广东鲜食橄榄果实质构特性比较

为比较分析广东省主要鲜食橄榄果实质构特性的差异,探讨鲜食橄榄果实质地评价的量化参数,验证感官评价质地的有效性。采用质构刺穿试验法对7个优质鲜食橄榄品种果肉质构参数和2种水肥管理方式不同成熟期的‘香甜榄’果实品质进行测定和比较分析。结果表明,不同品种之间果肉的各质构参数变异系数为12.57%~23.95%,差异性显著,与感官评价一致;果皮强度与果皮脆性和果皮韧性均呈显著正相关,果皮破裂深度与果肉硬度呈显著负相关。采用本次试验栽培管理方式可以提高橄榄完熟果实可溶性固形物6%、可滴定酸3.5%、单宁54.9%、果皮强度12.7%、果皮脆性23.5%,降低粗纤维10%、果皮韧性13.7%。果实质地品质参数主成分分析表明,果皮强度、果实硬度和纤维指数可作为质地参数量化区分不同品种间的差别,并明确果皮强度、果实硬度分别小于2300、1600 g和纤维指数大于10,为鲜食橄榄果肉质地品质较好的数值范围。研究初步建立了利用质构刺穿试验法量化评价鲜食橄榄果实质地品质的方法。     

荔枝果实成熟特性的研究

为研究荔枝果实的成熟特性,以‘糯米糍’和‘桂味’2 个花期和成熟期较一致的荔枝品种为试验材料,当‘桂味’果皮首先开始转黄时,定期测量2 种果实的纵横径和果实各部分质量,测定果实固形物(TSS)、糖、酸和Vc等含量,从果实外观成熟度变化、果实的生长情况和果实品质等方面探讨荔枝的成熟特性。结果表明,‘糯米糍’果实的初始缓慢生长期较‘桂味’长,果皮推迟转黄约13 天,但后期大部分时间内生长速度更快,两者果径和单果重的差异在缩小,成熟度趋于一致;后期果径的生长以横径为主;当果实的鲜食品质趋于最佳时,果径有暂时收缩的趋势;‘糯米糍’和‘桂味’的果肉分别以积累蔗糖和还原糖为主,过熟时还原糖含量增加;可滴定酸持续下降,当可滴定酸含量位于0.23%~0.69%、糖酸比位于20.93~61.75 时,果实鲜食品质较佳;‘糯米糍’可食率较高,维持在约80%,过熟时‘桂味’可食率下降,单果重的增加以果皮和果核增重为主;2 种果实过熟时继续生长,‘糯米糍’生长速度较快,但果实TSS 下降,Vc含量较低,果实品质劣变更加严重。2 个荔枝品种的果实具有独特的成熟特性。可滴定酸和糖酸比可作为判断果实成熟度的参考指标。‘糯米糍’成熟果实衰退快速,维持适宜含酸量和糖酸比的时间较短,宜鲜食的品质保持期和适宜采收期较短,‘桂味’果实衰退速度较慢,适宜保质采收期较‘糯米糍’长,这也是‘桂味’品种的成熟特征。     

不同品种及采收时期番茄果实的品质分析

以丰收560、京采8号、Cap、Saopolo和Jua 5个番茄品种为研究对象,设置了5个采收时期,通过测定可溶性固形物、可滴定酸、可溶性糖含量等品质指标,分析不同品种番茄及采收时期的品质差异性,以期为番茄品质分级提供依据。结果表明:不同番茄品种的品质存在明显差异性,其中Saopolo的可溶性固形物、可溶性糖、可滴定酸、VC含量平均值最高,分别为8.92%、7.35%、0.66%和4.57 mg/g,均显著高于除Jua外的其他品种;丰收560的可溶性固形物、可溶性糖含量平均值最低,分别为3.64%、2.04%;不同采收时期的番茄果实品质存在一定差异性,其中可溶性固形物含量、固酸比、VC含量和a*值等果实品质均存在显著差异,可溶性糖含量、可滴定酸含量、糖酸比、L*值、硬度和感官品质等差异较小。综上,在番茄品质分级时,可将可溶性糖含量、可滴定酸含量、糖酸比、L*值、硬度和感官品质作为分级指标,以减少采收时期对品质分级的影响。     

贵州柑橘主栽品种果实品质分析

以贵州不同区域主栽脐橙类、椪柑及柚类柑橘成熟期果实为试材,对各柑橘品种果实的主要品质特性,如果皮颜色、单果重、果形指数、可食率、维生素C含量、可溶性固形物含量、可滴定酸含量、可溶性糖含量、糖酸比和固酸比等指标进行测定和比较分析.结果表明,脐橙类果实、椪柑及柚类可溶性固形物、可溶性糖含量在罗甸地区均高于其他区域,可滴定酸含量低于其他区域;椪柑在全省不同区域生理品质变异系数不大;柚类中琯溪蜜柚果实单果重最大,具较高可食率,可溶性固形物、可溶性糖和可滴定酸含量较其他品种合适.     

设施桃果实品质发育生理研究

以设施栽培的曙光、早红珠、春捷为试材,研究了桃果实发育过程中,主要品质指标的变化动态。结果表明:维生素C、可溶性蛋白、果皮叶绿素和类胡萝卜素含量随着果实的发育呈下降趋势,总糖、可溶性固形物含量及糖酸比不断增加。可滴定酸、总糖、维生素C和类胡萝卜素含量均在果实接近成熟期迅速变化。果实中淀粉含量很低且呈下降趋势,只是在果实发育前期有所升高。果实中干物质含量变化在花后50d内变化趋势是由低到高,此后,三者呈现不规则变化。可溶性蛋白在果实内含量由高到低递减,前期降减程度最大,后期含量保持相对稳定,其变化规律与果实生长一致。     

采收成熟度对‘金艳’猕猴桃果实品质及香气成分的影响

以不同采收期的中华猕猴桃‘金艳’为试材,研究不同采收成熟度对果实品质及香气种类和相对含量的影响。以盛花期后110天为第一次采样时间,之后每隔10天采一次样,共采样6次（采收期Ⅰ~Ⅵ）。果实采收后立即测定外观品质和内在品质,于果实达可食状态后测定果实内在品质,并采用固相微萃取-色谱-质谱联用法(SPME-GC-MS)分析可食期果实香气成分。结果表明,采收期越晚,单果重越大,果实可溶性固形物含量越高。采收期Ⅵ果实硬度较前期急剧下降。采收期Ⅴ果实达到可食时的总酸含量最低,固酸比及总抗坏血酸含量最高,对香气成分分析时发现酯类种类最多,相对含量最高。研究认为‘金艳’猕猴桃在采收期Ⅴ时,果实适宜采收,果实可食期内在品质最好,酯类香气种类最多,果实可溶性固形物在7.5%左右,总酸含量在1.3左右,固酸比在5.5左右。     

不同采收期对阿克苏富士苹果贮藏品质的影响

以阿克苏红富士苹果为试材,研究了不同采收期对采后果实品质的影响,为苹果选择合理的采收期和保持果实良好的贮藏品质提供依据。结果表明:采收期对苹果呼吸高峰的出现时间影响较小,但对呼吸高峰的峰值影响明显;早期采收的果实硬度较大,但失重率也明显高于其他晚采果实;适宜采收期采收的果实在贮藏期间,其VC、可滴定酸、可溶性固形物含量变化幅度小。用于鲜食的果实可在10月22左右采收,此时果肉硬度为10.01 kg/cm2,固酸比为29.16,口感酸甜。用于长期贮藏的阿克苏红富士苹果的最佳采收期为11月1日左右,低温贮藏150 d后果实硬度≥8.79 kg/cm2,可溶性固形物含量≥14.67%。     

套袋对大棚‘翠冠’梨果实品质及K、Ca、Mg含量的影响

在大棚栽培条件下,以‘翠冠’梨为试材,以不套袋果实为对照（CK）,研究普通双层袋（处理Ⅰ）、小林双层袋（处理Ⅱ）和小林单层袋（处理Ⅲ）3种不同果袋套袋对果实品质以及果实不同部位（果皮、果肉、果核）中K、Ca、Mg含量的影响。结果表明：套袋显著提高果面亮度（L*）,其中处理Ⅰ和处理Ⅱ促进了‘翠冠’梨果实锈斑的形成,锈斑指数分别比CK提高15.2和3.6个百分点,显著降低了果皮叶绿素和类胡萝卜素含量;处理Ⅲ的锈斑指数、果皮叶绿素和类胡萝卜素含量与CK无显著差异。套袋降低了果实单果重和可溶性固形物含量,其中处理Ⅰ和处理Ⅱ的果实单果重分别比CK减少8.3%和7.9%,处理Ⅱ和处理Ⅲ的可溶性固形物含量分别比CK降低0.54和0.74个百分点,且差异显著;而对果形指数、总糖、总酸、糖酸比等品质指标无显著影响。套袋降低了果皮和果肉中Ca的含量。因此,在大棚栽培条件下‘翠冠’梨应采用无袋栽培,或选用高透光性的小林单层袋（NK-1）进行套袋栽培。     

采收期对‘黄冠’梨果实品质影响的研究

研究采收期对‘黄冠’梨果实品质的影响,旨在揭示‘黄冠’梨果实发育后期果实品质因子的变化规律,为生产中确定‘黄冠’梨的最佳采收期提供理论依据。以‘黄冠’梨为试材,通过测定不同采收期时的单果重、可溶性固形物含量、Vc含量、硬度,并利用液相色谱法测定不同采收期果实的糖酸组成和含量,分析‘黄冠’梨果实发育后期果实品质因子与采收期的关系。结果表明,自果实发育106天开始,随采收期的延后,果实硬度呈显著下降,果实可溶性固形物含量呈上升趋势,并于果实发育137天时达到高峰;Vc含量变化较小,仅在120天时显著较高;在近成熟期采收的果实中糖以果糖为主,占70.09%~84.00%,以果实发育137天时最高;果实中酸以苹果酸为主,苹果酸占酸总量的93.05%~97.28%,苹果酸D占苹果酸的82.92%~91.84%。随采收期的延后,果实发育天数延长,果酸含量下降,采收越晚糖酸比越高。‘黄冠’梨果实发育130~137天时,果实的可溶性固形物、果糖、葡萄糖、蔗糖和Vc含量都较高,糖酸比和果肉硬度适宜,以获得‘黄冠’梨最佳品质为目标的适宜的采收期为8月8—15日。     

不同杏品种果实营养成分分析及综合评价

为综合评价不同杏品种果实营养品质,选择具开发利用前景的品种,测定11个杏品种果实的3项外观品质（果形指数、单果重、可食率）和8项营养物质含量（可溶性固形物、可溶性糖、可溶性蛋白、可滴定酸、类胡萝卜素、Vc、固酸比、糖酸比）,并通过相关性分析和主成分分析对所测杏品种进行综合品质评价。结果显示,11个杏品种果实的营养成分等各项指标均存在差异,但变异程度不大。相关性分析结果表明,杏果实单果重与可食率、可溶性固形物与Vc、可溶性糖与糖酸比、固酸比与糖酸比均呈极显著正相关,可滴定酸与固酸比、糖酸比呈极显著负相关,可溶性糖与Vc、Vc与固酸比呈显著正相关。主成分分析共提取了4个主成分,累积方差贡献率为91.002%,表明影响杏果品质的主要指标为糖酸比、固酸比、可食率、单果重、果形指数、可溶性固形物等。根据这几项指标数据杏农可以进行品种选择,杏育种者可以确定新品种的开发利用前景。‘金荷包’、‘凯特’、‘兰州大接杏’、‘晚红杏’、‘新疆杏晚熟’5个品种的营养品质更优。。     

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.