Low light intensity and flower bud abortion in Asiatic hybrid lilies. I. Genetic variation among cultivars and progenies of a diallel cross

Summary When Asiatic lilies are forced during the winter period, additional light is needed to prevent flower bud abscission and flower bud blasting. Growth room experiments showed considerable differences among eight lily cultivars in their response to low light. Among these cultivars, Connecticut King and Enchantment appeared to be the most sensitive to low light conditions while Uncle Sam and Scout were the least sensitive.Analysis of an incomplete diallel cross between nine cultivars showed significant differences in general combining ability (GCA) for flower bud abortion, number of buds, forcing time, plant height and leaf scorch under winter greenhouse conditions. Enchantment had the highest positive GCA for bud abortion, indicating a high sensitivity to low light conditions. Uncle Sam had the lowest GCA. Pirate and Scout appeared to have a high GCA for sensitivity to leaf scorch. Connecticut King was found to be a probable source of cytoplasmic male sterility. The data suggest that male sterility is associated with better response to low light conditions.     

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

     

Resistance to the glasshouse whitefly (Trialeurodes vaporariorum Westw.) in sweet pepper (Capsicum annuum L.)

Summary Fourteen cultivars, one F₁-hybrid and one half-wild type (Cind) of sweet pepper were tested on resistance to glasshouse whitefly. Several mutually significant levels of resistance were found. Most resistant appeared to be California Wonder, Severka M, Korál and Yolo Wonder. During the test sweet pepper plants were infested both with whiteflies and their parasite — Encarsia formosa, which caused the blackening of whitefly puparia. The blackened puparia are easily seen, enabling an easier and more rapid evaluation of the number of puparia present.     

Genetic variation for resistance to Phytophthora fragariae var. rubi in red raspberries

Summary The inheritance of root rot resistance in red raspberry, caused by Phytophtora fragariae var. rubi, was investigated using two experimental breeding designs. Design A was not randomly mated and genetic parameters could not be calculated. Design B was therefore randomly mated to make it possible to do such estimations. Considerable genetic variation was associated with the recorded traits on seedlings tested in a glasshouse. Disease index and % survival were both found to be highly heritable with broad sense heritabilities (H²) close to 0.9 in each design. Estimates of narrow sense heritability (h²), indicated that progress towards resistance would be moderate. In the first design the cultivars Festival, Asker, Boyne and Sentry and the clones N85-02-13 and N85-06-140 had high general combining abilities. Some crosses had a high specific combining ability indicating the presence of non-additive genetic variation.     

Histological analysis of embryo-sac formation and detection of meiotic diplospory in cassava (Manihot esculenta Crantz)

Summary Embryo-sac formation in six cultivated Asian cassava clones and one unknown wild type, was histologically investigated to determine apomictic potential in the genus Manihot. All the 6 clones were found to possess one single sexual embryo-sac containing 6–8 nuclei at maturity. However, one clone, Rayong 3 possessed two functional embryo-sacs at 12 hours after controlled pollination (HACP). The larger embryo-sac was 6-nucleate (all 3 nuclei of the egg apparatus, 1 polar and 2 antipodal cells) and located towards the false micropylar or the nucellar beak region. The smaller embryo-sac also contained a total of 6 nuclei and approximately 10 m³ or 1/2 the volume of the former and located towards the chalazal pole. Percentage sexuality estimates indicated a 100% sexual reproduction in embryo-sacs of all the clones analysed. However, apomeiotic relationships indicate a low (0.3%) degree of meiotic diplosporous embryo-sac formation, thus suggesting facultative apomixis in cv. Rayong 3. This is the first embryological identification and evidence of apomeiosis and apomictic potential in cassava.Contribution from Plant Breeding Laboratory, Applied Genetics & Biotechnology Division, Faculty of Agriculture, Miyazaki University, No. 91.     

Resistance to Corynebacterium michiganense in tomato genotypes

Summary The highest level of resistance to Corynebacterium michiganense was found in Irat L3 and Okitsu Sozai 1–20. Resistance was partial and symptomless plants proved to be carriers of the disease. The resistance is at least partially based on a diminished multiplication of the pathogen in the host plant.     

New sources of nonspecific resistance to rust and common bacterial blight in dry bean landrace Pompadour

Summary Inheritance of resistance of five melon lines to two strains of Sphaerotheca fuliginea belonging to races 1 (Sf1) and 2 (Sf2) and to one strain of Erysiphe cichoracearum (Ec) have been studied. PMR 45 possesses one dominant gene controlling only Sf1. WMR 29 has one dominant gene for resistance to Sf1 and another for Sf2 and these genes seem to be linked. In line PMR 5, one dominant gene (or a group of three closely linked genes) is involved in the control of the three strains with one complementary gene for Sf1 and another one for Ec. PI 124112 has one dominant gene or two closely linked loci controlling Sf1 and Sf2 and two complementary different genes controlling Ec. Nantais Oblong has one dominant gene controlling only Ec. A nomenclature of the genes described is proposed.     

Inheritance of seed coat colour in broad bean (Vicia faba L.)

Summary The inheritance of the seed coat colours violet, spotted, brown, green, red, black and beige was investigated in a 10×10 diallel cross between broad bean (Vicia faba L. major) lines. Spotted seed colour was dominant over any uniform seed coat colouring. Brown was dominant over black, green and normal (beige colour). Black and red seed parents behaved as recessive in all F₁ progenies. A 3 (coloured): 1 (normal) segregation ratio was observed in the F₂ of crosses of violet, brown, black, red and spotted seed coat parents to nornal seed coloured parents. Green x beige gave a segregation ratio of 9:7 in F₂. When two parents with different seed coat colour were involved in a cross, the F₂ showed a typical digenic segregation ratio thus demonstrating two unlinked and sometimes epistatic loci.Segregation of a multiallelic series at two loci explains all segregation ratios observed for seed coat colour in broad bean.     

Rhodes grass breeding in Kenya. III. Seed and herbage yield in selections of four maturity classes based upon intra variety variation

Summary Selections of four maturity classes developed from within each of three commercial varieties of Rhodes grass, Mbarara, Masaba and Pokot, were assessed for yield of PGS (pure germinating seed), speed of establishment after sowing, total dry matter yield and dry matter yield under frequent clipping (persistence), over three years.The range in heading date between the selections was well outside the range of the original varieties. The best selection with the highest overall response was the early-heading selection developed out of Mbarara with a 127% gain in PGS yield, 75% gain in dry matter yield three months after sowing, 11% gain in overall dry matter yield and 17% gain in dry matter yield under frequent clipping, compared with the standard Mbarara.Mbarara entries were the best in PGS yield, herbage yield and % dry matter. Masaba entries were better in persistence, while the late-heading Pokot entries were the poorest in PGS yield, herbage yield and persistence.Within varieties, yield of PGS dropped progressively and sharply in later maturity classes, whereas dry matter yields were largely unaffected by heading date. Thus late-heading selections dropped below the standard varieties in PGS yield but remained above the standard varieties in dry matter yield.Early-heading selections were generally more persistent than late-heading selections.     

Study of the parentage of grape cultivars by genetic interpretation of GPI-2 and PGM-2 isozymes

Summary Two highly variable enzyme systems of glucosephosphate isomerase (GPI) and phosphoglucomutase (PGM) were used to investigate the parentages of grape cultivars. Of 35 parent/offspring combinations that we investigated, 30 combinations gave alleles in the offspring which were presented in the reported parents, whereas 5 combinations gave alleles in the offspring which were not extractable from the reported parents. The Gpi-2 genotype of Hiro Hamburg and the Pgm-2 genotype of Pione indicated that Koshu Sanjaku and Cannon Hall Muscat may not have been the paternal parent respectively. The Gpi-2 genotype of New Niagara and the Gpi-2 and Pgm-2 genotypes of Beniyamabiko indicated that Niagara and a hybrid from DxK151 x Delaware may not have been the maternal parent respectively. The Gpi-2 genotype of Cannon Hall Muscat grown in Japan indicated that this cultivar may not have originated as a tetraploid sport of Muscat of Alexandria.     

The presence of three groups of Scalavatis and other hexaploid bread wheat plants contaminating durum wheat fields in Cyprus

Summary The mutual resemblance of 81 hexaploid wheat plants contaminating durum fields on Cyprus was investigated by determining their phenotypes of gliadins, glutenins and peroxidase. Three groups were generated by clustering programs. Group 1 consists of plants with ears resembling those of durum plants, plants of groups 2 and 3 have a bread wheat appearance. Suggestions on the origin of these three groups are made. Group 1 may derive from (back)crosses between hexaploid and durum plants since time immemorial. If so, the hexaploid plants would have served as donor of the D genomes, and durum plants as the recurrent parent. Groups 2 and 3 may derive from two introductions, either from two countries, or from the same country, but then in different periods.     

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.     

Lack of interplot competition in Swedes (Brassica napus ssp rapifera L.)

Summary An experiment comparing double row plants with four row plots where only the centre two rows were harvested (guarded double row plots) were laid out in two subsequent years. Fresh weight yields, dry matter yields, bulb dry matter content, refractometer index and harvest index were recorded and analyzed statistically. The cultivar x plot type interactions were in none of the cases significant. The increase in error variances when comparing double row plots with guarded double row plots was significant only for harvest index in the first year.Taking into account the low selection intensity when small plots are used, i.e. in early stages of plant breeding programmes, we conclude from these experiments that guarded plots are not necessary when breeding swedes under our growing conditions.     

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.     

Cytoplasmically controlled cold tolerance in a cytoplasmic-genetic male sterile line of rice

Summary The cytoplasmic-genetic male sterile line, Krishna-A with Kalinga-I cytoplasm was developed in rice through repeated backcrossing the completely pollen sterile F₁ of the cross Kalinga-I/Krishna with the recurrent male parent cv. Krishna. The germination percentage and root-shoot length in Krishna-A at 12°C and 9°C indicated a higher degree of tolerance to low temperature than the cold tolerant female parent Kalinga-I. The high yielding cold tolerant variety Kalinga-I was developed from a cross involving the cold tolerant variety Dunghansali and the high yielding variety IR 8. It is inferred that tolerance to low temperature during germination in Krishna-A was inherited from the cytoplasm of cv. Dunghansali through Kalinga-I besides male sterility. The cytoplasmic control of cold tolerance is reported here for the first time in rice literature. The male sterile line Krishna-A because of its tolerance to low temperature would be suitable for the development of hybrid rice especially for areas where low temperature is a problem during germination.     

Molecular and biological studies on male sterile cytoplasm in Cruciferae. II. The origin of Ogura male sterile cytoplasm inferred from the segregation pattern of male sterility in the F1 progeny of wild and cultivated radishes (Raphanus sativus L.)

Summary To determine the origin of Ogura male sterile cytoplasm in radish (Raphanus sativus L.), wild and cultivated radishes were crossed. Three types of progeny resulted from the F₁ hybrids between the wild radish from Kushikino with Ogura-type mtDNA and the cultivars (Uchiki-Gensuke or Comet). The segregation patterns of the male sterility were compared with those of Ogura cytoplasm. The male sterility induced in the F₁ hybrid was maintained by crossing with Uchiki-Gensuke, that maintains Ogura male sterility. In the two types of progeny, in which Comet (a restorer of Ogura cytoplasm) was used as one of the parents, both fertile and sterile plants segregated at the predicted ratio on the assumption that a single dominant fertility restoring gene exists in the restorer. From these results, we concluded that the Ogura cytoplasm is identical to that of the wild radish, and the former originated in a population of Japanese wild radish.     

Comparison of leaf and pod disease reactions of beans (Phaseolus vulgaris L.) inoculated by different methods with strains of Xanthomonas campestris pv. Phaseoli (Smith) dye

Summary Common blight disease in beans (Phaseolus vulgaris), caused by the bacterium Xanthomonas campestris pv. phaseoli, reduces crop yield and seed quality. Information is needed on the variation of leaves and pods disease reaction to strains of the bacterium after different inoculation methods. Phaseolus vulgaris cultivars Red Kidney Charlevoix, GN Harris, GN 1140, and GN Emerson were inoculated with three different strains of Xanthomonas campestris pv. phaseoli at two inoculum concentrations (10⁸ and 10⁶ bacterial cells/ml) using water soaking, multiple needle, and razor blade inoculation on leaves, and razor blade scratch, dissecting needle, and razor blade cut inoculation on pods. Differential cultivar disease reactions of leaves, pods, or both to the bacterial strains were observed in some cases. Significant interactions among cultivars, inoculation methods, strains, and inoculum concentrations (leaves) were found. A rapid leaf chlorosis developed 6 to 7 days after inoculation. Strains of bacteria did not show specificity in inducing this reaction, but rapid leaf chlorosis was associated with high inoculum concentration and with the water soaking and multiple needle methods. Another experiment was conducted to count the number of living bacterial cells deposited in the leaf tissue after inoculation by different methods. The number of bacteria deposited by water soaking or multiple needle was higher than that deposited by razor blade.Published as Paper No. 8584, Journal Series, Nebraska Agricultural Experiment Station. Research was conducted under Project No. 20–36.     

The effect of anther orientation on microspore-derived plant production in barley (Hordeum vulgare L.)

Summary The effect of anther orientation on culture response has been examined in a range of barley cultivars of agronomic importance. Anther orientation did not significantly affect the percentage of anthers responding. However, orientation of the anthers in the up position with one lobe in contact with the medium significantly increased the number of green plants produced when compared to anthers cultured in the flat position. Green plantlet production was observed directly from embryoids i.e. without an intermediate callus phase. Cytological examination of the regenerants indicated that the majority of the plantlets possessed the normal barley karyotype. The implications of these results for Barley breeding are discussed.     

Genetic control of low temperature tolerance in germination of the common bean (Phaseolus vulgaris L.)

Summary Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed to increase the success of irrigated common bean in Southern Minas Gerais State. To study the genetic mechanisms controlling these traits and assess the possibility of generating the desirable materials, a diallel cross involving ten cultivars including introductions and pure lines from the breeding program of ESAL was carried out. Speed of germination of the F₂ generation from the crosses was assessed under laboratory conditions at 12°C. The diallel analysis was carried out using Griffing's method IV (1956) and predictions of the cross potential were made by the methodology developed by Jinks & Pooni (1986). The results indicated that the parents differed in germination speed at low temperatures with Small White, A-488 and Rio Vermelho being the most tolerant and Carioca, ESAL 591 the most sensitive. No effect of the reciprocal crosses was observed either for germination percentage or germination speed. The parents A-488, Small White and Rio Vermelho showed the greatest general combining ability. Additive genetic effects predominated for both traits. Our results suggest that cold tolerance can be bred successfully into commercially acceptable cultivars.     

Effects of nucleus,cytoplasm and male sterile nucleus-cytoplasm combinations on callus initiation in anther culture of wheat

Summary Nuclear and cytoplasmic factors affect tissue culture response in wheat (Triticum aestivum), and cytoplasmic male sterility may enhance callus initiation in anther culture. Three wheat nuclear genotypes, each in normal and two alien cytoplasms conferring cytoplasmic male sterility, were evaluated for callus initiation frequency in anther culture. Nuclear genotype had the greatest effect on callus initiation, but cytoplasm and nucleus X cytoplasm interaction also produced significant effects. The nuclear genotype of Chris outperformed Butte and Coteau in all cytoplasms. Ordinary wheat and Triticum timopheevi cytoplasms outperformed Aegilops speltoides cytoplasm. Cytoplasmic male sterility did not increase callus initiation. This suggests manipulating the nuclear genotype is the best strategy for improving the capacity of wheat to initiate callus in anther culture.