Book Reviews

Book reviewed in this article: How Much Is Enough?
Paul Burrows, The Economic Theory of Pollution Control. The High-Tech Dilemma
New England Regional Commission, The New England Regional Plan: An Economic Development Strategy. Masters of Development
Saburo Okita, The Developing Economies and Japan: Lessons in Growth. Perils of the Protoproletariat
Ingolf Vogeler, The Myth of the Family Farm: Agribusiness Dominance of U.S. Agriculture. For Better or Worse
Martin Kupferman and Maurice D. Levi, Slowth: The Changing Economy and How You Can Successfully Cope. Uncle Sam and Old Sol
John H. Minan and William H. Lawrence, eds., Legal Aspects of Solar Energy. Managing Agricultural Resources
Sandra S. Batie and Robert G. Healy, eds., The Future of American Agriculture as a Strategic Resource. Boom Town Women
Elizabeth Moen et al., Women and the Social Costs of Economic Development: Two Colorado Case Studies. The British Economy
Bill Jordan, Automatic Poverty. Planning by Synthesis
Melville C. Branch, Continuous City Planning: Integrating Municipal Management and City Planning. Social Cleavage
Lynne C. Burkhart, Old Values in a New Town: The Politics of Race and Class in Columbia, Maryland. Unconventional Wisdom
P. T. Bauer, Equality, the Third World, and Economic Delusion. Fueling Better
Joy Dunkerley et al., Energy Strategies for Developing Nations. Michael Satow and Ray Desmond, Railways of the Raj. Also of Interest
J. A. Allan, Libya: The Experience of Oil. Boulder, Col.: Westview I. Amon, Modernization of Agriculture in Developing Countries: Resources, Potentials, and Problems. James E. Austin, Agroindustrial Project Analysis. Robert H. Bates, Markets and States in Tropical Afica: The Political Basis of Agricultural Policies. Ian Bell, The Dominican Republic. Mark Blacksell and Andrew W. Gilg, The Countryside: Planning and Change. Larry S. Bourne, The Geography of Housing. P. R. Brahmananda, Growthless Inflation by Means of Stockless Money: A New Classical lYeatise on Rising Prices. Lawrence A. Brown, Innovation Diffusion: A New Perspective. Stanley D. Brunn and James O. Wheeler, The American Metropolitan System: Present and Future. Robert W. Burchell and David Listokin, eds., Cities under Stress: The Fiscal Crises of Urban America. Chong-Shik Chung and Gahb-chol Kim, eds., North Korean Communism: A Comparative Analysis. Albert M. Church, Taxation of Nonrenewable Resources. Diana Conyers, An Introduction to Social Planning in the Third World. Michael Dunn, Marilyn Rawson, and Alan Rogers, Rural Housing: Competition and Choice. John Gilderbloom, ed., Rent Control: A Source Book. David G. Green, Power and Party in an English City: An Account of Single-Party Rule. Philip Hanson, Trade and Technology in Soviet-Western Relations. George W. Hoffman, ed., Federalism and Regional Development: Case Studies on the Experience in the United States and the Federal Republic of Germany. Richard H. Jackson and Lloyd E. Hudman, World Regional Geography: Issues for Today.     

Genetic mapping of the barley Rrs14 scald resistance gene with RFLP, isozyme and seed storage protein markers

The scald susceptible barley cultivar ‘Clipper’ and a third‐backcross (BC₃) line homozygous for the Rrs14 scald resistance gene that originally came from Hordeum vulgare ssp. spontaneum were grown in replicated field trials. The level of resistance that Rrs14 confers against field populations of the pathogen Rhynchosporium secalis, the causal agent of scald disease, was evaluated. The Rrs14 BC₃ line exhibited 80% and 88% less leaf damage than ‘Clipper’ in 1995 and 1996, respectively. Given this effectiveness of Rrs14, research was undertaken to identify a linked marker locus suitable for indirect selection of Rrs14. Based on linkage to a set of previously mapped loci, Rrs14 was positioned to barley chromosome 1H between the seed storage protein (hordein) loci Hor1 and Hor2, approximately 1.8 cM from the latter locus. The Hor2 locus is thus an ideal codominant molecular marker for Rrs14. The tight linkage between Rrs14 and Hor2 and the availability of alternative biochemical and molecular techniques for scoring Hor2 genotypes, permits simple indirect selection of Rrs14 in barley scald resistance breeding programmes.     

A gametocidal factor of Oryza glaberrima Steud. in O. sativa L.

Summary Recurrent backcrossing has been carried out with a view to transfer a gene for non-glutinous endosperm from two strains of O. glaberrima (Wx _g /Wx _g ) to glutinous japonica and indica varieties (wx/wx) of Oryza sativa. In the course of backcrosses Wx _g /wx segregants were crossed with each of the two glutinous varieties of sativa as the respective recurrent male parent. The wx/wx and Wx _g /wx segregants in the successive generations were consistently fully fertile and semi-sterile, respectively. The semi-sterility of Wx _g /wx plants was attributable to abortion of most of the pollen grains carrying the gene wx. The nucleus but not cytoplasm was related to the semi-sterility. The Wx _g /Wx plants having the gene for non-glutinous endosperm of a glaberrima strain and a japonica variety of sativa were also semi-sterile. Both wx- and Wx-megaspores in the plants heterozygous for the gene Wx _g were deleteriously affected. The results could be explained by assuming that a factor tightly linked with the gene Wx _g of glaberrima sterilizes gametes not carrying it in the heterozygotes and that the gametocidal action is exerted when combined with the sativa nucleus by the recurrent backcross method.     

Cytological and microsatellite mapping of mutant genes for spherical grain and compact spikes in durum wheat

Two mutants for sphaerococcoid seed (MA 16219) and compact spike (MA 17648) were isolated from M₃ progeny of durum wheat cultivar, Altaiskaya Niva, mutagenized with chemical mutagens. The chromosomal locations of the genes involved were determined by the use of a complete set of D-genome disomic substitutions in durum cultivar, Langdon. The gene for sphaerococcoid grain, s ¹⁶²¹⁹ , was allelic to S2, located in the centromeric region of chromosome 3B in hexaploid wheat. The gene for compact spike, C ¹⁷⁶⁴⁸ , was located on chromosome 5AL distal to the Q locus. Using microsatellite markers, C ¹⁷⁶⁴⁸ and awn inhibitor B1 were located in the F₂ of LD222 × MA17648. The gene order was Xbarc319—C ¹⁷⁶⁴⁸ —Xgwm179—Xgwm126—Xgwm291—B1.     

Comparative molecular marker-based genetic mapping of flavanone 3-hydroxylase genes in wheat,rye and barley

The F3 h gene encoding flavanone 3-hydroxylase, one of the key enzymes of the flavonoid biosynthesis pathway, is involved in plant defense response, however, it has not yet been genetically mapped in such important crop species as wheat, barley and rye. In the current study, the F3 h genes were for the first time genetically mapped in these species, using microsatellite and RFLP markers. The three wheat F3 h homoeologous copies F3 h-A1, F3 h-B1 and F3 h-D1, and rye F3 h-R1 were mapped close to the microsatellite loci Xgwm0877 and Xgwm1067 on chromosomes 2AL, 2BL, 2DL, and 2RL, respectively. Wheat F3 h-G1 and barley F3 h-H1 were also mapped at the homoeologous F3 h-1 position on chromosomes 2GL and 2HL, respectively. The non-homoeologous F3 h gene (F3 h-B2) was mapped on wheat chromosome 2BL about 40 cM distal to the F3 h-1 map position. The results obtained in the current study are important for further studies aimed on manipulation with F3 h expression (and, hence, plant defense) in wheat, barley and rye.     

Book Reviews

Book reviews in this article: Predictable Views The New Economics of Richard Nixon: Freezes, Floats, and Fiscal Policy by Roger LeRoy Miller and Raburn M. Williams. The Voice of the Dodo Let Me Say This about That: A Primer on NIXONomics by Ralph Jensen. An Authoritative Analysis Making Monetary and Fiscal Policy by G. L. Bach. Bullish on Puerto Rico The Role of the Financial Sector in the Economic Development of Puerto Rico by Rita M. Maldonado. About Underdeveloped Societies Economic Progress and the Developing World by Edward Marcus and Mildred Rendl Marcus. Updating Development Protagonists of Change: Subcultures in Development and Revolution, edited by Abdul A. Said. The Transcendent Behaviorist Society and Economic Growth: A Behavioral Perspective of Social Change by John H. Kunkel. Viewing History Afresh At the Edge of History by William Irwin Thompson. The Snow of Yesteryear Public Affairs by C. P. Snow. Government Personnel Public Service: The Human Side of Government by John W. Macy, Jr. Labor Relations in Government The Unions and the Cities by Harry H. Wellington and Ralph K. Winter, Jr. Revolting Students, Then and Now Student Activism: Town and Gown in Historical Perspective, edited by Alexander DeConde. 1972 Is Another Ball Game Passion and Politics: Student Activism in America, Part 1 by Seymour Martin Lipset and Part 2 by Gerald M. Schaflander. Tullock's Law The Logic of the Law by Gordon Tullock. Grace and Works in Latin America Human Rights and the Liberation of Man in the Americas, edited by Louis M. Colonnese. Man and Beast The Cougar Doesn't Live Here Any More by Lorus J. Milne and Margery Milne. Getting to Know the Bomagai-Angoiang Place and People: An Ecology of a New Guinean Community by William C. Clarke. Geography in the Seventies The North American City by Maurice H. Yeates and Barry J. Garner. Learning from the Past The New Deal in the Suburbs: A History of the Green-belt Town Program, 1935–1954 by Joseph L. Arnold. Slow Progress Urban Land Economics and Public Policy by Richard B. Andrews. Stop the Music Noise Pollution: The Unquiet Crisis by Clifford R. Bragdon. On Behalf of the Indian Big Brother's Indian Programs-With Reservations by Sar A. Levitan and Barbara Hetrick. Near-White Status The Mississippi Chinese: Between Black and White by James W. Loewen. Lost Ground The Job Crisis for Black Youth Financial Dilemma Fiscal Pressures on the Central City: The Impact of Commuters, Nonwhites, and Overlapping Governments by Werner Z. Hirsch Red Roundup Yearbook on Latin American Communist Affairs, 1971, edited by William E. Ratliff. Comprehensive Guide The Cambridge History of Islam: Vol. 1, The Central Islamic Lands The Value of a Degree Economic Dimensions in Education by Martin O'Donoghue. Demographic Dimensions Population Growth and the Brain Drain, edited by F. Bechhofer. Agricultural Sagacity The Economics of Agriculture by Margaret Capstick. A Brief Rapid Population Growth: Consequences and Policy Implications, Vol. 1, Summary and Recommendations A Challenging Question Is Law Dead?, edited by Eugene V. Rostow. One River's Environment Swan River Landscapes by George Seddon. An Objective Method Voting and Collective Choice: Some Aspects of the Theory of Group Decision-Making by Prasanta K. Pattanaik. A Practical Handbook Regional Economic Analysis for Practitioners by Avrom Bendavid. Chicano Manifesto by Armando B. Rendon. Politics, Position, and Power: The Dynamics of Federal Organization by Harold Seidman. Economic Development and Population Control: A Fifty-Year Projection for Jamaica by B. Thomas Walsh. SDS by Alan Adelson.Now Is the Time: A New Populist Call to Action by Fred R. Harris. Japan: Its History and Culture by W. Scott Morton. The Emerging Japanese Superstate: Challenge and Response by Herman Kahn. Hanging Together: Equality in an Urban Nation by William L. Taylor. A Mind of One Piece: Brandeis and American Reform by Melvin I. Urofsky. Sentencing in a Rational Society by Nigel Walker. Social Experimentation and Manpower Policy: The Rhetoric and the Reality by Sar A. Levitan and Robert Taggart 111. Social Control and Social Change, edited by John Paul Scott and Sarah F. Scott. The State of the Nations: Constraints on Development in Independent Africa, edited by Michael F. Lofchie. The Presidency by Dale Vinyard. The American Left: Radical Political Thought in the Twentieth Century, edited by Loren Baritz. Design for the Real World: Human Ecology and Social Change by Victor Papanek. Man and Atom: Building a New World through Nuclear Technology by Glenn T. Seaborg and William R. Corliss. Toward a Rational Power Policy: Energy, Politics, and Pollution by Neil Fabricant and Robert M. Hallman. Land of Urban Promise: Continuing the Great Tradition-A Search for Significant Urban Space in the Urbanized Northeast by Julian Eugene Kulski. The Politics of Disorder by Theodore J. Lowi. The Shape of Likelihood: Relevance and the University Regional Economics: Theory and Practice, edited by David L. McKee, Robert D. Dean, and William H. Leahy. The Foreign Affairs Fudge Factory by John Franklin Campbell. The Public Economy of Metropolitan Areas by Robert L. Bish. The Future of the Oceans by Wolfgang Friedmann.     

Molecular mapping of an aluminum tolerance locus on chromosome 4D of Chinese Spring wheat

Summary The tolerance of aluminum (Al) of disomic substitution lines having the chromosomes of the D genome of Triticum aestivum L. cv. Chinese Spring individually substituted for their homoeologues in T. turgidum L. cv. Langdon was investigated by the hematoxylin method. The disomic substitution lines involving chromosome 4D were more Al tolerant than Langdon. The tolerance was found to be controlled by a single dominant gene, designated Alt2, that is in the proximal region of the long arm of chromosome 4D. The locus was mapped relative to molecular markers utilizing a population of recombinant chromosomes from homoeologous recombination between Chinese Spring chromosome 4D and T. turgidum chromosome 4B. Comparison of the location of Alt2 in this map with a consensus map of chromosomes 4B and 4D based on homologous recombination indicated that Alt2 is in a vicinity of a 4 cM interval delineated by markers Xpsr914 and Xpsr1051. The Alt2 locus is distal to marker Xpsr39 and proximal to XksuC2. The Altw locus is also proximal to the Knal locus on chromosome 4D that controls K⁺/Na⁺ selectivity and salt tolerance. In two lines, Alt 2 and Knal were transferred on a single 4D segment into the long arm of T. turgidum chromosome 4B.     

The inheritance of top-necrosis to viruses X,A, B and C in Solanum tuberosum

The top-necrotic reactions of potatoes to viruses X, A, B and C are determined by four dominant genes, Nx, Na, Nb and Nc respectively. In two families evidence was obtained that Nx, Na and Nc are all in the same linkage group. The genes were present in three different chromosomes of the same homologous group of four. The other gene, Nb was found to be independent of Nx and Nc. In a third family, of a different origin from the previous two, Nx, Nb and Nc were independent of each other.     

Kunitz trypsin inhibitor polymorphism in the Korean wild soybean (Glycine soja Sieb. & Zucc.)

Kunitz trypsin inhibitor (KTi) in 1368 accessions of wild soybean (Glycine soja Sieb. & Zucc.), collected from three regions of Korea, was examined for allelic diversity and geographical distribution. Five electrophoretically distinguishable KTi forms were detected: three were common (Tia, Tib and Tia/Tib) and two were previously unreported (Tib^i7‐1 and Tibⁱ⁵). The Tia allele was predominant (93.49%). Alleles Tib, Tib^i7‐1 and Tibⁱ⁵ were detected with the frequencies of 3.47, 0.55 and 0.11%, respectively. The heterozygous form (Tia/Tib) was detected with the frequency of 2.26%. The nucleotide sequence of Tib^i7‐1 was identical to that of the Tib‐derived variant allele Tif, with the exception of three nucleotides: A→G at position +244, A→C at position +286 and G→C at position +601. The latter two were similar to Tia, suggesting that Tib^i7‐1 is an intermediate allele between Tia and Tib. The gene for Tibⁱ⁵ showed 100% similarity with the Japanese intermediate allele Tibⁱ⁵. This study demonstrates that Korean wild soybeans are remarkably rich source of new KTi alleles not reported before.     

Breeding of tetra null soybean (Glycine max) for lipoxygenase,kunitz trypsin inhibitor,lectin, and 7S α' subunit proteins

Soybean seed includes various bioactive substances. Also, they contain a variety of antinutritional factors including lipoxygenase, Kunitz trypsin inhibitor (KTI), lectin, and 7S α' subunit proteins. The genetic removal of these proteins will improve the nutritional value of soybean seed. The objective of this research was to breed new soybean with tetra recessive alleles (lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1) for lipoxygenase, KTI, lectin, and 7S α' subunit proteins. Seven parents were used to breed tetra null strain. SDS‐PAGE and Western blot analysis were used to determine the presence or absence of lipoxygenase, 7S α' subunit, KTI, and lectin proteins in mature seed. Tetra null soybean line has a purple flower, determinate growth habit, tan pod, and yellow seed coat colour. Stem height of the breeding line was 62.3 cm. The 100‐seed weight of the breeding line was 27.1 g and yield (t/ha) was 2.84. This is the first soybean strain with lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1 genotype (absence of lipoxygenase, KTI, lectin, and 7S α' subunit proteins).     

Genetic diversity of Indian Jatropha species as revealed by morphological and ISSR markers

The selection of Jatropha based on morphological information and molecular markers is essential as it is more reliable and consistent. Hence, twelve Jatropha accessions from different geographical areas of India were screened for genetic diversity using 19 morphological traits and 21 ISSR primers. The analysis of morphological traits grouped the accessions into five clusters. The cluster I consisted of J. curcas (CJC 18), J. curcas (CJC 20), J. curcas (CJC 22), J. curcas (CJC21), and J. curcas (CJC 25), and contained the maximum number of accessions; clusters II and IV contained the minimum number of accessions. Among all the characters, the highest range was exhibited by plant height and the least value by the number of branches. The twenty-one ISSR primers generated 156 polymorphic alleles. The average number of ISSR alleles generated was 7.47 per primer. The ISSR primer UBC 884 was highly informative with the maximum of 12 alleles. The 12 genotypes were grouped into eight clusters. The cluster I contained the maximum number of accessions, namely J. curcas (CJC 18), J. curcas (CJC 20), J. curcas (CJC 22), J. curcas (CJC21), and J. curcas (CJC 25). The clusters II, III, IV, V, VI, VII, and VIII (J. tanjorensis, J. gossypiifolia, J. glandulifera, J. podagrica, J. ramanadensis J. villosa, and J. integerrima) contained the minimum number of accessions. Maximum diversity between J. villosa and J. integerrima was noticed and the least diversity between J. curcas (CJC21) and J. curcas (CJC 25) seen because the ISSR markers differentiated the Jatropha accession into a wide genetic diversity as compared to the morphological data. The species-specific diagnostic markers identified in the study such as 1000 bp alleles for J. glandulifera by the primer UBC 826 is suitable for discriminating species of Jatropha, and thus can be used for identifying a Jatropha species from any mixed population comprising other members of the Jatropha complex.     

Genes for resistance to wheat powdery mildew in derivatives of Triticum timopheevi and T. carthlicum

Summary The winter wheat line TP 114 derived from CI 12633, a Triticum timopheevi derivative, has two unlinked dominant genes conditioning resistance to the powdery mildew fungus (Erysiphe graminis f. sp. tritici). One of the genes is identical to gene Pm2 (Ml _u ). The other gene differs from the eleven Pm and/or Ml designated genes; a temporary designation, Ml _f ,is proposed for this gene. Gene Ml _f is closely associated with a gene conditioning resistance to the stem rust fungus (Puccinia graminis f. sp. tritici), probably gene Sr9c.The winter wheat line TP 229 derived from Triticum carthlicum has one dominant mildew resistance gene identical to gene Ml _e in Weihenstephaner M 1.     

Comparative genetic mapping of homoeologous genes for the chlorina phenotype in the genus <Emphasis Type="Italic">Triticum</Emphasis>

Triticum monococcum L. (2n = 2x = 14, A^mA^m genome) is one of the most ancient of the domesticated crops in the Middle East, but it is not the ancestor of the A genome of durum wheat (T. durum Desf. 2n = 4x = 28, genomes BBAA) and bread wheat (T. aestivum L., 2n = 6x = 42, genomes BBAADD). It has been suggested that some differentiation has occurred between the A^m and A genomes. The chlorina mutants at the cn-A1 locus located on chromosome 7AL have been described in T. aestivum L. and T. durum, and a chlorina mutant has been found in T. monococcum. The aims of our study were to establish linkage maps for chlorina mutant genes on chromosome 7A of T. aestivum and T. durum and chromosome 7A^m of T. monococcum and to discuss the differentiation that has occurred between the A and A^m genomes. The chlorina mutant gene was found to be linked with Xhbg234 (8.0 cM) and Xgwm282 (4.3 cM) in F₂ plants of T. aestivum ANK-32A/T. petropavlovskyi k54716, and with Xbarc192 (19.5 cM) and Xgwm282 (12.0 cM) in F₂ plants of T. durum ANW5A-7A/T. carthlicum #521. Both the hexaploid and tetraploid wheats contained a common marker, Xgwm282. In F₂ lines of T. monococcum KT 3-21/T. sinskajae, the cn-A1 locus was bracketed by Xgwm748 (25.7 cM) and Xhbg412 (30.8 cM) on chromosome 7A^mL. The distal markers, Xhbg412, Xgwm282, and Xgwm332, were tightly linked in T. aestivum and T. durum. The common marker Xhbg412 indicated that the chlorina mutant genes are located on chromosome 7AL and that they are homoeologous mutations.     

Seventh supplementary list of wheat varieties classified according to their genotype for hybrid necrosis and geographical distribution of Ne-genes

Summary The seventh supplement of the genotype hybrid necrosis in Triticum is presented. This list contains 414 Ne ₁-, 179 Ne ₂- and 662 non-carriers. The total number of varieties tested is 4629 viz. 1298 (28.0%) Ne-, 1031 (22.3%) Ne ₂- and 2300 (49.7%) non-carriers.The various aspects reported in literature and those studied by me are discussed.The geographical distribution of Ne-genes and their alleles indicates two Ne ₁ ^w -areas, one Ne ₁ ^m -area, probably two Ne ₂ ^ms.s -areas and four non-carrier-areas.     

Classification of GA response,Rht genes and culm length in Japanese varieties and landraces of wheat

Summary The GA response, Rht genes and culm length of 133 Norin varieties, 6 breeding lines and 16 landraces of Japanese wheat were investigated. Out of 133 Norin varieties tested, 103 were GA-insensitive and 30 GA-responsive. The 6 breeding lines were all GA-insensitive. Out of 16 landraces tested, 10 were GA-insensitive and 6 GA-responsive. Among the 10 GA-insensitive landraces, only Daruma had a Rht1 genotype. The other 9 had a Rht2 genotype. None of the landraces tested carried both Rht1 and Rht2 or Rht3. Out of the 103 GA-insensitive Norin varieties, 22 carried only Rht1, another 79 carried only Rht2, and only Norin 10 and Kokeshikomugi carried both Rht1 and Rht2. No tested variety carried Rht3. Some Norin varieties carrying Rht2 showed tall culms comparable to that of the rht tester line Chinese Spring. These results suggest that these varieties had a nullifier or modifier gene(s) or height promoting genes in the background controlling the height-reducing effect of Rht2. Conversely, six GA-responsive Norin varieties were as short as Akakomugi which carries the GA-responsive Rht genes, Rht8 and Rht9. The also seemed to carry a GA-responsive Rht gene or genes, and moreover all but one may carry gene(s) other than the Akakomugi genes. The origin of Rht1 and Rht2 of Norin 10 was speculated on the GA-response and Rht genotypes of its related varieties and landraces.     

Granule‐bound starch synthase (GBSS) diversity of ancient wheat and related species

Granule‐bound starch synthase of ancient wheat and related species was examined by sodium dodecyl sulphate polyacrylamide gel. A total of 13 different alleles were revealed in a collection of three accessions of diploid wheat, six accessions of tetraploid wheat, 49 accessions of spelt wheat, nine accessions of Sitopsis and two accessions of Aegilops tauschii. A new allele named Wx‐A1a′ appeared in four spelt wheat accessions. The tetraploid wheat accessions evaluated did not show any polymorphism; nevertheless the tetraploid accessions of Sitopsis section revealed three novel alleles. The novel allele Wx‐D^dn1g was found in two accessions of A. ventricosa and the Wx‐D^dcm1h and Wx‐D^dcm1i in two accessions of A. crassa. A novel allele named Wx‐A^u1g was found in Triticum urartu, which is different from the also new Wx‐A^m1h allele of T. monococcum. The diploid‐related species accessions revealed two novel alleles named Wx‐B^sl1h and Wx‐B^s1g found, respectively, in A. longissima and A. speltoides. The amylose content was measured for the different alleles found in all evaluated species and no significant effects of the allele composition on the amylose content were detected.     

Nitrogen efficiency components of winter cereals

A model to describe the importance of different physiological processes to explain grain yield differences (ΔG_w) between cropping systems (Huggins and Pan, 1993) was modified to evaluate the nitrogen use efficiency of different cereals. The method uses measurements of grain yield (G_w), grain N (N_g), above-ground plant biomass (B), above-ground plant N (N_t), applied fertilizer N (N_f), and post-harvest inorganic soil N in control plots without fertilizer (N_h). The components are N supply (N_s), N uptake efficiency (N_t/N_s), assimilation efficiency (B/N_t), harvest index (G_w/B) and N harvest index (N_g/N_t). For a first verification of the model different winter cereal species, i.e., one genotype of winter wheat, one of winter rye and one of spelt wheat, were compared in a 2-year field experiments at two sites with different soil fertility and climate. The modified nitrogen efficiency component analysis provided a good understanding of yield differences at different levels of applied N and soil fertility. The method could be useful for selection of genotypes with a high N use efficiency in breeding programmes.     

Geographical distribution of genes causing hybrid dwarfness in hexaploid wheat of the old world

Summary The distribution of the three different dominant genes for hybrid dwarfness in the Old World is given. It appears thatD ₁ is found in southern Europe, Africa and Asia, whileD ₃ is located in Europe.D ₂ is common in all wheat-growing areas. The distribution ofD ₁ coincides with that ofNe ₁, while the distribution ofD ₃ is probably similar to that ofNe ₂.TheD ₁-gene is still present inAegilops squarrosa. The sources ofD ₂ andD ₃ have not yet been determined with certainty.     

Identification of self-incompatibility (S) alleles in Latvian and Swedish sweet cherry genetic resources collections by PCR based typing

The Latvian and the Swedish sweet cherry (Prunus avium L.) genetic resources collections comprise valuable material for breeding. The collections represent local Latvian and Scandinavian genetic resources: semi-wild samples, landraces, and cultivars developed in local breeding programmes, as well as diverse germplasm from the northern temperate zone. The objective of this investigation was to determine which S ₁ –S ₆ alleles are most important in the sweet cherry genetic resources collections and to compare the identified allelic and genotypic frequencies in material of different origin. Accessions in the two collections were screened for the presence of the self-incompatibility (S) S ₁ to S ₆ alleles, using PCR based typing. Significant differences (P < 0.05) between screened collections were found in frequencies of S ₄ and S ₅ alleles. Analysis of allele combinations identified the high occurrence of selections with the S-genotype S ₃ S ₆ in both collections. Compared to the S-allele frequencies published for over 250 sweet cherry cultivars from Western and Southern Europe, the Latvian and Swedish germplasm appeared to have a high frequency of the S ₆ allele in both collections, and a relatively high frequency of the S ₅ allele in Latvian germplasm. This study represents the first comprehensive S-allele screening for the sweet cherry genetic resources collections in Latvia and Sweden. Both sweet cherry collections contain high proportion of accessions adapted to north central European growing conditions, not typical for the majority of the documented sweet cherry genetic resources, which explains differences in certain S-allele occurrence.     

Identification by genetic analysis of two races of Erysiphe polygoni DC. causing powdery mildew disease in mungbean

Powdery mildew disease is one of the important foliar diseases of mungbean. Earlier, resistance sources have been identified and their genetic nature studied, but there is no information on race identification of Erysiphe polygoni so far. Different genotypes having combinations of the host resistance genes Pm₁Pm₁Pm₂Pm₂‘TARM‐1’, Pm₁Pm₁pm₂pm₂ (S‐158‐16) and pm₁pm₁Pm₂Pm₂ (S‐2‐4‐1) and no resistance genes pm₁pm₁pm₂pm₂ (TPM‐1) were used in the present investigation. The genotypes were screened with four isolates from Akola, Trombay, Jabalpur and Gauribidanur centres in India. The interactions of resistant differentials with the Akola isolate were different from the other three isolates. The inheritance patterns of different resistance genes in various crosses also differed with respect to the Akola isolate. The variation observed in the Akola isolate could be explained as the result of mutation of the dominant avirulence Avr₁Avr₁ genes to virulence avr₁avr₁ genes corresponding to host resistance Pm₁Pm₁genes. Therefore, the Akola isolate is identified as a second race of E. polygoni.