Characterization of seed producing pearl millet x elephantgrass hexaploid hybrids     

D. A. Diz  S. C. Schank 《Euphytica》1993,67(1-2):143-149

Summary Successful widespread use of a forage or biomass plant depends largely on its ease of establishment. Elephantgrass (Pennisetum purpureum Schum.) is used for both forage and biomass production, due to its high dry matter production, aggressiveness, perenniality, and forage quality. However, lack of high quality seed has limited the use of elephantgrass and its hybrids to pearl millet (P. glaucum L. R.Br.). Development of a seed-propagated pearl millet x elephantgrass hexaploid cultivar, which would combine desirable characteristics from both of these species, would be highly desirable. The objectives of this study were to characterize morphological and seed-related traits from the selfed progeny of seven hexaploid hybrids, and to determine whether seed size had any influence on these traits. Traits studied included number of tillers, height, leaf length and width, panicles per plant, days to flowering, panicle length, seed set, seed production, and weight of 100 seeds. Genetic differences were found among the progeny of the seven hybrids. Differences were also found between plants derived from large- and small-seed lots within families. Plants descended from larger seed had better growth and seed-related characteristics, which resulted in more desirable plants. These hexaploid hybrids showed potential for direct seeding into the field for biomass or forage production.  相似文献   

Recurrent Addition of the Pennisetum americanum Genome in a P. americanum×P. orientale Hybrid     

S. N. Zado  Amar  Singh 《Plant Breeding》1986,97(2):187-189

An interspecific hybrid involving Pennisetum americanum (2 n = 14) and a diploid cytotype of P. orientale (2 n = 18) was backcrossed to P. americanum using the hybrid (2 n = 16, 7‘A’+ 9 ‘O’) as the female parent. Pollen mother cells of 13 BC₁ plants contained a complement of 14‘A’+ 9 ‘O’ chromosomes. Five BC₂ plants obtained through further backcrossing to P. americanum had 21‘A’+ 9 ‘O’ chromosomes revealing another addition of the P. americanum genome. The role of such recurrent additions of parental genomes in the evolution of polyploid species has been discussed.  相似文献   

The implications of 2n egg gametes in nobilization and breeding of sugarcane     

Shripad R. Bhat  S. S. Gill 《Euphytica》1985,34(2):377-384

Summary Nobilization in sugarcane is viewed from a genetic angle considering the significance of 2n gametes. The inbreeding coefficients resulting from 2n gametes, for first and second nobilizations are worked out. The implication of 2n gametes to sugarcane breeding are discussed.  相似文献   

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. Oleracea spp. Capitata). IV. A resistant 18-chromosome B1 plant and its B2 progenies     

B. Y. Chiang  M. S. Chiang  W. F. Grant  R. Crete 《Euphytica》1980,29(1):47-55

Summary The somatic karyotype and meiotic chromosome behavior were studied in an 18-chromosome B₁ plant derived from backcrossing a triploid (Brassica napus x B. oleracea ssp. capitata) F₁ hybrid to cabbage. It is considered that cabbage chromosomes no. 1 and no. 7 were substituted by two shorter B. napus chromosomes. Meiotic disturbances were more apparent during the late stages of second division. Seed fertility of this plant was largely restored in the second backcrosses with both cabbage and broccoli. 18-chromosome B₂ plants resistant to race 2 of Plasmodiophora brassicae were recovered among the progenies.Contribution no. J. 725 from the Research Station, Research Branch, Agriculture Canada, St-Jean, Québec J3B 6Z8.  相似文献   

Genetical studies of embryo survival and embryo breakdown in Pelargonium × hortorum Bailey     

Ayad J. Kubba  Richard A. E. Tilney-Bassett 《Euphytica》1981,30(3):881-887

Summary The 6×6×4 analysis of variance of the mean percentage embryo survival for six variegated cultivars of Pelargonium × hortorum Bailey, with mutant plastids in their germ layers, and for their isogenic green (G) clones, shows highly significant differences between females (81 to 91 per cent) and between plastid crosses (83 to 91 per cent). Between cultivar differences are attributed largely to additive effects corresponding to additive gene action, and between plastid differences to a lower survival after crosses with white (W) males than with green males. The relationship between overall fertility (% fertilization × survival) and plastid crosses is a stepwise decline in the order G×G>G×W>W×G>W×W (28 to 19 per cent) in which the white embryos growing in a white mother are approximately 30 per cent less fertile than the green embryos in a green mother. The non-surviving embryos are classified into empty, undeveloped and dwarf embryos and submitted to a 6×4 analysis of variance after summing through males. The significant heterogeneity between females is attributed largely to a difference between one cultivar-with a high frequency of dwarf and a low frequency of undeveloped embryos-and the other five cultivars. The absence of a significant plastid effect upon any stage of embryo breakdown indicates that the depressive effect of white plastids is spread evenly throughout development.  相似文献   

Interspecific hybrids of sunflower as a source of Sclerotinia resistance     

S. Rönicke    V. Hahn    R. Horn    I. Grone    L. Brahm    H. Schnabl  W. Friedt 《Plant Breeding》2004,123(2):152-157

Sclerotinia sclerotiorum is considered the most devastating pathogen of sunflower grown in humid environments. In this study, progenies of partial hybrids between Helianthus maximiliani, a wild species that has been shown to be resistant to S. sclerotiorum, and H. annuus were characterized by amplified fragment length polymorphism (AFLP) analysis to identify whether there are introgressions from H. maximiliani into the cultivated sunflower at the molecular level. Wild species‐specific fragments as well as fragments not found in either parent were detected. Progenies tended to cluster together according to the original partial hybrids in the dendrogram by the use of bootstrap procedures. The progenies were studied for their reaction to S. sclerotiorum using artificial inoculation of sunflower heads. Some of the progenies showed a higher level of resistance compared with resistant inbred lines. It was possible to identify two AFLP‐fragments which seem to be linked to Sclerotinia resistance.  相似文献   

Rhizobium specificity of Trifolium ambiguum M. Bieb × T. repens L. hybrid clovers     

W.L. Lowther  H.N. Pryor  R.P. Littlejohn  S.W. Hussain  W.M. Willliams 《Euphytica》2002,127(3):309-315

Growth of full-sib families of an F₁ interspecific hybrid between Trifolium ambiguum M.Bieb and T. repens L, and two generations of backcross hybrids (BC₁F₂ and BC₂F₁) with T. repens as the recurrent parent, were compared to their parental species. Plants were grown in a N-free medium and inoculated with Rhizobium leguminosarum biovar trifolii rhizobia effective on T. ambiguum or T. repens. Hybridisation produced progeny that nodulated with rhizobia from either T. ambiguum or T. repens, but plant growth varied. Mean weights of T. repens and hybrids, particularly F₁ and BC₁F₂, were higher when inoculated with a mixture of strains isolated from field grown T. repens than with the New Zealand inoculant strain for T. repens. When inoculated with the mix of rhizobia from T. repens, mean weights were 242, 189, 132, 125, and 100 mg/plant for T. repens, BC₂F₁, BC₁F₂, F₁ and T. ambiguum, respectively. However, although the mean weight of BC₂F₁ lines was significantly less than T. repens, there was considerable variation in individual full-sib families indicating the potential to select within BC₂F₁ hybrids for high plant growth/symbiotic nitrogen fixation. The weight of T. ambiguumplants inoculated with the New Zealand inoculant strain for hexaploid T. ambiguum was similar to T. repens inoculated with the mix of rhizobia from T. repens (253 and 242 mg/plant, respectively). Mean fresh weights of F₁ hybrid plants were similar when inoculated with rhizobia for T. ambiguum or T. repens (125 and 130 mg/plant, respectively). However, weight of T. repens, BC₁F₂ and BC₂F₁ hybrids inoculated with rhizobia for T. ambiguum were all less than 90 mg/plant. There was a significant relationship between plant fresh weight and ethylene production. The results indicate that measuring weights of inoculated plants growing in N-free media is a rapid initial method of screening a range of plant germplasm for plant growth/symbiotic nitrogen fixation rates. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Male fertility and cytology of triploid hybrids between tetraploidSolanum commersonii (2n=4x=48, 2EBN) and Phureja-Tuberosum haploid hybrids (2n=2x=24, 2EBN)     

Domenico Carputo  Teodoro Cardi  Luigi Frusciante  Stanley J. Peloquin 《Euphytica》1995,83(2):123-129

Summary Solanum commersonii Dun. is a diploid (2n=2x=24, 1EBN) wild species of potential value for potato breeding. It is a reproductively isolated species and cannot be crossed with Tuberosum haploids (2n=2x=24, 2EBN) or other diploid 2EBNSolanum species. In order to overcome the EBN barriers, triploid hybrids were produced between Phureja-Tuberosum haploid hybrids, which form 2n pollen grains by parallel spindles, and tetraploidS. commersonii. Microsporogenesis analysis of the triploids indicated a trend towards low values of chromosome distribution at Anaphase I; lagging chromosomes were often observed as well. Despite these abnormalities, the percentage of stainable pollen was very high, ranging from 5.0% to 74.3%. A high variation in pollen grain diameter was also evident. Parallel and tripolar orientation of spindles at Metaphase II of microsporogenesis was a common feature of all the triploids analyzed, but dyads and triads were observed at a very low frequency. Therefore, also the frequency of 2n pollen was very low; the different size of stainable pollen appears to represent the ploidy levels which are possible according to the distribution of chromosomes in Anaphase I. The results obtained also suggest thatS. commersonii could have minor genes acting at the end of meiosis in such a way that, despite the presence of parallel/tripolar spindles, dyads/triads are not formed.Contribution no. 124 from the Research Center for Vegetable Breeding.  相似文献   

Glucosinolate content in interspecific crosses of Brassica carinata with B. juncea and B. napus     

A. Getinet    G. Rakow    J. P. Raney  R. K. Downey 《Plant Breeding》1997,116(1):39-46

Brassica carinata A. Braun is a highly productive oilseed crop in the Ethiopian highlands, but the seed has a high 2-propenyl glucosinolate content, which is undesirable. The objective of this study was to introgress, through interspecific crosses, genes for low 2-propenyl glucosinolate content from the B genome of B. juncea and C genome of B. napus into the B. carinata B and C genomes and thus develop low glucosinolate B. carinata. The cross [(B. carinata×B. juncea) ×B. carinata] yielded plants that contained only ～ 20 μmoles of 2-propenyl glucosinolate, which was an 85% reduction compared with levels in B. carinata seed. Plants of the [(B. carinata×B. napus) ×B. carinata] cross had normal high concentrations of 2-propenyl glucosinolate. Backcross plants of both interspecific crosses also contained 3-butenyl and 2-hydroxy-3-butenyl glucosinolates. The results of these crosses suggested that genes for glucosinolate synthesis were located on B genome chromosomes of B. carinata because B. napus C genome introgressions did not result in reductions of total glucosinolate contents. The total alkenyl glucosinolate content of one F₃ family of the B. juncea backcross was similar to that of the B. juncea parent. It was concluded that through further selection in this family, B. carinata plants could be identified that would be basically free of 2-propenyl glucosinolate, and have a low total alkenyl glucosinolate content.  相似文献   

Interspecific hybridization between Cicer arietinum and C. pinnatifidum     

P. S. Badami    N. Mallikarjuna  J. P. Moss 《Plant Breeding》1997,116(4):393-395

An interspecific hybrid between Cicer arietinum cv. GL 769 and a wild species C. pinnatifidum was obtained after emasculation, pollination and application of growth regulators. Ovules were cultured and embryos were later dissected to obtain hybrid plants. These plants were albinos and morphologically resembled C. pinnatifidum. Shrivelled seeds were also obtained in 2% of the crosses, which on germination gave rise to albino plants. These plants did not survive beyond 20 days. The hybrid nature of these plants was confirmed by esterase isozyme studies. Hybrid shoots obtained from germinating embryos were cultured on modified ML-6 medium with BAP 2 mg/1, IAA 0.5 mg/1, where they turned green after 3–4 weeks. Transmission electron microscopy (TEM) studies on leaf sections from green hybrid shoots showed an improvement in the chloroplast structure, with better organized grana.  相似文献