Inheritance of firmness in raw cucumber (Cucumis sativus L.) fruit

Summary Inheritance of raw cucumber fruit texture (Magness-Taylor Fruit Pressure Tester firmness) was investigated over a 4-year period from 1971–1974. Results from 2 separate but related experiments suggested that firmness was quantitatively inherited with sufficient additive effects to permit gain from selection. In a selection study within 4 F₂ populations derived from crosses between firm (Chipper and Gy3) and soft (Mincu and Green F) fruit type cultivars, variation among and within F₃ and F₄ families was significant but overall family means were not significantly higher than the high parent in any of the 4 crosses. Narrow sense heritability estimates for fruit texture were 0.80 in the Mincu × Chipper population and 0.77 in the Green F × Chipper, Mincu × Gy3, and Gy3 × Green F crosses. In a separate experiment, generation means analysis was used to assess the mode of gene action in 2 crosses: Green F × Chipper, and Gy3 × Green F. Additive genetic effects accounted for 98.8% and 99.3% of the total genetic variation within each cross, respectively.Scientific Journal Series Paper No. 9794.     

Genetics of resistance to five strains of turnip mosaic virus in Chinese cabbage

Summary Inheritance of resistance to turnip mosaic virus (TuMV) strains C1, C2, C3, C4, and C5 in Chinese cabbage (Brassica campestris subsp. pekinensis) was evaluated using monoclonal antibodies. Crosses were made between a resistant line, 0–2, and four susceptible line. Seoul (SE),SSD31 (SS), Cheongbang (CH), and Yaki 1 ho (YA), to determine the inheritance of resistance of 0–2 in different genetic backgrounds. Resistance to TuMV was controlled by a single dominant gene or double dominant genes depending on the strain and cross. The resistance genes of 0–2 were modified by susceptible parents such that a single dominant gene was involved in the SS×0–2 combination, but double dominant genes in the SE×0–2 against TuMV-C3 or TuMV-C5. ELISA tests using inoculated and noninoculated leaves in the same plant suggested that the dominant resistance genes inhibit virus movement rather than virus multiplication.     

Diallel analysis of yield components of snap beans exposed to two temperature stress environments

Ten snap beans (Barrier, Brio, Carson, Cornell 502, CT 70, HB 1880, Hystyle, Labrador, Opus and Venture) were selected for differential temperature tolerance and used as parents in a complete diallel mating design. The 45 F₁ hybrid lines (with reciprocals) and parents were screened at 32 C day/28 C night, and in a separate experiment, 16 C day/10 C night, during reproductive development in replicated controlled environments. Variation for yield under temperature treatments was observed among parents and hybrids, with certain hybrids exceeding parental performance. Significant (P 0.0001) general combining ability (GCA), and significant (P 0.05) specific combining ability (SCA) were observed for yield components including pod number, seed number, and seeds per pod. There was evidence that pod number and seeds per pod under temperature stress are under separate genetic control. Reciprocal effects and heterosis were not significant. GCA could not be predicted from parental performance. The breeding line Cornell 502 had the highest GCA under high temperature, and the cultivar Brio had the highest GCA under low temperature. The cross Brio × Venture was high yielding in both temperature treatments. Heat tolerance and chilling tolerance were associated in certain parents and hybrids. However, performance under high and low temperature treatments was not generally correlated in the parents and hybrids, indicating that these traits should be selected separately.     

Inheritance of aroma in rice

Summary Inheritance of an aroma was worked out in crosses between Brimful from Nepal as an aromatic rice and leading Japanese varieties Koshihikari and Nipponbare as non-aromatic ones. The F₂ pattern of segregation for aroma to non-aroma was 3:13 indicating one dose gene for aroma and one dose inhibitor gene in two crosses. This ratio was confirmed by genetic behavior of F₃ populations.     

The production of hexaploid Solanum x juzepczukii

The colchicine-grafting method of doubling the chromosome number of potato cuttings was used successfully for producing hexaploids from the triploid species, Solanum x juzepczukii. All the plants with hexaploid flowers were triploid/hexaploid sectorial chimeras. Seeds were obtained from crosses of the hexaploid parts with both an andigena-tuberosum hybrid and a tuberosum variety.     

Inheritance studies of characters associated with floating habit and their linkage relationship in rice

Summary Deep water rice varieties in general have certain peculiar characters which are associated with floating habit. These characters are (i) early nodal differentiation, (ii) nodal rooting, (iii) spreading habit, (iv) awned grains, (v) brown hull colour, (vi) red pericarp (red rice), and (vii) seed dormancy. Inheritance of these characters and linkage relationship of genes governing these characters were studied in a cross between Pankaj (non floating) and Nageribao (floating) rice varieties. Nageribao, a cultivar from Assam possesses these characters.Early nodal differentiation was observed to be controlled by a single dominant gene, designated as Nd. Nodal rooting was controlled by two dominant complementary genes, designated as Nr ₁ and Nr ₂. We found an inhibitory factor for spreading habit and one for brown hull colour in Pankaj; the operation of two dominant duplicate genes An ₁ and An ₂ for controlling awning characters, a single dominant gene Rd for red pericarp colour and a single dominant gene Gd for grain dormancy. Joint segregations between these characters resulted in the assignment of genes in the X linkage group of indica rices with estimated map distances based on the cross-over values. The genes An (awning), Es (spreading habit), Nr (nodal rooting) and Nd (nodal differentiation) were observed to be associated with each other. The gene for red pericarp (Rd) was observed to be linked with the grain dormaney gene Gd.     

Genetics and histology of powdery mildew resistance in apple

Summary Eight scab-resistant cultivars and selections along with eight commercial apple cultivars were evaluated for powdery mildew resistance in greenhouse and nursery tests. Dayton, Liberty, Delicious and Tolman Sweet were rated moderately resistant to infection in both greenhouse and nursery tests. Segregation of seedlings among 14 progenies for mildew reaction indicated that mildew resistance is polygenically controlled in this material with additive gene effects. Recovery of mildew resistant seedlings from crosses involving a scab-resistant parent(s) suggested that this material can be useful in developing scab- and mildew-resistant apple cultivars. Histological investigations were conducted to describe mildew symptoms of infected leaves.     

Mutant induction through adventitious buds of Kohleria

Summary Freshly cut leaves of Kohleria eriantha and K. x Longwood were exposed to a wide range of gamma irradiation doses and allowed to root and form adventitious buds. K. Eriantha could not be successfully propagated from leaf half cuttings. Longwood produced a small number of adventitious plantlets as compared to other Gesneriads. Colchicine treatments reduced leaf half survival in Longwood by more than 50%. Leaf halves exposed to low and moderate doses of gamma irradiation showed increased overall plantlet production compared to nonirradiated leaf halves.Of the mutation parameters calculated, the number of mutants per 100 surviving leaf halves appears to be the most useful since it relates the number of mutants within a dose to the number of surviving leaf halves, the number of mutants to the number of plants produced, and the number of mutants within doses to control values.Using the criteria, number of mutants per 100 surviving leaf halves, optimum production of all mutants, of useful and of dwarf mutants was obtained at 2.5 kR for noncolchicine treated leaf halves and 1.5 to 3.0 kR for colchicine treated leaf halves.Of the adventitious plantlets produced, 13.8% were classified as mutant types. Mutant plants were found in radiation dose levels up to 5.5 kR. The array of mutants produced was skewed toward plant habit and flower characteristic mutants with several leaf characteristic, lethal, and polyploid mutants observed. A high frequency of mutants, 10 of 93 plants, occurred in the nonirradiated controls. Four sectorial chimeras were identified from both control and irradiation exposed groups. Several potentially useful flower color and dwarf mutants have been selected for further study. Adventitious buds may have developed from callus at petiole and leaf-vein bases. Colchicine treatments severely inhibited adventitious plantlet production and because of this could not be used as a criterion to identify the origin of adventitious buds. Conclusive determination of the organogenesis of adventitious buds from Longwood leaf halves could not be made. Mutant plantlets formed from adventitious buds on detached leaf halves of Longwood appear to arise from single cells as has been found with other Gesneriads.Scientific Journal Series Article No. 10 330 of the Minnesota Agricultural Experiment Station.     

Genetic analysis of inbred lines and their crosses for resistance to head blight (Fusarium culmorum,F. graminearum) in winter rye

Summary For genetic analysis of head blight in winter rye (Secale cereale) caused by Fusarium culmorum, six homozygous inbred lines from the Petkus gene pool were crossed in all combinations to obtain 15 diallel F₁ crosses and the corresponding 15 F₂ crosses. These materials and 10 additional inbreds were artificially inoculated in a 2-year field experiment. The inbreds were also tested with F. graminearum in a separate sub-experiment.Single disease rating, average disease rating, and yield components (grain-weight per spike, 1000-grain weight, kernel number per spike) relative to the non-inoculated treatment were significantly affected by Fusarium head blight in all material groups. The relative grain weight per spike ranged from 26% to 88%. Significant genotypic and genotype x year interaction variances were found throughout. Heritabilities were highest for homogeneous inbreds (h²=0.6–0.8) and lowest for heterogeneous F₂ crosses (h²=0.4–0.6). Disease rating and relative grain-weight per spike were highly correlated for the inbreds and F₂ crosses (r0.7, P0.01), but lower for the F₁ crosses (r0.6, P0.05). Inter-annual correlation coefficients for disease ratings and relative grain-weight per spike ranged from r0.7 (inbreds) to r0.5 (F₂ crosses). The diallel analysis showed significant GCA effects only for relative 1000-grain weight in 1990, but significant SCA and SCAx year interaction variances for most traits. The resistances of 16 inbreds to F. culmorum and F. graminearum were tightly associated for all traits (r=0.96–0.97, P0.01).In conclusion, only slow progress can be expected from selecting for Fusarium head blight resistance in rye due to the limited amount of additive genetic variance and the great improtance of environmental factors.     

Trials to overcome the incompatibility of crosses between Lycopersicum esculentum and Lycopersicum glandulosum by repeated grafting

In breeding tomatoes for resistance to Corky root Lycopersicum glandulosum is used as a resistant parent. Crosses of tomato with L. glandulosum are difficult to effect because of the incompatibility of the partners. To overcome this incompatibility the approach method was applied beside the conventional crosses.Repeated reciprocal grafting of tomato onto L. glandulosum and also L. glandulosum on tomato did not increase the number of effected matings. The statement that by repeated grafting the characters of the scion change under the influence of the stock could not be confirmed.     

Relationship between allelic variation of Glu-1 and Gli-1/Glu-3 prolamin loci and gluten strength in hexaploid wheat

Summary Allelic variation of prolamin loci was examined in the F₂ from crosses between the hexaploid wheat varieties: Cajeme 71, Yécora 70, Ablaca, Anza, Pané 247 and Axona. Different allelic blocks for gliadins and LMW glutenin subunits were determined in Gli-1, Gli-2 and Glu-3 loci. A percentage of recombination of 1.5 ± 0.3 was determined between Gli-A1 and Glu-3 in the F₂ progeny of Yécora 70 x Axona. A significant positive association was found between gluten strength, measured by SDS-sedimentation volume, and the prolamins coded by Anza Gli-D1/Glu-D3 loci and Yécora 70 Gli-A1/Glu-A3 loci. Interactions between non homeologous loci Glu-1 and Gli-1/Glu-3 were also found.     

Limited but specific variations of seed storage proteins in Japanese common wheat (Triticum aestivum L.)

The electrophoretic banding patterns ofgliadin in common wheat lines derived fromJapan were determined byacid-polyacrylamide gel electrophoresis. For the 107 wheat lines used in our study,27 different patterns were identified, 13corresponding to the -gliadin, 8 tothe , -gliadin and 6 to the-gliadin. The gliadin patterns ofJapanese wheat cultivars and landracesgreatly differed from the patterns of wheatlines from other countries, and thevariation seen in wheat lines from Japanwas limited to 46 patterns. Sevencollection or breeding areas in Japanshowed different frequencies in theirgliadin patterns. Combining the gliadinpatterns with high molecular weightglutenin subunit compositions, 67combinations were observed. One gliadinpattern consisting of -gliadinpattern F, , -gliadinpattern H and -gliadin pattern Dwas frequently found in many Japanese wheatlines, though the other patterns werelimited to only one or two wheat lines.     

Vaktijdschriften op het gebied van de plantenveredeling

Summary The English abstracting journal Plant Breeding Abstracts gives a satisfactory synopsis of books on plant breeding and of articles in this field that have appeared in general and professional journals.In the above survey are mentioned the following periodicals: Sveriges Utsädesföreningstidskrift (1891 ), Zeitschrift für Pflanzenzüchtung (1913 ), Der Züchter (1929 ), Agri Hortique Genetica (1943 ), Indian Journal of Genetics and Plant Breeding (1941 ), Melhoramento (1948 ), Annales de l'Amélioration (1951 ) and Euphytica, Netherlands Journal of Plant Breeding (1952 ).

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Vaktijdschriften op het gebied van de plantenveredeling

     

The influence of cytokinins and ionic strength of Anderson's medium on shoot establishment and proliferation of evergreen azalea

Shoot-tip explants of evergreen azalea cv. Fuchsia grown on Anderson's medium and containing different cytokinins produced the highest proliferation rate on a medium containing thidiazuron (TDZ). TDZ concentrations ranging from 0.23 to 2.3 M resulted in both good bud-break rate (4 to 5) and shoot quality (> 0.5 cm in length). Adding 2.3 M zeatin to Anderson's medium containing 0.23 or 2.3 M TDZ increased the number of axillary shoots/explant. However, increasing the zeatin concentration to 4.6 M resulted in a reduced shoot proliferation rate. A medium containing 1.15 M TDZ and 2.3 M zeatin resulted in an 18-fold increase for 'Fuchsia' and a 9-fold increase for 'Hino Crimson' after 6 weeks of culture. It was found that explants grown on a half-strength Anderson's medium with 87.6 mM sucrose generally had better shoot proliferation rate and shoot quality than at higher ionic strength.     

Lilium x ‘Black Beauty’—a potential bridging hybrid in Lilium

Summary Lilium Black Beauty, a rare intersectional hybrid previously reported sterile, was re-examined for pollen and ovule fertility. No pollen tubes were detected following incubation of styles pollinated with Black Beauty pollen. However, embryos varying in size from small globular to long boat-shaped and only rarely associated with endosperm, were found in 0.1–1.0% of the ovules in Black Beauty pistils pollinated with Oriental or Aurelian division lilies. Aseptic extraction and culture of these embryos on a nutritive medium resulted in growth, germination, and plantlets. It is apparent that with embryo culture, Black Beauty has unique value as a species bridge in that it accepts pollen of both Oriental and Aurelian lilies, two of the major commercial lily divisions.Scientific Journal Series Paper Number 9197 of the Minnesota Agricultural Experimental Station.     

Effect of genetic blends of dry beans (Phaseolus vulgaris) of different Plant architecture on apothecia production of Sclerotinia sclerotiorum and white mold infection

Summary The determinate Phaseolus vulgaris L. cvs Dark Red Kidney Charlevoix, and near-isogenic Great Northern Nebraska 1 were grown in blends with the indeterminate GN Nebraska 1 in white mold (Sclerotinia sclerotiorum) disease field nurseries. A critical difference between Charlevoix and indeterminate GN Nebraska 1 is that the latter has a greater leaf area closer to the soil surface, and this is associated with increased numbers of apothecia beneath the canopy and higher disease severity. White mold infection and apothecia number/m² beneath the canopy of the blends containing Charlevoix were significantly reduced in comparison with the severely infected, homogeneous, indeterminate GN Nebraska 1. A reduction of white mold infection for the indeterminate GN Nebraska 1 was not observed in blends grown under severe or moderate white mold incidence, but did occur under slight incidence in blends containing 65% and 75% Charlevoix.No significant difference for seed yield occurred between the blends and homogeneous cultivars planted in four experiments under severe, moderate, slight and zero white mold incidence, respectively, except in Experiment 1 under moderate white mold incidence, the blend of 50% indeterminate GN Nebraska 1 and 50% Charlevoix exceeded the yield of the indeterminate GN Nebraska 1. Mean weight of white (GN Nebraska 1) and red seed (Charlevoix) increased and decreased, respectively, in some blends due to the more vigorous growth of the indeterminate GN Nebraska 1.Published as Paper No. 5341, Journal Series, Nebraska Agric. Exp.t Station. Research was conducted un under Project 20–3.     

Results of one cycle of recurrent selection in rye

A sufficiently variable rye population was subjected to one cycle of recurrent selection for combining ability in order to ascertain whether this complex property can be repatterned.Some hundreds of clones derived from this population were toperossed to an other unrelated variety used as tester. Through visual selection, more than half of these clones were rejected. The topcross progenies of the remaining clones were subjected to a comparative test whereby, as was to be expected, a considerable degree of variability was demonstrated. From the best 10% and the poorest 10% that is from those which surpassed the general average by at least 1.5 standard deviation units or remained below that average by at least 1.5 , narrowed populations were built up. This was done with the aid of reserve seed which in the year in which the top cross was made had been obtained from these clones, either through compulsory selfpollination or by allowing the clones to fertilize each other in isolation. The two subpopulations obtained through selection in opposite directions further indicated as high and low were crossed en masse with the same tester variety as the first time. In addition a large number of randomly taken individuals from the high synthetic were cloned and toperossed to this common tester. On testing the top crosses carried out en masse, the high synthetics clearly yielded more than the low ones. In one trial it was even found that the high synthetic surpassed our standard variety Petkus by approximately 20%. It is possible, therefore, to segregate a population into two fractions of different combining ability.The optimistie pieture to be derived from the foregoing trials unfortunately is shaded by the results of the individual test crosses pointing to a shift of the frequency distribution in a negative sense in regard to the original population. The influence of the year may be mentioned as a possible cause of this contrast and also the fact that in the original population a close visual selection had been practised while those obtained from the synthetic resulting after one cycle were derived from individuals which had been taken entirely at random.

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Samenvatting Een voldoende variabele roggepopulatic werd onderworpen aan één ronde van cyclisch herhaalde selectic op combinatie-geschiktheid ten einde na te gaan of deze complexe eigenschap kan worden vervormd.Enige honderden klonen voortgekomen uit deze populatie werden onderworpen aan een top-cross door een als tester gebruikt ander, onverwant, ras. Op grond van visuele selectie werd meer dan de helft van deze klonen afgekeurd. De proefkruisings-nakomelingschappen van de overblijvende klonen werden aan een vergelijkende toets onderworpen waarbij zoals viel te verwachten een aanzienlijke variabiliteit in opbrengstvermogen aan het licht trad. Uit de beste 10% en de slechtste 10%, d.w.z. die welke het algemeen gemiddelde met minstens 1,5 overschreden resp. daar minstens 1,5 beneden bleven, werden vernauwde populaties opgebouwd. Dit geschiedde met behulp van reservezaad dat in het jaar waarin de top-cross werd verricht van deze klonen was gewonnen, hetzij door gedwongen zelfbestuiving, hetzij door de klonen in isolatie aan onderlinge bestuiving over te laten. De op deze wijze verkregen twee in tegenovergestelde richting geselecteerde sub-populaties-aangeduid als high en low-werden en masse gekruist met hetzelfde tester ras als de eerste keer. Bovendien werd een groot aantal willekeurig uit het high syntheticum genomen individuen tot klonen gemaakt en onderworpen aan een top-cross door het zoëven genoemde tester ras. Bij de toetsing van en masse uitgevoerde proefkruisingen bleek de combinatie high x tester duidelijk meer op te brengen dan low tester. In een proef werd zelfs gevonden dat high x tester ons standaardras Petkus met ongeveer 20% overtrof. Het blijkt dus mogelijk een populatie te splitsen in 2 fracties van uiteenlopende combinatie-geschiktheid.Het optimistische beeld dat men uit de zo juist vermelde proeven krijgt wordt helaas verduisterd door de resultaten van de individuele proefkruisingen welke wijzen op een verschuiving van de frequentieverdeling in negatieve zin ten opzichte van de oorspronkelijke populatie. Als mogelijke oorzaken van deze tegenstelling kunnen worden aangewezen jaarinvloeden en tevens het feit dat onder de klonen uit de oorspronkelijke populatie een scherpe selectie op het oog werd toegepast terwijl die uit het na één cyclus verkregen syntheticum werden afgeleid van volkomen willekeurig genomen individuen.

     

Inheritance of gliadin composition in bread wheat,Triticum aestivum L.

Summary The gliadin compositions of 101 selected lines from 2 crosses between varieties of T. aestivum were examined by applying starch-gel electrophoresis at pH 3.1. The gliadin patterns of these lines were recognized to be composed of sections of the parental patterns. In a wheat variety the gliadin pattern proved to be divisible into 6 or 7 sections, the configurations of which are inherited unaltered. Its gliadin composition, consequently, is determined by at least 6 genetic factors. The sections appeared to be identical to the gliadin fractions currently known as , , , and ; the gliadin proved to consist of 2 sub-fractions and the gliadin of 2 or 3 sub-fractions.Dedicated to Professor Dr H. Veldstra on the occasion of his retirement from the chair of biochemistry of the University of Leiden.     

Effect of ploidy on stomatal and other quantitative traits in plantain and banana hybrids

Summary Ploidy polymorphism occurs in the hybrid offspring derived from interspecific crosses between triploid plantains (Musa spp. AAB group) and diploid bananas (M. acuminata). Therefore,Musa breeders are interested in the determination of ploidy and its effects on phenotypic expression of quantitative traits. The aim of this research was to examine the reliability of stomatal and other phenotypic traits to determine ploidy in segregating plantainbanana hybrid families. Stomatal density and size were significantly correlated (P<0.01) with ploidy, although the correlation coefficients were not high (r=–0.49 and r=0.47, for stomatal density and size, respectively). High density of small stomata was correlated with low ploidy level, and vice versa. However, stomatal size and density were also influenced by a significant genotype effect (P<0.001) within the same ploidy level. Ploidy had an important effect on fruit traits and plant height in the hybrids of Obino l'Ewai×Calcutta 4, but this was not so clear in Bobby Tannap×Calcutta 4 hybrids. Obino l'Ewai derived tetraploids have medium to tall plants with large bunches and big fruits. Most of the tetraploids derived from Bobby Tannap have short stature due to the gene action of the dwarf,dw, allele. Also, a few selected diploids derived from Bobby Tannap outyielded their non-selected tetraploid full-sibs. In conclusion, chromosoem counting remains the only accurate proof of ploidy levels inMusa germplasm.     

The black currant leaf curling midge,Dasyneura tetensi Rübs.; its host range,and the inheritance of resistance

Summary Established Western European black currant cultivars are susceptible to Dasyneura tetensi but the Scandinavian Sunderbyn II, Kangosfors and Hedda, and 10 out of 33 Russian cultivars showed very slight or no leaf symptoms of midge attack in the field.Of species within the black currant Section Eucoreosma, Ribes dikuscha, R. pauciflorum (probably=syn R. ussuriense), and R. americanum were not attacked, but an accession of R. bracteosum proved very susceptible. Species within other sections of the genus were not attacked.A strong dominant resistance gene in R. dikuscha, designated Dt, appeared to be linked with (a) gene(s) controlling resistance to American gooseberry mildew, Sphaerotheca mors-uvae. Resistance in Sunderbyn II and, probably, in R. pauciflorumwas oligogenic and dominant.