纳他霉素结合1-MCP处理冬枣果实的耐贮性研究

探讨纳他霉素结合1-MCP处理对冬枣果实耐贮性的影响,以促进其产业健康、可持续发展.以湖南地区冬枣为试材,果实经0.5、1.0 mg/mL纳他霉素结合1.0 μL/L 1-MCP处理后于(4±1)℃条件下进行贮藏,同时以蒸馏水喷施为对照(CK).结果表明,贮藏90 d时,与CK相比,1.0 mg/mL纳他霉素结合1.0 μL/L 1-MCP处理组的好果率提高了 58.82％,失重率减少了 28.63％,VC含量提高了46.28％,前期还原糖、可溶性固形物含量的增加量及游离酸的降低量有所减缓;同时在峰值时期,果实果胶酶、淀粉酶活性以及呼吸、乙烯释放量有所降低,而SOD和CAT活性有所升高,且均具有显著性差异(P＜0.05).总体上,0.5或1.0 mg/mL纳他霉素结合1.0 μL/L 1-MCP处理对提高冬枣果实耐贮性的效果明显.纳他霉素与1-MCP结合作为一种新型防腐鲜剂为冬枣果实长期高效、绿色、环保贮藏提供了方向,具有一定实际意义.     

不同保鲜膜不同保鲜剂处理对甜瓜贮藏品质的影响

为高品质甜瓜选择较适宜的包装保鲜膜和保鲜剂,提高其贮藏保鲜品质。本试验以西州密25号为试材,采用常规的PE和PVC保鲜膜包装,并用目前保鲜效果较好的1-MCP保鲜剂和壳聚糖进行保鲜处理,研究保鲜膜和保鲜剂处理对甜瓜贮藏品质的影响。结果表明,使用保鲜膜比不使用保鲜膜效果好,使用保鲜剂比不使用保鲜剂效果好,PE保鲜膜比PVC保鲜膜效果好,1-MCP保鲜剂和壳聚糖因其保鲜机理不一样,保鲜效果有差异,但两者对提高甜瓜贮藏品质均有很好的效果。因此PE保鲜膜包装结合1-MCP保鲜处理或壳聚糖涂膜是获取高品质甜瓜的有效手段之一。     

不同贮藏温度和保鲜剂对秋洋梨保鲜效果的影响

为研究贮藏温度和保鲜剂处理对秋洋梨保鲜效果的影响,考察了不同贮藏温度(-1、0℃)下,分别采用0.5μL/L 1-甲基环丙烯(1-MCP)熏蒸12 h和乙烯吸附剂处理对秋洋梨果实贮藏品质的影响。结果表明:贮藏120 d后,相同处理条件下,0℃贮藏的果实腐烂率低于-1℃,270 d时,两种保鲜剂处理组的果实在0℃和-1℃贮藏的腐烂率均低于CK组(未用保鲜剂处理);CK组和乙烯吸附剂处理组在0℃贮藏的果实表皮亮度高于-1℃;贮藏240 d后,1-MCP处理组果实硬度显著高于其他处理组(P<0.05),270 d时0℃贮藏的1-MCP处理组果实硬度显著高于-1℃(P<0.05);两种保鲜剂处理组的果实在贮藏270 d时可滴定酸含量均高于CK组;各组果实的可溶性固形物含量在贮藏期间变化均不明显。综上,秋洋梨在0℃贮藏时,腐烂率较低,且果皮亮度保持较好;两种保鲜剂处理均可降低秋洋梨腐烂率,并延缓可滴定酸含量的下降,其中1-MCP处理效果更好;1-MCP处理能有效维持秋洋梨果皮亮度和果实硬度。     

不同保鲜膜、保鲜剂处理对甜瓜贮藏品质的影响

为高品质甜瓜选择较适宜的包装保鲜膜和保鲜剂,提高其贮藏保鲜品质。本试验以‘西州密25号’为试材,采用常规的PE和PVC保鲜膜包装,并用目前保鲜效果较好的1-MCP保鲜剂和壳聚糖进行保鲜处理,研究保鲜膜和保鲜剂处理对甜瓜贮藏品质的影响。结果表明,使用保鲜膜比不使用保鲜膜效果好,使用保鲜剂比不使用保鲜剂效果好,PE保鲜膜比PVC保鲜膜效果好,1-MCP保鲜剂和壳聚糖因其保鲜机理不一样,保鲜效果有差异,但两者对提高甜瓜贮藏品质均有很好的效果。因此,PE保鲜膜包装结合1-MCP保鲜处理或壳聚糖涂膜是获取高品质甜瓜的有效手段之一。     

1-MCP结合CT复合保鲜剂对木纳格葡萄保鲜效果的研究

以新疆木纳格葡萄为试材,采用1μL/L 1-MCP熏蒸(0℃、24 h)结合CT复合保鲜剂处理,研究0℃条件下贮藏期间各处理对木纳格葡萄呼吸强度、果梗褐变指数、腐烂率、落粒率、可溶性固形物含量、可滴定酸含量等生理指标及食用品质的影响。结果表明,1-MCP熏蒸结合CT复合保鲜剂处理很好地抑制葡萄果实的呼吸作用和果梗褐变的发生,保持果实可溶性固形物含量,延缓可滴定酸含量下降,贮藏末期好果率较高。1-MCP在木纳格葡萄贮藏上的适用性良好。     

壳聚糖-植物提取物复合涂膜对樱桃番茄保鲜效果的影响

为了研究壳聚糖-植物提取物复合涂膜对樱桃番茄保鲜效果的影响,利用壳聚糖与不同浓度的丁香或荷叶提取物制备复合膜溶液对樱桃番茄进行涂膜处理,考察樱桃番茄在4 ℃冷库贮藏过程中的硬度、失重率、腐烂率和营养成分的变化。结果表明：经壳聚糖-植物提取物复合涂膜处理后,樱桃番茄的保鲜效果有了明显的提升,较好地保持了果实色泽和新鲜度;贮藏56 d时,10 g/L壳聚糖和10 g/L丁香提取物复合涂膜处理的果实硬度最高,为220.8 g,腐烂率比空白对照组果实降低了10.00个百分点,失重率降低了0.06个百分点,与其他处理组相比,该处理抑制可溶性固形物、可滴定酸、VC等营养成分流失的效果最好。该研究为开发新型果蔬生物保鲜剂提供了理论依据。     

不同保鲜剂处理对红阳猕猴桃贮藏品质的影响研究

为评价不同保鲜剂处理结合微孔膜对低温贮藏红阳猕猴桃品质的影响,以宁海主产的红阳猕猴桃为试材,采用1.0μL/L 1-MCP,1.0μL/L二氧化氯,0.1%二氧化氯含量缓释保鲜剂,0.2%二氧化氯含量缓释保鲜剂处理,放置于1~3℃冷库中,每隔15 d测试相关指标。结果表明,0.2%的缓释保鲜剂结合微孔膜处理可较好抑制猕猴桃果实品质的下降,同时抑制猕猴桃TSS的上升;0.2%缓释保鲜剂结合微孔膜与1-MCP结合微孔膜处理的猕猴桃组可抑制果实可滴定酸的下降,延缓呼吸高峰的出现,电导率相对较低;1-MCP处理与0.2%的缓释保鲜剂处理无显著性差异;1-MCP与缓释保鲜剂结合微孔膜可有效抑制乙烯生成,阻止呼吸跃变效应,从而延缓果实采后果实代谢和衰老。     

保鲜剂处理对清香青皮核桃贮藏品质的影响

为研究不同保鲜剂处理对青皮核桃贮藏期间品质的影响,以清香核桃为试材,分别采用3、5μL/L 1-甲基环丙烯(1-MCP)、伊源保鲜剂、果蜡进行处理,贮藏于-2~0℃条件下,定期测定核桃种仁风味及核仁品质指标。结果表明:与未处理的对照相比,3μL/L与5μL/L的1-MCP处理均能较好地保持清香核桃的种仁风味,并显著提高核仁含水量、总脂肪含量与碘值,有效抑制核仁油脂酸价、过氧化值、皂化值和脂肪酶活动度的升高,保持核仁较好品质。1-MCP处理效果优于果蜡和伊源保鲜剂处理。3μL/L与5μL/L 1-MCP处理两个浓度之间差异性不显著,从保鲜效果和成本考虑,生产上可使用3μL/L的1-MCP对清香鲜核桃进行贮藏保鲜。     

壳寡糖复合1-MCP处理对贵妃枇杷采后贮藏品质的影响

以贵妃枇杷(Eriobotrya japonica Lindl.)为试材,采后以1%壳寡糖、1.0μL/L 1-MCP单一及复合处理,处理后置于20℃、相对湿度85%~95%环境中贮藏,分析不同处理对果实贮藏品质的影响。结果表明:壳寡糖与1-MCP熏蒸复合处理较两者单一处理更能降低枇杷果实的失重率、腐烂率,保持果色;延缓果实还原型抗坏血酸、可溶性固形物、可滴定酸含量的下降;抑制枇杷果实的呼吸强度、相对电导率的上升;显著改善果实贮藏期间的感官品质、营养品质;1%壳寡糖+1.0μL/L 1-MCP熏蒸复合处理技术比两者单一处理具有更好的保鲜效果。     

生物保鲜剂对樱桃贮藏品质的影响

对生物保鲜剂进行复配后处理樱桃,探讨不同生物保鲜剂(保鲜剂A:15 g/L壳聚糖+10 mL/L冰乙酸+20 g/L茶多酚;保鲜剂B:10 g/L普鲁兰糖+0.3 g/Lε-聚赖氨酸(ε-PL)+0.1 g/L纳他霉素+0.04 g/L乳酸链球菌素(Nisin);保鲜剂C:11.5 g/L普鲁兰糖+6 g/L海藻酸钠+6 g/L羧甲基纤维素)浸泡处理5 min对樱桃贮藏期间品质的影响。结果表明,3种复配生物保鲜剂均可不同程度地减缓樱桃品质的下降,其中10 g/L普鲁兰糖+0.3 g/Lε-PL+0.1 g/L纳他霉素+0.04 g/L Nisin复配可显著降低樱桃的失重率和腐烂率,减缓VC、可溶性固形物(TSS)和可滴定酸(TA)含量的下降,保持较好的感官品质。     

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.     

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.     

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...     

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.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

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...     

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.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.