采收期和品种对枣果实品质的影响*

以灵武长枣、冬枣和梨枣为试材,研究了不同采收期对灵武长枣果实品质的影响;以及在同一采收期下,灵武长枣、冬枣和梨枣在低温贮藏前后营养成分的变化规律。试验结果表明：灵武长枣在不同的采收期中,全红果的果肉硬度小于大半红果,头蓬果高于三蓬果;全红果的可溶性固形物、蔗糖、可溶性果胶含量均高于大半红果;三蓬果的葡萄糖、果糖含量高于头蓬果,头蓬全红果的蔗糖、总糖含量高于三蓬全红果;抗坏血酸含量在各个采收期变化不明显。同一采收期的灵武长枣、冬枣和梨枣,在贮藏95 d后,3个品种的果肉硬度、抗坏血酸、可溶性固形物、蔗糖、总糖均呈下降趋势,其中梨枣的果肉硬度、抗坏血酸含量下降均最多;灵武长枣采收时抗坏血酸含量最高且降解最少;冬枣蔗糖含量下降了88.5个百分点;灵武长枣、冬枣可滴定酸含量有所增加,而梨枣出现下降;冬枣的果糖上升了113.6个百分点,明显高于其它两个品种,是贮藏后风味更为浓甜的主要原因。     

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.     

自制保鲜剂对灵武长枣低温贮藏保鲜效果的研究

以可溶性固形物含量24.3%的灵武长枣为试材,研究了冷藏过程中果实品质变化及贮藏保鲜效果。结果表明,保鲜剂浸果极显著降低了霉烂果率,显著减缓了贮藏中后期果肉硬度下降和维生素C氧化分解,明显抑制了果肉蔗糖水解,显著提高了贮藏中后期脆好果率。但保鲜剂浸果对可溶性固形物、还原糖、总糖和果胶含量没有明显影响。脆好果率与果肉硬度、抗坏血酸含量和蔗糖含量均呈极显著正相关性,拟合曲线为二次多项式,相关系数分别为0.9266、0.9937和0.9971。果肉抗坏血酸含量和果肉硬度均与蔗糖含量呈极显著正相关性,相关系数分别为0.9894和0.9343。     

1-MCP结合CT复合保鲜剂对木纳格葡萄保鲜效果的研究

以新疆木纳格葡萄为试材,采用1μL/L 1-MCP熏蒸(0℃、24 h)结合CT复合保鲜剂处理,研究0℃条件下贮藏期间各处理对木纳格葡萄呼吸强度、果梗褐变指数、腐烂率、落粒率、可溶性固形物含量、可滴定酸含量等生理指标及食用品质的影响。结果表明,1-MCP熏蒸结合CT复合保鲜剂处理很好地抑制葡萄果实的呼吸作用和果梗褐变的发生,保持果实可溶性固形物含量,延缓可滴定酸含量下降,贮藏末期好果率较高。1-MCP在木纳格葡萄贮藏上的适用性良好。     

不同品种甜樱桃果实贮藏期间品质及生理特性变化

以“砂蜜豆”、“拉宾斯”、“雷尼”、“萨米脱”、“奇好”5个晚熟甜樱桃品种为试材,研究自发气调包装（MAP）结合低温贮藏（0±0.5）℃条件对5个品种甜樱桃贮藏期间的果实品质及生理特性的影响,探索不同品种甜樱桃品质及耐贮性差异。结果表明：①采收时,“雷尼”果实硬度、可溶性固形物含量和固酸比最高,品质最佳,“砂蜜豆”果实硬度、可溶性固形物及抗坏血酸含量最低,品质最差;贮藏期间,“奇好”果实硬度下降最少,为14.3%;“砂蜜豆”可溶性固形物含量升高3.5%,其余品种均有所降低;“砂蜜豆”可滴定酸和抗坏血酸含量损失最小,分别下降40.5%和53.0%;②“拉宾斯”和“萨米脱”果实失重率最低,分别达到4.5%和7.3%;“拉宾斯”和“萨米脱”果柄保鲜指数最高,分别为72.4和67.3;“拉宾斯”果实乙醇含量升高最低,为0.068 g/kg;“拉宾斯”、“雷尼”和“萨米脱”果实腐烂率最低,分别达到18.2%、20.1%和23.4%;“雷尼”和“奇好”果面颜色饱和度降幅最小,降幅分别为10.7%和9.1%;③“萨米脱”和“拉宾斯”花青素、总酚和类黄酮含量最高,超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性较强,有较高的抗氧化能力;④“拉宾斯”、“奇好”和“萨米脱”保鲜袋内的气体成分变化较大,自发气调能力较强。综合考虑贮藏期内各因素的差异变化,5个品种耐贮性好差顺序依次为：“拉宾斯”＞“萨米脱”＞“雷尼”＞“奇好”＞“砂蜜豆”。     

臭氧处理对哈密瓜常温贮藏品质的影响

以"西州蜜25号"哈密瓜为原料,在常温下分别对其进行0 mg/m³(对照组)和10 mg/m³臭氧(处理组)处理4 h,并置于常温(22±2)℃下进行贮藏。通过观察哈密瓜果实的腐烂症状,测定腐烂指数、可溶性糖等指标,研究10 mg/m³臭氧处理对哈密瓜贮藏品质的影响。结果表明:与对照组相比,臭氧处理可降低果实腐烂指数,减轻腐烂症状,抑制果实呼吸作用,并延缓果实硬度和抗坏血酸含量的下降速度,较好地维持了果实可溶性固形物、可滴定酸、可溶性糖和可溶性蛋白含量,一定程度上保持了果实的贮藏品质。     

果梗涂蜡复合处理对红地球葡萄贮藏品质的影响

以红地球葡萄果实为试验材料,研究了果梗涂蜡方法及添加CT2保鲜剂、1-MCP等处理方式对其贮期内果实腐烂率、干梗指数、SO2伤害指数以及硬度、呼吸强度、还原糖、可滴定酸和VC等指标的影响.结果表明:果梗涂蜡和果梗带枝条配合使用保鲜剂的处理方式,能有效降低红地球葡萄呼吸强度、腐烂率、干梗指数和SO2伤害指数,保持其硬度及还原糖、可滴定酸和VC含量的稳定性,提高贮藏品质,延长葡萄的贮期.     

不同预冷温度对番茄贮藏品质的影响

为研究不同预冷温度对番茄贮藏品质的影响,以‘京采8号’番茄为研究对象,选取红熟中期的果实,采用冷库预冷方式,分别在8、10、12、23 ℃（常温）下预冷24 h,预冷后置于10 ℃下贮藏,通过测定可溶性固形物、可溶性糖、可滴定酸含量,以及色泽、硬度、感官品质、失重率和腐烂率等指标,确定适宜的预冷温度。结果表明：番茄适宜的预冷温度为10 ℃,其次是12 ℃,在贮藏过程中二者均可以保持较高的可溶性固形物、可溶性糖和可滴定酸的含量,延缓果皮转色、果实硬度下降及感官品质劣变,降低失重率和腐烂率;8 ℃预冷的效果较差,贮藏过程中番茄的可溶性固形物和可溶性糖含量较低,腐烂率较高;23 ℃（常温）预冷效果与不预冷直接贮藏无明显差异。     

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。。     

“储良”和“石硖”龙眼果实采后品质变化和贮藏性比较

以海南省龙眼主栽品种"储良"(CL)和"石硖"(SX)为试材,比较了两种龙眼种子的大小、果皮和果肉厚度、果皮色泽等外观品质特性。并分别在冷库(6±1)℃、相对湿度75%、内衬有孔塑料袋纸盒外包装的条件下贮藏17 d,测定和分析了2种龙眼的低温贮藏性能。结果表明,SX果实较小、果皮厚且粗糙、果肉清脆;CL果实较大,果皮薄且光滑,果肉绵软。采后低温贮藏期间,SX龙眼果肉可滴定酸(TA)含量变化较缓慢,贮藏17 d时,SX龙眼果实好果率、果肉可溶性固形物含量(SSC)、VC、还原糖含量显著高于CL果实(P0.05),SX果实呼吸强度、果皮相对电导率、丙二醛(MDA)含量、果肉褐变度、多酚氧化酶(PPO)活性和过氧化物酶(POD)活性均低于CL果实。综上所述,SX龙眼果实在耐低温贮藏方面明显优于CL龙眼果实。     

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.