超声波辅助提取干辣椒辣椒素工艺技术研究

旨在优选超声波辅助提取干辣椒中辣椒素工艺。以辣椒素得率为考察指标,通过单因素实验初步确定乙醇浓度、提取温度、提取时间和料液比的较优范围,然后通过正交实验以及最佳方案验证性实验,优化筛选了超声波辅助乙醇溶剂提取辣椒素工艺技术。结果表明,超声波辅助提取辣椒素的过程中,各因素对辣椒素得率影响的主次顺序为乙醇浓度＞料液比＞提取时间＞提取温度,最优工艺技术为乙醇浓度95%、提取温度60℃、提取时间45 min、料液比1:35,在该工艺条件下,辣椒素得率为0.87%,显著高于水浴浸提法提取得率0.43%,且验证性实验显示标准差为0.04%,相对偏差0.04%,说明实验重复性、稳定性好。     

超声波辅助提取辣椒素工艺技术研究

旨在优选超声波辅助提取干辣椒中辣椒素工艺。以辣椒素得率为考察指标,通过单因素实验初步确定乙醇浓度、提取温度、提取时间和料液比的较优范围,然后通过正交实验以及最佳方案验证性实验,优化筛选了超声波辅助乙醇溶剂提取辣椒素工艺技术。结果表明,超声波辅助提取辣椒素的过程中,各因素对辣椒素得率影响的主次顺序为乙醇浓度料液比提取时间提取温度,最优工艺技术为乙醇浓度95%、提取温度60℃、提取时间45 min、料液比1:35,在该工艺条件下,辣椒素得率为0.87%,显著高于水浴浸提法提取得率0.43%,且验证性实验显示标准差为0.04%,相对偏差0.04%,说明实验重复性、稳定性好。     

均匀设计法优化超声波提取蜂胶精油工艺条件的研究

优选了超声波提取蜂胶精油工艺参数。以蜂胶精油得率为评价指标,采用均匀设计试验对超声波提取蜂胶精油提取工艺进行优选。结果表明,超声波辅助蜂胶精油提取的最佳提取工艺条件为:提取温度59℃,料液比为1:15,提取时间62 min,蜂胶精油得率达8.83%。     

超声波辅助浸提木枣多糖优化工艺的研究

通过正交试验,研究了超声波功率、提取温度、提取时间、料液比和提取液pH值对木枣多糖得率的影响。结果表明,各因素影响程度依次为:提取液pH值>料液比>提取时间>提取温度>超声波功率;得到最佳工艺参数为:超声波功率为200W,料液pH值为9,料液比为1∶12,温度为50℃,提取时间为15min。在此参数条件下,木枣多糖提取得率为1.81%。     

油菜蜂花粉醇提工艺的优化

本实验以未破壁和破壁油菜蜂花粉为材料,通过正交试验获得两种花粉最佳醇提工艺。未破壁和破壁油菜蜂花粉最佳醇提工艺分别为：固液比1:8、提取时间2 h、提取温度55℃、震荡频率145 rpm和固液比1:8、提取时间2 h、提取温度65℃,震荡频率145 rpm。在各自最佳醇提工艺条件下,未破壁和破壁花粉的平均提取率存在极显著差异（P<0.01）,分别为32.00％和43.16％。以破壁油菜蜂花粉为原料,可极显著地提高提取率。本文为油菜蜂花粉加工过程中普遍应用的醇提工艺环节,提供优化的工艺实验数据和原料选择的依据。     

龙眼壳黄酮的超声波提取工艺研究

采用超声波法对龙眼壳中黄酮类化合物进行提取,在单因素分析的基础上,采用正交试验优化工艺。结果表明,影响龙眼壳黄酮超声波提取主要因素为乙醇体积分数,其次为料液比、温度和提取时间。超声波提取的最佳工艺条件为提取剂乙醇体积分数为30%,料液比1:30,超声波时间为20 min,温度为70℃。     

响应面法优化回流提取苦荞麦黄酮工艺研究

为优化苦荞麦黄酮的回流提取工艺,采用单因素和响应面试验研究回流法,研究乙醇体积分数、液料比、提取温度、提取时间对苦荞麦中黄酮提取效果的影响。研究表明,最佳提取工艺条件为液料比6 mL/g,提取时间30 min,提取温度40℃,乙醇体积分数56%。在此条件下,苦荞麦中黄酮得率为3.378 mg/g,验证值为3.434 mg/g,误差为1.66%。     

蜂胶中黄酮类化合物提取工艺的优化

蜂胶具有消炎、杀菌及抗氧化等生理活性。通过对蜂胶有效成分黄酮提取工艺的研究表明,影响蜂胶总黄酮提取率的主要因素是提取温度、提取时间、乙醇体积分数和料液比对提取率影响甚微。水浴条件下蜂胶总黄酮的最佳提取工艺是:提取温度60℃,提取时间3h,乙醇体积分数为80%,料液比1∶25,此条件下测得黄酮得率为43.50%。     

玉米须黄酮超声波提取工艺优化及数学模拟

采用正交试验的方法优化了玉米须黄酮的超声波提取工艺,同时对提取进行了数学模拟。试验结果表明,优化的超声波提取工艺条件为：以50 %的乙醇为提取剂,料液比（g︰ml）1︰84,提取温度75℃,超声波提取时间75 min。此条件下,玉米须黄酮提取率可达1.51 %。与加热浸提法相比,提取时间缩短了25%,提取率提高了约20 %。超声波提取的数学模拟值与试验结果基本吻合。     

油菜花多糖提取工艺优化研究

为提高油菜花多糖的应用价值,以十字花科芸苔属植物油菜花朵为研究对象,研究了油菜花多糖提取优化工艺。油菜花干燥、粉碎,过100目筛,脱脂,通过热水浸提法并结合浸提时间、浸提温度、浸提料水比以及浸提次数等单因素条件进行实验,在此基础上进行正交设计,获得油菜花多糖提取工艺优化条件。实验结果表明,单因素最佳条件下,油菜花多糖得率最大为17.85%;正交优化最佳条件下,油菜花多糖得率为19.18%。正交实验最佳条件为油菜花多糖优化提取工艺,即提取条件为：浸提温度100℃,浸提时间1.5 h,浸提料水比1:40(m:v),提取次数为2次。     

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.     

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.     

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.     

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.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.     

Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm

Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre- and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability available in the group into a useful form. This revised version was published online in July 2006 with corrections to the Cover Date.