bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Isozyme‐Marked Segments from Wild Barley (Hordeum spontaneum) in Barley Breeding
Authors: Brown A. H. D. , Munday J. , Oram R. N.
Published: April 2006

Fifty‐six accessions of Hordeum spontaneum from various Israeli habitats were hybridized with, and their progeny backcrossed three times to H. vulgare cv. ‘Clipper’. Selected chromosome segments marked by one of 24 isozyme loci were transferred to form 84 backcross lines which were nearly isogenic with ‘Clipper’. Each line was made homozygous for a single isozyme‐marked segment. These lines were evaluated in preliminary and advanced field trials. The yield, malt extract percentage and grain size of the lines approached or equalled, and sometimes significantly surpassed, that of ‘Clipper’ and more recent commercial cultivars. Three isozyme‐marked segments were combined in pairs and the three resultant doubly‐marked lines were compared with the reconstituted parental, singly‐marked lines and with the ‘Clipper’ recombinant from the same F2‐array. The additive effects of single segments on yield or gram size were not significant, whereas half of the six interactions were significant, but in the unfavorable direction. It was concluded that near‐isogenic lines can identify segments of wild barley germplasm that are useful for improving yield, but that pairs of these from different habitats may interact unfavourably.
Selection in Faba Bean for Tolerance to Broomrape, Orobanche crenata Forsk.
Authors: Radwan M. S. , Abdalla M. M. F. , Fischbeck G. , Metwally A. A. , Darwish D. S.
Published: April 2006

Six populations of faba bean (Vicia faba L.) were developed through various selection schemes to examine the influence of selection In improving tolerance to Orobanche crenata (Forsk.) in local faba bean stocks. All populations trace their origin to 209 farmers’ seed lots that were collected from Egypt. The entries of each population were grown during the 1982/1983 season in the Orobanche nursery located at Giza in Egypt. Comparison among means of the selected, populations showed that more progress in improving Orobanche tolerance could be achieved from combined selection between and within lots. Between‐lots selection was less efficient than single‐plant selection. Results, of this study show that considerable progress could be achieved from selection for Orobanche tolerance in local faba bean germplasm. There was sufficient residual genetic variation in the selected populations to expect substantial progress from further selection for most tolerance traits.
Effective Transfer of Cytoplasmic Male Sterility from Radish (Raphanus sativus L.) to Rape (Brassiest napus L.)1)
Authors: Paulmann W. , Röbbelen G.
Published: April 2006

One of the CMS systems presently investigated by rape breeders is the alloplasmic system derived from a male sterile radish and transferred to rape. However, these male sterile lines of rape with the radish cytoplasm exhibit yellow leaf colour at low temperatures. Moreover, no restorer genes for this system are known to occur in rape. The present investigation was, therefore, directed to the formation of new cross combinations between radish and rape in order to eliminate the above mentioned problems by additional transfer of corresponding radish genes into the rape recipient.

After the initial intergeneric crosses, male sterile hybrids were received by in‐vitro embryo culture and colchicine treatment. These hybrids were not backcrossed to rape as usual, but to one of the monogenomic ancestral species of rape, in order to increase the probability of allosyndesis between radish and rape chromosomes. After subsequent back‐crossing with rape, the desired male sterile plants with 38 chromosomes were recorded, forming normal green leaves even at low temperatures.

In a parallel backcross programme, restorer genes from male fertile radish were also transferred into rape by the same backcrossing procedure. The first alloplasmic male fertile plants were found in the BC: generation. They were cross pollinated to male sterile plants to prove their potential of fertility restoration.
Chromosomal Stability in the Backcross Progenies of Pentaploid Hybrids between Avena sativa L. and A. maroccana Gdgr.
Authors: Zadoo S. N. , Choubey R. N. , Gupta S. K. , Premachandran M. N.
Published: April 2006

In a backcrossing programme to transfer desirable characters from wild Avena maroccana Gdgr. to cultivated oats, A. sativa L., meiotically stable plants in BC1F3 and BC2F2 progenies were isolated. The recovery of stable genotypes with 2n = 6×= 42 chromosomes indicated that two backcrosses are enough for such a programme. The cytological observations in various backcross generations are presented and discussed.
An Improved In Vitro Culture Procedure for Embryoids Derived from Isolated Microspores of Rape (Brassica napus L.)
Authors: Mathias Regine
Published: April 2006

An in vitro culture technique was developed that allowed the effective culturing of embryos derived from isolated microspores of rape (Brassica napus L.). The method consists of the use of microspores from buds at well‐defined development stages, the use of a double‐layer culture medium containing activated charcoal and the incubation of embryoids in culture flasks on a shaker. These culture modifications, together with the growing of embryoids on solid medium with high agar concentration, resulted in a high frequency of embryoids growing directly into plants.
The Effect of Isozyme Selection on Yield and Flowering Time in Lolium perenne
Authors: Hayward M. D. , McAdam N. J.
Published: April 2006

A series of lines, differing in isozyme genotype, were constructed by selection from within three cultivars of Lolium perenne. Field assessment of the progeny of these selected line? revealed variation in yield and timing of inflorescence emergence. This variation between lines from within a cultivar could not be accounted for by the differing levels of homozygosity attained. In some instances differences in yield were associated with homozygosity for specific alleles at the PGI/2 locus, background genotype was however, of major importance. The variation identified could be attributable to founder effects or possible linkage of quantitative trail loci to the PGI/2 locus.
Location of a Gene for Resistance to Eyespot (Pseudocercosparella herpotrichoides) on Chromosome 7D of Bread Wheat
Authors: Worland A. J. , Law C. N. , Hollins T. W. , Koebner R. M. D. , Giura A.
Published: April 2006

Chromosome 7D of the wheat line VPM1 derived from a cross of Aegilops ventricosa with wheat confers resistance to the facultative fungal parasite Pseudocercosporella herpotrichoides. To determine the number of genes responsible fur this resistance, homozygous recombinant lines were developed from an F1 between the wheat variety ‘Hobbit sib’ and a substitution line carrying chromosome 7D of VPM1 in a ‘Hobbit sib’ background.

Resistance to Pseudocercosporella herpotrichoides is shown to be determined by a single gene located distally on the long arm of chromosome 7D. EpD1b, a unique allele of a gene encoding the readily detectable isoenzyme — endopeptidase, maps without recombination to Pch1 suggesting for two separate genes a maximum recombination value of 0.03 (P 0.05). Resistance to Pherpotrichoides could alter‐natively be a product of Ep‐D1b.

Pch1 is also mapped against a gene for adult plant resistance to brown rust (Puccinia recondita), to Rc3 which confers coleoptile colour, and to α‐Amy‐D2, an isozyme that encodes α‐amylase production.
Anther Culture Response in Perennial Ryegrass (Lolium perenne L.)
Authors: Olesen A. , Andersen S. B. , Deu I. K.
Published: April 2006

20 diploid clones from 7 varieties, and 10 tetraploid clones from 3 varieties of Lolium perenne were tested in replicated anther culture experiments. Embryos or calluses, were obtained from all clones, and plants were regenerated from all clones except one. The total yield of plants (albino and green plants) ranged from 0 to 61 plants per 100 cultured anthers among genotypes, and there was a general tendency for tetraploic genotypes to be more responsive. Viable green plants were obtained from 5 diploid and 7 tetraploid clones representing 2 and 3 varieties, respectively. Their origin from reduced pollen was confirmed by a haploid chromosome number in some regenerants and by homozygosity for isozyme loci in spontaneously chromosome doubled plants produced from heterozygous diploid donor plants. A large number of the plants were successfully established in the soil. For most donor genotypes, green plants were rare exceptions, but two diploic clones consistently produced 2.3 and 3.8 green plants per 100 cultured anthers, respectively. Estimates of variance components from replicates with greenhouse and field‐grown donor plants showed that genotypes accounted for about 73 per cent of the total variation in yield of embryos/calluses, while only 14—15 per cent of the total variation was due to replicates. Hence at present, emphasis should be placed on die selection of high‐response genotypes in material of high agronomic potential.
Amino Acid Resources of the Wild Relative of Barley (Hordeum spontaneum) in Israel
Authors: Corke H. , Atsmon D.
Published: April 2006

Measurements were made on amino acid contents in collection of wild barley (Hordeum spontaneum)., grown in pot conditions, and in some Israeli breeding lines and cultivars of Hordeum vulgare. H. spontaneum was low in lysine content and high in prolilne plus glutamic acid compared to H. vulgare. Lysine content was positively correlated, in H. spontaneum, to all other ammo acids except proline and giutamic acid. Inter‐populanon rnean differences for Iv‐saie in H. spontaneum were small and lysine variation was obscured due to variation in protein content.

The use of H. spomancum in breeding high protein. nutritionally improved barley is discussed.
Evaluation of Barley (Hordeum vulgare L.) Landrace Populations Originating from Different Growing Regions in the Near East*
Authors: Weltzien Eva
Published: April 2006

This study characterizes barley (Hordcttm vulgare L.) garmplasm that evolved under continuous cultivation in highly drought‐prone areas of the Near East. Landrace population:) originating from 70 locations in Syria and Jordan were evaluated under field conditions in Tel Hadia, Svria, on the basis of single head‐row progeny performance. Significant genetic variation was found for all traits recorded: seed colour, kernel row number, growth habit, awn barbing, days to heading, culm length, leaf widths, awn length, early growth vigour, lodging score, and mildew resistance.

For most traits, large proportions oi the total variation were tound between head progenies tvhh.in single populations. The qualitative traits, growth haba, seed colour, and awn barbing showed higher variation indices in populations originating from the drier regions ol Syria. Populanons from tbe drier regions; headed slightly earlier, had narrower leaves, longer eulms and tended to be more susceptible to lodging and mildew than populations originating in the higher rainfall areas in Syria.

For all traits, the variance components resulting from differences among populations within a particular growing region, as well as those among populations from differences regions, were highly significant. This indicates that this germplasm stock contains materials with adaptability to these diverse growing conditions. The vanabili:y present within populations, as well 25 that among populations with similar adaptability, is sufficient to allow successful election for productivity‐related traits.
Effectiveness of Ethrel as a Male Gametocide in Pearl Millet and its Influence on Ergot
Authors: Thakur R. P. , Rao V. P.
Published: April 2006

In field and greenhouse experiments Ethrel (2‐chloroethyl phosphonic acid) was tested for its male garnetocidal effects on pearl millet (Pennisetum americanum) and its subsequent effects on ergot development. Application of Ethrel at 2000 ppm at late boot or early protogyny was the most effective for inducing male sterility in the hybrid, EJ 104. Female fertility in a male sterile line, however, was not affected by Ethrel treatment. Ethrel at 2030 ppm applied at ihe late boot stage resulted1 in partial paniele exsertion, and reduced plant height anc. panide length. In vitro Ethrel (2000 ppm) completely inhibned pollen germination but did not affect germination of conidia of Claviceps fusiformis, the causal agent of ergot of pearl millet. Ergot resistance or susceptibility in pearl millet lines was not affected., probably because Ethrel could not induce complete male sterility.
Synthetic Amphiploids of Wheet as a ource of Resistance to Karnal Bunt (Neovossia Indica)
Authors: Multani DilbagS. , Dhaliwal H. S. , Singh Paramjit , Gill Khem S.
Published: April 2006

Twelve synthesized ainphiplonds involving Karnal bunt (Neovossia indica)‐resisiant accessions of Triticum monococum, T. boeoticum and Aegilops sqiwrrosa and susceptible but otherwise well adapted and high yielding T. Durum cultiviars were evaluated for Karnal bunt resisiance under artificial inoculation conditions. All ihe synthetic amphiploids, except DWI. 5031 x T. monocoirtum aniphlploid, were free from Karnal bunt disease indicating that the Karnal bunt resistance or T. motsococcum, T. boeoticMrn and Ae, squarrosa is expressec in the presence of the dnrum complement. The importance and utilization of the amphiploids fox breeding wheat varieties resistant to karnal bunt are discussed.
A Genetic Study of Frost Resistance in Wheat Callus Culture
Authors: Galiba G. , Sutka J.
Published: April 2006

The genetic control of frost resistance was studied in callus cultures using some of the chromosome substitution lines of the variety ‘Cheyenne’ into ‘Chinese Spring’. The survival of the calli derived from immature embryos was studied with triphenyltet‐razolium chloride (TTC) and fluorescein diacetate (5DA) methods after hardening and freezing at a temperatures of ‐7 °C, ‐9 °C, ‐11 °C, ‐13 °C, and –15 °C. The donor ‘Cheyenne’ and the substitution lines 5A and 5D proved to be more frost resistant than the recipient ‘Chinese Spring1. These results are well correlated with the previously published studies when seedlings were tested under controlled conditions. Based on these results the tissue culture technique seems to be useful for testing varieties and lines for different levels of frost resistance and even for mutant selection.
Attempts at Interspecific Hybridization Between Phaseolus vulgaris L. and P. acutifolius A. Gray‐Using Embryo Rescue
Authors: Andradf‐Aguilar J. A. , Jackson M. T.
Published: April 2006

Attempts at interspecific hybridization were made between Phaseolus vulgaris (common bean) and P. acutifolius (tepary bean) using a new pollination method and embryo rescue. The success of interspecific hybridization depended upon the pollination technique, the species and individual genotypes used as female and male parents, and the growth conditions. A high hybridization efficiency was achieved when P. vulgaris was used as female parent. When pods were left on the maternal plants hybrid seeds were obtained which developed into abnormal seedlings. These died at an early stage of growth. Hybrid plants were grown to maturity following embryo rescue, but all showed different developmental abnormalities. The growth of these was determinate like the female parent, P. vulgaris, but leaf morphology was closer to the male parent, P. acutifolius. The utilization of P. acutifolius germplasm for the improvement of common bean remains limited, and further studies are needed to develop promising embryo rescue protocols in such wide crossing programmes.
Somatic Fusion for Breeding of Tetraploid Potatoes
Authors: Deimling S. , Zitzlsperger J. , Wenzel G.
Published: April 2006

From two tetraploid, one Transformed tetraploid, one triploid and 11 dihaploid clones of Solanum tuberosum somatic hybrids were produced by polyethylene glycol mediated somatic fusion. The inter‐dihaploid clones comprised clones of agronomic value, homozygous doubled monohaploids, and in vitro selected clones resistant t0 Fusarium or Phytophthora toxins. Presumptive hybrids were enriched at the callus Stage in vitro by using differentiating media and by growth characteristics; further identification was performed by chromosome counting in vitro shoots and by isozyme analysis of in vitro plants. Final analysis was made from morphological characteristic of plant and tuber phenotypes. From 15 different combinations, 6009 plantlets have been regenerated. From five combinations, 310 reentrants were checked for hybrid nature by morphology and cytology and 88 by peroxidase and esterase isozyme analyses. Amongst these, from two combinations, a total of 17 different hybrids were confirmed by all methods. The procedures described are general enough to allow genome combination of interdihaploids resulting in tetraploids of practical breeding value.
Selection Among Early Generation Peanut Progeny for High and Low Acetylene Reduction and Plant Weight*
Authors: Arrendell Susan , Wynne J. C. , Elkan G. H. , Schneeweis T. J.
Published: April 2006

Selection of superior host genotypes in symbiosis with native Bradyrhizobium has been suggested as a means of increasing nitrogen fixation m peanut (Arachis hypogaea L.). In this study progeny from a cross of cultivars ‘Florigiant’ and ‘Florunner’ inter‐mated twice and selected for yield formed the base population. The 44 selected S2,1 families, ‘Florigiant’ and ‘Florunner’ were evaluated at two sampling dates at each of two locations for traits indicative of nitrogen fixation. Five families were selected in each of four selection groups — high and low acetylene reduction and high and low plant weight. Selected families were retested in a second year and inter‐mated. S2,1 progeny within each selection group were bulked and evaluated for nitrogen‐if using characteristics at two ‘sampling dates at two locations. After intermating, the mean of the high acetylene reduction group, 62.9 μ/moles C2H4/plant hr, was Significantly greater than the mean of the low acetylene reduction group, 52.5 μmoles C2H4/plant/hr, and of the mid‐parent, 55.8 μ/moles C2H4/plant/hr. The associated estimate of realised heritability was 55 ± 08 indicating the response to selection was approximately halt the selection differential and that the distinction between families selected for high and low acetylene redaction was maintained after intermating. However, the realized heritability estimate obtained from the means of the base population and the selected families inbred one generation was .14 ± .06 indicating a failure to maintain distinct groups after one generation of inbreeding. The utility of early generation selection for enhanced N: fixation is, therefore, doubtful in this population.

Selection based on plant weight was not effective. A significant difference in the plant weight means of the high and low plant weight groups was not detected when selections were retested or after inter‐mating. Plant weight was not a useful indirect selection criterion for enhanced N2 fixation.
Genetic Analysis of Developmental Traits in Chickpea
Authors: Kidambi S. P. , Sandhu T. S. , Bhullar B. S.
Published: April 2006

Chickpea (Cicer arietinum L.) is an important legume crop in India. The present study was conducted to investigate the inheritance of several developmental traits in three crosses of chickpea, viz., WFWG III’×‘T20’, ‘T88’×‘Bold Seeded’, and ‘NP34’×‘P1528‐1‐1’, each having seven generations. The seven generations were P1, P2, F1, B1, B2, F2, and F3. The experimental lay‐out was randomized complete block design with three replications. Data were acquired on days to flowering (DF), days to maturity (DM), plant height in cm (PH), number of primary branches (PB), and number of secondary branches (SB). Generation mean analysis was used to estimate the genetic components; narrow sense heritability was estimated using variance components; and correlation analysis to estimate correlation coefficients among different traits. Genetic differences were found in all three crosses for all traits studied. Additive, dominance, and epistatic effects were found for many traits'. Duplicate epistasis was observed for all traits except number of PB. Higher order interactions and/or linkage were detected for DM and SB. For many traits the relative magnitudes of the genetic effects differed among crosses, thus the extrapolation to other crosses may be difficult. The inheritance becomes more complex as the fate of the character is decided at a later stage in the life cycle. Positive heterosis was observed for some traits, but the exploitation of this component may not Feasible since stable male sterile lines are not available. Early maturity and high yield ‘may be selected independently because of the absence of any significant correlation between these two traits.
Stand der Hybridweizenzüchtung in der DDR
Authors: Merfert W. , Schilowa Irina , Faustmann M.
Published: April 2006

Present state of hybrid wheat breeding in the GDR

The possibility of developing economically efficient hybrid wheat is demonstrated by own experimental results. Male sterile analogues, based on T. timopheevi, with a satisfactory level of yield and sufficient sterility were produced. Restores were obtained by combining analogues and use of the pedigree method which resulted in strains with complete restoration and high grain yield. Hybrid seed yields approaching 70% of normal wheat yields were obtained on 1‐ and 3‐m ms strips with a ms: Rf ratio of 1: 1.5—2.5

The yields of the best hybrids in a tweleve‐location trial rose from 98% compared to the standard variety ‘Alcedo’ (5.8t/ha) in 1975—1980 to 109% (7.24t/ha) in 1981—1985. In 10‐ and 30‐ha fields, yields were 122% and 110% of those recorded in the reference variety. Better results are expected form the use of new restorers and genetically divergent ms‐forms and will probably be accomplished through international cooperation.
Single and Multiple Traits Selection in a Segregating Population of Wheat, Triticum aestivum L.
Authors: Mahdy E. E.
Published: April 2006

The breeding materials used in this study were the F3, F4 and F5‐generations of the cross between Giza 158 × Sonora 64 (Triticum aestivum L.). The objective of this study was to compare the relative merits of Smith‐Hazel, desired gain selection indices, independent culling levels and single trait selection in improving grain yield, heading date and several agronomic traits. Highly significant differences among F3 families and a satisfactory genotypic coefficient of variability were obtained for all the traits studied. The genotypic correlations were high between yield and each of spike weight, kernels/spike and spikes; plant, intermediate with 1000 kernel weight and very low with heading date, plant height and spike1 length‐After two cycles of selection, the results of the gains realized indicated that the most effective method for improving yield was the Smith‐Hazel index (SH7) of seven traits followed by the desired gain index of seven traits (DG7), SH5, independent culling levels, DG5 and direct selection (or grain yield/plant. Direct selection for heading date, plant height and spike length was the best method for improving these traits, but undesirable correlated responses in the other traits were obtained.
Identification of the First Rye‐Cytoplasmic Rye‐Wheat‐Addition Using LAP‐Isozymes
Authors: Thiele V. , Buschbeck R. , Seidel A. , Melz G.
Published: April 2006

Rye‐cytoplasmic rye‐wheat‐additions were produced by double backcrossing rye‐cytoplasmic tetraploid triticale with an inbred line of diploid rye cv. ‘Esto’. Addition 6B was identified using LAP‐isozymes.
Synthesis of Alloplasmic Brassica campestris as a New Source of Cytoplasmic Male Sterility
Authors: Prakash Shyam , Chopra V. L.
Published: April 2006

Cytoplasmic male, steriles of Brassica campestris ssp. oleifera var. brown sarson were obtained m BO generation progenies Following the repeated back‐crossing of the synthetic alloploid B. oxyrrhina (2n = 18, OO) ×B. campestris. (2n = 20, AA). Alloplasmic B. campestris plants resemble B. campestris in morphology and growth pattern and do not exhibit any trait of B. oxyrrhina, However, the leave; arc mildly chlorophyll deficient in the earlier stages and turn green at late stages In the development. The reproductive parts do not show and abnormalities except that the anthers are smaller and slenderer that the normal ones and are non dehiscent, containing only sterile pollen.
The Importance of the Bolivian Wild Potato Species in Breeding for Globodera pallida Resistance
Authors: Jackson M. T. , Hawkes J. G. , Male‐Kayiwa Beatrice S , Wanyera N. W. M.
Published: April 2006

Screening for resistance to the potato cyst nematode, Globodera pallida, in potatoes from. Bolivia, was carried out in 1983 and 1984, using a mixture of four nematode populations representing pathotypes Pa1, Pa2 and Pa3 From the 66 accessions of 17 species and subspecies evaluated, highly resistant genotypes were identified in 21 accessions from seven species. All had Pf/Pi values of 2 or less, whereas the susceptible control, Solanum tuberosum cv. ‘Disiree’ had Pf/Pi values of more than 2G in both tests. Two diploid wild species, S. brevicaule and S. leptophyes, showed the best resistant. The geographical distributional of resistant populations and the evolution of resistance in wild potato populations are discussed.
Winter Hardiness in Faba Beans: Varietal Differences and Interrelations among Selection Criteria
Authors: Herzog H.
Published: April 2006

Nine European varieties of winter beans (Vicia faba L‐ var. minor and equina), pre‐germinated at 20°C and raised at 15°C until plant emergence, were hardened at 8/2°C (day/night) for severals week;, and then “dehardened” at 15°C or 10°C.

Development and varietal expression of freezing resistance (FR). und of several characters generally supposed to be linked with winterhardness, were examined during hardening and dehardening. Alter 5 weeks of hardening, most leaf traits remained constant while growth of plants and development of new leaves continued slowly. At the onset of dehardening FR and DM‐content of tissue decreased, whereas most traits increased, rapidely or were enhanced considerably resulting in positive or negative phenotypical correlations of the traits with FR.

With respect to winterhardiness, the old French landrace ‘Cote d'Or’ had the most advantages for almost each trait compared to the other varieties tested, Genotypic correlations established among leaf and plant traits, and with FR, might allow a limitation of the number of selection criteria for winterhardness. Even the laborious determinations of FR. might be omitted or minimized, since its genotypic variation was determined to 64 % by the variation in the rate of development, the change in height and water/D:M‐ ratio, and the leaf area. The validity of a winterhardness ideotype and the restrictions which havt1 to be considered with respect to the measurement of the proposed selection criteria are discussed.
Phaseolin Diversity in the Tepary Bean, Phaseolus acutifolius A. Gray
Authors: Schinkel Christiane , Gepts P.
Published: April 2006

The tepary bean (Phaseolus acutifolius A. Gray) is grown mainly in and regions of Mexico and the southwestern U.S. as a subsistence crop by small farmers. It is also a store of genetic variability for traits such as disease and pest resistance and stress tolerance to improve the common bean (P. vulgaris L.). To determine geographic patterns of variation and the influence of domestication on genetic variability, the genetic diversity of phaseolin, the major seed storage protein, was characterized among 55 wild and 8 cultivated teparies using polyacrylamide gel electrophoresis. Fifteen electrophoretic phaseolin patterns were identified among wild forms, whereas only one pattern was exhibited by cultivars. This result suggests a single domestication in this species leading to a strong reduction in diversity. An additional finding is the divergence m phaseolin types between populations east and west of the Sierra Madre Occidental mountains.
Direct and Correlated Responses to Four Cycles of Divergent Selection for Heading Date in Barley*
Authors: Sanguineti M. C. , Tuberosa R. , Landi P.
Published: April 2006

In order to investigate the direct and correlated responses to selection for heading date in barley, two F2 populations were subjected to four cycles of divergent selection. For each cross, eight populations selected for earliness (from 1E to 4E) and for lateness, (from 1L to 4L) and four unselected populations (1, 2, 3 and 4 SSD) were obtained and than compared together with parental lines. Selection caused a change greater than one day/cycle in Doth directions, and the cumulative responses were ‐5.4 and ‐5,9 days in the direction of earliness, 7.7 and 7,1 days in the opposite direction. Such results suggest that in the two base populations the heading, date is under the control of a polygenic system with prevailing additive effects and a slight directional dominance toward earliness.

Early populations showed a reduction of ear moisture and an increase of plant height, ear extrusion, kernel weight and harvest index, whereas late populations showed the opposite changes. Grain yield was linearly reduced by selection for lateness, whereas no substantial change was evidenced in the opposite direction, so that 4E significantly out‐yielded 4L in both crosses.
Screening and Evaluation of Somaclonal Variations for Quantitative and Qualitative Traits in an Aromatic Grass, Cymbopogon winterianus Jowitt*
Authors: Mathur A. K. , Ahuja P. S. , Pandey B. , Kukreja A. K. , Mandal S.
Published: April 2006

A procedure has been established for high frequency, long‐term plant regeneration from leaf sheath‐derived callus cultures a‐ Citronella Java, variety ‘Jorhat’. A total of 600 plants were successfully transferred to the glass house, and subsequently 500 of these were shifted to the field in TWO batches of 250 plants each. From amongst 230 plants of the firs; hatch, on which data were recorded, extensive somaclonal variations were observed for seven agronomic traits, viz., herbage yield, tiller number, diameter of the bush, length and area of the longest leaf, fresh and’ dry weight ratio and oil content. In addition, variations were also recorded for six major constituents of the essential oil pool, i.e., citronellal, citronellol, geraniol, citronellyl acetate, geranyl acetate and elemol. Correlation analysis between agronomic traits revealed a significant negative correlation between oil content and herbage yield. Haw‐ever, plants with higher herbage yield (> 3 fold) and oil content (> 1.5–2.0 fold) than the parent variety could be selected from amongst the variants. Furthermore, plants could be recovered with improved oil quality, possessing higher levels (> 1.5 fold) of desirable constituents of the oil like citronellal, citronellol, geraniol and geranyl acetate together with a reduced level (> 5 fold) of elemol which is an undesirable component of the citronella oil. Out of the 19 selected somaclones that were evaluated in a replicated trial with the donor parent as control, 5 lines have been further placed under multitocational trials for stability assessment. The scope of sormaclonal variation is discussed in the improvement of vegetatively propagated aromatic grasses that have a narrow genetic base.
Cytogenetic Studies of Hybrids between Festuca gigantea Vill. and Lolium multiflorum Lam.
Authors: Morgan W. G. , Thomas H. , Lewis E. J.
Published: April 2006

The meiotic behaviour of the hybrid between Festuca gigantea (2n – 6x = 42) and Festuca gigantea (2n = 6x = 42) indicates distinct structural differences between the two species. These differences are also apparent in the degree of chromosome pairing observed in Lolium multiflorum×F. gigantea compared with previous reports on the L. multiflorum×F. arundinacea hybrids.

Although the L. multiflorum×F. gigantea 8x amphiploid com Dines the complementary characters of the two species and is agronomically interesting, there are some irregularities in meiotic behaviour that could affect the stability of the amphiploid. Seed fertility in the amphiploid is high and preliminary studies show evidence of a high degree of self‐fertility.

The pentaploid hybrid between autotetraploid L. multiflorum×F. gigantea is sufficiently fertile to be used as the pollen plant in crosses with diploid L. multiflorum (BC1). Backcrossing the BC3 hybrid to L. multiflorum results in mainly diploid progeny. The possibilities, of using this crossing scheme to introgress F. gigantea characters into L. multiflorum is discussed as an alternative approach to amphiploid breeding as a means o: combining specific complementary characters of the two species.
Genetics of Hordeum chilense– Current Status
Authors: Fernández J. A.
Published: April 2006

Hordeum chilense, a South‐American wild barley, is being used in cereal breeding because of its good crossability with both wild and cultivated Triticeae species. Amphiploids and chromosome addition lines of H. chilense in common and durum wheats have been obtained as a means to transfer desirable agronomic characters from wild barley to wheat. No allosyndetic pairing has been detected in diverse hybrids involving H. chilense. Several biochemical markers have been associated with the seven chilense chromosome pairs. New approaches are necessary to transfer genes from H. chilense to cereals.
Are Beta procumbens Chr. Sm. and Beta webbiana Moq. Different Species?
Authors: Wagner Hadwig , Gimbel Eva‐Maria , Wricke G.
Published: April 2006

Different Origins of Beta procumbens and B. webbiana, which are wild species of the section Procumbentes, were investigated by means of electrophoretical techniques. The isozyme patterns did not show any differences between the two species. Assignment of accessions to either one of the two species was not possible using the differences occurring in the banding patterns of some enzyme systems. One can raise the question, therefore if the classification of B. procumbens and B. Webbiana into two species is justified.
Genomic Affinity Relationships in the Genus Avena
Authors: Nishiyama I. , Yabuno T. , Taira T.
Published: April 2006

Many interspecific hybrids between diploid, tetraploid and hexaploid Avena species were obtained without artificial embryo cultures. Most of the hybrids showed variable chromosome pairing with univalents, bivalents and multiple associations, even in PMC in the same hybrid, at first metaphase; making ii very difficult to understand the degree of genome affinity between parent species, and especially between different species. The basic or theoretical chromosome pairing consisting of bivalents and univalents is presented, in which the chromosome ratios (%) statistically agree with observations. In addition, the per cent frequency of chromosomes forming multivalents is calculated. On the bases of these numerical data, the genomic affinity relationships are discussed for present and previously reported interspecific hybrids or Avena.
Pollen Longevity in Wheat, Rye and Triticale
Authors: Fritz S. E. , Lukaszewski A. J.
Published: April 2006

The duration of pollen life was measured for several varieties of wheat, rye and triticale to determine whether the inclusion of alleles for pollen longevity from alien sources would be necessary and effective in hybrid wheat production. Percent seed set was calculated from spikes in which emasculated flowers had been pollinated with pollen stored for specified time intervals under desiccation and under normal greenhouse conditions. Seed was set on wheat, rye and triticale lines using pollen stored for 45, 220, and 80 minutes, respectively. These results indicate that the duration of wheat pollen life is adequate for fertilization to occur under conditions normally used in hybrid wheat production, and that. Introgression of alien alleles is not necessary.
A Dominant Inhibitor Gene Inhibits the Expression of Ht2 against Exserohilum turcicum Race 2 in Corn Inbred Lines Related to B14
Authors: Ceballos H. , Gracen V. E.
Published: April 2006

The purpose of this study was to elucidate the genetic cause for the lack of express ion of the gene Ht2 against Exserohilum turcicum race 2 on certain genetic backgrounds related to the inbred line B14. Two such inbreds (A635Rp and B59), susceptible to this pathogen were crossed onto the inbred Oh43—‐Ht2Ht2. The following generations: F1, F2, F3, F4, backcrosses to both parents, selfings of the backcrosses, in addition to the parent lines, were evaluated for Ht2 expression in this study. Plants of each generation were inoculated with E. turcicum race 2 and evaluated for the expression of the chlorotic‐lesion resistance determined by the gene Ht2. In spite of the reported dominance of Ht2 on some genetic backgrounds, the F1 generations studied here did not show Ht2 resistant lesions. The data presented herein suggest that B14 and related inbred lines carry a dominant gene(I) that inhibits the expression of the Ht2 gene. Chi‐square analyses of the reactions of 108 progeny families studied supported this hypothesis.
A Simple Method of Inducing Somatic Embryogenesis in Brassica juncea (L.) Czern & Coss.
Authors: Kirti P. B. , Chopra V. L.
Published: April 2006

A single‐step method for the induction and development of somatic embryoids from hypocotyls explains of Brassica juncea is reported. On modified MS medium containing 2 % sucrose, 0.25 mgl 1 2,4‐D, 0.5 mgl 1 each of NAA and BaP‐R, each explant calluses at both of and at its best, 31% of explants produce embryoids. In the variety RLM‐198, the number of embryoids ranges from 8–21 per culture. Each embryoid, upon proliferation, developed up to the 25 shoots. The method is rapid; the time La ken from inoculation to the development of intact plantlets is 8–10 weeks. Regenerated plants have flowered normally and have set seed. The system can profitably be used for in vitro mutant selection and early bulking in mustard.
Effects of Pollination Method on Strain Cross Yield in Lucerne
Authors: Smith S. E. , Fairbanks D. J.
Published: April 2006

Because of difficulties in pollination, control, F1 hybrids have not been widely explioted in lucerne’ (Medicago sativa L.). Strain crossing (uncontrolled hybridization between two or more self‐fertile populations with seed of the populations combined to product a “strain cross” population) represents a potentially valuable alternative procedure for exploiting heterosis in this species. Strain crosses in lucerne are typically produced using insect pollination in the field. Using hand pollination under glasshouse houses could increase the number of strain crosses available for tests of combining ability. The objective of this study was to determine whether forage yield of strain crosses produced using hand pollination were sufficiently similar to that of insect‐produced populations to allow the use of the former in lucerne breeding. Forage yields of eight pairs of hand‐ and insect‐produced strain crosses did not differ significantly in 15 of 16 pairwise comparisons and were positively correlated (rs= 0.90) for 20 harvests at two locations. Yield amp of band produced strain crosses could be used, with reasonable accuracy to accuracy the eventual performance of strain crosses produced between the same populations using insect pollination.
High Frequency of Somatic Embryogenesis and Plant Regeneration of Rye (Secale cereale L.)
Authors: Zimny J. , Lorz H.
Published: April 2006

An in vitro system for the initiation of somatic embryogenesis and plant regeneration of spring‐ and winter‐type rye has been developed. The optimal developmental stage of immature embryos to be used as explants is the late stage of spherical coleoptile when the tissue turns milky in colour and the coleoptile is enlarged but spherical. The type and concentration of auxin in the induction medium is of importance for obtaining high efficiency of somatic embryogenesis. CC‐medium high 30 μM Dicamba resulted in well developed somatic embryos in large umbers. Positive effects on the efficiency, intensity and speed of development of somatic embryos have been observed by the addition of coconut water to CC‐medium, replacing agar by agarose and culturing the explants in low light intensity.

Following a “step by step” optimization, culture conditions have been defined giving rise to a 90—100% efficiency of somatic embryogenesis and a high number of regenerated plants.
Frost Resistance of Somaclones Derived from Triticum aestivum L. Winter Wheat Calli
Authors: Galiba G. , Sutka J.
Published: April 2006

Frost resistance was studied in SC4 seedlings generated by self pollination from 31 (SC4) plants of ‘GK Csongor’ winter wheat variety derived from resistance than ‘GK Csongor’. With respect to percentage survival, one family possessed significantly higher frost resistance as compared to the control at a temperature of ‐13°C In the case of regrowth analysis, 22 of the 31 families showed less growing capacity and 5 proved to be significantly better than ‘GK Csongor’. According to both testing methods, one family showed significantly higher frost resistance than the control.
The Inheritance of Earliness and Fruit Weight in Crosses between Cultivated Tomatoes and two Wild Species of Lycopersicon
Authors: Banerjee M. K. , Kalloo
Published: April 2006

The inheritance of earliness and fruit Weight in tomato was studied in tour interspecific crosses. Two cultivated varieties, i.e.‘HS 101’ and “HS 102′, were hybridized with two wild species. L. birsutum f. glabratum‘B 6013’ and L. pimpinellifolium‘A 1921′. Six generations of these crosses were evaluated for these traits and the estimates of gene effects were derived from the generation mean using an epistatic (six parameters) model. There were very wide differences between cultivated and wild species for earliness and fruit weight and in the segregating populations, plants with delayed maturity and smaller fruit size were recorded with high frequency. It was found that the inheritance pattern was mainly governed by additive gene action. Epistatic effects also contributed towards the inheritance of both traits.
Line × Tester Analysis Involving Diverse Cytoplasmic Systems in Sorghum
Authors: Kishan A. Ganga , Borikar S. T.
Published: April 2006

Sorghum hybrids, involving three iso‐sterile (A1, A2 and A4) females and a set of five fertility restorers, were evaluated for yield components in both rainy and winter seasons. In general A2 cytoplasm had larger grain size and higher yield than traditional milo (A1) cytoplasm and cytoplasm A4 had an adverse effect of yield and yield components. Cytoplasmic systems also affected plants height, days to bloom and grain size. Restorers IS 12567C, IS 12662C and SPV 650 had desirable general combining ability effects. The cross (A2T × 398) × IS 12662C had the highest mean yield coupled with positive heterosis and specific combining ability effects, Exploitation of A2 cytoplasm in Sorghum heterosis breeding is suggested.
Inheritance of Isoproturon Tolerance in Durum Wheat Transferred from Triticum monococcum
Authors: Multani Dilbag S. , Dhaliwal H. S. , Sharma S. K. , Gill Khem S.
Published: April 2006

The inheritance of isoproturon tolerance exhibited by the selected progenies of durum wheat was investigated. This tolerance to the herbicide isoproturon had been transferred from Triticum monococcum to durum wheat cultivars. It was shown to be conditioned by a single dominant gene
Allozyme Variability in the Tepary Bean, Phaseolus acutifolius A. Gray
Authors: Schinkel Christiane , Gepts P.
Published: April 2006

The tepary bean (Phaseolus acutifolius) is the object of renewed interest because it possesses some interesting agronomic attributes such as tolerance to drought and salinity. In order to gain a better understanding of the organisation of its genetic diversity, we have examined patterns of diversity for nine polymorphic enzyme systems representing 12 loci, in a sample of 55 wild and 8 cultivated accessions. Several geographic patterns were identified, including an East‐West differentiation, (across the Sierra Madre Occidental mountains), a North‐South differentiation, and a localized differentiation. Wild teparies displayed a higher number of polymorphic loci, as well as a higher number of alleles per polymorphic locus compared to cultivars, consistent with previous observations indicating a reduction of phaseolin diversity on domestication. No clearcut separation with respect to isozyme differentiation was observed between P. acutifolius var. tenuifolius and var. acutifolius, further questioning the validity of this taxonomic separation based on leaflet shape.
Genetics of Resistance to Four Races of Xanthomonas campestris pv. oryzae in Some Rice Cultivars
Authors: Sahu R. K. , Khush G. S.
Published: April 2006

Inheritance of resistance to four Philippine races of bacterial Might caused by Xanthomonas campestris pv. oryzae was investigated in four cultivars of rice, Oryza sativa L. Resistance to three races in ‘Benamuri’ and ‘Aus 192’ is governed by xa‐5. In ‘Tepal Boro’ and ‘Bazail 975′, resistance to races 1, 2. and 3 is conferred by xa‐5, but another recessive gene confers resistance to race 4. This recessive gene is closely linked to xa‐5 and may be allelic to xa‐13. Rice cultivars with xa‐13 are resistant to prevalent races of bacteria] blight in the Indian subcontinent and should thus prove useful as donors for resistance to bacterial blight in rice breeding programs.
Maternal and Genetic Effects on Seed Weight of Tomato, and Effects of Seed Weight on Growth of Genotypes of Tomato (Lycopersicon esculentum Mill.)
Authors: Nieuwhof M. , Garretsen Frida , van Oeveren J. C.
Published: April 2006

A study was made on the inheritance of seed weight of tomato, and on the effect of seed weight on growth of tomato plants. Use was made of 15 parental genotypes and 105 F1s produced by diallel crossing (F1‐seeds). From combining ability analysis of variance carried out for weight of F1‐seeds it appeared that the weight of seeds harvested from tomato plants was mainly determined by the maternal genotype and largely independent of the genotype of the male parent. A combining ability analysis of variance for weight of seeds produced by seilfing F1's (F2‐seeds) showed, however, that female and male parents contributed equally to the inheritance of seed weight and that the inheritance of seed weight is determined mainly by chromosomal additiveiy acting factors, but that also non‐additive gene action occurred.

Genotypes with large seeds produced heavier seedlings than genotypes with small seeds, In later growth stages, the correlation between seed weight and plant weight became smaller, presumably, due to a lower relative growth rate of the seedlings from large seeds. For this reason, it is doubtful whether breeding of large seeded tomato cultivars opens up prospects of improving growth and yield of tomato plants.
Linkage Between the Incompatibility Locus Z and a β‐Glucosidase Locus in Rye
Authors: Gertz A. , Wricke G.
Published: April 2006

Crosses of plants from the same I0.1 line can be used for studying linkage relations between incompatibility loci and marker genes. Only one of the two incompatibility loci of rye has so far been localized, on chromosome 1R. In order to locate the second locus, crosses were performed with plants possessing known isozyme markers of the rye genome. Linkage was found with the β‐glucosidase locus on chromosome 2R. By combined analysis a recombination value of C.144 was determined.