稻谷储藏中温湿度变化与微生物活动相关性的研究

对不同温度和相对湿度条件储藏的稻谷进行微生物活动和品质监测,实验结果表明,稻谷在30℃、相对湿度70%~80%条件下储藏42 d,微生物活动的水平相对较低,没有对储藏稻谷的品质造成明显的影响;当储藏环境相对湿度超过80%后,稻谷中的微生物活动明显增加,储藏21天的微生物活性检测值均可超过500 u;特别是当环境相对湿度大于90%时,储藏稻谷的品质将受到显著的影响。高相对湿度环境主要影响储藏稻谷表层的微生物活动,粮层对湿度的扩散有显著的阻挡作用,相对湿度低于90%,30℃、21 d内,不会对0.25 m粮层以下稻谷微生物活动产生明显的影响。     

稻谷、糙米、精白香米在储藏期间挥发性组分的变化

澳大利亚研究者最近对稻谷、糙米、精白香米在储藏期间的挥发物成分变化进行了研究。试验条件是，相对湿度为84％，储藏温度30℃，储藏时间为3个月，储藏方式为常规储藏和150磅气调储藏，受试样品均为澳大利亚YRF9稻谷，统一去壳为糙米和加工成精白香米。试验结果：储藏在常规条件下的稻谷、糙米和精白香米，3个月后都显示出轻微的霉味，经测试，其挥发物含量也明显增高，其中精白香米的霉味比较明显。挥发性气味的增加主要是由于醛、酮含量增高，而糙米和稻谷中霉味较低是因为稻谷和糙米的谷壳、表皮、糠层对其有一定保护作用．香味成分…     

稻谷储藏真菌危害早期预测的研究

对稻谷储藏过程中,水分和温度的变化与真菌生长关系进行了研究,建立了一种稻谷储藏真菌危害早期预测方法.将12.5％％、13.4％、14.5％、15.6％和16.2％水分稻谷样品,置于10℃、15℃、20℃、25℃、30℃、35℃恒温箱中储藏180 d,每10 d取一次样检测真菌生长状况.结果表明:12.5％水分稻谷长期储藏是安全的;13.4％水分稻谷短期储存是安全的,长期储藏仍存在潜在风险;14.5％水分稻谷在15℃以下储存半年是安全的;15.6％和16.2％稻谷在实验的6个温度下储存20 d内均检出有真菌生长.不同温度下稻谷储藏真菌生长顺序为:35℃＞30℃＞25℃＞20℃＞15℃＞10℃.基于上述真菌生长规律的研究,对稻谷储存水分、温度和真菌起始生长时间进行幂函数分析,得出稻谷储存水分、温度和真菌危害早期预测曲线,通过本曲线可进行高水分稻谷储存安全期预测.     

不同水稻品种对麦蛾的相对抵抗力

在控制的实验室条件下进行了几种水稻品种对麦蛾危害的相对抵抗力的研究。研究的水稻品种有法国培育的Ariette，Cigalon，Delta，Lido，Onda和印度尼西亚的IR－42，Cisadane，Sirendah，Hawara-Batu，Bah-Butong，pandan-Wangi。试验使用了用麦蛾感染的稻谷和糙米。实验室的温度25℃，相对湿度80％，观察到的参数有幼虫蛀入率，成虫羽化率和敏感性指数。表现稻谷状态下CisadaneBah-Butong，IR－42和Deta对麦蛾有抵抗力，而Cigalon，Ariette和Lido则敏感。稻谷去壳后，情况略有改变，如Delta，Ariette和Onda对麦蛾敏感，而IR-42和Bah-Butong仍然具有抵抗力。因此，与法国品种相比（除稻谷状态的Delta外），印度尼西亚品种对麦蛾危害具有较强的抵抗力。     

不同储藏形式粳谷品质变化研究

试验选择15％，10％水分的粳谷，采用四种储藏温度（15℃、20℃、25℃、常温），八种储藏形式（露天散装、露天包装、仓内散装、仓内包装密闭、磷化氢低剂量1g／m3、28／m3、对照）储藏三年．试验证明，粳谷品质的变化与储藏温度、储藏年限、储藏形式有关。低温15℃、准低温20℃条件下储藏，稻谷的品质变化效慢，储藏三年后，粳谷粘度12cst，脂肪酸值17mg／100g，品尝回归评分70分．30℃常温条件下包装稻谷储藏三年后，稻谷粘度6cst，脂肪酸20mg／100g，品尝回归评分68分．散装稻谷三年后，稻谷粘度4cst左右，脂肪酸25mg／100g，品尝回归评分65分左右．根据品质指标，初步得出各种储藏模谷的安全储藏期，15℃、20℃条件较谷可以储藏3年以上，常温条件包装稻谷可以储藏2～3年，散装稻谷可以储藏1．5～2年。     

稻谷储藏安全水分研究

以麦角甾醇为参考指标,分析了在不同温度下籼稻和粳稻中的不同水分对其储藏过程中真菌生长的影响.确定了实验室条件下籼稻安全储存水分为13.5％,粳稻安全储存水分为14.0％;确定了稻谷安全水分曲线,可作为偏高水分稻谷短期安全储存指导.     

不同温度下稻谷的品质变化

三种不同温度条件下储藏稻谷的试验表明：稻谷的发芽率、粘度和脂肪酸值等指标均随着储藏时间延长而发生变化，但变化的幅度不同。高温条件下稻谷的陈化速度最快，不利于粮食储存与保鲜；变温条件下品质陈化速度次之；而低温条件下的稻谷品质指标变化最小，都与原始数值相差无几，说明在低温下储存能够很好保持稻谷原有的食用品质。     

不同饵料毒饵防治农田黑线姬鼠效果试验研究

试验选用玉米粒、大米、红茹块、小麦粒、稻谷5种不同的饵料采用0．5％溴敌隆水剂配制成毒饵，通过对农田黑线姬鼠的适口性比较和毒杀效果观察结果表明，在大米、玉米粒毒饵的取食率最高分别为17．3％和17．1％，红茹块毒饵和小麦粒毒饵次之为15．8％和15．2％，稻谷毒饵最差为7．5％，5种毒饵灭鼠率分别为86．4％，85．5％，84．7％，84．2％和82．3％。     

储藏条件对油菜籽品质的影响

Elias，S．G．等研究了不同储藏条件对油菜籽品质的影响。研究将四个品种的湛诺拉油菜籽入工陈化成三种不同的品质，再分别储藏于5℃、75％相对湿度和22℃、30％相对湿度两种储藏条件下。在储藏4、10、17和24个月后测定种子的标准发芽率、冷冻试验、传导率试验等，以评定种子的     

石榴采后保鲜技术要点

１成熟标准果表颜色：红色因品种而异。果汁颜色：红色与Ｍｕｎｓｅｌｌ果汁颜色：红色与Ｍｕｎｓｅｌｌ色谱ＳＲ－Ｓ／１２相同或再深些。果汁酸度：低于１．８５％。２质量标准果皮颜色、光滑度；无果裂、伤痕、擦伤和腐烂；口味、依赖于可溶性固形物含量ＳＳＣ与酸度ＴＡ比ＳＳＣ／ＴＡ，品种间有差异；ＳＳＣ要高于１７％；丹宁含量：低于０．２５％。３最适贮藏温度５℃下可贮藏２个月，长时间贮藏应在１０℃温度下，以免造成冷害。４最适相对湿度９０％～９５％。石榴易失水皱缩，用塑料或蜡质膜包装为宜，尤其在相对湿度较低的情况下…     

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.