1-MCP处理对黄金梨采后生理及保藓效果的影响

研究了常温(20℃)和冷藏(0℃)条件下不同浓度1-MCP处理对黄金梨采后贮藏品质及保鲜效果的影响.研究结果表明,1-MCPO(1-Methylcyclopmpene)处理能显著地降低黄金梨果实呼吸强度,降低黄金梨果实冷藏期间的乙烯释放量.0～1℃贮藏180天+20℃7天或20℃30天,明显地延缓黄金梨果实的硬度、可溶性固形物含量和可滴定酸含量的下降,有利于果实外观、风味的保持和梨果柄保绿.1-MCP处理对黄金梨果实长期贮藏保鲜效果较为明显.1-MCP处理显著地降低果心褐变指数,可完全抑制黄金梨贮藏期间果实黑皮病的发生,但可能会增强果实对二氧化碳的敏感性.     

1-MCP处理对黄金梨采后生理及保鲜效果的影响

研究了常温(20℃)和冷藏(0℃)条件下不同浓度1-MCP处理对黄金梨采后贮藏品质及保鲜效果的影响。研究结果表明,1-MCP(1-Methylcyclopropene)处理能显著地降低黄金梨果实呼吸强度,降低黄金梨果实冷藏期间的乙烯释放量。0～1℃贮藏180天+20℃7天或20℃30天,明显地延缓黄金梨果实的硬度、可溶性固形物含量和可滴定酸含量的下降,有利于果实外观、风味的保持和梨果柄保绿。1-MCP处理对黄金梨果实长期贮藏保鲜效果较为明显。1-MCP处理显著地降低果心褐变指数,可完全抑制黄金梨贮藏期间果实黑皮病的发生,但可能会增强果实对二氧化碳的敏感性。     

1-MCP、薄膜包装和乙烯吸收剂对黄金梨冷藏品质的影响

针对黄金梨长期贮藏期间容易发生果肉软化和果心褐变的问题,研究1-MCP(1.0μL/L)、CO2高渗型PE薄膜(15μm厚)包装(MAP)和乙烯吸收剂(EA)单一或复合处理对0℃下贮藏200 d期间黄金梨品质的影响。结果表明,1-MCP+MAP+EA三者复合处理的保鲜效果最好,可显著延缓果实硬度的下降,抑制可溶性固形物含量、果皮细胞膜透性和果心多酚氧化酶活性的升高,保持较高的可滴定酸含量,减少果心褐变的发生。表明采后黄金梨冷藏之前采用1-MCP+MAP+EA三者复合处理的方式,能达到改善黄金梨冷藏品质的效果。     

不同温度条件下1-MCP对圆黄梨和黄金梨及丰水梨保鲜效果的影响

在不同温度条件下,研究了不同浓度1-MCP处理对圆黄梨、黄金梨和丰水梨保鲜效果的影响。试验结果表明,3个梨品种在-1.5℃条件下贮藏易发生冷害,1.0mL/L1-MCP处理果实冷害率较高;0.5mL/L1-MCP处理能明显地降低0℃和1.5℃条件下果实的果心褐变指数和果实腐烂率,贮藏期可达120天以上;不同浓度1-MCP处理对5℃条件下果实作用效果较明显,但只能应用于短期贮藏（60天左右）。     

1-MCP处理对绿宝石梨保鲜效果的研究

研究了常温（20℃）与冷藏（0℃）条件下不同浓度1-MCP处理对绿宝石梨采后贮藏品质及保鲜效果的影响。结果表明,绿宝石梨属非呼吸跃变型果实,1-MCP处理降低了果实乙烯释放量和呼吸强度,能较好地保持果实硬度,但对果实可溶性固形物与可滴定酸含量无影响。1-MCP处理对绿宝石梨果柄保鲜效果显著,1.0μL·L^-1 1-MCP处理加重了果实真菌病害的发生,对照果实冷藏120天后货架7天后出现轻微的果皮黑点病。     

1-MCP对丰水梨果实的保鲜效果

比较了不同剂量1-MCP(1-甲基环丙烯)处理对丰水梨果实的保鲜效果。结果表明,无论是常温贮藏还是冷库低温贮藏,在贮前进行1-MCP处理,都可以显著抑制丰水梨贮藏过程中果实硬度的下降,防止果实腐烂;冷藏条件下还可显著抑制丰水梨可滴定酸含量的降低,使果实的风味和品质好于同期对照,延长果实的货架寿命,提高贮藏质量。不同剂量1-MCP处理对丰水梨果实的保鲜效果无显著差异。     

圆黄梨和黄金梨的贮藏保鲜试验研究

结合新型乙烯抑制剂1-MCP(1-甲基环丙烯)和温度预处理,对圆黄梨和黄金梨的贮藏特性进行试验研究。结果表明,无论是常温贮藏还是冷库低温贮藏,在贮前进行1-MCP处理和适当的温度预处理,都可以显著抑制果实贮藏过程中的软化和可滴定酸含量的下降,使果实的风味和品质好于同期对照,延长果实的贮藏寿命,提高贮藏质量。不同剂量1-MCP处理对圆黄梨和黄金梨果实的保鲜效果无显著差异。过度热处理会加重果实腐烂和褐变,预处理温度以35℃为宜。     

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。     

1-MCP结合硅窗MAP对新疆毛杏贮藏品质的影响

本文研究了1μL/L 1-甲基环丙烯(1-MCP)、硅窗自发气调包装(MAP)、1-MCP+MAP协同处理对新疆毛杏低温冷藏期间贮藏品质的影响。结果表明,硅窗MAP包装贮藏9 d后,CO2含量维持在3.14%~3.61%之间,O2含量维持在7.88%~9.00%之间,说明硅窗具有较好的气体通过率;1-MCP和MAP单独处理可以显著抑制新疆毛杏的呼吸速率,降低果实乙烯释放量,延缓果实TA、硬度下降速率,维持果实贮藏期感官品质;1-MCP+MAP处理具有协同作用,可显著延缓果实硬度、TA、VC含量和果实色调角值H的下降速率,感官品质评价最好。1-MCP和MAP处理对新疆毛杏均有明显的保鲜效果,1-MCP+MAP处理保鲜效果优于单独处理。     

不同来源1-MCP处理对冷藏富士苹果保鲜效果的影响

以富士苹果为试材,研究(0±0.5)℃条件下冷藏180 d期间两种不同来源和不同浓度(0.5、1.0μL/L)的1-MCP处理对富士苹果采后生理及贮藏品质的影响。结果表明,富士苹果属呼吸跃变型果实,与空白对照相比,两种不同来源的1-MCP处理均可明显降低冷藏期间果实的乙烯释放量和呼吸强度,较好地保持果实硬度,对富士苹果的商品品质和风味的维持具有良好的作用效果,但对果实可溶性固形物和可滴定酸含量影响不显著。结论:除1.0μL/L浓度的1-MCP处理抑制乙烯释放速率的作用效果极显著好于0.5μL/L浓度处理外,两种不同来源与不同浓度1-MCP处理冷藏富士苹果的保鲜效果无显著差异。     

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.     

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.     

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.     

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.