高温对安徽省水稻汕优63结实率、千粒重的影响分析

摘要：本文利用安徽省农科院2000-2004年中稻分期播种试验水稻发育期资料、产量结构资料和相应的气象地面观测资料为基本数据源,分析了水稻汕优63不同生育阶段内高温日数、危害积温、高温日平均最高气温和高温日平均最低气温对结实率、千粒重的影响。结果表明,不同生育期内高温日数、危害积温对结实率、千粒重的影响为孕穗期>幼穗形成期>抽穗灌浆期;孕穗期内高温日平均最高气温对结实率、千粒重影响显著,幼穗形成期、抽穗灌浆期内高温日平均最高气温对结实率、千粒重的影响相对较小;高温日平均最低气温对结实率、千粒重的影响在抽穗灌浆期最为显著,孕穗期次之,幼穗形成期最小。     

低温对玉米光合作用、超氧物歧化酶活性和籽粒产量的影响

玉米在孕穗期和灌浆期,尤其是在孕穗期遇低温逆境会导致光合速率下降,光合有效叶面积降低,叶片和雌穗(或籽粒)超氧物歧化酶(SOD)活性下降、丙二醛含量剧增和相对电导率提高,造成低温冷害。孕穗期低温处理主要抑制了雌穗分化和发育,减少了穗粒数,灌浆期低温逆境主要影响了籽粒灌浆,致使百粒重下降,引起产量降低。     

孕穗期低温胁迫对优质香稻产量及其构成因素的影响

为探明孕穗期冷害对优质香稻产量及其构成因素的影响，以冷敏感品种绥粳4和冷钝感品种垦稻08-169为试验材料，于孕穗期17℃低温处理0(CK)、3、6、9d，研究孕穗期低温胁迫对优质香稻产量及其构成因素的影响。结果表明，孕穗期低温胁迫降低优质香稻产量及其构成因素。其中低温胁迫3、6、9d极显著降低2个品种的穗上、中、下部每穗粒数，使整穗每穗粒数下降。低温胁迫6、9d极显著降低2个品种的穗上、中、下部千粒重，使整穗千粒重下降。低温处理6d极显著降低了绥粳4的穗上、中、下部结实率和垦稻08-169穗下部结实率，低温处理9d极显著降低了2个品种穗上、中、下部结实率，使整穗结实率下降。不同耐冷品种产量构成因素对低温胁迫的响应存在差异，结合生产实际以低温6d为标准，孕穗期低温胁迫对冷敏感绥粳4穗上、中部结实率影响更大，对冷钝感品种垦稻08-169的穗下部千粒重影响更大。因此，孕穗期低温胁迫通过降低穗上、中、下部每穗粒数、千粒重和穗下部结实率来减少优质香稻产量。     

气象条件对杂交水稻汕优63产量构成因子的影响

以水稻品种汕优63为材料,分析了信阳地区水稻不同生育期的气象条件与产量构成因子之间的相互关系。研究发现分蘖率在300％左右成穗率较高,适宜的日平均温度和日照时数分别为26℃和5.5h;分蘖期有效穗数与日照时数的变化成正比,当日照时数达到5h以上时有效穗数的变化不大;孕穗期温度在28~30℃,日较差在8~10℃时有效穗数较高;孕穗、抽穗期的高温（>30℃）及光照不足（<5h）会显著降低水稻的结实率;灌浆期日照总量、降水总量和气温日较差对水稻千粒重均有影响;各产量构成因子的重要程度依次为结实率>有效穗数>千粒重     

不同时期断水对高原粳稻产量和品质的影响

不同时期断水处理对高原粳稻产量和物理品质都有不同程度的影响。分蘖期适时断水对产量影响最小，且有利于提高品质；幼穗分化期、孕穗期和灌浆期断水对产量和品质的影响明显，断水时间越长，对产量和物理品质的负面影响越大。     

孕穗期高温对水稻生理特性和产量性状影响研究

为探索水稻孕穗期高温对生理生化特性和产量性状的影响,降低水稻生长发育过程中孕穗期高温对水稻的危害提供理论依据。以‘泰优553’和‘隆晶优1212’为材料,在孕穗期幼穗分化Ⅳ-Ⅵ期利用人工气候室以29、32、35、38℃处理7天,以同时期田间自然温度条件作对照（CK,平均温度30.6℃）,研究孕穗期不同温度对水稻生理特性和产量性状的影响。与对照相比,38℃处理显著降低了‘泰优553’和‘隆晶优1212’的可育花粉数和可育率,可育率分别比对照下降了60.2%、54.7%。随温度的升高,2个品种的脯氨酸和丙二醛(MDA)含量呈上升趋势,在38℃处理显著高于对照(CK)和其他处理,过氧化物酶(POD)活性呈先上升后下降的趋势。高温处理显著降低了2个品种的结实率、千粒重和产量,但对有效穗影响较少。水稻孕穗期高温能显著降低可育花粉数和可育率,同时影响幼穗生理指标的变化,致使结实率和产量下降,不同品种对高温危害的表现存在差异。     

信阳地区2003年光温条件对水稻产量的影响

通过对信阳地区1991—2004年的气象数据和水稻产量数据的分析,发现2003年水稻的减产是由于7—9月光温条件的剧烈变化所造成,产量相比近五年平均（2000—2004年）降低了28.28%。产量构成因子中结实率和每穗粒数所受影响最大,二者分别降低了23.71%和7.82%,而有效穗数与千粒重与其它年份相比并无显著差异。扬花至灌浆后期的光照不足对产量的影响最大,关联度达到0.7011。分蘖孕穗期的低温寡照、孕穗后期高温和扬花期低温也对产量有一定的影响。     

超级杂交早稻分蘖期低温胁迫效应研究

分蘖是影响水稻穗数进而影响单产的重要农艺性状,气象条件对分蘖有很大影响。为了研究超级杂交早稻分蘖期低温对分蘖的影响,以中熟超级杂交早稻组合‘淦鑫203’为材料,利用人工气候箱,采用人工控制方法,在分蘖始期进行温度和持续时间双因子胁迫试验,借助统计分析、多重比较、聚类分析等手段,分析了总穗数、有效穗的差异及其与温度和低温天数的关系。结果表明：总穗数、有效穗随温度的降低而减少,温度差异造成的总穗数、有效穗差异极其显著,分蘖期温度低于19℃,对分蘖极为不利;总穗数、有效穗随低温天数的增加而减少,但差异不显著,短时间的低温天气对分蘖的不利影响,同样不容忽视。

     

土壤水分调控对高产冬小麦生理特性及产量影响

采用田间防雨旱棚方法研究了高产小麦分蘖期、孕穗期、灌浆期的三个生育时期在不同水分胁迫下,冬小麦生理特性指标的变化、产量构成因素及最终产量的变化。结果表明：冬小麦各个生育时期对水分胁迫反应有显著差别,主要表现为光合速率、蒸腾速率、叶水势等方面;生育后期比生育前期对水分敏感性强,产量受后期水分影响较大;根据各时期光合速率、蒸腾速率、最终产量等指标得出高产冬小麦合理节水灌溉指标主要为各生育期田间持水量分蘖前期为45%~50%,分蘖后期到孕穗前期为55%~60%,孕穗后期至灌浆期要维持60%~65%左右。这种条件下可以获得较合理的生物产量和经济效益。     

皖浙地区早稻高温热害发生规律及其对产量结构的影响研究

探讨高温与水稻产量的关系,在水稻高温热害防御中有重要意义。利用皖浙地区气象数据与早稻生育状况观测数据,分析了皖浙地区早稻高温热害规律及高温为害与早稻产量结构的关系。结果表明：皖浙2省早稻受高温热害危害的敏感期常年为6月中旬至7月中旬,且高温热害发生在时间分布上存在着周期震荡,其中20世纪80年代中期以前高温热害在发生日数和次数上呈减少趋势,其后则呈增多趋势;在空间分布上,安徽省沿江、江淮早稻主产区的高温热害重于沿淮地区;浙江省的金华—丽水一带为早稻高温热害重发区。在高温热害对早稻产量结构因素的影响中,高温热害与穗结实粒数、千粒重之间为负相关,与空壳率和秕谷率之间呈正相关,且扬花灌浆期高温热害对水稻空壳率和穗粒数影响较为显著。研究认为早稻抽穗扬花期遭遇高温热害,会对水稻结实率、千粒重、空壳率、秕谷率造成不等程度危害,其中穗粒数减少、空壳率增加是高温热害影响产量的主要原因。     

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.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.     

Isozyme variation between diploid and tetraploid cytotypes of Glycine tabacina (Labill.) Benth.

Summary Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids.     

Some physiological and photosynthetic characters of rice × sorghum and rice × wheat hybrids

Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO₂ compensation pointdistinguishing C₃ and C₄ plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO₂ compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C₃ rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T CO₂ compensation point - T21 CO₂ compensation point at 21% O₂ - T2 CO₂ compensation point at 2% O₂ - dR/sR deep Root-to-shoot Ratio - LAR Leaf Area Ratio - CER photosynthetic rate - TR/SR Total Root-to-Shoot Ratio