松山自然保护区蒸发量和降水量的变化特征及其原因分析

为了研究北京松山自然保护区的水分循环变化规律,利用松山气象观测站1971—2011年共41年的降水量、温度、日照时数和蒸发量等观测资料,对松山蒸发量和降水量的月、季节、年的变化特征,以及各气象因子与蒸发量之间的相关关系进行分析。结果表明：松山自然保护区的蒸发主要集中在4—6月,降水主要集中在7—8月;41年的蒸发量、降水量分别以约27 mm/10 a、5mm/10 a的速率呈下降趋势;各月、各季节及各年的蒸发量均明显大于降水量;从月、季节的分布来看,蒸发量与日照时数、温度均为极显著正相关,两因素对蒸发量的影响次序均为：温度＞日照时数;从年的分布来看,蒸发量受日照时数和温度的影响不显著。     

本溪山区主要气象要素对水面蒸发量影响程度的灰色关联分析

为了探讨本溪山区水面蒸发量的变化特征和影响水面蒸发的主要气象因子,利用本溪市草河口气象站1953-2010年E601小型蒸发皿蒸发量、气温、降水、日照时数、相对湿度、风速和水汽压等气候资料,运用灰色关联度分析法对影响蒸发的主要气象要素进行统计分析。结果表明,本溪山区水面蒸发与气温、降水和水汽压关系比较密切,与日照时数、相对湿度和风速相关较差。影响水面蒸发的主要气象因子从大到小的排列顺序为：气温＞水汽压＞降水量＞日照时数＞相对湿度＞风速。如果年平均气温升高1℃,年水面蒸发将增大66 mm;年降水量增大10 mm,水面蒸发将减少2.7 mm;年相对湿度增大1%,水面蒸发将减少16 mm;年平均风速增大1 m/s,水面蒸发量将减少154 mm。本研究揭示了主要气象因子对本溪山区水面蒸发量的影响程度,为山区水资源进一步合理开发利用提供科学的依据。     

气象条件对水稻生产影响研究

为了研究气象条件对水稻生产的影响,为当地水稻的种植生产提供依据,对安徽南陵2005—2014年早稻、中稻和一季晚稻、双季晚稻全生育期的主要气象因子进行分析评价,研究其对各类水稻气象产量的影响,并定量计算出各气象因子与该三类水稻气象产量的相关系数。结果发现：水稻气象产量具有明显的年际变化,早稻和双季晚稻整体呈上升趋势,中稻和一季晚稻基本持平,略有下降。对比分析和相关性显示,早稻气象产量与降水量和蒸发量相关性较大,且与降水量和蒸发量分别呈负相关和正相关;中稻和一季晚稻受温度、蒸发量和降水量影响显著,与蒸发量相关性最大,并且与降水量成正比,与温度、蒸发和日照时数成反比;双季晚稻与各气象因子的相关性较前两种水稻偏小。该研究获得了南陵不同气象因子对水稻生长的影响程度,为今后水稻种植合理避开气象灾害打下基础。     

气象条件对水稻生产影响研究——以安徽南陵为例

为了研究气象条件对水稻生产的影响,为当地水稻的种植生产提供依据,对安徽南陵2005—2014年早稻、中稻和一季晚稻、双季晚稻全生育期的主要气象因子进行分析评价,研究其对各类水稻气象产量的影响,并定量计算出各气象因子与该三类水稻气象产量的相关系数。结果发现:水稻气象产量具有明显的年际变化,早稻和双季晚稻整体呈上升趋势,中稻和一季晚稻基本持平,略有下降。对比分析和相关性显示,早稻气象产量与降水量和蒸发量相关性较大,且与降水量和蒸发量分别呈负相关和正相关;中稻和一季晚稻受温度、蒸发量和降水量影响显著,与蒸发量相关性最大,并且与降水量成正比,与温度、蒸发和日照时数成反比;双季晚稻与各气象因子的相关性较前两种水稻偏小。该研究获得了南陵不同气象因子对水稻生长的影响程度,为今后水稻种植合理避开气象灾害打下基础。     

湖南年蒸发量时空演变特征及气象影响因子分析

利用湖南省地面气象站点1971—2012 年的地面气象观测数据,采用线性趋势、经验正交函数分 解、相关分析法和相对权重法,分析了湖南省蒸发皿年蒸发量时空变化及主要气象影响因子。结果表明：在过去的42 年,湖南全省年平均蒸发量呈不显著下降趋势;大部分地区年蒸发量有比较明显的年代际波动,在湘中及湘东大部分地区表现为显著的下降趋势,湘东南的东部地区表现为显著上升趋势,其余区域变化趋势不明显;蒸发量与日照时数、降水量、平均气温、气温日较差和饱和水汽压差等多个气象因子都存在显著的相关关系,与日照时数的正相关程度最大,与降水量的负相关程度最大;在年蒸发量下降的区域的主导因素是日照时数的减少,在年蒸发量上升的区域的主导因素是降水量的减少。     

黑龙港流域冬小麦产量与气象因子相关与通径分析

研究表明,气象因子与小麦产量密切相关。在与小麦产量相关的35个气象因子中有12个因子的相关系数达到了显著水平;其中灌浆期降水与冬小麦产量呈极显著相关,且直接通径系数最高,对小麦产量形成的贡献率最大;其次是拔节期降水量和返青期降水量;5月份的蒸发量与冬小麦产量密切相关,达到极显著水平,其对小麦产量形成起较大的负向作用;小麦越冬期间的气温也是不可忽视的气象因素。据此,在制定小麦生产管理计划时,应将以上因素作为考虑的重点。     

黄淮海夏玉米籽粒脱水与气象因子的关系

玉米籽粒脱水与气象因子之间存在密切的关系, 明确影响籽粒脱水的主要气象因子及其影响程度, 能够更好地预测籽粒含水率的变化动态, 对筛选玉米机械粒收品种, 从而合理安排粒收时间等具有重要的实践价值。本研究于2015—2017年在河南新乡进行, 选用4个目前当地生产中主栽玉米品种京农科728 (JNK728)、郑单958 (ZD958)、先玉335 (XY335)和农华816 (NH816), 通过连续测定获得玉米籽粒含水率的变化过程, 并利用Logistic Power模型拟合, 借鉴去趋势的分析方法, 将玉米籽粒的实际含水率分为趋势含水率、气象含水率与随机误差, 明确黄淮海区域夏玉米籽粒的气象含水率与气象因子之间的关系, 利用逐步回归和通径分析的方法筛选出玉米籽粒生理成熟前后影响籽粒脱水的主要气象因子。分析发现, 玉米籽粒气象含水率与研究分析的大部分气象因子呈显著或极显著相关; 生理成熟前筛选得到的主要气象因子为平均温度(x₁)、平均风速(x₅)和蒸发量(x₁₁), 生理成熟后为平均温度(x₁)和平均相对湿度(x₇), 回归模型均达到极显著水平; 通径分析表明, 生理成熟前蒸发量的贡献最大, 而温度、风速主要通过蒸发量起间接作用, 生理成熟后温度和相对湿度主要为直接作用, 且相对湿度的作用略大于温度。本研究所用去趋势的方法, 从理论和实际操作层面均更具科学性, 其研究结果也更为可信, 对其他类似研究也具有借鉴意义。     

黑龙江省双鸭山地区土壤相对湿度气象模型研究

为了定量描述气象因子的协同作用对土壤相对湿度的影响,并对农业旱涝进行定量评估,利用黑龙江省三江平原双鸭山地区1994-2007年各旬气温、降水量、蒸发量、日照时数、土壤相对湿度(10~30 cm)观测资料,基于灰色关联度分析及检验,采用数理统计分析方法(CAR),建立了土壤相对湿度气象因子模型。结果表明：（1）土壤相对湿度与多项气象因子有较好的相关关系,与各气象因子的关联度大小依次为：旬降水量、旬日照时数、旬蒸发量和旬平均气温,降水量与蒸发量在土壤相对湿度变化中占有重要地位,平均气温与日照时数通过蒸发量起作用。（2）模型模拟效果较好,参数物理意义明确,可合理地解释气象因子对土壤相对湿度的影响,也能综合定量地描述气象因子的协同作用对土壤相对湿度的影响程度。10~30 cm各层土壤相对湿度模拟平均误差为7.2%;20 cm、30 cm和10~30 cm土层模拟效果要优于10 cm土层;夏季和秋季模拟效果优于春季,但春季5月份作物播种期模拟效果很好,模拟误差为4.4%。模型可为土壤旱涝定量评估及黑龙江省农业防灾减灾工作提供一定参考。     

降水量与积温对玉米气象产量影响的综合分析

采用相关分析、回归分析及通径分析的方法,综合分析了肇州地区玉米气象产量与降水量和积温的关系.结果表明,玉米气象产量与生育期内降水呈极显著正相关,相关系数为0.74;与生育期内积温呈极显著负相关,相关系数为-0.48.对玉米气象产量与生育期间降水量和积温进行二元线性回归拟合表明,可以用二元回归方程Y=10267.62+7.57x1-4.58x2,对玉米气象产量与生育期间降水量和积温的关系进行描述,对各变量进行偏回归分析以及通径分析都表明降水量对玉米气象产量的影响要大于积温对玉米气象产量的影响,对肇州地区而言降水量对气象产量起正向的促进作用,积温起负向作用.     

环县近60年蒸发量变化特征及影响因子分析

为了研究陆面水分循环特征以及干旱致灾过程和机理,利用甘肃环县1958—2014 年的气象资料,分析环县57 年来蒸发量的季节和年际变化趋势、阶段性突变特征及影响因子。结果表明：蒸发量具有明显的年际变化特征,年及四季最大蒸发量均出现在20 世纪50 年代后期,最小蒸发量出现在2000 年后。通过相关分析发现,蒸发皿蒸发量与平均风速、平均气温和日照时数具有极显著的正相关,与相对湿度、降水量具有较显著的负相关。分析发现环县蒸发量出现减少趋势的原因主要是风速减小,其次是日照时数的减少和降水量的增加。     

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.     

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.