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1.
Mesophyll protoplasts were produced from clones of two cultivars of Medicago sativa, Rangelander and Regen S. Protoplasts from the Regen S clone generally gave rise to calli while those from the Rangelander clone would undergo direct embryogenesis. Effects of plant growth conditions, donor tissue pretreatment and protoplast culture conditions on mesophyll protoplast production and subsequent development patterns were investigated. The major factor determining whether or not mesophyll protoplasts would be produced from either of the clones was the pretreatment in water of shoots excised from the donor plants. Pretreatment in water containing growth regulators did not alter protoplast production or development in the Regen S clone. Pretreatment of the Rangelander clone shoots with abscisic acid or naphthaleneacetic acid was slightly beneficial to embryo production while pretreatment with benzylaminopurine was detrimental. Altered leaf morphology induced by growth condition changes did not affect mesophyll protoplast production or subsequent development patterns when shoots were pretreated in water. Culture of protoplasts in liquid droplets or solid agar medium increased low density protoplast survival and subsequent embryo production in the Rangelander clone.  相似文献   

2.
Barley anthers from cold pretreated spikes produced no or few calluses when plated with both loculi in contact with the medium (flat). When anthers were plated with only one loculus in contact with the medium (up), a high proportion of the anthers produced calluses. The top loculus of the up anthers was most productive. Flat anthers, when compared with up anthers, were not only slower to produce multicellular pollen grains (MCPs) and microcalluses, but also produced fewer of them and ceased production earlier. The MCPs and microcalluses in flat anthers grew more slowly and few developed beyond the 30 cell stage. These results establish the importance of anther orientation for barley anther culture.  相似文献   

3.
Summary The subunit composition of glutenin was analysed by SDS-polyacrylamide-gel electrophoresis using two varieties of contrasting pedigrees. Maris Widgeon, a variety of good bread-making quality, was shown to contain 2 glutenin subunits not present in Maris Ranger, a much higher yielding variety that is unsuitable for making bread. A third subunit was only found in Maris Ranger glutenin. To determine if any of these subunits are directly related to bread-making quality, 60 randomly-derived F2 progeny from a Maris Widgeon x Maris Ranger cross were analysed for bread-making quality and for glutenin subunit composition. A strong correlation was demonstrated between the presence of one of the two subunits inherited from Maris Widgeon, and quality. This subunit (termed subunit 1 glutenin) had an approx. mol. wt. of 145,000. It was also found in Maris Freeman, a bread-making variety selected from the same cross previously made in 1962. In further crosses involving Maris Widgeon or its descendants, more bread-making varieties have been produced in the last decade at the Plant Breeding Institute, Cambridge and all but one have inherited glutenin subunit 1. The subunit has been traced back through Holdfast to White Fife, a Canadian hard spring wheat of excellent breadmaking quality. Some 67 varieties were screened for the presence of glutenin subunit 1 and it was found in 31% of them. Several unrelated varieties of good bread-making quality did not contain subunit 1 glutenin.  相似文献   

4.
Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F2 progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.  相似文献   

5.
Summary Information regarding the relative levels of salt tolerance between cultivars of Kentucky bluegrass (Poa pratensis L.) is lacking. The objectives of this study were to 1) develop a simple, quick and sensitive method of screening turfgrass species for NaCl tolerance and 2) to compare the relative salt tolerance of five cultivars of Kentucky bluegrass (Ram I, Adelphi, Baron, Bensun, and Nassau) to other known salt tolerant turfgrass species such as alkalaigrass (Puccinellia distans (L.) Parl. cv. Fults) and two cultivars of red fescue (Festuca rubra L. Dawson, and Checker).Alkalaigrass and both cultivars of red fescue retained a high level of salt tolerance compared to the Kentucky bluegrass cultivars. Significant variability in salt tolerance was apparent among the Kentucky bluegrass cultivars with Adelphi and Ram I exhibiting the best overall tolerance.  相似文献   

6.
The bean-pod weevil (BPW), Apion godmani Wagner, often causes heavy losses in crops of common bean (Phaseolus vulgaris L.). Farmers need resistant bean cultivars to minimize losses, cut production costs, stabilize seed yield, and reduce pesticide use and consequent health hazards. To design effective breeding methods, breeders need new and better sources of resistance and increased knowledge of their modes of inheritance. We therefore: (1) compared sources of resistance to BPW, (2) studied the inheritance of resistance, and (3) determined whether the sources possess similar or different genes for BPW resistance. The following sources of resistance, originating from the Mexican highlands, were evaluated for 3 years at INIFAP-Santa Lucía de Prias, Texcoco, Mexico: Amarillo 153, Amarillo 169, Hidalgo 58, J 117, Pinto Texcoco, Pinto 168, and Puebla 36. All except Puebla 36 were crossed with the susceptible cultivar Jamapa. Amarillo 153 and Puebla 36 were crossed with another susceptible cultivar, Bayo Mex. The parents, F1 hybrids, and F2 populations were evaluated for BPW damage in 1992. Backcrosses of the F1 of Jamapa/Pinto 168 to the respective susceptible and resistant parents were also evaluated in 1992. All seven resistant accessions were crossed in all possible combinations, excluding reciprocals. The resulting 21 F1 hybrids and 21 F2 populations were evaluated for BPW damage in 1994. J 117 had the highest level of resistance to BPW. Pinto Texcoco and Puebla 36 had the highest mean damage score of all seven sources of resistance. The F1 hybrids between susceptible parents and resistant sources were generally intermediate. Two genes segregating independently controlled the BPW resistance in each accession. One gene, Agm, has no effect when present alone, whereas the other gene, Agr, alone conferred intermediate resistance. When both genes were present, resistance to BPW was higher. Based on mean BPW damage scores, all 21 F1 hybrids and their F2 populations, derived from crosses among seven resistant accessions, were resistant. However, data from individual plant damage scores in F2 populations of Amarillo 169/Pinto 168 and Pinto Texcoco/Pinto 168 suggested that at least one gene in each of the three accessions was non-allelic. Data also indicated that Amarillo 169 had a dominant gene that conferred high levels of BPW resistance, irrespective of the alleles at the other locus; and that Pinto Texcoco and Pinto 168 possessed two different genes for intermediate resistance.  相似文献   

7.
Summary Nine genotypes of sorghum were screened for their relative susceptibility to zinc deficiency in soil. All the varieties were highly responsive to zinc application, but behaved differently under zinc stress conditions in respect of dry-matter production, zinc concentration and uptake. The varieties, JS-263, 29/1, JS-20 and Son 127×SL-245 and CSH-1 were relatively more susceptible to zinc deficiency than 3677×6352, Son 3×SL 209, CSH-3 and 2077×1151. re]19730102  相似文献   

8.
The unity of organisms can be viewed in terms of the concepts of enkapsis and complementarity. A model (or a type) represents those properties (of elements, structure, and system) which renders cases - the organisms under consideration — comparable. Comparability is established by operations (or metamorphoses) which relate a case to a model. Therefore, the model and the operations must be enumerated together, if a certain morphology is to be established and applied. Two models, which in some way are related, are conjunct, otherwise they are disjunct. If one model is deducible from the other, they are enkaptic conjunct. If the models are essentially different, that is to say that they cannot be transduced into each other, although they condition each other, they are complementary conjunct: although not comparable themselves, only both together describe a case (or a set of cases) completely. Now, the comparability of a case with two models is considered. The two basic patterns of general comparability are homology and analogy. If the two models are complementary conjunct, nine patterns of special comparability can be distinguished. Each is named in accordance with the general meaning of homology and analogy and, as far as possible, with conventional scientific usage. With minor modifications the terminology also applies to more complicated patterns of comparability including distinct or different conjunct models.  相似文献   

9.
Predominance and tissue specificity of adenine methylation in rice   总被引:2,自引:0,他引:2  
Summary Using A and C methylation-specific restriction enzymes, namely, MboI, Sau3AI, DpnI, MspI, and HpaII, total rice cv Basmati 370 DNA, repetitive DNAs, and a specific repeat sequence indicated an abundance of adenine methylation. Although cytosine methylation in 5-CCGG-3 sequences suggested more CpC methylation than CpG, the C methylation in sequence 5-GATC-3 was comparatively less than A methylation. Furthermore, the presence of adenine methylation was tissue specific; it was predominant in rice shoot DNA as compared to embryo DNA. This pattern was also observed in two other cultivars of rice, i.e., R-24 and Sona, and was again confirmed using a cloned probe of a specific repeat sequence. Besides the changes in adenine methylation, there was also a qualitative change in 5mC from CpG to CpC dinucleotides in these two tissue systems.  相似文献   

10.
In a previous study, cDNA microsatellite markers were described in apricot (Prunus armeniaca L.). Specific PCR primers were designed to amplify the microsatellite-containing regions from genomic DNA in different Prunus species. In the present work, cDNA microsatellite markers were developed in the hexaploid Prunus domestica L. species and polymorphism was ascertained in a segregating plum population. Co-dominant mendelian segregation of alleles was demonstrated and microsatellite polymorphism displayed up to 6 alleles per SSR locus per individual. Parentage lineage of three full-sib European plum cultivars (cv. Cacanska najbolja, Cacanska rana and Cacanska lepotica) was reconstructed by the analysis of the above nuclear SSR markers, completed by four chloroplastic microsatellite loci. The six most informative nuclear loci enabled discrimination between the three Cacak cultivars and unrelated individuals as well as the previously proposed parents, Wangenheim and Pozegaca. Data obtained support previous evidence that these cultivars originated from the Stanley cultivar. However, SSR analysis finally excluded Wangenheim as the other possible parent. Based on the results obtained with nuclear and chloroplast SSR loci, we propose the origin of those three Cacak cultivars in a cross between Stanley as the mother plant and Ruth gerstetter as the pollinator. Furthermore, we demonstrate the utility of these apricot SSR markers for genotype fingerprinting of the hexaploid plum cultivars.  相似文献   

11.
Beans (Phaseolus vulgaris) are regarded as a susceptible crop to suboptimal temperatures. In temperate regions, low temperatures reduce establishment of beans when planted early in the growing season. Seeds of 14 cultivars/lines or beans were germinated in petri dishes at a constant 8, 10, 12, or 18°C or at 12 h alternating temperatures of 10/8, 12/8 or 18/8°C. Differences in germination percentages and rates between cultivars/lines were significant, especially at low temperatures. Cultivars/lines that germinated best and quickly at constant 8°C were Volare, Great Northern (G.N.) Tara, G.N. Belneb # 1, G.N. Spinel, and San Cristobal. Germination percent and rate of Pinto-UI-111 and Canadian Wonder increased significantly when temperatures were increased by 2 to 4°C for 12 h per 24 h, compared with a constant 8°C. Whereas, germination of G.N. Belneb # 1 was reduced. Polyacrylamide gel electrophoresis was used to study the effect of cold treatment on polypeptide patterns of seven cultivars/lines. Seeds were germinated at 18°C constant for 96 h or at 18°C for 48 h followed by 48 h at 2 or 8°C. During cold treatment the synthesis of some polypeptides increased. Volare, G.N. Tara Pinto-UI-111 and Canadian Wonder showed changes in polypeptide patterns, while Alubia-33-1, Michigan 84100 and BAT-1225 showed no changes in polypeptide patterns if compared to the control (96 h at 18°C in the dark). This suggests a likely essential role of these proteins in the development of chilling tolerance.  相似文献   

12.
Summary Thirteen maize (Zea mays L.) populations including five adapted, five adapted x exotic, two composites of adapted and exotic, and one exotic selected for adaptability were crossed in a diallel mating system. The parents and 78 crosses and nine check hybrids were evaluated for grain yield and plant height in five environments. The Gardner-Eberhart model Analysis II indicated that additive and nonadditive gene effects accounted for 60 and 40% of the total variation among populations, respectively, for grain yield and 86% and 14% of the total variation, respectively, for plant height. Components of heterosis were significant in the combined analysis for both traits. Adapted Corn Belt populations tended to have higher performance in crosses and greater values of variety heterosis than 50% adapted populations. Nebraska Elite Composite, Corn Belt x Mexican, and Corn Belt x Brazilian showed high mean yields in crosses, however, they were not among those with high estimates of variety heterosis. One exotic population (Tuxpeno x Antigua Grupo 2) and three adapted populations [307 Composite, NB(S1)C-3, and NK(S1)C-3] might be combined together to form a high-yielding population. It may be possible to synthesize two useful populations for reciprocal recurrent selection by grouping Tuxpeno x Antiqua Grupo 2, NB(S1)C-3, and NS(FS)LFW-8 into one population and NK(S1)C-3, KrugxTabloncillo, and 307 Composite in the other one.Contribution from the Department of Agronomy, University of Nebraska, Lincoln, NE 68583. Published as Paper No. 8011. Journal Series, Nebr. Agric. Exp. Station. Research was conducted under Project 12-049  相似文献   

13.
Summary One hundred and twenty-two varieties, lines and wild accessions of Lycopersicon were screened under three different regimes during the autumn/winter season of 1982–83 and 1983–84 for resistance to tomato leaf curl virus (TLCV). L. hirsutum f. glabratum (B6013) and L. hirsutum f. typicum (A1904) proved to be highly resistant to TLCV in all three environments. Various accessions of L. peruvianum were also highly resistant. L. pimpinellifolium (A1921) exhibited no TLCV symptoms within 90 days. Of the cultivated varieties, Acc 99 exhibited the minimim score for susceptibility; AC 142, Collection No. 2, Kalyanpur Angurlata and HS 101 had a low rating for virus incidence. The inheritance of resistance was studied in the interspecific crosses between a TLCV resistant line of L. pimpinellifolium (A1921) and five (HS 101, HS 102, HS 110, Pusa Ruby and Punjab Chhuhara) susceptible cultivars of L. esculentum. Parents, F1, F2 and backcross progenies were artificially inoculated with local strains of TLCV using vector the viruliferious whitefly, Bemisia tabaci (Genn.). Data indicated that the resistance of L. pimpinellifolium (A 1921) is monogenic and incompletely dominant over susceptibility.  相似文献   

14.
In Fuji, the production of ethylene was increased with the addition of AgNO3 and inhibited with the addition of 10 M aminoethoxyvinylglycine (AVG). The addition of 80 M AgNO3 to transformed explants of Fuji cultured on selection medium resulted in increased ethylene production (20 l l–1) at 3 weeks. Under examining the effect of AgNO3 in Fuji, the 40 M AgNO3 showed with higher 33.8% and 6.5% in the efficiency of regeneration and transformation. However, ethylene production in Gala explants treated with 10M AgNO3 (3 l l–1) decreased after 2 weeks compared with the control (5 l l–1). Although the regeneration efficiency of Gala with 10 M AgNO3 was higher (41.1%) than the control (20.1%), there was no significant difference in the transformation efficiency at the same concentration. Shoot regeneration of Fuji and Gala was completely inhibited with 10 M AVG. These results suggest that the addition of AgNO3 affects the efficiency of Agrobacterium-mediated gene transfer in Fuji.Eun Soo Seong, Ill Min Chung- These two Authors Contributed equally to this work  相似文献   

15.
The number of primary feathers in a birds wing has been used as a systematic character since the first half of the nineteenth century. During the years, though, the definition of which feathers to count as a primary has changed and today the species historically denoted as having only nine primaries are instead said to have, for example, nine functional primaries. In this study, I investigated the borderline between nine-primaried and ten-primaried birds to search for a proper definition of the term nine-primaried. A total of 161 specimens of 104 bird species, mainly passerines, were examined. All species examined had ten primaries although the nine-primaried species had primary ten more or less concealed under primary covert nine. The number of primary coverts has decreased over time, with ten primary coverts as the ancestral state within Passeriformes and nine primary coverts among most oscine species. In conclusion, a proper definition of nine-primaried might be with primary ten concealed by primary covert nine. This definition includes all taxa historically denoted nine-primaried, i.e. systematically it is a definition of a paraphyletic group. The term nine-primaried is thus too inclusive to be of more than very limited systemtic value and, consequently, the New World nine-primaried oscines group might gain from a new denotation.Electronic Supplementary Material Supplementary material is available for this article at  相似文献   

16.
Summary Differences in reaction to exogenous insulin and adrenalin were studied among chickens of Leghorn, White Rock and Rhode Island Red breeds, using level of blood glucose as indicator of the reaction to hormones. It was found that: 1.) The physiological quantity of glucose in blood in chickens of the three breeds ranged from 157 to 194 mg %. 2.) The reaction of chickens to insulin and adrenalin given alternately, measured by changes of blood glucose, differed according to the breed. The smallest reaction to hormones was in Leghorn, the biggest in White Rock. 3.) The chickens of Leghorn and Rhode Island Red breeds, as well as Leghorn and White Rock breeds, differed significantly in maximal glucose level after adrenalin, 4.) The correlation between the normal quantity of blood glucose and the body weight of birds appeared highly significant in cockerels of all three races combined.  相似文献   

17.
The extension into tropical areas of Beverton and Holt's yield per recruit approach for stock assessment represents a straightforward case of normal science, the common Kuhnian counterpart to his much rarer paradigm shifts. It is shown that the normal science which, in recent decades, has led to new methods for estimating growth, mortality and other statistics required for yield per recruit analyses in data-sparse environments, has not only enriched fisheries science and aquatic biology as a whole, but has also contributed to identify the limitations of the single-species research programme originally defined by Beverton and Holt. The most likely prospect for that programme, in the tropics and elsewhere, is to become a component of the multispecies, or rather ecosystem approach that is emerging, and to which Beverton and Holt will have contributed many of the concepts, and much of the rigour.  相似文献   

18.
Summary Progenies of a tetraploid 1BL/1RS wheat-rye translocation line, CV 256, selected from the cross Cando x Veery, were analyzed by means of Giemsa C-banding. CV 256 is cytologically stable for the presence of the 1BL/1RS translocation but still segregating for A- and B-genome chromosomes of Cando and Veery. In CV 256, nucleolar activity of the 1RS NOR locus is suppressed, as judged by the absence of a secondary constriction in that rye segment and the capability of organizing nucleoli. PAGE analysis of prolamins confirmed the presence of two 1RS secalins in all single seeds analyzed. SDS-PAGE analysis of reduced glutenins of single seeds indicated that some seeds contained the Cando Glu-B1 locus (subunits 6+8), some contained the Veery Glu-B1 locus (subunits 7+9) while others contained all four subunits, indicating that the material was heterozygous. Pm8 resistance is expressed in the tetraploid 1BL/1RS translocation line based on the reactions of six well-defined powdery mildew isolates. However, Pm8 resistance is not expressed in the hexaploid wheat cultivars Olymp, Heinrich and Florida, which also contain the 1BL/1RS translocation. Obviously, the existence of the 1BL/1RS translocation is not a proof for the expression of the associated genes. PAGE results did not show a clear linkage between powdery mildew resistance and the presence of 1RS secalins.  相似文献   

19.
Summary The genetics of tiller number at different development stages in rice was studied in a 6 x 6 diallel cross set involving six indica rice varieties in which a large difference of phenotypes existed. Estimates of genetic parameters following Hayman's method showed significant additive and nonadditive gene action, and the latter appeared to be solely due to dominance. High tillering ability was inherited as a partial dominant character conditioned by two or more blocks of genes, and var H1459 had more dominant genes, whereas Zhu-Yun-Luo had more recessive ones. Combining ability analysis by Griffing's method also indicated significance of both additive and nonadditive effects, but the former was more important than the latter. H1459 and Bi-Yu-Zao-Luo were good general combiners, and their hybrids H1459 x Le-Yi and Zhu-Yun-Luo x Bi-Yu-Zao-Luo were better crosses for combining an optimum tiller number with high percentage of productive tiller. An identical polygenic system appeared to be responsible for the genetic control of both tiller number at the different growth stages and the terminal character, productive tiller number. However, with growth of the plant, relative contributions of nonadditive gene action and environmental factors to the variation decreased, while those of additive gene action increased. Selection for high tillering ability, therefore, should be exercised at peak tillering or later stages.  相似文献   

20.
Summary Genetic analysis for leaf rust reaction of two widely adapted cultivars, Sonalika and WL 711, has been done using 21 near isogenic Lr lines and rust culture IL004 — avirulent on the two cultivars and all the Lr lines used. The segregation pattern in the F2 generation indicated the presence of a recessive gene in Sonalika and of a dominant gene in WL 711. These genes in cultivars Sonalika and WL 711 have been identified as Lr 11 and Lr 13, respectively. Gene Lr 13 is no longer effective in WL 711 but it continues to give field resistance in the backgrounds of Chris, Prelude and Thatcher. There has been no significant change in the virulence spectrum of the leaf rust pathogen in India with the release of WL 711. High susceptibility of WL 711 seems to be due to the evolution of more aggressive forms of the pathogen to this cultivar. The gene Lr 11, which behaves as a recessive in Sonalika, was effective against leaf rust when this cultivar was released. The high susceptibility of Sonalika is probably due to an increase in the frequency of race 77 virulent on Lr 11. Lr 11 has shown a dominance reversal in the background of Sonalika. Present results suggest that interaction of resistance genes with the background genotype must be studied for their effective use in breeding programme.  相似文献   

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