上海地产叶菜真空预冷保鲜效果的研究

为探讨上海地产叶菜真空预冷保鲜的效果,采用实际生产使用的真空预冷设备对沪产生菜和小白菜进行小批量(100 kg/次)的真空预冷保鲜试验,研究预冷过程中叶菜的质量损失、温度随时间的变化情况及相互关系,以及真空预冷后的叶菜在4℃,湿度85％的贮藏条件下,叶菜叶片的含水量、VC含量变化.结果表明,生菜真空预冷至2.5℃和小白菜预冷至2℃,只需12 min,质量损失率分别为1.85％和1.50％;经真空预冷处理后贮藏的生菜和小白菜贮藏品质下降缓慢,组织含水量和VC含量减少受到明显抑制.生菜和小白菜对真空预冷有良好的适应性.     

不同保鲜剂处理对切割生菜品质影响的研究

研究了5种保鲜剂（1mmol／L苯甲酸、0．5％氯化钙、1．0％过氧化氢、1．0％维生素C、1．0％柠檬酸）处理对新鲜切割生菜（10～15mm切割度）在3℃贮藏期间品质变化及贮藏效果的影响。结果表明,在3℃贮藏条件下,5种处理中,1mmol／L苯甲酸和0．5％氯化钙显著延缓切割生菜的叶绿素、总酸、VC以及可溶性固形物含量的下降,保持了较好感官品质,贮藏到第12天仍有商品价值;1,0％过氧化氢和1,0％VC处理对保持切割生菜的品质有一定的作用,但处理效果略次于苯甲酸和氯化钙,商品贮藏期仅为8天：1．0％柠檬酸的处理效果不明显,商品贮藏期仅为6天左右。     

钾对生菜产量和品质的影响

通过对生菜进行不同钾肥量级田间试验,研究钾对生菜产量和品质的影响。结果表明,在试验条件下,生菜的经济产量与钾的用量具有良好的二次曲线相关性:Y=-0.0389X2 29.904X 21994;施钾可显著增加生菜Vc含量,改善生菜品质;贮藏后,高钾处理的Vc含量损失率较低。但生菜体内的全钙含量随钾施用量的增加而下降。综合考虑钾对生菜品质、产量以及钙素吸收影响,钾(K2O)的施用量在240 kg/hm2左右较适宜。     

上海地产叶菜真空预冷保鲜效果的研究

为探讨上海地产叶菜真空预冷保鲜的效果,采用实际生产使用的真空预冷设备对沪产生菜和小白菜进行小批量(100 kg/次)的真空预冷保鲜试验,研究预冷过程中叶菜的质量损失、温度随时间的变化情况及相互关系,以及真空预冷后的叶菜在4℃,湿度85%的贮藏条件下,叶菜叶片的含水量、VC含量变化。结果表明,生菜真空预冷至2.5℃和小白菜预冷至2℃,只需12 min,质量损失率分别为1.85%和1.50%;经真空预冷处理后贮藏的生菜和小白菜贮藏品质下降缓慢,组织含水量和VC含量减少受到明显抑制。生菜和小白菜对真空预冷有良好的适应性。     

动态气调对"翠香"猕猴桃贮藏效果的影响

为了提高"翠香"猕猴桃在贮藏和销售中的果实品质,采用乙醇含量为指示的动态气调(0～30 d:1.5％O2+5.5％CO2;30～60 d:2.5％O2+4.5％CO2;60～100 d:3.5％O2+3.5％CO2),并与普通气调(2.5％O2+4.5％CO2)、机械冷藏相比较,研究其对"翠香"猕猴桃贮藏期间生理营养品质变化和冷害表现的影响.结果表明:贮藏100 d时,与机械冷藏相比,动态气调显著延缓了果实硬度和可滴定酸含量的下降,保持了可溶性固形物和VC含量,降低呼吸强度和乙烯生成速率;与普通气调相比,动态气调可有效抑制果实的腐烂率和失重率的上升,显著减少贮藏后期冷害的发生,更好地保持果实品质,延长猕猴桃的贮藏期与货架期.动态气调的保鲜效果最好,在一定程度上减少了果实后期病害,提高果实的贮藏品质.     

超干贮藏对生菜种子生活力和活力的影响

试验以氯化钙为干燥剂，将种子含水量降至5.17％、4.48％、3.13％和2.71％。每隔三个月取出检测种子生活力和活力，一年的监测结果显示：生菜种子开放贮藏时生活力和活力下降最快，经过脱水干燥的种子耐藏性增强，随着种子含水量的降低，种子的各项生活力和活力增强，2.71％含水量的生菜种子贮藏效果最好。     

含水量对黄精种子贮藏生理的影响

为了探索种子含水量对黄精种子贮藏生理的影响,采用硅胶干燥法超干处理黄精种子,将种子含水量由10％分别降至7％和3％,同时采用增湿法,使黄精种子含水量达到15％,在室温条件下贮藏5个月后,对黄精种子活力及生理指标进行测定.分析了不同含水量条件下随着贮藏时间的延长种子的各项生理指标的变化.结果表明:1)超干贮藏条件是黄精种子活力有效保持的重要因素,适度超干是保持种子较高抗氧化能力,减轻膜脂过氧化的重要途径.高含水量的种子在贮藏期间由于膜脂过氧化严重而使活力迅速下降.2)随着贮藏时间的延长,3％含水量的种子发芽率保持在较高的水平,为72.5％.3)3％含水量的种子在贮藏期间CAT、POD和SOD活性都维持在较高的水平,MDA含量及膜脂过氧化程度较低.     

不同贮藏方法对鸽蛋保鲜效果的影响

以失重率、蛋黄指数、哈夫单位和散黄率为评价指标,研究了不同贮藏方法对鸽蛋的保鲜效果.结果表明,鸽蛋常温25℃条件下贮藏的保鲜期只有7d;(2±1)℃冷藏条件下的保鲜期可达到40 d;0.5g/m3臭氧杀菌3 min+冷藏可使鸽蛋的保鲜期延长到60 d;采用清水清洗+臭氧杀菌+6％聚丙烯酸涂膜+冷藏的综合技术措施,可使鸽...     

半夏人工种子制作技术及其萌发研究

以半夏为实验材料,通过固体培养转液体悬浮培养建立小块茎悬浮系,并以小块茎为人工种子的繁殖体,研究了人工种皮基质、人工胚乳组分、贮藏条件、萌发基质等对人工种子萌发率和成苗率的影响.结果表明,以4.0%海藻酸钠+2.0% CaCl_2+2.0%壳聚糖为人工种皮基质,1/2 MS液体培养基+0.2 mg/L NAA+0.1 mg/L GA_3+0.5 mg/L BA+0.4mg/L青霉素+0.3%多菌灵粉剂+0.2%苯甲酸钠+1.0%蔗糖+0.5%活性炭作为人工胚乳成分制作的人工种子,其萌发率和成苗率最高.这样的人工种子在4℃条件下贮藏20 d后的萌发率及成苗率分别达82.8%和78.6%,随着贮藏温度的升高和贮藏时间的延长,人工种子的萌发率和成苗率均大幅度下降.     

多频超声波清洗机在叶类蔬菜清洗中的应用

清洗是蔬菜加工的关键环节,对品质至关重要.采用自行研制的超声及气泡式清洗设备对消费量较大的叶类蔬菜(生菜)进行清洗,以洗净率和破损率为指标,对清洗效果进行评价.结果表明,气泡式清洗在清洗时间40 s,洗菜量500 g条件下,生菜洗净率达到100％,此时破损率为12.89％;采用超声清洗时,在频率68 kHz,功率900 W,时间40 s,洗菜量750 g条件下,生菜洗净率为100％时,破损率为9.62％.可见当清洗时间相同,洗净率均达到100％时,超声清洗方式的洗菜量增加50％,破损率降低25.4％.因此,超声清洗方式更具优势.     

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...