壳聚糖-明胶复合涂膜处理对南果梨保鲜效果的研究

采用壳聚糖、明胶、甘油制备不同配比的壳聚糖-明胶复合涂膜保鲜液,对南果梨进行涂膜处理,在室温下进行贮藏,通过对果实的失质量率、硬度、可溶性固形物和VC含量的测定,评价壳聚糖-明胶复合涂膜保鲜液对南果梨的保鲜效果。结果表明,壳聚糖-明胶复合涂膜液可以降低果实的失质量率,减缓硬度的下降速率,维持可溶性固形物和VC的含量,保鲜效果显著。保鲜效果最佳的涂膜保鲜液配比为壳聚糖0.9%,明胶1.25%,甘油0.4%。在此条件下,南国梨的保鲜期可延长至20 d左右。     

壳聚糖复合膜对黄瓜货架期保鲜的研究

以山梨酸钾、壳聚糖、酒石酸为保鲜剂,进行L9(34)正交试验,分析不同配比的壳聚糖复合膜对黄瓜进行涂膜保鲜性能的影响。通过测定其货架期间的失水率、硬度、可溶性固形物、呼吸强度,叶绿素及VC含量等指标以研究保鲜效果。结果表明,壳聚糖复合膜的膜特性良好,涂布均匀,可有效保持黄瓜的感官质量,降低黄瓜的失质量率和硬度,抑制其呼吸强度,减少可溶性固形物、叶绿素和VC含量的损失。其中以2.0%山梨酸钾、1.5%壳聚糖、1.5%酒石酸为配比的复合膜保鲜效果最好。     

可食性液态膜复合保鲜剂对番茄保鲜效果的研究

以番茄为试材,通过壳聚糖、可溶性淀粉、羧甲基纤维素钠配制成不同浓度的复合保鲜液浸泡涂膜处理,研究其对番茄保鲜效果的影响。结果表明,复合保鲜液涂膜可有效地降低番茄果实的失重率、腐烂率、可溶性固形物含量,抑制多酚氧化酶活性,维持番茄VC含量,保持番茄果实较好的感官品质,且以0.5%壳聚糖+0.8%可溶性淀粉+0.3%羧甲基纤维素钠复配的复合保鲜液涂膜对番茄有较好的保鲜效果,15℃环境下其货架期延长到15 d以上。     

纳米SiOx对青椒常温贮藏保鲜的影响

以鲜青椒为试材,在常温条件下,以不作任何处理为对照,研究1-MCP、壳聚糖膜剂(壳聚糖含量1.5%,脱氢醋酸钠含量0.05%)和纳米SiOx壳聚糖膜剂处理对青椒果实贮藏保鲜的效果。结果表明,纳米SiOx壳聚糖膜剂对青椒的保鲜效果最佳,其次为壳聚糖膜处理,再次为1-MCP处理。与对照相比,青椒呼吸强度降低10.56mgCO2/kg·h,VC含量保存提高10.92mg/100g;还原糖含量保存提高1.36mg/100g,好果率提高39%;失质量率降低0.397%,腐烂率降低38.6%。说明应用纳米SiOx涂膜方式进行常温青椒保鲜,有促进其保鲜的作用。     

几种可食膜在杭晚蜜柚柚瓣保鲜中的应用研究

采用3种可食性复合涂膜剂对杭晚蜜柚柚瓣进行涂膜保鲜,同时以不做任何处理的柚瓣为对照,研究常温货架期间蜜柚柚瓣的失重率、可溶性固形物含量、有机酸含量、VC含量、乙醇含量、粒化指数、硬度、菌落总数等指标的变化。结果表明：与对照组相比,涂膜能减少货架期间蜜柚柚瓣的水分损失,抑制VC含量的下降,保持较高的可溶性固形物和有机酸含量,延缓粒化发生,延长货架期。其中,以葡甘聚糖复合膜的保鲜效果较好。     

不同天然生物保鲜液对桑葚贮藏品质的影响

以桑葚为试材,以果实感官品质评分、失重率、VC含量、色差和腐烂指数为指标,研究山豆根、肉豆蔻及其复合提取液和不同浓度壳聚糖涂膜液对(2±1)℃下贮藏6 d桑葚品质的影响。结果表明,1山豆根、肉豆蔻及其复合提取液与对照(蒸馏水)相比,均对桑葚有较好的保鲜效果,可在一定程度上抑制桑葚的品质下降,降低果实失重率,减缓VC的降解,其中保鲜效果最佳的是山豆根提取液(料液比为1∶10);2在不同浓度的壳聚糖涂膜液中,以1.0%的浓度处理对保持桑葚的VC含量、感官品质以及抑制果实腐烂的效果最明显;在贮藏前3天,浓度为1.5%的壳聚糖涂膜液对桑葚失重率控制最好;在贮藏3~6 d时,壳聚糖浓度越高,失重率越小。     

壳聚糖涂膜对冬枣室温条件下生理生化的影响

以壳聚糖为成膜物质制得可食性涂膜保鲜剂,研究其不同浓度(1%,1.5%,2%)对冬枣生理生化效果的影响.结果表明,涂膜处理可以明显地抑制冬枣果实硬度下降,可溶性固形物含量下降,酸含量下降,VC含量下降和叶绿素分解及多酚氧化酶活性.其中以1.5%壳聚糖涂膜处理效果最佳.     

不同处理方式对五叶草莓贮藏品质的影响

采用6种不同处理方式对五叶草莓进行保鲜处理,以蒸馏水处理组为对照,测定贮藏过程中五叶草莓果实感官性状、失重率、可溶性固形物、可滴定酸、VC及丙二醛含量等指标的变化,研究不同处理方式对其贮藏保鲜效果的影响.结果表明:6种处理组五叶草莓果实保鲜效果均显著优于对照组,其中2％柠檬酸+3％CaCl2处理、1％壳聚糖处理和2％柠檬酸+2％VC 3种处理组的五叶草莓果实感官性状维持最好,且1％壳聚糖处理组还在减少可溶性固形物、可滴定酸、VC损失及丙二醛产生等方面显著优于上述两种处理组.综合各项指标考虑,五叶草莓采用1％壳聚糖处理保鲜效果最好,保鲜期可延长至6d左右,具有一定的市场应用前景.     

壳聚糖涂膜保鲜对香蕉贮藏的影响

通过测定失质量率、硬度、可溶性固形物含量以及可滴定酸含量,研究香蕉在壳聚糖涂膜、保鲜膜包装、壳聚糖涂膜+保鲜膜包装等情况下贮藏的性能,并设置对照试验。结果表明,在壳聚糖涂膜+保鲜膜包装情况下的香蕉,其失质量率和可溶性固形物含量均较低、硬度和可滴定酸含量均较高,更有利于香蕉的贮藏。此外,1%的壳聚糖溶液对香蕉的保鲜效果最好。     

壳聚糖-山梨酸复合涂膜对宣城圆枣保鲜效果的影响

针对鲜食红枣成熟后贮藏期短,商品性会随贮藏期延长而降低等问题,以宣城圆枣为试材,采用5个浓度(0.1%、0.25%、0.5%、1.0%、1.5%)壳聚糖与浓度为0.1%的山梨酸混合,配制成复合保鲜液,对其进行涂膜保鲜处理。结果表明:在4℃条件下,壳聚糖-山梨酸复合涂膜处理在一定程度上能延缓宣城圆枣果实失重率与腐烂率上升的速度,同时抑制硬度及VC含量的下降,从而延缓果实的成熟衰老进程,提高贮藏品质,延长货架期。通过对各项果实品质指标数据的综合分析得出,复合涂膜溶液的最佳使用浓度为0.25%壳聚糖+0.1%山梨酸。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

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.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...