北疆高产棉田群体光合速率及与产量关系的研究

研究了北疆２２５０ｋｇ·ｈｍ－２高产条件下棉花群体光合速率的变化及与产量之间的关系。结果表明，２２５０ｋｇ·ｈｍ－２高产棉田群体光合速率在整个生育期的变化呈单峰型曲线，在盛花期以前稳定上升，至盛铃期达最大，值为４．０５ｇ·ｍ－２·ｈ－１，吐絮盛期尚保持较高水平。全生育期平均值为２．６３ｇ·ｍ－２·ｈ－１。群体光合速率的日变化也呈单峰曲线，在１ｄ内至北京时间１４∶００～１５∶００达最大值。与其它产量条件下棉花群体光合速率的变化结果进行统计分析，盛花结铃期和吐絮期群体光合速率与皮棉产量呈显著正相关。在生产上，加强棉田后期管理，保持较高的群体光合速率，有利于棉花高产。     

棉花超高产群体质量与产量关系研究

试验结果表明，皮棉产量在１８７５ｋｇ．ｈｍ￣（－２）以上时，必须保持较高的群体质量。其中果节量为２２５～３２２．５万个·ｈｍ￣（－２），富照期成铃强度在２１６００个·ｈｍ￣（－２）·日以上，晚秋桃形成期成铃强度在１０９８２．７个，ｈｍ￣（－２）·日以上。株型较紧凑，最大ＬＡＩ在３．８７～４．４５范围内，成熟期（９月１５日）ＬＡＩ保持在２．３５～２．５７，叶铃比３．５５～４．１１：１，叶面积载铃量在３２个·ｍ￣（－２）叶以上。     

小麦孢囊线虫病瘿瘤密度对麦苗生长的影响

根据小麦孢囊虫病典型症状－根据部形成瘿瘤及其密度变化，探讨了该病害对小麦苗期生长影响，结果表明，瘿瘤密度与麦苗长势呈极显著负相关；瘿瘤密度在0．21－1．83，麦苗主茎高降低27．5％－45．4％，单株分蘖减少4．3％－77．0％，叶片减少7．9％－65．7％，次生根条数及根生分别减少1．3％－61．6％，8．0％－71．9％，瘿瘤密度达4．22以上时，麦苗不能形成分蘖和次生根，且弱小黄化严重而及早枯死。     

棉花蕾铃受害后的损害函数及补偿效应数学模型研究

试验采用五因素五水平二次正交旋转回归组合设计，建立了以皮棉产量、子棉产量、单株成铃及单株产量的目标函数，考虑种植密度、追氮量、果枝数、模拟被害蕾和被害幼铃五决策变量的数学模型。模型信息表明：低密度或高果枝数条件下棉花补偿能力衰减；受害铃达３个·株－１以上时，增加追氮量（大于１８０ｋｇ·ｈｍ－２）将会伤失棉花群体的补偿能力；被害蕾量的增加在一定范围内有增产作用；被害幼铃的多寡对产量的影响较大。模拟计算表明：百株允许被害蕾６０８～６４２个和允许被害幼铃１９６～２１４个，采取６．６９～６．７９５万株·ｈｍ－２的密度、留果枝数１４．７～１５．０２个·株－１和追氮量１５４．５～１６６．５ｋｇ·ｈｍ－２的农艺措施，可望获得皮棉１３５０ｋｇ·ｈｍ－２以上。最后提供了不同农艺措施下棉花的损害函数。     

长效尿素在块根、块茎作肥上肥效初报

国产，德产长效尿素在块根，块茎作物上肥效试验表明，长效尿素比等N量普通尿素平均增产块根6．8％－19．3％，N利用率增加4．1－11．5个百分点，增产块茎17．9％－24．3％，N利用率增加11．9－16．5个百分点，块茎作物肥效优于块根作物，国产长效尿素增产效应不亚于德产品种，增产率为19．3％－24．3％，德国产品增产6．8％－15．4％和17．9％－23．6％，推荐国产品种MUA，德产品种SUC，SUD较优的长效N肥品种。     

甘蓝型油菜隐性胞核不育两型系花粉与外源花粉竞争能力研究

甘蓝型油菜胞核不育两型系117AB在先授花恢花粉，1－48小时后授以可育株花粉的条件下，其异交率为45.75％－70．83％，比对照增加3．89％－28．97％，在先授可育株花粉，1－48小时后再授以花恢花粉时，其异交率为41．29％－15．77％，比对照减少0．75％－26．09％，该类材料不存在异品种优先授精现象，而且可育株花粉比花恢花粉有更强的竞争能力，其竞争优势系数为1．13-1．73之间，平均值为1．49，在制种中无论何种行比，不拔可育株，后代将不能作为种子用。     

边行效应在套播麦种繁育田中的应用研究

本研究通过对冬小麦鲁麦15号调查分析，明确了小麦边行优势的形成具有时间积累效应：（1）小麦不同生育时期对边行产量优化形成的贡献呈现不均衡性，其大小为拔节－挑旗（31．2％）＞挑旗－开化（22．3％）＞灌浆－成熟（19．4％）＞起身－拔节（11．2％）；（2）小麦边行优势形成对产量构成的时间效应：拔节－挑旗为主要增穗期，挑旗－开花为重要增粒期，开花－成熟为增加粒重期；（3）套播麦种繁育田合理地开发利用小麦边行优势，达到了麦种和套种作物整体效益的双丰收。     

旱地棉花有限补水效应研究

研究了旱地棉花不同生育期补水对棉花生长发育和产量的影响．试验结果表明，有限补水棉花根系伤流量提高３７．５％～５６．３％，干物质和叶面积增多，光合势和净光合率提高，叶绿素含量提高２９．８％～４７．１％。补水比不补水棉花产量增加２２．０％～１８３．８％，其中补水３次＞２次＞１％＞ＣＫ，不同干旱年型，有限补水关键时期不同，在前期干旱年型补蕾水，后期干旱年型补花水，补１水（蕾或花）棉花产量过７５０ｋｇ·ｈｍ￣（－２），补２水产量（底＋花或蕾＋花）过１１２５ｋｇ·ｈｍ￣（－２）。     

水稻制种保健栽培综合抗病技术研究

水稻制种插秧密度大，投肥多，又因异交结实，最易产生病害，严重制约水稻制种产量和质量。针对此种不良因素，本文特进行了水稻制种保健栽培综合抗病技术研究。两年的研究结果表明：保健栽培综合抗病技术不但有效地抑制和减轻病害的发生，而且使父母本生育期缩短3－4d,制种产量比对照增产35．5％－46．6％，经t值测验增产达极显著水平，其增加投入与增产效益比值为1：5．2－6．73，经济效益显著。     

ASI土壤养分状况系统研究法在棉田上的应用

应用化学分析、吸附反应和生物诊断方法，系统研究了两种棉田土壤速效养分的丰缺状况。结果表明，土壤对磷、硫、铜、锰的吸附曲线呈近似的指数曲线，低浓度时，吸附强烈，随浓度增加，土壤的吸附能力下降。在吸附液浓度＜２０ｍｇ·Ｌ－１，加入的锰几乎全部被土壤吸附固定。在吸附液浓度＜７．５ｍｇ·Ｌ－１时，对锌的吸附强度较大，在吸附液浓度＞７．５ｍｇ·Ｌ－１时，吸附强度减少。盆栽生物效应试验证明，所有土壤均缺氮，另外扶沟潮土的磷、钾，南阳黄褐土的磷、钾、硫，是主要的养分限制因子。在剖析养分吸附特性的基础上按适宜的比例补充营养元素后，棉花产量及净收益显著提高。     

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...     

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.