon gayanus (Kunth); buffel grass Cenchrus ciliaris (L.); birdwood grass Cenchrus setigerus (Vahl.); and rhodes grass Chloris gayana (Kunth.). Apart from ether extract, which generally decreased from the inflorescence down to the basal culm, and crude fibre, which increased from the inflorescence down to the basal culm, no clear gradient of constituents within the plants could be established for any of the forage grass species.     

观赏草在美国园林中的应用

在美国,观赏草越来越受到风景园林师和园丁的青睐。这些容易生长的植物不仅维护简单,而且适应较大范围的设计用途:可以与其他植物配置,也可以单独成景,或丛植,或作为地被,或作为屏障和边界。观赏草能很好地融合草地和自然种植,而且也适宜盆栽。观赏草丰富了园林的叶色,增加了园林的季相。     

Genetic diversity of phalaris arundinacea populations in relation to river regulation in the Merkys basin,Lithuania

During the 1950s–1960s, the Merkys river basin, the largest protected area of Lithuania, underwent severe anthropogenic regulations. Within the Baltic States, the genetic diversity of Phalaris arundinacea populations is unknown and how they might be affected by anthropogenic activities such as river regulation. The objectives of this study were to compare molecular parameters (SSRs or microsatellite loci) within and among populations from natural river fragments with populations from regulated river parts. Study populations have greater genetic diversity within, rather than among, populations. The upstream portion of the Merkys basin populations had lower genetic diversity compared with further downstream. The mean number of polymorphic SSR loci was lower for populations from regulated parts of the river basin compared with natural ones. Main principle coordinate analysis revealed populations of regulated rivers at marginal positions. Bayesian clustering showed that current populations are admixtures of 3 distinct genetic groups, based on STRUCTURE analysis (K = 3 groupings) in geographic subdivisions of (a) downstream populations (Var?n?, Verseka, Upper Grūda, Lower Grūda, Upper Merkys, Lower Merkys), (b) upstream populations (Upper ?al?ia, Ber??, Lower ?al?ia, Visin?ia, Lower ?altyk??ia, Nedil?), and (c) the 2 regulated sites in the distinct geographic area of Taurupis and Upper ?altyk??ia. P. arundinacea in the Merkys river basin does not all belong to a single, random‐mating population encompassing its tributaries or among populations across its geographic scales. In several instances, river regulation might impair the genetic diversity of P. arundinacea populations.     

狼尾草对嗯草酮、二甲戊乐灵和异丙甲草胺的抗药性

（Pennisetum alopecuroides）是新型的园林观赏植物，在我国具有广阔的发展前景。利用化学除草剂防除狼尾草生产与应用中的杂草问题，对减少生产与管理费用意义很大。采用盆栽方法研究了狼尾草对常用的苗前型除草剂的抗药性，以期找出适宜控制狼尾草杂草的安全除草剂与安全用量。结果表明，狼尾草喷施异丙甲草胺后叶片变为紫红色，产生严重药害，晤草酮在2700mL／hm^2用量下或二甲戊乐灵在3500mL／hm^2用量下狼尾草的生长仍安全。     

Nitrogen fixation associated with grasses and cereals: Recent progress and perspectives for the future

Over the last 20 years many new species of N₂-fixing bacteria have been discovered in association with grasses, cereals and other non-nodulating crops. Virtually all of these bacteria are microaerophylic, fixing N₂ only in the presence of low partial pressures of oxygen. Until a few years ago much attention was focussed on members the genusAzospirillum and it was assumed that N₂ fixation was restricted to the rhizosphere or rhizoplane of the host plants. Through the use of N balance and¹⁵N techniques it has been shown that in the case of lowland rice, several tropical pasture grasses and especially sugar cane, the contributions of biological N₂ fixation (BNF) are of agronomic significance.More detailed study of the N₂-fixing bacteria associated with sugar cane (Acetobacter diazotrophicus andHerbaspirillum spp.) has shown that they occur in high numbers not only in roots of this crop but also in the stems, leaves and trash but are rarely found in the soil. Some of these endophytic diazotrophs have now also been found in forage grasses, cereals, sweet potato and cassava, although evidence of significant BNF contributions is still lacking.The identification of these endophytic diazotrophs as the organisms probably responsible for the high contributions of N₂ fixation observed in sugar cane suggests that it may be possible to attain significant BNF contributions in some other gramineae and perhaps root crops.