基于GIS的我国玉米秸秆纤维生产潜力研究

基于农作物生产潜力研究基础,利用GIS建立了我国玉米生产的空间数据库和属性数据库。通过对玉米生长期所需有效光和辐射进行光、温、水、土逐级修正后,计算得出玉米的生产潜力,根据一定的谷草比折算出玉米的秸秆生产潜力,以2006年我国各省玉米种植面积最终得出我国玉米秸秆纤维的潜力产量。我国玉米秸秆纤维生产潜力在2447.832-14079.55 kg•hm2之间,本研究为将来可用于生物燃料乙醇生产的纤维素资源的研究提供了基础。     

基于GIS的中国玉米秸秆纤维生产潜力研究

为了进一步分析中国以玉米秸秆纤维素为原料生产生物燃料乙醇的潜力,利用GIS建立了中国玉米生产的空间数据库和属性数据库,运用机制法对玉米生长期所需有效光合辐射进行光、温、水、土逐级递减修正后,计算得出玉米的生产潜力,根据一定的谷草比折算出玉米的秸秆生产潜力.以2007年中国各省玉米种植面积最终得出中国玉米秸秆纤维的潜力产量.结果表明:中国玉米秸秆纤维生产潜力在2448-14080kg/hm2之间.此研究为将来可用于生物燃料乙醇生产的纤维素资源的研究提供了基础.     

基于温室育秧的水稻光温生产潜力指数修正——以黑龙江省富锦市为例

作物光温生产潜力指数的准确性直接影响着农用地质量分等成果的真实性。使用逐级订正模型先后从播种日期、插秧日期、育秧期间水稻所处气温、气候数据4个方面对富锦市水稻光温生产潜力指数进行修正,并对修正结果进行分析,以期为后续的农用地分等工作提供参考依据。研究结果表明:原插秧日期并不符合水稻生长的客观规律,接下来的农用地分等工作应该对水稻的播种日期、插秧日期进行修正更新;温室育秧技术通过提前水稻播种日期、插秧日期并增加育秧期间水稻所需积温,从而提高水稻光温生产潜力指数;温室育秧技术和气候变化均使水稻光温生产潜力指数增加,但温室育秧技术对富锦市水稻光温生产潜力指数影响程度较大。     

新疆棉花光温生产潜力估算与分析

依据《新疆棉花区划新论》,从光热资源的角度,对新疆各个棉花分区的光合生产潜力、光温生产潜力进行了测算与分析.结果表明,新疆光热资源丰富,各棉花亚区的光合生产潜力都很高,平均高达13076.7 kg·hm-2,是近三年棉花平均现实生产力的8.6倍.光温生产潜力达4391.2～5502.6 kg·hm-2,比现实生产力高出2.3～3.9倍.其中,中熟棉亚区的光温生产潜力最高,达5502.6 kg·hm-2,其余依次是早中熟棉亚区、早熟棉亚区、特早熟棉亚区.     

南方稻区水稻产量差的变化及其气候影响因素

为了研究南方稻作区水稻理论生产潜力、单产的提升空间以及气候变化因素对水稻生产潜力的影响,探索区域水稻生产的限制因素和提高水稻产量的技术途径,本研究利用AZE (农业生态区域法)模型对南方稻区1980—2010水稻光温生产潜力进行测算,结合水稻大田平均产量,对该区域水稻光温生产潜力和大田平均单产之间的产量差及其时空变化特点进行研究,并分析了产量差变化的气候影响因素。分析表明,30年来该区域早稻光温生产潜力呈上升趋势,且增幅大于实际产量增加的幅度,二者之间的产量差不断扩大;一季中稻光温生产潜力呈下降趋势,产量差逐步缩小;晚稻光温生产潜力亦呈不断下降的趋势,产量差不断缩小。对区域气候变化分析表明,水稻生育期内辐射总量及温度变化是影响光温生产潜力的关键因子,早稻生育期内温度升高对水稻产量的正效应超过辐射下降的负效应,光温生产潜力不断增加,而一季中稻及晚稻生育期内辐射下降对产量的影响更大,水稻生产潜力呈下降趋势。不同省份间,水稻生育期内辐射及温度变化不同,光温生产潜力及产量差变化趋势空间差异明显。     

基于试验数据的河南省可实现粮食生产潜力研究

为了回答河南省可实现粮食生产潜力问题,基于河南省测土配方试验、施肥示范试验数据和河南省耕地地力评价成果,测算了在试验条件下河南省可实现粮食生产潜力。结果表明：河南省小麦、玉米、水稻在测土配方施肥试验和施肥示范推广试验条件下,最高单产的平均值分别为4726.2、5817.6、5409.15 kg/hm²。河南省可实现粮食生产潜力为7487.27万t,河南省粮食生产目前还有约35%的增产空间。     

基于DSSAT模型模拟的气候变化对棉花生产潜力影响研究

【目的】运用农业技术转移决策支持系统(Decision support system for agrotechnology transfer, DSSAT)模型分析石河子地区气候变化对棉花生产潜力的影响,为棉花种植管理的可持续发展提供思路。【方法】本研究以石河子地区田间试验数据为基础,验证DSSAT V4.7模型适用性,模拟棉花光温生产潜力和气候生产潜力,并分析了气候变化对棉花生产潜力的影响。【结果】经过品种参数调试校正,模型的模拟值与试验的实测值吻合度较高,可用于石河子地区棉花的研究。近51年来石河子地区棉花生育期的平均气温和太阳总辐射呈显著上升趋势,降水量变化不显著,并且在棉花的不同生育阶段气候变化趋势有所差异;棉花的实际产量和光温生产潜力都呈极显著上升趋势,其中生产潜力的平均值是实际产量的3.6倍,由于该地区降水量的稀少导致气候生产潜力模型模拟结果不理想;棉花光温生产潜力与生育期内的气象因子有较强的相关性,与月平均最低气温和月太阳总辐射呈极显著正相关,与大多月降水量和部分月平均最高气温相关性不显著,因此气温和太阳总辐射的增加,有利于棉花增产。【结论】气候变化对石河子地区棉花的产量和生产潜力具有一定的正面影响。     

基于AEz模型的广西甘蔗生产潜力分析

基于地理信息系统(G1s)技术和联合国粮农组织(FAO)农业生态区域法(AEZ)对广西甘蔗生产的光温生产潜力、气候生产潜力进行佑算口结果表明:广西甘蔗光合生产潜力均值为183.27t/hm²,理论值范围为169.03~201.33t/hm²,开发度均值为37.21%;光温生产潜力均值为175.51t/hm²,理论值范围为154.19~200.75t/hm²,光温生产潜力开发度均值为38.85%;气候生产潜力理论值范围为142.94~197.21t/hm²,其平均值为165.88t/hm²,现实生产潜力平均开发度为41.11%。由此可知,广西甘蔗生产潜力理论值与现实生产力之间的差距较大,开发前景广阔。     

夏季干旱期间贵州农业气候资源优劣分析

为定量评估夏季干旱期间光照、热量和水分农业气候资源对粮食作物的客观影响,采取粮食光温生产潜力、光温水生产潜力评估方法,对比分析夏季干旱期间粮食生产潜力相对于气候平均状态的偏差,客观定量地分析夏季干旱期间贵州农业气候资源优势和劣势。研究表明：夏季干旱背景下,贵州水稻、玉米光温生产潜力相对于正常气候年份普遍偏高10%左右,光照和热量资源优势明显;而水稻、玉米光温水生产潜力却普遍偏低30%~40%,水分资源劣势限制了作物生长。通过水资源的合理开发和高效利用,满足干旱期间农作物的水分需求,良好的光照和热量条件可更加有利于农业生产。     

基于知识模型和GIS的棉花生产潜力评价系统

引入知识模型概念,建立以棉花生产潜力知识模型为特征的知识系统,将知识工程和数据库有机结合,以 Mapinfo 5.5 为系统开发平台,利用 MapBasic和 Visual Basic程序设计语言,建立基于知识模型的棉花生产潜力评价系统,实现棉花生产潜力评价的计算机辅助决策。应用本系统对江苏地区棉花生产潜力进行实例评价,并与实际单产相比较,进行单产潜力、潜力系数和总产潜力的对比分析,确定棉花生产地域优势。     

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.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

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...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

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.     

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...