低温结合保鲜剂处理对哈密瓜保鲜效果的研究

以沪产9818黄皮哈密瓜为试材,采用二氧化硫保鲜剂处理,以未做处理的哈密瓜室温条件贮藏为对照,研究分别在3,5,8℃低温条件下保鲜剂处理哈密瓜采后贮藏品质的变化。结果表明,SO2保鲜剂处理结合3℃下贮藏,可显著抑制9818黄皮的果实硬度及总酸、总糖和可溶性固形物含量的下降,贮藏20d时,总酸含量为0.082%,仍为贮藏前的81.6%;贮藏30d,总糖含量为11.6%,仍为贮藏前的93.5%,可溶性固形物含量是12.4%,显著高于9.1%的对照含量。SO2保鲜剂处理结合3℃贮藏保鲜的效果最佳,能够有效地保持哈密瓜的营养和外观品质,贮藏时间可达30d。     

毛酸浆果涂膜保鲜技术的探讨

选用天然壳聚糖保鲜剂对毛酸浆果进行涂膜保鲜实验,探讨了不同条件下壳聚糖涂膜处理对毛酸浆果生理及贮藏效果的影响.并通过正交实验确定了最佳保鲜条件,涂膜保鲜剂浓度为15%,保鲜助剂为1%,温度为4℃.     

不同保鲜剂处理对茉莉莎葡萄贮藏品质和生理生化的影响

以茉莉莎葡萄果实为试材,分别采用8包CT2保鲜剂、5包简化保鲜剂、SO2熏蒸24 h+8包CT2保鲜剂和SO2熏蒸24 h+5包简化保鲜剂进行处理,于(0±1)℃、相对湿度(90±5)%条件下贮藏,研究不同保鲜剂处理方式对其贮藏期间品质和生理生化指标的影响。结果表明:保鲜剂处理可增强茉莉莎葡萄果实的耐贮藏性,有效降低贮藏期间的掉粒率、失重率和腐烂率,减少可溶性固形物、VC和可滴定酸含量的下降,维持葡萄果实和果皮的硬度,保持较好的外观品质和风味,另外还能抑制丙二醛(MDA)的积累和多酚氧化酶(PPO)活性的上升,保持较高的总酚、总糖含量以及过氧化物酶(POD)活性,延缓衰老,延长贮藏时间。其中以处理Ⅳ即SO2熏蒸24 h+5包简化保鲜剂处理的保鲜效果最佳。     

不同保鲜处理对鲜食葡萄贮藏期间褐变的影响

以白罗莎和马奶两种易褐变葡萄为试材,分别采用SO_2熏蒸+CK和SO_2熏蒸+CT2保鲜剂进行处理,在(0±1)℃、相对湿度(90±5)%条件下贮藏84 d,研究不同保鲜处理对鲜食葡萄贮藏期间褐变的影响。结果表明,SO_2处理结合CT2保鲜剂能有效保持易褐变绿色葡萄品种的色泽品质,降低褐变指数,维持较低的PPO活性和相对电导率,有效保持叶绿素和类胡萝卜素含量,提高鲜食葡萄的外观品质和商品价值。     

不同保鲜方法对新疆木纳格葡萄贮藏效果的影响

以新疆木纳格葡萄为试材,研究和田地区常规贮藏方法(悬挂式贮藏和纸箱包装冷藏)和自发气调(MA)贮藏方法(PVC或PE膜包装+保鲜剂冷藏)的保鲜效果。结果表明,采后木纳格葡萄采用PVC或PE保鲜包装+保鲜剂冷藏,能够有效抑制果实贮藏期间可溶性固形物和水分含量的下降,保持果梗的绿色,显著抑制腐烂与脱粒现象的发生,在(0±0.5)℃条件下,贮藏90 d的好果率可达95%左右,脱粒率<6%,保鲜效果极显著(P<0.01)好于和田地区的常规贮藏方法。     

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。     

多糖复合涂膜保鲜剂对不同杨梅品种低温贮藏品质的影响

旨在研究低温中湿条件下,多糖复合涂膜保鲜剂对不同杨梅品种的贮藏保鲜效果,为杨梅的长距离运输和商业冷藏保鲜提供理论依据。多糖复合涂膜以魔芋粉和海藻酸钠与壳聚糖的复配胶为基质,以甘油为成膜助剂配成;采用该复合涂膜处理‘乌梅’和‘东魁’杨梅并在低温(1~2℃,相对湿度80%~85%)条件下贮藏,分析好果率、霉变率、烂果率、裂果率、失重率、有机酸、可溶性固形物、果实硬度、花色苷和MDA等贮藏品质指标的变化,研究复合涂膜对杨梅贮藏品质变化的影响。结果表明:魔芋粉和海藻酸钠与壳聚糖复合涂膜保鲜剂处理显著提高了杨梅贮藏后的好果率,减缓了有机酸和可溶性固形物等营养成分的转化和降解,抑制了果实的软化和MDA含量升高;此外,多糖复合涂膜保鲜剂对‘乌梅’和‘东魁’贮藏期间的失重率、霉变率和花色苷等品质指标的影响存在差异。在低温中湿条件下,多糖复合涂膜保鲜剂对‘乌梅’和‘东魁’都具有良好的保鲜效果,但品种间的保鲜效果存在差异,生产应用时需考虑所贮藏品种间的差异。     

SO_2气态熏蒸复合保鲜剂处理对维多利亚葡萄贮藏效果的影响

以维多利亚葡萄果实为试材,分别采用SO2气态熏蒸结合CT2保鲜剂、SO2气态熏蒸结合简化保鲜剂、简化保鲜剂和CT2保鲜剂进行处理,研究不同保鲜处理方式对其在(0±0.5)℃下贮藏期间品质和生理指标变化的影响。结果表明:SO2气态熏蒸结合简化保鲜剂处理与其他3种处理比较,在贮藏末期120 d时,其脱粒率(2.25%)、腐烂率(4.50%)和漂白指数(6.2%)都最低,并可明显降低贮藏期间果实的呼吸强度,较好地保持果实的硬度、可溶性固形物含量、可滴定酸含量和VC含量,保持葡萄原有的风味;同时可减缓果实丙二醛(MDA)含量和多酚氧化酶(PPO)活性的增加,保持较高的过氧化物酶(POD)活性。表明SO2气态熏蒸结合简化保鲜剂处理对维多利亚葡萄的贮藏效果最佳。     

鲜切莲藕微生物模型的建立及货架寿命预测

研究鲜切莲藕在不同贮藏温度下细菌生长趋势和感官质量的变化,建立微生物生长模型,预测鲜切莲藕的货架寿命;将莲藕切片经保鲜处理、包装后,置4、8和20℃贮藏温度下贮藏,测定贮藏期间鲜切莲藕中细菌总数,利用DPS软件,建立Gompertz模型;结果表明,试验中所建立的Gompertz模型能有效地拟合在不同贮藏温度下鲜切莲藕中细菌总数的动态变化;建立的微生物模型能预测不同贮藏温度下、不同贮藏时间内鲜切莲藕中的细菌总数,为快速、有效地评估鲜切莲藕的货架寿命和微生物安全性,提供了一个方便有效的方法。     

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。     

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.     

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...     

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.