冬小麦品种——行距——群体——产量相关规律的研究

本文在高产田条件下，选用了少穗大穗型核生２号、多穗小穗型烟农１５及中间类型的８７６１６１三个冬小麦品种，设计２０、３０、４０、及１００ｃｍ四种行距，配合一米行长基本苗１８、３６、５４及７２四个播种密度，研究了小麦品种－行距－群体－产量的相关规律。主要结果是：（１）行距２０ｃｍ，在精量（１８苗／米）和半精量（３６苗／米）播种密度下，取得亩产量最高。（２）２０ｃｍ及３０ｃｍ小行距下，随播种密度加大，产     

天目笋干

１选料 天目笋干是以天目山区野生石竹、刚竹、淡竹等所长的笋为原料，要求笋身３０ｃｍ左右时采回。最多不超过３５ ｃｍ。２煮制 将壳笋去箨后，置于锅中，一层笋、一层盐，每１００ ｋｇ笋肉，食盐６ ｋｇ，清水４０ ｋｇ，煮 ８－１０ ｈ，待笋变黄绿时取出。３烘守 出锅后     

杂交中稻不同栽插方式群体发育规律研究

本试验研究杂交中稻在相同密度下，不同栽插方式群体发育规律及其穗粒结构特点。结果表明：宽窄行及宽行窄株栽插方式的各项生育指标、产量结果都优于分厢和２６．６７ｃｍ×１６．６７ｃｍ栽插方式。在同一密度下确保落田苗数相互接近的群体，其最佳栽培规格依次为：（３３．３３＋２０）／２ｃｍ×１６．６７ｃｍ、（４０＋２６．６７）／２ｃｍ×１３．３３ｃｍ、（３０＋２３．３３）／２×１６．６７ｃｍ、３３．３３×１３．３３（单位：ｃｍ）。     

不同灌水次数对日光温室番茄土壤水分动态变化规律的影响

根据番茄在整个生育期内土壤水分变化特点,充分利用有限水资源,调节土壤水分状况。在相同灌水量条件下,利用时域反射仪研究不同灌水次数对土壤含水量的变化的影响。结果表明：各处理土壤贮水量变化的深度一般在0~100 cm内,尤其在0~60 cm变化最为激烈,100~180 cm范围内土壤水分变化不明显。按土壤水分运移规律进行划分,将土壤水分的垂直变化分为4层,即活跃层（0~30 cm）、次活跃层（30~60 cm）、缓变层（60~100 cm）和均稳层（100~180 cm）。灌水次数越少对土壤水分消耗的越多,易造成活跃层和次活跃层土壤水分亏缺;反之,则土壤水分消耗较少。     

玉米大垄覆膜栽培技术的研究初报

大垄玉米覆膜主要有两种方式：一种是将三条６５ｃｍ小垄改成两条９７５ｃｍ大垄，每条大垄种植２行玉米，小行距３０ｃｍ；另一种是将两条６５ｃｍ小垄改成一条垄距为１３０ｃｍ超大垄，每条大垄种植４行（大垄上开两个播种沟，沟间距离４０ｃｍ，沟宽２０ｃｍ，沟内双...     

灌溉对青刈黑麦生产影响的研究

以青刈黑麦品种冬牧７０黑麦为材料,以利用棉花冬闲田为目的,在田间条件下研究了不同灌水处理对青刈黑麦株高、叶面积指数、干物质积累以及产量的影响。结果表明在１０月中、下旬至翌年４月下旬青刈黑麦生长期间,土壤主要耗水层位在０～１００ｃｍ土体。一般年份在足墒播种（７５０ｍ３／ｈｍ２）条件下,翌年４月１日前后青刈黑麦拔节期浇水一次（７５０ｍ３／ｈｍ２）,就能满足青刈黑麦生长发育对水分的需求;在雨水偏多土壤水分含量较多的年份,可以不浇水或少浇水,充分利用土壤中的水分以提高水分利用率。     

巴西橡胶树自根动态无性系的试管微繁

带有腋芽的橡胶花药苗切段中在ＭＳ＋６－ＢＡ２ｍｇ／Ｌ的培养基上，３０～４０天新芽可长至３～５ｃｍ高，并可切割再次增殖，切取３～５ｃｍ高带叶片的增殖芽作为插条，基部经５０～１００ｍｇ／ＬＩＢＡ预处理再插到生根培养基上，生根率达９５％，诱发的根系与茎杆之间愈合良好，输导组织连接紧密，生极植株移栽成活率达８５％以上。     

太行山前冲洪积扇地区土壤水分动态变化特征研究

土壤水分含量对土壤物理性质和植被生长状态有重要影响，但土壤水分在时间上具有一定的变异性。大规模开采地下水导致地下水位急剧下降，包气带不断增厚，使土壤水分的储存、运移和转化发生了变化，影响了土壤水的动态变化特征。本研究利用连续多年的土壤水分观测数据，分析了太行山前包气带土壤水分动态变化特征，结果表明：土壤含水量受丰水年枯水年影响存在年际差异，根据不同季节土壤水分的动态特点，可将其划分为三个时期，即土壤水分消耗期土壤水分累积期和土壤水分相对稳定期。在垂向上，土壤含水量从上层向下逐渐增大，土壤水分变异程度随土壤深度的增加而减弱。     

兰椒1号辣椒

兰椒１号辣椒１品种来源：甘肃省兰州市农科所用自育的自交系３３号作母本、２２号作父本配制的杂交种。１９９５年５月兰州市农作物品审小组受甘肃省品审会的委托审定通过并定名。２特征特性：株高７０～１００ｃｍ，侧枝为无限分枝型，茎粗１～１．５ｃｍ。叶卵圆形，绿...     

西瓜小棚半覆盖栽培技术

西瓜小棚半覆盖栽培是一种简易的保护地西瓜早熟栽培方式。在春季低温条件下,采用高４０ｃｍ～５０ｃｍ、跨度宽６０ｃｍ～１５０ｃｍ的聚乙烯塑料薄膜覆盖,保护西瓜前半期生长,待自然温度上升到能满足西瓜生长时拆棚,使西瓜后半期在露地条件下生长。小棚覆盖明显地提...     

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...     

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.