葡萄套袋警惕“日灼”

葡萄属浆果类树种，果皮相对较薄，果实易感“日灼”，特别是近几年发展面积较大的“红地球”品种，“日灼”尤为严重。笔者结合近几年对葡萄套袋中发生“日灼”现象，提出几点建议，供套袋用户参考。１正确选择果实袋葡萄套袋，尤其是红地球葡萄套袋是当前栽培中必不可少的技术措施，正确选择适合葡萄栽培用户当地生产条件的果实袋是防“日灼”的首要条件。从近几年葡萄套袋发生“日灼”的结果看，多为套用低劣质袋或选择了不适合当地气候条件型的果实袋引起的。所以购买葡萄果实袋一是要选择具有研究、开发、生产为一体的正规厂家的果实袋…     

萄萄套袋警惕“日灼”

葡萄属浆果类树种,果皮相对较薄,果实易感"日灼",特别是近几年发展面积较大的"红地球"品种,"日灼"尤为严重.笔者结合近几年对葡萄套袋中发生"日灼"现象,提出几点建议,供套袋用户参考.     

葡萄套袋中存在的问题与解决途径

在葡萄栽培生产中,对果穗进行套袋、实施物理隔离,可有效地降低农药等有害物质的残留和污染,改善和提高果品的外观品质,这项措施已成为一些主要葡萄品种(如红地球等)必不可少的栽培技术环节.但是葡萄果实套袋,由于起步晚、时间短,其应用过程中表现为"应用在先,研究滞后".因而,在果实袋销售市场中适宜各生产区的系列果袋少,低劣质袋充斥市场、配套技术缺乏,不合理使用套袋给果农带来损失的事件屡屡发生.为此,总结葡萄套袋中存在的问题、探索其解决途径,是当前葡萄生产中为贮藏保鲜做前期准备亟待解决的问题.     

不同果袋对大五星枇杷果实品质影响

为了提高枇杷产量,生产精品枇杷,于2013年4-5月在贵州省余庆县进行了枇杷不同果袋套襞试验.试验结果表明：枇杷大五星品种果实套袋后果实橙黄色、茸毛多、果锈少,未套袋（CK）的果实橙红色、茸毛少、果锈多,果袋外黄内白、外黄内黑、外黄内黄的平均单果重与未套袋（CK）的平均单果重43.00 g相比,分别增加11.54 g、11.19g、7.22g,耒套袋的日灼率11.50％、鸟食率9.5％、裂果率11.2％、农药残留抑制率1.60％,套袋处理的日灼率0、鸟食率0、裂果率1.9％～2.2％、农药残留抑制率0.枇杷采用套袋技术,可提高果实品质,防止日灼和鸟害,降低裂果率,减少果实农药残留和大气污染.综合各因素分析,建议在贵州省枇杷种植区推广应用外黄内白或外黄内黑的双层果袋套袋.     

红地球葡萄保鲜设施与材料保障体系的建立

针对红地球葡萄的果粒、果梗呼吸、乙烯代谢、SO2伤害的生理特点,表皮腊质层薄而不均、果梗木质化程度低、果肉弹性差等生物学特性,以及气调不耐高CO2、防腐不耐SO2的问题,提出快速预冷、全自动恒温保鲜的“-1～0℃ PVC袋MA SO2防腐”的综合配套技术体系。     

苹果秋季管理要点

秋季是中晚熟苹果的成熟、采收时期,也是苹果果实管理的关键季节,加强管理不但能增加营养物质积累,提高树体越冬抗寒能力,还能为来年优质丰产奠定基础。一、果实管理1．适时除袋。①定期检查果袋。高温、多雨季节要注意检查套袋果,持续高温干旱时要扩大袋底通气孔,防日灼和黑点病     

红提葡萄套戴不同果袋的比较试验

受夏季高温、干燥、强光等气候影响,红提葡萄常常表现出日灼较重、颜色过深等缺点。葡萄套袋可以创造小环境,改善果实颜色,保持果粉完整,降低农药残留,提高果实商品性。同时,对于日灼这一生理病害也有预防作用。目前,不同材质的果袋类型较多,应用较多的是白色纸袋。其他类型果袋性能如何?为此,我们进行了不同材质果袋套戴红提葡萄的比较试验。1材料与方法1.1供试材料试验地为4年生红提葡萄园,双主蔓龙干修剪,棚架栽培,南北行向,栽植株行距1×4m,树势中庸,质地沙壤土,肥力中等,肥水供应充足。果园管理按照统一技术要求进行。于开花前,选择树…     

套了袋的葡萄为什么还有烂果?

正1.套袋时间不对。相对来说套袋宜早又不能过早,一般在膨大期套。套得晚,有些葡萄已感染上病菌,喷药也难以全部铲除,仍在袋内繁衍。据实验,膨大期套袋,葡萄烂果率仅为2.5%,而晚20天套袋,烂果率为17.8%。2.套袋方法不对。有人称,套袋葡萄要在喷药后6天内套完,其实不然。实践证明,葡萄喷药后,应等药液     

套袋对‘红富士’苹果品质和Ca、Mg、K营养的影响

分别于盛花后25、35、45、55d对‘红富士’苹果进行套袋（果袋为内层红色袋、外层外灰内黑双层纸袋）处理,结果表明,早期套袋有提高果实单果重的趋势,降低果实可溶性固形物含量,对硬度和可滴定酸影响不大。果实成熟时,不同时期套袋对果肉Ca、K含量没有显著差异,但早期套袋增加果肉Mg含量,降低Ca/Mg比值。同时,在盛花后35d进行3种果袋（内层白、外层外灰内灰双层纸袋;内层黑、外层外灰内黑双层纸袋;内层红、外袋外灰内黑双层纸袋）处理表明,与对照（不套袋）相比,套袋使果实单果重增加,可溶性固形物含量降低,Ca含量、Ca/K影响不显著;而内袋红、外袋内黑外灰双层纸袋处理的果实Mg含量显著高于对照,内袋黑、外袋内黑外灰双层纸袋的果实K含量显著低于对照,并且上述两种果袋处理的果实Ca/Mg比值显著低于对照,其余果袋对品质和Ca,Mg,K均无明显的影响。     

不同果袋处理对红富士苹果贮藏生理的影响

研究了套5种类型果袋对红富士苹果(Malus domestica cv. Red Fuji Spur)低温(0℃)贮藏品质的影响,部分果袋进行早套袋(6月10号)和晚套袋(6月23号)两个处理。各种套袋果实的呼吸速率和失水率在贮藏的第一个月内逐步提高达到峰值,其中套塑膜袋果实的呼吸速率比套小林袋的高47%,同时伴随着可滴定酸、可溶性糖以及硬度的持续降低;随后的一个月内呼吸受到明显抑制,各种品质指标下降缓慢,但在其后的贮藏时间里呼吸速率再次缓慢上升。套塑膜袋的果实仍具有较强的呼吸,晚套袋的果实比早套袋的呼吸略高。贮藏结束时(120d)套小林袋红富士的可滴定酸和果实硬度分别为0.2087%、9.43kg/cm2,套塑膜袋的分别为0.1812%、8.12kg/cm2。综合贮藏过程中果实的呼吸、糖、酸、硬度等指标的变化结果可以看到,不同果袋以套塑膜袋的果实品质下降最大,套小林袋(KM-2)的果实品质下降最小,其次是双层内红袋、双层内黑袋,再次是双层内塑袋。     

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.