水稻对有机态硒的吸收与积累

采用盆栽试验,研究叶面喷施有机态硒(Se-Met)对水稻吸收、积累硒的影响,明确以酵母硒作为有机硒源对提高植物富硒能力的影响。试验结果表明:叶面施用有机硒后,植株不同部位吸收、积累硒能力不同,按照叶、茎、穗顺序逐渐降低;植株中硒积累量以孕穗期施用高于苗期喷硒;籽粒中硒积累量以抽穗期施用最高,苗期喷硒最低;水稻籽粒中硒含量以稻壳中最高,是大米中硒含量的1.1~4倍左右;不同用喷施量表明,有机硒用量120 g/hm~2更有利于籽粒中硒的积累。有机硒作为一种外源硒,可以满足水稻生长对硒营养的需求,提高籽粒中硒的富集。     

不同时期施硒对谷子硒含量、有机硒转化率及谷子品质的影响

探索不同生育期叶面喷施外源硒对谷子品质指标、籽粒硒含量的影响,明确谷子外源硒的最佳施用期,为富硒谷子的栽培种植提供科学依据。以3个不同生态型谷子,春谷长农35、夏谷冀谷20、抗除草剂杂交谷晋谷50为试验材料,田间试验采用随机区组设计,设置喷施清水为对照(CK),在苗期、抽穗期、灌浆期叶面喷施Na2Se O367. 84 g/hm2,研究各关键生育期在喷硒条件下,谷子不同生态型品种的品质性状、籽粒硒含量以及硒的累积、转运的影响。结果显示,不同生育期叶面喷硒处理均可以改善谷子品质,参试品种尤以灌浆期喷施硒对谷子品质性状改善最佳,晋谷50、冀谷20、长农35的赖氨酸含量分别增加0. 03,0. 05,0. 02百分点,叶酸含量增幅分别为2. 4%,7. 5%,5. 5%,灌浆期喷硒处理粗蛋白与对照间差异达到极显著(P 0. 01),不同生育期叶面喷施亚硒酸钠,谷子籽粒含硒量均有提高,硒含量增加趋势为灌浆期抽穗期苗期对照(CK),灌浆期喷硒处理谷子籽粒硒含量平均增加0. 250 mg/kg,是对照的8. 0～9. 9倍;灌浆期为提高谷子有机硒转化率和籽粒硒利用率的关键时期。晋谷50、冀谷20和长农35灌浆期喷硒处理后的有机硒转化率分别比对照提高13,13,10百分点,且与对照间差异显著(P 0. 05),与对照相比,灌浆期硒处理后的硒收获指数增幅为5. 32,5. 82,2. 70百分点。灌浆期叶面喷施适量的外源硒是改善谷子品质性状,提高谷子硒含量、有机硒转化率和硒收获指数的最佳叶面喷硒处理时期。     

施硒对小麦籽粒硒富集、转化及蛋白质与矿质元素含量的影响

为研究小麦对外源硒的吸收、转化规律及施硒效应,于2012-2013和2013-2014年冬小麦生长季,通过叶面喷施亚硒酸钠溶液,分析了田间施用硒肥后小麦产量变化、籽粒中硒的富集和转化特征,不同施硒量与施硒时期对硒利用率、籽粒粗蛋白和矿质元素含量的影响。结果表明,施硒对小麦籽粒产量和千粒重无显著影响;籽粒中总硒和有机硒含量随施硒量增加而增大,且有机硒占总硒的比例稳定在78.5%~82.1%之间,相同施硒量条件下,灌浆前期的施用效果好于孕穗期;灌浆前期喷施150 g hm^–2纯硒,籽粒中总硒含量可达3101 μg kg^-1。小麦对硒的利用率在3.3%~19.0%之间,随施硒量的增加而降低,相同施硒量下,硒利用率以灌浆前期喷施最大,孕穗期喷施最小。施硒提高了籽粒中粗蛋白含量,促进了磷、铁、锰、锌4种元素及降低了钠在籽粒中的累积,对钾、镁、铜的含量影响不显著。     

外源硒对高粱产量、籽粒硒含量及品质的影响

在高粱关键生育期叶面喷施不同剂量Na₂SeO₃,研究外源硒对高粱产量、品质及籽粒硒含量的影响,明确施用外源硒的最佳剂量和最适宜时期,同时为研究硒对高粱生理方面的影响及富硒高粱的生产提供理论依据。以糯高粱品种晋糯3号为材料,采用随机区组试验,设置0（CK）、40（T1）、80（T2）、120（T3）和160mg/kg Na₂SeO₃（T4）5个供硒水平,分别在苗期、拔节期和挑旗期进行叶面外源硒喷施,研究不同时期、不同剂量供硒条件下高粱产量、品质及籽粒硒含量的变化规律。结果表明,施用外源硒一定程度上可以提高高粱籽粒硒含量,不同时期喷施外源硒对高粱籽粒硒含量的影响为挑旗期>拔节期>苗期。在人体吸收硒的安全摄入范围内,挑旗期T2施硒剂量下,晋糯3号籽粒硒含量2年平均为0.295mg/kg,比CK平均提高83.5%。叶面喷施硒对提高高粱籽粒粗蛋白和粗淀粉含量有促进作用,喷施时期对高粱品质的影响为挑旗期>拔节期>苗期>CK。挑旗期T2处理的籽粒粗蛋白和粗淀粉含量最高,分别比CK提高11.25%和1.40%。叶面喷施合适剂量的Na₂SeO₃能够明显提高高粱籽粒硒含量,改善高粱籽粒营养品质,对高粱增产有一定促进作用。综合所述,挑旗期是高粱富硒的最佳喷施时期,最适宜的叶面施硒（Na₂SeO₃）剂量为80mg/kg。     

施硒方式对不同类型品种(系)小麦籽粒硒利用效率的影响

为探究不同施硒方式对小麦籽粒硒生物强化以及营养品质的影响,以贵紫麦1号、中国春和RIL群体为材料,通过土壤施硒和叶面喷施硒两种方式对不同小麦品种(系)的硒积累和营养积累机制进行研究。结果表明,在相同施硒量下,两种施硒方式对小麦各部分生物量无显著影响,说明无论何种施硒方式都没有对小麦产生不良影响;两种施硒方式均能提高小麦籽粒中的硒含量,且土壤施硒的效果优于叶面喷施硒;施硒对小麦籽粒中其他矿质元素含量有一定的影响,两种方式施硒方式都能提高小麦籽粒中锰、铁、锌的含量,且土壤施硒方式效果更佳。施硒还能提高小麦籽粒中有机硒和蛋白质的含量,而有机硒主要以SeMet含量的增加为主。     

叶面施硒对北疆冬小麦生长、产量及富硒作用的影响

以冬小麦品种新冬33号为试验材料,采用小区试验研究叶面喷施硒肥对冬小麦养分吸收、生长及籽粒富硒的影响,结果表明:在施用浓度小于90 mg/kg范围内,施用硒肥能促进冬小麦对氮、磷、硒养分的吸收,减少对钾的吸收,同时促进冬小麦生长和产量,且冬小麦植株氮、磷含量及株高、单穗重、穗粒数、地上部干重、千粒重、产量随着喷施浓度的增加呈先增加后减少的趋势;冬小麦喷施60 mg/kg硒肥时产量最高,较对照增加4.68%;冬小麦籽粒、面粉、麸皮硒含量随着喷施浓度的增加呈增加现象,喷施90 mg/kg硒肥时,籽粒、面粉及麸皮的总硒含量分别为0.608 mg/kg、0.103 mg/kg和0.969 mg/kg。综合考虑,在石河子垦区富硒冬小麦的生产以喷施60 mg/kg的硒肥为宜。     

不同硒处理对大蒜含硒量及产量和品质的影响

采用不同浓度Na2SeO3进行大蒜叶面喷施的田间试验,以研究大蒜对硒的吸收、转化和硒对大蒜产量、品质等的影响规律。结果表明,叶面施硒可明显提高大蒜中总硒、有机硒和无机硒含量,并且有机硒转化率与硒浓度增加呈正比,其总硒、有机硒和无机硒在最高硒浓度(1000mg/kg)达最高,分别是CK的6.5、7.8和2.0倍。大蒜产量在0.5、10mg/kg浓度较CK增加,其后产量降低。施硒促进大蒜对Mg的吸收,而K、P、Fe在一定硒浓度(0.5、10mg/kg)有不同程度提高。因此,在此试验条件下,既能增加大蒜有机硒含量和产量,又可适当提高其营养品质的叶面施硒浓度,以不超过10mg/kg为宜。     

中国富硒大米的生产与富硒效应

统计分析中国20多年来富硒水稻研究的文献数据,得到富硒大米产量和硒含量的分析结果。数据表明：生产富硒水稻的硒肥施用方式以叶面喷施为主,占统计样本量的92.86%;主要肥料种类包括有机硒肥和无机硒肥,分别占样本总量的67.35%和32.65%;在齐穗期和抽穗期,水稻富硒效应研究的最多,分别占搜集样本量的36.54%和21.15%;有机富硒叶面肥施用量超过20 g/hm²时（以硒量计）,可造成水稻一定程度的减产;叶面喷施有机富硒肥料,水稻增产范围在-3.09%~18.77%之间,平均增产5.55%,大米硒富集量在0.04~0.78 mg/kg之间,平均硒含量为0.24 mg/kg;施用无机亚硒酸钠可使水稻增产-7.20%~20.00%,平均增产7.36%,大米富硒范围在0.09~53.39 mg/kg之间,平均含量为4.04 mg/kg;在施用无机硒肥的情况下,有60%的样本硒含量超出了富硒大米相关标准(DB34/T 847—2008)的规定。总体来看,仅有38.96%的样本大米硒含量符合DB34/T 847—2008的规定,因此,在生产富硒水稻时,推荐优先考虑使用有机硒肥,少用并且慎用无机亚硒酸钠硒肥。     

叶面喷施硒肥对绿茶硒含量及品质的影响

为科学开发富硒茶，通过田间小区试验，研究叶面喷施不同浓度硒肥对茶叶硒形态、茶多酚、咖啡碱、水浸出物、游离氨基酸等化学品质的影响。结果表明，茶叶无机硒含量、有机硒含量与总硒含量随叶面喷施硒浓度的增加而增加，茶叶中茶多酚、咖啡碱、水浸出物、游离氨基酸含量随叶面喷施硒浓度增加呈先升高后降低的趋势，叶面喷施0.02 g/L处理茶叶各化学品质指标含量最高，化学品质满足GB/T14456.3—2016标准要求，茶叶硒含量满足GH/T1090—2014标准要求。     

中低镉胁迫下叶面肥对水稻生长状况及镉积累调控效果的影响

为探究自制多养分复合叶面肥对水稻生长状况及Cd积累调控效果的影响。[方法]以中早39水稻为试验材料,通过盆栽试验的方法测定了中低Cd胁迫下,喷施叶面肥对水稻生长状况、各部位Cd含量、Cd富集转运的影响,同时分析了水稻籽粒Cd含量与各器官Cd含量的关系。[结果]喷施5种叶面肥对水稻籽粒降Cd效果依次为S＞P＞Se＞Mg＞Si,分别降低73.50%、66.41%、58.55%、58.50%、46.86%;叶面喷施S肥籽粒Cd富集系数降低73.5%,籽粒Cd转运系数降低72.9%。[结论]5种叶面肥对比而言,叶面喷施S肥降Cd效果最好,若综合考虑水稻生长状况、产量和降镉效率等因素,则叶面喷施Si肥效果最好,且水稻茎秆是影响籽粒Cd积累量的最主要部位,是籽粒积累Cd的主要通路之一。     

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.     

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.     

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...     

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.     

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.