bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrids of Bread Wheat (Triticum aestivum) with Thinopyrum scirpeum (4x) and Thinopyrum junceum (6x)
Authors: Gupta P. K. , Fedak G.
Published: April 2006

Hybrids were obtained by crossing Thinopyrum scirpeum (4x) and T. junceum (6x) onto Triticum aestivum cv, ‘Chinese Spring’. An average meiotic pairing of 24.44I+ 5.07II+ 0.14IIIin the ‘Chinese Spring’×T. scirpeum hybrid (ABDE1E2) is attributed to two similar genomes from T. scirpeum (E1E2E3E4). An average meiotic chromosome pairing in the other hybrid (ABDJ1J2E3) was 31.70I+ 3.80II+ 0.90III and is attributed to autosyndetic pairing between the three genomes of T. junceum.
Effect of D‐Genome Chromosome Substitutions on Hybrid Seed Development and Viability in T. turgidum var. durum X S. cereale Crosses
Authors: de V. Pienaar R. , Marais G. F.
Published: April 2006

Triticum turgidum var. durum cv. ‘Langdon’ and the set of D‐genome disomicsubstitutions in ‘Langdon’, produced at Fargo, U.S.A., were grown in a temperature controlled greenhouse and crossed with diploid spring rye (Secale cereals), to determine the effect of each substitution on 1. the crossability with rye, and 2, the viability of the resulting hybrids kernels. None of the disomicsubstitutions lines, with the possible exception of the 5D (5Bj line, gave an appreciable improvement in hybrid kernel set, ‐development, and ‐viability over the control, ‘Langdon’ The post‐zygotic barrier to endosperm and embryo development, which operates in crosses between durum wheat and rye, could therefore not be suppressed by any specific chromosome of the D‐genome.
Self‐Compatibility/Incompatibility in Some Orchids of the Subfamily Vandoideae
Authors: Agnew J. D.
Published: April 2006

Self‐pollination of 2f species of vandaceous orchids was followed by later embryo culture carried out to determine which species are self‐compatible (SC) or incompatible (SI): 10 are SC, 1 are SI and the remaining:8 require further study. In the SI species, a few progeny could usually be recovered and these are interpreted as arising from mutation at the incompatibility locus (loci). The implications of the findings for current models of incompatibility are discussed.
Recurrent Addition of the Pennisetum americanum Genome in a P. americanum×P. orientale Hybrid
Authors: Zado S. N. , Singh Amar
Published: April 2006

An interspecific hybrid involving Pennisetum americanum (2 n = 14) and a diploid cytotype of P. orientale (2 n = 18) was backcrossed to P. americanum using the hybrid (2 n = 16, 7‘A’+ 9 ‘O’) as the female parent. Pollen mother cells of 13 BC1 plants contained a complement of 14‘A’+ 9 ‘O’ chromosomes. Five BC2 plants obtained through further backcrossing to P. americanum had 21‘A’+ 9 ‘O’ chromosomes revealing another addition of the P. americanum genome. The role of such recurrent additions of parental genomes in the evolution of polyploid species has been discussed.
A Major Gene for Delayed Senescence in Maize. Pattern of Photosynthates Accumulation and Inheritance
Authors: Gentinetta E. , Ceppl D. , Lepori C. , Perico G. , Motto M. , Salamini F.
Published: April 2006

A description is given of the major modification induced in the pattern of photosynthates accumulation by the delayed senescence behaviour of the maize inbred line Lo87602. The major effects noted are: (1) high water and chlorophyll contents in leaves at physiological maturity, (2) high sucrose content in the stalk during grain filling, (3) busks and cobs with more water, sucrose and proteins, (4) high protein content in the grain. The high level of sucrose in the stalk at physiological maturity protects the plant from stalk rotting organisms.

The delayed senescence phenotype depends on a major dominant gene, the same genetic factor which favours the accumulation of a high level of sucrose in the stalk.
A Dominant Gene for Male Sterility in Wheat
Authors: Bing‐Hua L. , Jing‐Yang D.
Published: April 2006

A dominant gene inducing male sterility in wheat is described. It is located on the short arm of chromosme 4D with a recombination percentage of 31.16 with the centromere. The potential use of this allele in breeding and cytogenetic studies in both tetraploid and hexaploid with is discussed.
Cytogenetics of Cultivated Bougainvilleas. IX. Precocious Centromere Division and Origin of Polyploid Taxa
Authors: Ohri D. , Zadoo S. N.
Published: April 2006

Precocious centromere division at metaphase I leading to diploid gamete formation has been observed in three cultivars. Some of the PMC's are characterized only by rod bivalents whose centromeres split at metaphase I. After passing to respective poles, the already divided centromeres fall apart at telophase I, with the result that each pole has unreduced number of 34 chromosomes. There is no second division and such cells form dyads which give rise to diploid pollen grains. Such unreduced pollen are 100 per cent fertile because of reduced (or no) recombination between hamoeolugous genomes and the presence of two sets of chromosomes. Thus, triploids or even tetraploids can arise when such pollen grains are involved in tertilization with reduced or unreduced egg of other cultivars.
Path‐Coefficient Analysis of Leaf‐Anatomical Characters Affecting Frost Injury in Potato
Authors: Tiwari S. P. , Sukumaran N. P. , Khushu C. L.
Published: April 2006

Correlation and path‐coefficient analysis for leaf‐anatomical characters affecting frost injury was carried out in twenty eight varieties and accessions belonging to several wild and cultivated tuber‐bearing species of Solanum in order to identify selection criteria in breeding for frost resistance in potato Palisade thickness and palisade proportion showed a significant negative correlation with frost injury Path‐coefficient analysis revealed that palisade thickness had the highest direct negative effect on frost injury whereas leaf thickness, not conforming to its behaviour as found in simple correlation analysis, emerged ax the next highest factor to have direct positive effect on frost injury. Direct and indirect effects of these factors on frost injury vis a vis their interdependence were found to be in support ot the ‘palisade thickness method’ for screening frost resistant genotypes in potato breeding programmes.
Genes for Resistance to Yellow Rust in Seedlings of Wheat Cultivars from Pakistan Tested with British Isolates of Puccinia striiformis
Authors: Perwaiz M. S. , Johnson R.
Published: April 2006

Seedlings of 26 wheat caltivars from Pakistan were tested with 18 British races of P. striiformis. It is postulated that the race‐specific genes Yr6, Yr7, Yr9 and perhaps Yr2 were present among the cultivars, and that there was other resistance not controlled by these genes.
Effect of Selection for Days to Flower in X‐ray Treated Population of Jute (Corchorus capsularis L.)
Authors: Sinhamahapatra S. P. , Rakshit S. C.
Published: April 2006

Dry seeds of an early variety of jute (Fanduk) were X‐irradiated to study the effect of selection for days to flower. Variation was induced in days to flower as evident from the high values of genotypic variances and hen lability estimates in the Mi generation. Asymmetric‐response was realized in the M4 generation following disruptive selection — response being more towards lateness than earliness. However, significant variances for days to flower were present among both early and late selections in M4 generation. While late lines were superior to the mother variety in plant height and fibre vie Id: pi ant, early lines were inferior to the mother variety in these‐traits. Distribution of 15 late lines in fibre yield and plant height classes showed that S lines exceeded the mother variety in fibre yield, plant and 7 of them exceeded it in plant height. In general, gradual shift towards lateness was associated with gradual shift towards greater plant height and fibre yield. Two late lines were very promising and earlier in maturity than the recommended early varieties.
Productivity and Cytogenetic Analysis of an Unbranched Mutant in Hyoscyamus niger L.
Authors: Sharma J. R. , Lal R. K. , Lavania U. C. , Gupta M. M. , Mishra H. O.
Published: April 2006

An unbranched mutant (Ub) with marginal arrangement of large leaves substantially altered floral and reproductive features in H. niger was isolated in M2. It bred true for all mutant characteristics in M2 generation. Appearance of restricted branching (Rb mutant) in some M3 families seems 10 be a transient phase. Erect growth habit Coupled with non‐overlapping leaf‐disposition is useful for high crop density to obtain higher biomass field and, in turn, more crude drug production per unit area. Improvement in alkaloid content is an additional advantage augmenting its economic viability. Seed setting was, however. Poor due to pollen‐polymorphism accruing from desynapsis and lack of organized alignment of chromosomes at Ml and subsequent abnormal disjunction at Al.
Inheritance of White Rust Resistance in Brassica juncea
Authors: Uhukral S. K. , Singh Hari
Published: April 2006

Inheritance of white rust resistance was studied in two crosses between resistant (R) and sensitive (S) types of Brassica juncea, namely EC 12749 ×‘Parkash’ (R × S) and EC 12749 ×‘Varuna’ (R × S) under conditions of normal and late sowing. Analysis of six generations revealed the importance of additive, dominant and epistatic effects. Disease was more prevalent under late sowing due to favourable environment. Reciprocal recurrent selection is advocated for exploiting the additive and non‐additive gene effects for resistance to white rust.
Selection of Head Blight Resistant Wheats Through Improved Seedling Resistance
Authors: Mesterhazy A.
Published: April 2006

In a four years' test (1982—1985) it was shown that there are highly significant differences in resistance to seab and seedling blight in wheat. Using a novel approach, that head blight resistance should be measured on stands free of leaf diseases and with a number of isolates with different pathogenicity in the inoculation tests, the rep‐rod Liability of results increased significantly over the levels so far published. The genotype‐ by‐year and the genotype‐by‐isolate interactions remained low. Beside differences in resistance deviations in tolerance were also detected. The best materials that were selected are near to the better spring wheat resistance sources. A tendency for correlation between seedling and head blight resistance was found and the most resistant genotypes in the seedling stage will, with high probability, yield head blight resistant material.

It thus became possible to include seedling resistance into the breeding program for head blight resistance, Further evidence for there being an identical genetic basis for resistance to F. graminearum and F. culmorum is presented.
Possible New Genes for Resistance to Powdery Mildew, Septoria Glume Blotch and Leaf Rust of Wheat
Authors: Negassa M.
Published: April 2006

An Ethiopian wheat collection consisting of 293 tetraploid and hexaploid entries was investigated for resistance to powdery mildew, Septoria glume blotch, and leaf rust with the aim of finding probable new genes for resistance to these diseases. Seedlings were screened with isolates of these diseases in the greenhouse or growth chamber. The material was also scored for field resistance to powdery mildew after the fifth leaf stale. The diversity of the reaction types to powdery mildew and Septoria glume blotch was estimated by the Shannon‐Weaver diversity index. Thirty‐nine entries (13%) of the collection were resistant to moderately resistant co the mildew isolates, 14S‐77 and 46—77, that had: a combined virulence spectrum effective against nine identified genes for resistance to powdery mildew. One hundred and et till TV‐tour entries (63 %) of the collection showed field resistance to mildew. One hundred and eighty‐one entries (62 %) of the collection were at least moderately resistant in an aggressive isolate of Sartorial nodorum. Resistance to a race of leaf rust was detected in one hundred and sixty‐eight entries or 58.% of the collection. Generally, resistance to these diseases is concentrated in Central and Southern Ethiopia. The different reaction types of the resistant entries to these diseases and the high estimates of diversity for reaction types indicated the presence of many different probable new genes and genetic backgrounds for resistance to these diseases.
‘Florin’: A Doubled Haploid Wheat Variety Developed by the Anther Culture Method
Authors: de Buyser J. , Henry Y. , Lonnet P. , Hertzog R. , Hespel A.
Published: April 2006

The cross from which the doubled haploid wheat variety ‘Florin’ is derived was made in 1978. As early as October 1985, after two years of official tests for registration, ‘Florin’ was licensed. The major advantage of anther culture is the lime saved in comparison with conventional pedigree breeding. Much research remains to be done to understand the anther culture system and to increase the efficiency of producing doubled haploids.
Natural Outcrossing in Rice Bean
Authors: Das N. D. , Dana S.
Published: April 2006

Natural outcrossing in rice bean (Vigna umbellata [Thumb.] Ohwi and Ohashi) was studied in the progenies of recessive plants in F generation of six crosses involving three loci — Ti (seed coat base colour), (seed coat mosaic) and Rr (seedling colour), The estimate of outcrossing (α) varied from 0.27 10 0.81 and the percentage of line showing outcrossing varied from 86.S to 100 and the outcrossing was non random.
Prospects for the Development of Rapeseed (B. napus L.) with Improved Linoleic and Linolenic Acid Content
Authors: Roy N. N. , Tarr A. W.
Published: April 2006

The special aspects of the Western Australian rape‐seed breeding programme for the improvement of C18 fatty acids (FA) have been highlighted. Progress made through the use of ‘Oro’‐mutant and IXLIN (interspecific X derived) as sources of genes fur improved C18 FA is discussed. These two donor lines were crossed or intercrossed with high yielding, disease resistant B. napus lines (summer and winter type) or their early generation progenies from interspecific crosses with B. juncea or B. carinata. Tins provided suitable genetic diversity and favourable agronomic background for the introgression of target genes or gene system for improved C18 fatty acids. Many of the polyenoic lines selected from these crosses have indicated scope for combining high linoleic and low linolenic acid levels, with maintenance of good growths and seed development in plants well adapted to the environment.
Genetic Variation for Regenerative Response in Immature Leaflet Cultures of the Cultivated Peanut, Arachis hypogaea*
Authors: Seitz M. H. , Stalker H. T. , Green C. C.
Published: April 2006

Forty‐seven genotypes of the cultivated peanut, Arachis hypogaea L., were screened for regenerative responses of immature leaflet cultures on two media varying in the auxin: cytokinin ratio. Statistical analysis revealed significant media and genotype differences for rhizogenesis plus media differences for callus proliferation but no differences for shoot formation. When genotypes were categorized according to botanical types, differences between subspecies were observed for rhizogenesis. Cultivars of the Virginia botanical type (subspecies hypogaea) were significantly different from either the Valencia or Spanish botanical types (both subspecies fastigiata). Overall, rhizogenesis varied from 0 to 70% among all genotypes. Shoot production was low (30%) while callus proliferation was extremely high (70%).
Identification of Wheat Powdery Mildew Resistance Genes by Analysing Host‐Pathogen Interactions
Authors: Heun M. , Fischbeck G.
Published: April 2006

Fifty‐nine winter wheat cultivars and thirteen lines possessing known powdery mildew resistance genes were inoculated with eleven different isolates. By comparing their resistance patterns the responsible major resistance genes of the above‐mentioned cultivars have been determined. The so‐called “Blaukorn” resistance is conditioned by gent Pm4b. The resistance patterns of Ml‐i and Pm5 being similar, the relationship between them has to be analysed by segregating populations.
Selection for Seed Yield in Lolium perenne L.*
Authors: Bugge Gisela
Published: April 2006

Components of seed yield were estimated for each set of 100 plants derived from six varieties of Lolium perenne. Significant differences between the varieties were found for all components of seed yield, but the range was broader within each variety. An indirect selection of seed yield using the character seeds per spike produced a selection response similar to that obtained by direct selection on high seed yield per plant. A direct and indirect selection of characters estimated in small, drilled plots of topcross off‐springs (F1) was less successful than the selection based on the single plants. Spearman rank correlation coefficients between the single plants and their offsprings did not show significant agreement for seed yield. But altogether the results indicated that the increase of seed yield/area was about 6 % when 10 % of the best plants were selected.
Studies on Pigmentation of Fruits in Derivatives of Crosses between Cucurbita maxima Duch. ×C. moschata Poir.
Authors: Shifriss C.
Published: April 2006

Precocious fruit pigmentation was found to be recessive in Cucurbita maxima. When precocious C. maxima cultivars were crossed with C. moschata and C. equadorensis, the trait was found to be dominant. Following the introduction of precocious pigmentation into C. moschatta cv. ‘Waltham Butternut’, the character was found to be recessive. In addition, foliage yellowing, spotting and leaf variegation were associated with the character.

At fruit maturity two new fruit colors were obtained; orange and green, vs the typical cream color of the cv. ‘Waltham Butternut’. It is suggested that at least two complementary genes from both parental species control orange fruit color, and a’ single gene is responsible for mature green pigmentation. Improvement of C. moschata cultivars is aimed at by assembling the beneficial effects of the various characters.
Intersubgeneric Crossability in the Genus Glycine Willd.
Authors: Singh R. J. , Hymowitz T.
Published: April 2006

In intersubgeneric crosses between wild perennial Glycine species of submenus Glycine and soybeans, Glycine max (L.) Merr., of subgenus Soja, all the putative hybrid pods aborted from 9 to 30 days after pollination (DAP). Spraying of 70 ppm gibberellic acid on hybridized gynoecia facilitated pod retention. Fluorescence microscopy revealed normal pollen germination and pollen tube growth in all the intersubgeneric crosses except in the G. cyrtoloba × G. max cross.
Epistasis in Maize (Zea mays L.) III. Comparison of Single and Three‐Way Crosses for Forage Traits
Authors: Melchinger A. E. , Geiger H. H. , Seitz G. , Schmidt G. A.
Published: April 2006

The importance of epistasis for forage performance and quality traits was studied in early maturing European maize (Zea mays L.) breeding materials. Sixty‐six three‐way crosses (3W), 33 of the flint x (dent · dent) and 33 of the dem × (flint · flint) type, were compared with the mean of their respective non‐parental single crosses () using data obtained in six environments. For each of the 11 traits examined, at least 6 out of the 66 three‐way crosses displayed significant (P < 0.05) epistatic deviations, calculated as – 3W. Averaged over crosses and environments, epistatic deviations were highly significant (P < 0,31] for 8 trails, but of minor importance except for grain yield. In general, the variance of epistatie deviations was appreciably smaller than the variance of genotype × environment interactions. Highly significant correlations occurred among epistatie deviations for silking date, dry matter content of ear, and dry matter yield of grain and stover. The reliability of predicting the performance of three‐way crosses from 2W as opposed to assessing them directly was investigated as a function of the number of test environments. Disturbing e fleets of epistasis on prediction only became important under intense testing (> 3 or 4 environments), With fewer test environments, both procedures were almost equivalent, due to a smaller influence of genotype × environment interaction on the values, Epistasis is concluded to be of minor importance with regard to the optimum type of hybrid for forage use.
A Major Gene for Resistance to Anthracnose Leaf Blight in Maize
Authors: Badu‐Apraku B. , Gracen V. E. , Bergstrom G. C.
Published: April 2006

The inheritance of the reaction of maize (Zea mays L.) to anthracnose leaf blight caused by Colletotrichum graminicola was studied in eight generations derived from a cross between a hypersensitively resistant inbred. LB–58, and a susceptible inbred, A632. The generations consisted of the two parents, F1, F2 backcrosses and the backcrosses‐selfed, Chisquare analysis of the data for individual locations as well as across locations indicated that resistance at both the seedling and mature plant stages of development is conditioned by a single dominant gene, designated CgL. A study of the reactions of LB‐58 in several hybrid combinations indicated that resistance was expressed in ail cast‐s even though the expression of CgL gene was modified somewhat in different hybrid combinations.
Selection of Diploid Nematode‐Resistant Sugar Beet from Monosomic Addition Lines
Authors: Jung C. , Wricke G.
Published: April 2006

Monosomic sugar beet/wild beet addition lines (2n = 19) with full resistance against the beet cyst nematode have been characterized in different ways. Within the B. procumbens and B. webbiana addition lines three groups could be classified according to their isozymes pattern, growth habit, transmission rate, and resistance level. It is assumed that B. procumbens and B. webbiana each possess three different chromosomes which carry genes for nematode resistance. In the offspring of the addition lines diploid translocation types appear at very low frequencies, Isozyme pattern or growth type of the resistant plants were used for selecting diploid types in the offspring of monosomic addition lines. Effective selection could be made in progenies of susceptible sugar beets pollinated by addition lines because the pollen transmission of the alien chromosome is very low. Using these methods 7 nematode‐resistant sugar beet lines could be selected. The transmission rates of the resistance gene ranged from 70.6% to 100%. Threw heterozygous progenies showed a 1:1 segregation indicating monogenic dominant inheritance of resistance. The level of resistance was as high as in the addition lines.
Nondestructive and Rapid Leaf Measurements for Use as Selection Criteria in Vicia faba L.*
Authors: Ricciardi L. , Pace C. De , Filippetti A.
Published: April 2006

Four Vicia faba F2 populations were studied to identify leaf characters that can be scored precisely at low cost and cause minimal disturbance to the plant during the leaf scoring in a selection program to change leaf canopy architecture. From correlation and biometrical analyses, involving eight measurements of leaflet and rachis characters, it was ascertained that the area index (length × width) of the first basal leaflet and the total rachis length of the leaf on the 5th flowering node, were the most informative, rapidly, and nondestructively determined leaf characters serving‐ the above‐men tinned requirements.
Genetic Variability among Nut Yield Traits and Selection in Cashew (Anacardium occidentale L.)
Authors: Faluyi M. A.
Published: April 2006

A study was conducted on eight nut traits within three generically broad‐based populations of cashew to determine the yield attributes that could be employee for selection of nigh yielding and good quality cashew materials. The analyses indicated appreciable valuation for the genotypes studied ‐with nut count and its weight per tree contributing most towards the total divergence. The heritability and the genetic advance estimates showed clearly that total nut yield u eight per tree can be improved through individual tree selection. Also the computed correlation coefficient for the traits indicated that selections based on nut weight per tree would be effective as a selection criterion for both quantitative and qualitative yield characters. Kernel and shell weights, the two main economic components of cashew nut. were found to be closely correlated with an approximate ratio 1:2.
The Influence of Combined Treatment of Fast Neutrons and NEU on the Mutation Spectrum in Peas
Authors: Swiecicki W. K.
Published: April 2006

Investigations were carried out on mutation induction in peas by using fast neutrons (Nf), N‐nitroso‐N‐ethylurea (NEU), And a combined treatment of both agents. In total, 1314 mutants were isolated representing a wide mutation spectrum. In comparison 10 the single mutagens the combined treatment acted as a different, third if it were mutagen, being the most effective and producing the highest number and the widest spectrum of induced mutants. Nf was clearly least effective with regard to the number of mutants, but it did induce the widest mutation spectrum per 100 induced mutants. Moreover, some mutation types appeared only with a given mutagen and in a given genotype. The greatest number of such specific mutants was selected in the line Wt 3527 after the combined treatment; among them some new genes in Pisum were found, e.g. orange pod, necrosis, arthritic or determinate growth.
Further Studies on Phylogenetic Relationships in Secale: On the Origin of its Species
Authors: Vences F. J. , Vaquero F. , Garcia P. , de la Vega M. Perez
Published: April 2006

Fourteen isozymatk loci have been analyzed in 23 samples of populations belonging to genus Secale by starch gel electrophoresis. The allelic frequencies for these loci have also been estimated and used in calculating genetic identity values between populations. Isozymatic data agree with the hypothesis that there are four species in the genus Secale: S. cereale, S. montanum, S. silvestre, and S. vavilovii. The characteristics of growth and outbreeding habits, and the isozymatic variability along with the previously known cytogenetic data, maintain S. montanum as the probable ancestor of the other three species: two are self‐pollinated and monomorphic for isozymes (S. silvestre and S. vavilovii) and the other is open‐pollinated and variable (S. cereale) and dearly distinguishable by its genetic variability from the other two. Finally, from isozymatic data it is not possible to distinguish between populations belonging to S. montanum and populations, belonging to. S. cereale.
Outcrossing Rates in Autumn and Spring‐Sown Barley
Authors: Doll H.
Published: April 2006

Natural outcrossing is a potential cause of the admixtures which are often observed, especially in winter barley. Outcrossing was studied in yield trials with hap laid ‐derived homozygous offspring, lines from tour crosses between winter and spring barley varieties. Outcrosses were recognised by heterozygosity in storage protein loci Hor1 and Hor2 as revealed by electrophoresis. Outcrossing, was, on average, about 5% in lines sown in the autumn and less than 0.5% after spring sowing. Autumn‐sown lines from one of the four crosses studied had about 10% outcrosses.
Nematode Resistance Derived from Wild Beet and its Meiotic Stability in Sugar Beet
Authors: Brandes Andrea , Jungand C. , Wricke G.
Published: April 2006

Three different karyotypes of sugar beet with resistance against the beet cyst nematode (Heterodera schachtii) have been investigated. These comprised monosomic addition lines (2n = 19) with one complete chromosome from B. patellarris or B. procumbens, one line with a chromosomal fragment added to the normal sugar beet chromosome complement (2n =18 + fragment) and one diploid line (2n = 18). The fragment originated from a B. procumbens chromosome since during meiosis it formed a univalem. It carries the gene for nematode resistance. Meiotic disturbances like univalems. laggards, anaphase I bridges, fragments and micronuclei were observed in all resistant genotypes. These may result in an exclusion of the chromosome fragment carrying the resistance from the rest of the genome. In the diploid resistant line, a chromosome with a translocation could be distinguished from the other B. vulgaris chromosomes. Meiotic irregularities also appeared in diploid resistant types and are one main reason for low transmission of the resistance. Tin‐relationship between meiotic stability and the transmission rate of the resistance gene is discussed.
Seed Color Inheritance in Brassica carinata A. Braun, Cultivar S‐67
Authors: Getinet A. , Rakow G. , Downey R. K.
Published: April 2006

The inheritance of seed color was studied in the brown seeded Ethiopian mustard (Brassica carinata A. Braun), cultivar S‐67. Seed color was controlled by a single gene pair. The heterozygous condition resulted in light yellow‐brown set‐d indicating incomplete dominance [semidominance] of brown over yellow. The homozygous recessive condition resulted in yellow seed. The significance of these findings in relation to seed color inheritance in other Brassica species is discussed.
Identification of Maintainer Genes in Brassica napus L. for the Male‐Sterility‐Inducing Cytoplasm of Diplotaxis muralis L.
Authors: Pellan‐Delourme R. , Renard M.
Published: April 2006

Male fertility of F1 interspecific hybrid plants derived from crosses between cytoplasmic male‐sterile Brassica campestris in Diplotaxis muralis cytoplasm and 147 B. napus cultivars was Investigated. F1, plants obtained, from crosses with the B. napus cultivars‘Mangum’and‘Hinchu’were male‐sterile while F1 plants derived from all other crosses were male‐fertile. This indicated that these two cultivars carried maintainer genes far the male‐sterility‐inducing cytoplasm of D. muralis. Sterility was stable In plants derived from backcrosses of male‐sterile F; plants with‘Mangun and‘Hinchu’but the seed set of backcross plants was low. With restorer genes readily available in B. napus, these findings could lead to the development of a new cytoplasmic male sterility system for the breeding of B. napus hybrid cultivars.
Joint Selection for High Yield and Low Sensitivity in Winter Wheat (Triticum aestivum L.)
Authors: Hughes W. G. , Westcott B. , Sharp P. L.
Published: April 2006

Early generation yield trials of families from a set of winter wheat crosses were grown in three contrasting environments chosen to represent differences in two important macro‐environmental variables affecting the wheat, crop in Eastern England. Joint selection for high yield and low sensitivity to these macro‐environmental variables over two seasons using the procedure of Brumpton et al. (1977) resulted in a group of genotypes which exhibited a much wider yield range than would have resulted from selecting for yield in each ‐environment separately. In spite of this, the top performing lines an yield trials grown in each of the environments during the next season exhibited good yield and stability over all three environments, demonstrating the feasibility of such a method for winter wheat breeding.
Response to Selection for Resistance to Macrophomina and Xanthomonas and its Association with Seed Colour in Cowpea*
Authors: Higuera A. , Murty B. R.
Published: April 2006

In cowpea, black seeded types are supposedly resistant to Macrophomina. A study was undertaken to verify the association of seed colour with resistance to Macrophomina and Xanthomonas and to examine the response over three cycles of selection for such resistance along with seed yield, determinate habit and synchronous flowering in five black‐and three white‐seeded cowpea varieties. Selection was done between and within progenies under heavy natural incidence of both pathogens supplemented by artificial inoculation of Macrophomina using the toothpick method at flower primordial stage. Among 414 single plant progenies in the first cycle all 193 white‐seeded progenies from three different varieties were highly susceptible to both pathogens, with considerable variation among the black‐seeded ones. All the black‐ and white‐seeded progenies derived from the same variety‘Floricream’were highly susceptible. Multivariate analysis for five characters in the ten best progenies after two selection cycles revealed significant genetic diversity between the progenies. Selection was successful with the isolation of three productive progenies resistant: to both diseases. The results indicated that seed colour had no influence on resistance m this material and that simultaneous improvement of seed yield, plant type and disease resistance could be achieved.
Cytogenetic Studies of Crosses between Lolium multiflorum Lam. and Festuca arundinacea Schreb. III. The Generations C1, C2 and C3
Authors: Kleijer G.
Published: April 2006

Meiotic observations of 56‐chromosome plants of the C1, C2 and C3 generations of the amphidiploid Lolium multiflorum × Festuca arundinacea showed that most of the chromosomes paired as bivalents. However, uni‐ and multivalents were frequently observed. No difference in meiotic regularity and stability could be detected between the different generations. The average chromosome number and; the percentage of 56‐chromosome plants decreased with increasing generations. The direct use of the 56‐chromosome amphidiploids of L. multiflorum and F. arundinacea in a breeding programme appears to be quite difficult, but these plants can be used in a backcross programme with Lolium and Festuca.
Regeneration of Pea (Pisum sativum L.) Plantlets by in vitro Culture of Immature Embryos
Authors: Natali L. , Cavallini A.
Published: April 2006

Plant regeneration was achieved from immature embryo‐derived, calli of Pisum sativum. Embryo axes were separated from cotyledons and cultured on different media containing BAP and NAA until plantlet regeneration. Rooting of the plantlets was obtained on MS medium supplemented with 2 mg/1 IBA. Frequency of regeneration was shown to be under the influence of the genotype. Histological preparations showed de novo origin of the shoots via organogenesis. Out of 2C regenerated plantlets, 11 were diploids (2n = 14) arid 9 aneusomatic (chromosomal mosaics) with chromosome numbers ranging from 12 to 16.
An Evaluation of Hordeum vulgare L. ×Psathyrostachys fragilis (Boiss.) Nevski Crosses for Doubled Haploid Barley Production
Authors: Pickering R. A.
Published: April 2006

Investigations were carried out to assess the suitability of the intergeneric cross Hordeum vulgare×Psathyrostachys fragilis for haploid barley production. H. vulgare cvs. ‘Emir’ and ‘Vada’ were each pollinated with P. fragilis P.I. 343192 and plants regenerated from embryos cultured on a modified B5 medium. Seed sets on ‘Vada’ were significantly lower than on ‘Emir’, and all the planes from ‘Vada’×P. fragile remained hybrid. Several of these flowered but there was little pairing between the parental chromosomes. Most of the plants from ‘Emir’×P. fragilis died, as seedlings but 3 plants developed into haploid barley. Because of the practical limitations of pollen availability from P. fragilis and the inconsistencies in haploid plant formation, it is unlikely that the cross will prove as valuable as that between H. vulgare×H. bulbosum for a doubled haploid barley programme.
The Response of Anther Culture in a Genetically Wide Material of Winter Wheat (Triticum aestivum L.)
Authors: Andersen S. B. , Due I. K. , Olesen A.
Published: April 2006

In a screening experiment with 215 different winter cultivars of Triticum aestivum L. for response in anther culture, pollen embryos or callus were obtained from 200 different cultivars and green plants from 93 different cultivars. On average, from the whole material, 1.3 green plants were obtained per 100 anthers cultured. Variance components estimated from replicates with selected parts of the plant material indicated that for the formation of pollen embryos from anthers, interactions between genotypes and replications were dominating, accounting for 45 to 50 per cent of the variation. Main effects from genotypes were less prominent, accounting for 25 to 30 per cent of the variation, and the replications showed relatively little effect, accounting, for about 4 to 12 per cent of total variation. Regeneration of plants from pollen embryos or callus was not significantly influenced by either genotype or replicates. The frequencies of plants regenerated being green, however, were influenced from both genotype and environments contributing 42.5 and 34.9 per cent of the total variation respectively, while only minor interactions between genotype and environments were indicated for this character.
Doubled Haploids of Cocoa (Theobroma cacao L.) 2. Observations of Monogenic and Polygenic Characters
Authors: Lanaud C.
Published: April 2006

The expression of monogenic and polygenic characters has been studied in families of spontaneous haploids of cocoa which nave been doubled with colchicine. Segregation of six enzyme markers, heterozygous in the various parent clones, has been analysed in the doubled haploids for alcohol dehydrogsnase (ADH), malate dehydrogenase locus B (MDH‐B), isocitrate dehydrogenase (IDH), acid phosphatase (ACP), phosphoglucomutase (PGM) and phosphoglucose isomerase (PGI). Nine of the eleven families showed a Mendelian‐type segregation, two presented distortions but all alleles were found in the haploid progenies.

Polygenic characters were expressed with great variability: A few DHs showed similar or even higher values than their parents for individual characters, but the majority were lower, and large depressions could be seen for the group of characters studied.

These results have consequences for the use of doubled haploids of cocoa which must both give a sure production of hybrid seeds and be good progenitors; no prediction of their value as progenitors seems possible after observation of their own characteristics and the only selection made from these plants will be a propos their characters directly involved in seed production. These selected doubled haploids will subsequently have to be tested as progenitors.
Cytological Study of Callus and Regenerated Plants of Sunflower (Helianthus annuus L.)
Authors: Cavallini A. , Lupi M. C.
Published: April 2006

In vitro culture of shoot apical meristems of Helianthus annuus was studied to determine the cytological condition of calli and regenerated shoots. A broad chromosome mosaicism (aneusomary) in bath callus and regenerated shoots was found, reflecting the cytological conditions of the explain. During in vitro plant development, a diplontic selection took place that was more rapid when very precocious in vitro flowering occurred.
Multiple Endopeptidasen als biochemische Marker für die Resistenz von Winterweizen gegenüber Pseudocercosporella herpotrichoides (Fron) Deighton
Authors: Vahl U. , Müller G. , Thiele A. , Thiele M.
Published: April 2006

Multiple endopeptidases as biochemical marker for resistance of winter wheat to Pseudocercosporella herpotnchoides (Fron) Deighton. Electrophoretic patterns of primary leaf endopeptidases in breeding material derived from crosses between different winter wheat genotypes and amphidiploids (Triticum turgidum×Aegilops ventricosa) were compared with those of cultivars susceptible to Pseudocercosporella herpotrichoides. The results indicate that the multiple endopeptidase EP‐1 coded by Wheat chromosome 7 D is absent in the international known lines ‘VPM 1’ and ‘Roazon’ and in all 24 winter wheat selections with increased resistance to P. herpotrichoides.

A close relationship between the absence of EP‐1 and the introduction of Aegilops ventricosa resistance is assumed. The use of this biochemical marker in wheat breeding is proposed.
The Grain Quality of Landraces of Wheat as Compared with Modern Cultivars
Authors: Blum A. , Sinmena Bebi , Golan G. , Mayer J.
Published: April 2006

Landraces of tetraploid and hexaploid wheat from the Northern Negev in Israel were evaluated over two years for their grain quality attributes. Twenty‐one populations of tetraploid wheat (Triticum durum, represented by 56 accessions) and 8 populations of hexaploid wheat (T. aestivum and T. compactum, represented by 13 accessions) were compared with 3 and 4 modern improved Israeli cultivars of tetraploid and hexaploid reheat, respectively. This comparison allowed to estimate the progress made in the improvement of gram quality m present‐day cultivars.

Except for grain protein content in the hexaploids, significant variation was revealed among landraces in kernel weight, protein content (tetraploids), sedimentation, mixograph score and carotin content. The best modern cultivars were comparable to the best landraces in kernel weight and carotin content (tetraploids), indicating that modern wheat breeding maximized kernel weight and carotin content, as compared with the tested landraces. Gram protein content and/or quality was not maximized in modern cultivars and its improvement was deemed possible by introgression from the best landraces in this respect.
Effects of Competition upon the Productivity of White Clover‐Perennial Ryegrass Mixtures. Genetic Analysis
Authors: Hill J. , Michaelson‐Yeates T. P. T.
Published: April 2006

A diallel cross amongst four contrasting white clover varieties was used to provide genetic information on those characters which affect the productivity of white clover‐perennial ryegrass mixtures when grown under a cutting‐only management regime. Generally speaking those characters recorded on the clover families and in mixtures exhibited highly significant additive and non‐ad dative genetic effects, though for1 sortie characters the latter could not be ascribed solely to dominance effects. For two of the clover characters, stolon and leaf number, the genetic picture was radically altered in mixtures by the effects of inter‐specific competition Pseudo‐genetic effects were also detected for the grass characters, bur it was suggested that the two ryegrass varieties used here were exhibiting phenotypic plasticity. As a group the four intra‐varietal crosses performed significantly better than the six intra‐varietal crosses for all clover and mixture characters. Only one of the inter‐varietal crosses had significantly positive specific combining ability effects for most characters and that was between the two long established varieties ‘S. 184’ and ‘S. 100’. The implications of these results for the breeding of white clover varieties for use in mixtures are briefly discussed.
Genetical Studies of Resistance of Powdery Mildew in Barley Lines Derived from Hordeum spontaneum Collected from Israel
Authors: Jahoor A. , Fischbeck G.
Published: April 2006

Genetical studies on mildew resistance were carried out with Hordem spontaneum derived lines. A total of 28 lines (66 %) showed monofactorial segregation for mildew resistance, For 14 lines, a bifactorial mode of inheritance was found. In total fifty six mildew resistance genes take part in the inheritance of mildew resistance of the H. spontaneum derived lines, while the presence of known genes for mildew resistance (i.e, Ml‐a.9 and Ml‐p) was established only in two cases. Independent segregation from the Ml‐a locus was found in 10 mbnofaetorial segregating lines, The genes conditioning mildew resistance in barley lines derived from the accessions 1B‐54B, RS 170‐47, RS 20‐1. 1B‐86B, RS 145‐39 and 1B–152B of H. spontaneum were closely linked or alleles to the Ml‐a locus, but shown to be different from 15 previously identified Ml‐a alleles. It is suggested that these genes should be designated Ml‐a16, Ml‐18, Ml‐19 Ml‐20 and Ml‐a21 respectively. No recombinants were found in test crosses when both parents carried genes/alleles of the Ml‐a locus. In addition, polymorphism has been observed also for the Ml‐a locus. In 4 lines mildew resistance was conditioned by two dominant complementary genes. For one of the 2 genes, conditioning mildew resistance of line RS 42‐8 × OrioL a new locus was found located near the centromere of the long arm of chromosome 5, and should be designated Ml‐i The potential use of H. spontaneum genes for mildew resistance in barley breeding is discussed.
Breeding Progress in Grain Yield and Selected Agronomic Characters of Winter Barley (Hordeum vulgare L.) over the Last Quarter of a Century
Authors: Martintello P. , Delocu G. , Boggini G. , Odoardi M. , Stanca A. M.
Published: April 2006

This study gives estimates of breeding progress achieved in winter barley (Hordeum vulgare L.) since the 1960′s in grain yield and the change in several morphological traits for seventeen historically important cultivars: 12 six‐rowed and 5 two‐rowed, grouped into four epochs according to the period of major commercialization in Italy. All genotypes were evaluated across a range of soil fertility and climatic environments.

The modern six‐rowed cultivars have shown a consistent increase in tillers/m2 and seeds/spike (16 and 28 %, respectively) over the local populations. In the modern two‐rowed cultivar ‘Igri’ the increase in tillers/m2 and seed weight were, respectively, 20 and 14 % snd seeds/spike decreased by 20 % over the local populations. The modern six‐rowed and two‐rowed cultivars have less lodging, are earlier and shorter than the old varieties and local populations. In the last quarter of a century, the breeding progress for gram yield has been increased by 52 and 74 kg/ ha/year or 0.75 and 1.1 % per year respectively, for six‐rowed and two‐rowed genotypes: while the gain in biomass yield in the same period was not uniform for six‐rowed cuitivars and increased by 64 kg/ha/ year or 0.46 % in two‐rowed cultivars. The grain yield improvement in the modern six‐rowed and two‐rowed cultivars is the result of a better partitioning of the photosynthetic products into the grain.
Determination of Ploidy of Single Plants and Plant Populations by Flow Cytometry
Authors: DeLaat A. M. M. , Gohde W. , Vogelzakg M. J. D. C.
Published: April 2006

An efficient method for the determination of the ploidy level is described, based on a measurement of the DNA content of interphase nuclei by flow cytometry. Both individual plants as well as plant populations can be used to obtain the desired DNA‐histograms Compared to conventional chromosome counting flow cytometry turned out to be highly competitive in terms of simplicity, accuracy, and costs.
Flower‐Colour Polymorphism in Lupinus pilosus in Israel
Authors: Pazy B.
Published: April 2006

Four rare flower‐colour mutants were detected in natural populations of Lupinus pilosus in Israel. The breeding systems and genetic bases of three oif them were examined.

Mutants were tagged in wild populations and seed obtained upon open pollination was collected and grown in a, net house which was insect‐proof. Mutant progenies were used in crosses with each other and with wild‐type plants.

Our results indicate the possibility that all three mutants are simple Mendelian recessives to the wild‐type deep‐violet colour and that in L. pilosus this colour is not monogenic but determined by at least two loci.

All these mutants show a high degree of selling when open‐pollinated in nature.
Stomatal Density and Length for Breeding of Evergreen Azaleas (Rhododendron simsii Planch.)
Authors: Heursel J. , Ceulemans R. , Ibrahim N.
Published: April 2006

The hentability of stomatal density and stomatal length has been studied for four evergreen azalea (Rhododendron simsii Planch.) cultivars with the aim to evaluate the possibilities of stomatal characteristics of parental plants for increasing the crown diameter – hence yield – of the offspring., A nearly complete diallel cross with reciprocals has been carried out with the four parental cultivars. Highly significant general combining ability (GCA) values of the parents were found for stomatal length and density, but not for the crown diameter. GCA values of crown diameters did not correspond with GCA values of either stomatal length or stomatal density. Therefore it was concluded that utilizing stomatal characteristics as a selection tool for an increased crown diameter (yield) in azalea., may not be feasible.

Differences in crown diameter could not be explained from correlations with either stomatal density or stomatal length.