不同气调贮藏方式对大久保桃冷藏后品质的影响

研究了不同气调贮藏方式(变动气调、间歇气调、常规(静态)气调)对大久保桃冷藏及货架期3 d后果实品质变化的影响.结果表明,与冷藏对照相比,适宜的气调处理可明显降低果实冷害的敏感性、延缓果肉组织膜透性和褐变度的上升趋势、减轻出汁率的上升,有效保持了果实硬度、色泽、风味;对可溶性固形物和可滴定酸含量的影响不大;其中较适宜气体指标是5% O2+ 10% CO2;与常规(静态)气调相比,变动气调贮藏进一步降低了果实的冷敏感性,减轻了在低温条件下果实的冷害症状,贮藏70 d,果肉无褐变,货架期间,仍保持了较好的后熟特性,改善了果实的贮后品质.     

蓝莓塑料箱式气调保鲜技术研究

采用4种调气嘴调控的塑料气调箱进行箱内气体成分变化规律及贮藏蓝莓的保鲜效果试验,结果表明：在冷藏（0±0．5）℃条件下,装有蓝莓果实的4种调气嘴调控的塑料气调箱内有相似的气体变化规律,即CO2含量不断上升,O2含量不断下降,均在22天时出现CO2明显增加现象。蓝莓贮藏75天结果表明．各处理气调箱内的气体环境均可显著地控制果实腐烂率与软果率．其中调气嘴B处理气调箱内的蓝莓果实保鲜效果最好．可保持较高的可溶性固形物含量。好果率达到91．23％。塑料箱式气调保鲜技术贮藏蓝莓适宜的气体浓度为：CO2 10％～12％,O2 6％～9％。应用该技术贮藏蓝莓可比现有其它贮藏方法延长保鲜期30～40天．     

动态冰温对红阳猕猴桃冷害与贮藏品质的影响

以红阳猕猴桃为试材,分别贮藏于(0±0.5)℃(CK)和动态冰温(-1.9~-0.5℃)下120 d,研究果实生理与品质指标的变化。结果表明,贮藏前期,动态冰温可显著延缓猕猴桃硬度的下降和可溶性固形物(TSS)含量的上升,降低腐烂率、呼吸强度和丙二醛(MDA)含量;动态冰温贮藏果实的冷害起始于75 d,对照果实的冷害起始于90 d,动态冰温会提前和加重猕猴桃果实的冷害,其典型症状为皮下组织木质化;随着冷害的发生,动态冰温贮藏猕猴桃的腐烂率反而高于对照,VC含量低于对照,硬度和TSS含量达不到正常后熟程度,但无法确定冷害对可滴定酸(TA)含量、呼吸强度和MDA含量的影响。因而,红阳猕猴桃贮藏期≤60 d时,动态冰温可以达到最佳的贮藏效果,冷害的发生限制了其在长期贮藏上的应用。     

不同浓度臭氧对皖翠猕猴桃冷藏过程中品质和生理的影响

采用不同浓度的臭氧(10.7、42.8、171.2 mg/m3)定期处理皖翠猕猴桃果实,研究在冷藏(2±1℃)条件下其品质和后熟生理生化的变化。结果表明:较低浓度的臭氧(10.7 mg/m3)处理能显著抑制猕猴桃果实的呼吸强度,降低腐烂率,延缓丙二醛(MDA)含量和相对电导率的上升,维持较高的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,保持良好的贮藏品质,皖翠猕猴桃冷藏140 d时的好果率可达95%。较高浓度的臭氧(171.2 mg/m3)处理则加速猕猴桃果实呼吸高峰出现的时间,贮藏中后期果实腐烂率、MDA含量和相对电导率快速上升,SOD和POD活性下降,从而加快果实的衰老进程。臭氧处理浓度越高对猕猴桃的贮藏品质和后熟生理损害越大。     

猕猴桃大帐气调贮藏技术措施

在普通冷库利用塑料帐密封果实,可调节帐内O2、CO2含量浓度,属于1990年前后适合国情的大帐气调贮藏方法.1994年陕西省科技厅率先采用该方法,随后建成猕猴桃大帐气调冷库70多座,贮藏量约2.5万t.     

外源乙烯对CA贮藏桃果实内源乙烯生物合成的影响

以八月脆桃果实为试材,研究了不同浓度外源乙烯（0μL／L,20～50μL／L,50～80μL/L）对桃果实气调贮藏（9％～11％CO2＋9％-11％O2）期间内源乙烯生成量、ACS和ACO活性变化的影响。结果表明,在整个贮藏过程中,外源乙烯处理果实的内源乙烯生成量显著高于未加外源乙烯的气调贮藏和冷藏对照果实;外源乙烯处理果实ACS活性亦高于气调和冷藏对照果实,但对ACO活性的影响不明显。     

红富士苹果气调贮藏参数的研究

气调对比试验结果表明，气调贮藏可明显抑制富士苹果果肉硬度下降，减少内源乙烯含量，贮期达8个月仍能保持良好的品质；富士苹果贮藏期间的果肉褐变主要同CO2浓度有关，降O2会增加果实对CO2的敏感性；果实衰老也可导致富士苹果的果实褐变；2％CO2＋5％O2是富士苹果长期贮藏的理想气体指标。     

树莓气调贮藏研究初报

研究了气调指标对树莓果实贮藏效果的影响。试验结果表明,树莓果实最佳气调贮藏条件为CO2≤10％,O2≥5％,在上述气调环境条件下,贮藏20天后树莓果实仍可保持较好的品质质量。     

气调处理对“早生新水”梨果实贮藏品质的影响

为研究气调环境对冷藏和货架期间早生新水’梨果实贮藏品质的影响,筛选其适宜的气调贮藏技术参数,对其冷藏和货架期间果实失重率、腐烂率、糖、酸、叶绿素含量及果皮色差进行测定。结果表明：低温冷藏60d,货架期3d,对照果实果皮和果心出现褐变,固有风味降低。处理Ⅴ的梨果实冷藏和货架期间果皮、果肉和果心严重发黑、果肉呈水渍状,果皮有汁液溢出。适宜比例的O 2、和CO 2气体配比组合可抑制冷藏和货架期间果实糖损耗和果实褐变。综合得出：1% CO2、8% O2 和92%N2 的气体配比（处理Ⅲ）可显著降低冷藏期间果实带皮硬度的下降速率,抑制果实葡萄糖、果糖和山梨醇的降解、以及果实果皮叶绿素尤其是叶绿素b的降解或氧化,延缓果实褐变,较好的保持果实固有风味;较好地保持货架期间胚乳的完整、色泽和果实固有风味,抑制果肉褐变。1% CO2、8% O2 和92%N2的气体配比结合温度为1±0.5 ℃、相对湿度为80%-85%的冷藏参数,可使果实的冷藏期延长至60d,货架期3d。     

采收期和入贮时间对猕猴桃贮后性状的影响

研究了冷藏和低乙烯气调贮藏下,采收期和入库时间对秦美猕猴桃后性状的影响。结果表明,采收期间果实可溶性固形物含量迅速升高,秦美猕猴桃的适宜采采收指标为可溶性固形物含量６．５％～８．０％,果实采后４８ｈ入库贮藏效果最佳。     

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...     

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.