壳聚糖涂膜对芒果采后品质及生理特性的影响

为了探讨壳聚糖涂膜保持芒果采后品质的相关生理机制,以‘台农1号’芒果(Mangifera indica L.‘Tainong No.1’)为材料,研究了1.0%壳聚糖涂膜处理对芒果在常温(28~30℃)贮藏条件下果实品质及生理特性的影响。结果表明,与对照相比,壳聚糖涂膜处理显著降低了果实的失重率和病果率,延缓了果皮颜色的转黄,保持较高的果实硬度;并且,壳聚糖涂膜有效保持了果实品质,能够显著延缓芒果可滴定酸(TA)含量的降低和可溶性固形物(TSS)含量的升高,维持芒果果实较高的Vc含量;同时,壳聚糖涂膜也提高了芒果果实贮藏后期超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性,并抑制MDA含量的积累,降低膜脂过氧化程度,从而延缓了采后芒果的后熟衰老进程。     

不同处理方法对枇杷贮藏品质的影响

以许昌地区广泛栽培的普通枇杷为试材,研究不同浓度(1.0%、1.5%、2.0%)壳聚糖涂膜处理、热激处理(45℃热水浸泡5 min、50℃热水浸泡2 min)、10%女贞子浸提液处理和0.5%虫蜡涂膜处理对枇杷果实贮藏品质的影响。结果表明,2.0%壳聚糖和0.5%虫蜡涂膜处理可有效抑制采后普通枇杷果实的失重和腐烂,延缓可溶性固形物含量的下降,激发过氧化物酶活性的上升,抑制纤维素酶活性,延缓果实软化进程,具有较好的保鲜效果。     

高分子量壳聚糖及其混剂对货架期葡萄的保鲜效果

以新鲜巨峰葡萄为试材,分析了浓度为10 g/L的4种高分子量壳聚糖(相对分子量50、150、250、500 kDa)及其等比例混剂涂膜处理对货架期葡萄的保鲜效果。结果表明:5种壳聚糖涂膜处理在感官指标、可溶性固形物含量、VC含量、呼吸强度、可滴定酸含量、花青素含量等方面均不同程度地有利于葡萄的保鲜,其中4种高分子量壳聚糖等比例混剂涂膜的效果最佳;货架期第9天与第1天相比,5种壳聚糖涂膜处理的可溶性固形物含量下降率为19.7%~31.6%,对照为38.2%,混剂处理组的下降率与其他试验组存在极显著差异(P<0.01);呼吸强度下降率为58%~85%,对照为30%,混剂处理组与其他试验组存在极显著差异(P<0.01);VC含量下降率为38.5%~65.5%,对照为71.9%,混剂处理组与对照组存在显著差异(P<0.05);由上可知,4种高分子量壳聚糖等比例混剂涂膜处理可显著延缓葡萄衰老和品质的下降,对巨峰葡萄的保鲜效果明显优于单一壳聚糖涂膜处理的保鲜效果。     

壳聚糖涂膜对常温贮藏兔眼蓝莓果实品质的影响

以“圆蓝”兔眼蓝莓为试材,研究了0．5％壳聚糖（0．4％高分子壳聚糖＋0．1％低分子壳聚糖）涂膜对常温贮藏蓝莓果实品质的影响。结果表明,在20℃常温条件下贮藏20d的过程中,壳聚糖涂膜可以有效减缓蓝莓果实感官品质及果实硬度的下降速度,降低腐烂率和失重率,保持较稳定的TSS和有机酸含量;抑制PPO活性的快速升高和MDA的大量积累：有效延长常温条件下的贮藏期,有利于保持采后蓝莓的品质。但对采后蓝莓果实中的花色苷含量无明显影响．对类黄酮的增加有一定的抑0作用。     

不同天然生物保鲜液对桑葚贮藏品质的影响

以桑葚为试材,以果实感官品质评分、失重率、VC含量、色差和腐烂指数为指标,研究山豆根、肉豆蔻及其复合提取液和不同浓度壳聚糖涂膜液对(2±1)℃下贮藏6 d桑葚品质的影响。结果表明,1山豆根、肉豆蔻及其复合提取液与对照(蒸馏水)相比,均对桑葚有较好的保鲜效果,可在一定程度上抑制桑葚的品质下降,降低果实失重率,减缓VC的降解,其中保鲜效果最佳的是山豆根提取液(料液比为1∶10);2在不同浓度的壳聚糖涂膜液中,以1.0%的浓度处理对保持桑葚的VC含量、感官品质以及抑制果实腐烂的效果最明显;在贮藏前3天,浓度为1.5%的壳聚糖涂膜液对桑葚失重率控制最好;在贮藏3~6 d时,壳聚糖浓度越高,失重率越小。     

壳聚糖可食膜的不同涂膜方式对蓝靛果贮藏的影响

以蓝靛果作为研究对象,壳聚糖为主剂制成的天然食品防腐剂作为保鲜膜,研究喷雾、浸泡、涂布3种涂膜方式,以感官评价、失质量率、还原糖含量、过氧化物酶(POD)活性为评价指标,讨论不同温度对蓝靛果贮藏的影响。结果表明,贮藏蓝靛果的最佳壳聚糖涂膜方式是浸泡涂膜;其最佳保鲜工艺为将蓝靛果浸泡于2%壳聚糖保鲜制剂中,成膜后置于4℃环境中贮藏,可贮藏18 d,第18天时蓝靛果的失质量率为45.7%,还原糖含量为3.6%,POD活性为0.84%。     

采前喷硼和采后壳聚糖涂膜对龙眼品质及耐贮性的影响

在龙眼假种皮发育期间,树冠喷施硼营养剂和清水2次,并在果实采收时进行浓度为3g/L、6g/L的壳聚糖溶液涂膜处理,以探讨硼营养和壳聚糖对龙眼果实品质和耐贮性的影响。结果表明：采前喷硼改善了龙眼果实的内在品质,提高了果实的耐贮藏性;采后壳聚糖涂膜处理都明显提高了贮藏期间龙眼果实的好果率、降低失重率,有效减缓了果肉营养成分的变化,其中采前喷硼和采后壳聚糖涂膜相结合处理的效应优于其它处理,但两个浓度壳聚糖处理产生的效应差异不明显。     

现场冷却与雷竹笋的中长期贮藏研究

采用新鲜雷竹笋进行试验,探索出一个能显著提高雷竹笋的保鲜期限的方法。雷竹笋采后,现场进行冰水混合物冷却,而后使用壳聚糖覆膜并真空包装冷藏保存。贮藏期间测定雷竹笋的蛋白质、氨基酸、维生素C、可溶性还原糖、失重率、粗纤维和粗脂肪的含量。研究结果表明,现场冷却可有效保持试材中蛋白质、氨基酸、维生素C和可溶性还原糖的含量,同时能够降低试材的失重率以及抑制其纤维素含量的增加。现场冷却配合壳聚糖覆膜,可以实现雷竹笋的中长期保鲜,其保鲜期可达80天以上。     

壳聚糖-明胶复合涂膜处理对南果梨保鲜效果的研究

采用壳聚糖、明胶、甘油制备不同配比的壳聚糖-明胶复合涂膜保鲜液,对南果梨进行涂膜处理,在室温下进行贮藏,通过对果实的失质量率、硬度、可溶性固形物和VC含量的测定,评价壳聚糖-明胶复合涂膜保鲜液对南果梨的保鲜效果。结果表明,壳聚糖-明胶复合涂膜液可以降低果实的失质量率,减缓硬度的下降速率,维持可溶性固形物和VC的含量,保鲜效果显著。保鲜效果最佳的涂膜保鲜液配比为壳聚糖0.9%,明胶1.25%,甘油0.4%。在此条件下,南国梨的保鲜期可延长至20 d左右。     

壳聚糖单一及复合涂膜对葡萄保鲜效果的影响

研究壳聚糖单一及复合涂膜对葡萄贮藏品质和生理代谢的影响,以黑提葡萄为研究材料,用壳聚糖单一涂膜及壳聚糖与高良姜或茶多酚复配涂膜葡萄,室温贮藏,测定贮藏期间好果率、失重率、呼吸强度、可滴定酸(TA)和丙二醛含量(MDA)、超氧化物歧化酶(SOD)活性等的变化。结果表明,壳聚糖涂膜可以明显降低贮藏葡萄的呼吸代谢强度和水分的散失程度,降低TA含量下降的速度,增加葡萄好果率,并降低MDA积累量和SOD活性下降的速度,且壳聚糖和茶多酚或大蒜素复配涂膜处理的效果好于单一壳聚糖涂膜处理。因此,壳聚糖复合涂膜用于葡萄保鲜有较好的应用前景。     

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.     

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...     

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.     

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).     

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...     

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.