罗勒叶黄酮的提取及其清除自由基作用

采用微波法提取罗勒叶中黄酮类物质,并研究提取物清除自由基的作用。通过单因素实验,确定微波功率、时间、料液比等为罗勒叶黄酮提取的关键影响因素,在此基础上,优化出罗勒叶抗氧化性成分的最佳提取条件。实验结果表明,罗勒叶中抗氧化物的最佳提取工艺条件为:微波功率420W,提取时间60s,料液比1∶40时,提取液中黄酮的质量浓度达到最大值1.1479mg/mL,提取液对羟自由基的清除率为61.34%。罗勒叶提取物具有良好的清除羟自由基的能力,同时对小鼠肝脏自发性脂质过氧化作用和脂质过氧化物具有较好的抑制效果。     

微波辅助有机溶剂法提取葡萄籽中原花青素的工艺研究

对微波辅助有机溶剂法提取葡萄籽中原花青素的工艺进行了研究,分析了不同溶剂、溶剂浓度、料液比、提取时间与提取次数对原花青素提取效果的影响。在单因素试验的基础上,通过正交试验,确定提取葡萄籽原花青素的最佳工艺条件为：微波功率中低火,料液比1∶12,乙醇浓度70%,微波作用时间60s,提取1次,提取液中原花青素的最大含量可达5.2023mg·mL-1。     

玫瑰花抗氧化活性研究

通过对不同提取溶剂、不同提取温度、不同提取时间和不同提取pH值等方面研究了不同条件对玫瑰花(Rosa hybriad cv.Cardinal)清除DPPH能力的影响.结果表明,沸水的提取效率比其他提取方法更有效,其提取液对DPPH的清除率显著强于其他提取液(P＜.05).100℃沸水提30min是最优提取条件,延长提取时间不会有效提高提取液对DPPH的清除能力(P＜0.05).然而,pH值明显影响提取液对DPPH的清除能力,pH值为5时,提取液的清除能力最强,碱性条件下提取液的清除能力明显减弱.同时,提取液对DPPH的清除能力与多酚含量有关,提取液浓度与DPPH清除率呈一定的线性关系(y=157.92x 14.745,R=0.9914).     

超声-微波提取蛤蒌中黄酮类化合物的工艺及成分初鉴

以野生蛤蒌为原料,以黄酮类化合物提取率为考察指标,在单因素试验的基础上,通过正交试验优化超声-微波提取野生蛤蒌中黄酮类化合物的最佳工艺条件。通过颜色和荧光反应鉴定蛤蒌黄酮提取液中黄酮类化合物种类,并测定其总抗氧化性、还原能力和对1,1-二苯基-2-三硝基苯肼(DPPH·)的清除效果。结果表明,超声-微波提取野生蛤蒌中黄酮类化合物的最佳工艺为:提取剂为体积分数50%乙醇,超声时间20 min,微波时间10 min,微波功率为260 W,料液比1∶40(g/m L),在该工艺条件下得到的黄酮类化合物的平均提取率为6.903%。蛤蒌黄酮提取液中黄酮物质的种类可能主要为:双氢黄酮、查尔酮和黄酮醇等。每克蛤蒌黄酮提取物的总抗氧化能力相当于107 mg抗坏血酸的抗氧化能力,其还原能力大于BHT,小于抗坏血酸,清除DPPH·的IC50为0.242 mg/m L。     

火龙果果皮红色素的微波提取工艺

就微波提取火龙果果皮天然红色素的工艺进行探讨。采用单因素和正交试验,研究微波功率、提取时间、料液比对色素提取的影响,确定微波提取火龙果果皮红色素的最佳工艺条件,并与传统溶剂浸提法进行比较。结果发现,微波萃取的最佳条件为：以纯净水为溶剂,微波功率60%（480W）,提取时间80s、料液比（g:ml）1:3,提取次数为3次。微波提取火龙果色素的效果明显优于常规的溶剂浸提法。     

微波辅助浸提南瓜多糖的工艺研究

研究了微波功率、浸提时间、固液比和提取液pH值等因素对多糖提取量的影响,并通过正交试验设计的方法得到了微波提取南瓜多糖的最佳工艺参数为:微波功率400W,提取时间16min,固液比为1g∶50mL,提取液pH值为10,在此条件下南瓜多糖的提取量为99.6mg/g。     

微波辅助提取光皮树油的工艺研究

用光皮树种子为原料,微波辅助有机溶剂提取光皮树油,试验了几种溶剂、溶剂与物料比、微波辐射时间及功率对提取得率的影响。在单因素试验的基础上,通过正交试验寻求最佳萃取工艺条件。结果表明,微波辅助萃取光皮树油的最佳工艺条件为:溶剂为石油醚,溶剂与物料比为1∶3,辐射时间7 min,辐射功率800 W,得率为7.13%。     

中药材中红景天苷及粗多糖的微波辅助提取工艺

以红景天、何首乌、黄芪、枸杞等8种中药材为原料,以水为溶剂研究微波辅助提取红景天苷以及粗多糖功能成分的最佳工艺参数。通过试验,分别考察了料液比、微波功率、微波处理时间、提取次数等因素对提取效果的影响,最后通过正交试验得出,中草药中红景天苷以及粗多糖的最佳提取工艺参数为料液比1:30,微波功率500 W,微波处理时间60 s,提取次数为1次时,红景天苷和粗多糖的提取效果最好。     

不同处理香蕉花黄酮提取工艺及DPPH自由基清除能力研究

试验以芦丁为标样,把香蕉花中黄酮提取量作为参考指标,探讨晒干和微波处理的香蕉花以乙醇、水为提取剂时的最佳提取工艺,通过单因素试验及正交试验得出最佳提取工艺并测定DPPH自由基清除能力。结果表明,用微波炉中火微波4 min,再用55℃烘箱烘干,粉碎60目的香蕉花,以蒸馏水为提取剂,料液比1∶30(g∶mL),提取温度70℃,每次提取3 h,提取2次,测定黄酮含量为20.36 mg/g,DPPH自由基清除率为76.63%。     

微波法提取石蒜中石蒜碱的工艺优化

为了优化微波法提取石蒜中石蒜碱的工艺条件,用野生石蒜作原料,以乙醇为提取剂,探索了料液比、微波功率、提取温度、提取时间、提取次数等单因素对微波法提取石蒜碱的影响,用正交试验L9(34)获得了最佳提取工艺条件,并与常规溶剂法进行了比较。结果表明:微波法提取石蒜中石蒜碱的最佳工艺条件为:料液比1:6,微波功率320 W,提取温度60℃,提取时间6 min,提取2次;石蒜碱的提取率为95.5%,产率为0.0391%;提取物中石蒜碱含量为12.35%。与常规溶剂法相比,微波法具备提取时间短、提取率高、提取次数少等优点,总体效果优于常规溶剂法。     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.