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1.
An evaluation of seed and seedling drought tolerance screening tests in wheat   总被引:10,自引:0,他引:10  
A. Blum  Bebi Sinmena  O. Ziv 《Euphytica》1980,29(3):727-736
Summary A series of experiments was performed in order to evaluate the significance of seed germination and seedling growth in osmotic media as screening methods for drought tolerance.Ten spring wheat (Triticum aestivum L. em Thell.) and one durum wheat (Triticum durum Desf.) were tested under controlled environments, using polyethylene glycol-6000 (PEG) solutions as the moisture stress inducing media.Tolerance in the rate of endosperm utilization, under stress, prior to the onset of germination varied among cultivars.Germination rate or injury to germination at various concentrations of PEG differed significantly among cultivars. Cultivar rating with respect to injury to germination changed with stress levels. Injury to germination did not correlate with endosperm utilization rate in PEG or in water.Germinating seedlings were tolerant to extreme desiccation up to the stage of emergence of the first leaf from the coleoptile.Growth of photosynthesizing seedlings was monitored as they were carried through an increasing concentration gradient of PEG solutions, ranging from –5.9 to –11.3 bars of water potential. Cultivars significantly differed in seedling growth tolerance to increasing levels of water stress. Seedling growth tolerance across cultivars was not correlated with their germination responses under srress.It is concluded that tolerance to water stress in growing seedlings can be screened for by using PEG-containing nutrient solutions. It can not be predicted from germination tests in osmotica.Work was done under a US-Israel Binational Science Foundation (BSF) Grant no. 1654/78.Contribution from Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 192-E, 1979 series.  相似文献   

2.
Problems in breeding and cytology of sugar cane   总被引:1,自引:0,他引:1  
G. Bremer 《Euphytica》1963,12(2):178-188
Occasion for writing this article was the appearance of two papers of Price, one concerning the occurrence of apomixis in sugar cane, the other dealing with cytological results of intra-and interspecific crosses of Saccharum. Especially in the latter he criticized Bremer's discovery of endo-duplication during megasporogenesis in Saccharum forms.The present author formulates his stand-point by an ample discussion of endoduplication as cause of chromosome increase in Saccharum crosses. The phenomenon of parthenogenesis is treated in relation to hybridization and speciation. The author concludes that Price gives evidence of insufficient understanding of endo-duplication while also about the occurrence of parthenogenesis he cannot agree with him.  相似文献   

3.
Erna Bennett 《Euphytica》1964,13(1):44-48
A modification of de Lautour's technique for grass leaf chromosomes is described which makes possible rapid sampling and bulk processing of grass shoot tissues for cytological examination. These tissues have a number of advantages over the root-tip tissues normally used for this purpose, of which the most important is that the supply of suitable cells in division is independent of season.  相似文献   

4.
Summary Tetraploid beets have produced interesting results abroad. This is the reason that in 1950 the Foundation for Agricultural Plant Breeding initiated a program for the development of tetraploid strains. By treating germinating seed with colchicine enough tetraploids can be secured, provided the material be examined during the first and the second year.Cytological studies made in 1951 with the aid of the phase-contrast microscope showed that a 0.1% colchicine solution is preferable to a 0.2% solution. The cytological examination has the object of purifying the material. If diploid cells are found the plants are discarded. In order to increase the number of tetraploid seeds it is necessary to examine the beets again during the second year. In 1951 this was done by studying the young leaves in the rosette stage and by taking the axillary leaflets of young stalks. As the number of tetraploids in the offspring was disappointingly small in 1952 the work was organized somewhat differently. Only one tetraploid stalk of each plant was kept, all other stalks were removed.The investigations are being continued.  相似文献   

5.
Summary A rapid fluorescent in situ hybridization protocol, which can be completed in one working day, has been utilised to visualize chromosome preparations of barley, chickpea, white clover, millet, rye, sugarcane, wheat, Aegilops spp. and Leymus spp. Both total genomic DNA and cloned nuclear rDNA were used as a probe. This protocol has the advantage of brevity and flexibility over more conventional approaches, and has made fluorescent in situ hybridization a routine cytological procedure.  相似文献   

6.
A. K. Handique 《Euphytica》1986,35(2):631-632
Summary In nature, Solanum khasianum Clarke (syn. S. varium Dunal) is a self pollinated plant. However, artificial cross pollination is feasible when pollination is done around the time of anthesis, which is between 09.30 and 10.00. Due to prevalence of heterostyly bud selection has to be highly specific.  相似文献   

7.
S. J. Dalton  P. J. Dale 《Euphytica》1985,34(3):897-904
Summary Eight Lolium multiflorum genotypes were micropropagated for over one year. Using Murashige & Skoog's basal medium, various growth regulators (6-benzylaminopurine, indole acetic acid, adenine sulphate) were tested for their effect on micropropagation. Plantlet handling methods, culture conditions and culture procedures were also compared. Differences were observed in rates of micropropagation between plant genotypes. Under the best conditions for micropropagation, an average of approximately 50 tillers were produced in a 5–6 week period, compared with an estimated 8–15 tillers from soil-grown plants over the same period. Tillers must reach a certain developmental stage before they will grow independently, therefore the number of surviving propagules at subculture under micropropagation and in soil is about half the number of tillers produced. A proposed system for the micropropagation of Lolium multiflorum is described.  相似文献   

8.
Summary In 1950, 1951 and 1952 germinated seed of various sugar beet and fodder beet strains were treated with colchicine, with the object of obtaining tetraploid plants. The plants were examined cytologically in their first and second year. Only stalks of the C0 generation (the treated one) in which no diploid cells were found were kept for seed production.By raising the tetraploid C1 plants in greenhouses the year that the seed has been harvested and by vernalizing the young plants seed production is made annual. For vernalization the plants are kept in a potato storage room cooled by outside air to a temperature of about 5°C and under a day length of 24 hours.The results of the cytological examination demonstrated that collecting seed from tetraploid stalks of the C0 presents advantages. The C1 had about 77% tetraploids.It should be noted that the determination of the chromosome numbers of polyploid material is preferable to measurements of stomata or pollen grains as the latter are not reliable.The investigations are being continued. Yield trials with tetraploid material have been made by D. Kloen.  相似文献   

9.
J. Sneep 《Euphytica》1958,7(2):119-122
In spinach the breeding of hybrid varieties is attractive because this may result in a heterosis and/or a transgressive effect. Resistance to downy mildew [Peronospora spinaciae (Mont.) de By] and against mosaic (Cucumis virus 1) can be combined rather easily, since in both cases the resistance depends on one dominant gene. Besides a hybrid variety excludes the growing of later generations.However, a careful removal of all pollen-producing plants demands so much labour that a production of hybrid seed on a commercial scale involves great difficulties. The creation of an entirely female variety would be a solution for this problem. An outline has been given of the way in which such a variety can be developed, starting from purely female and from intersexual plants.It is possible to simplify the production of hybrid seed by using a round-seeded female parent and a prickly-seeded male parent. Moreover this will prevent errors: all plants can then be harvested and threshed at the same time and in cleaning the prickly seed can be separated mechanically from the round-seeded commercial seed. The use of a prickly-seeded male parent will be an extra check on the possible growing of later generations by others.  相似文献   

10.
The breeding of scab-resistant frame cucumbers in the Netherlands   总被引:2,自引:0,他引:2  
J. M. Andeweg 《Euphytica》1956,5(2):185-195
Summary Scab caused by the fungus Cladosporium cucumerinum, may cause serious damage to frame cucumbers. Bulbosan (trichlorotrinitrobenzene) is an effective chemical means of control. Between 1945 and 1954 this German fungicide could not be supplied, and, as a result, the need for resistant varieties became very great.Before 1920 scab-resistance in pickling cucumbers was already known to Dutch growers. Selection started around 1920 on the initiative of W. G. v. d. Kroft and resulted in scab-resistant pickling cucumbers of which Baarlose Nietplekker VI is still widely grown. In 1948 G. W. v. d. Helm (Exp. Garden at Sloten) started breeding a scab-resistant yellow slicing cucumber destined for gardeners in the neigh-bourhood of Amsterdam. The resistant variety Highmoor was used as one parent. In 1954 the yellow variety Vios and the white variety Mabro were introduced. In 1952 G. W. v. d. Helm at the Exp. Garden Sloten, and J. M. Andeweg at the Institute of Horticultural Plant Breeding, Wageningen, simultaneously started breeding green scab-resistant frame cucumbers, using Highmoor as the resistant parent. In 1955 the experimental garden at Sloten introduced the scab-resistant green slicing cucumbers Amato and Proso, while in 1956 the Institute of Horticultural Plant Breeding introduced the scab-resistant green slicing cucumber Esvier. In 1953 seed of 2 first-backcross populations was supplied by the Institute to seed growers. At present intensive breeding for scab-resistance is also being carried out by a number of Dutch seed growers.Scab-resistance depends on one dominant gene; and young plants can readily be tested for resistance. Consequently a backcross scheme can easily be carried out. Rapid breeding is possible because at least 2 cultures can be carried out yearly. If necessary, cuttings of promising plants can be taken. Before and after artificial pollination the flowers can be tied up with raffia. It is simpler, however, to pinch the flowers with a special stainless clip as originally used for grafting cucumbers.The uniform fruit colour of the Dutch green frame slicing cucumbers is a recessive character; the fruit length of the Dutch varieties is dominant.  相似文献   

11.
A new version is presented of the hypothesis of McMillan (1937) to explain the segregation ratios for dwarf growth in hexaploid wheat. By crossing the series of substitution lines Chinese Spring (Timstein) with tester lines for each of the dwarfing genes of Timstein these two genes could be localized in the chromosomes 4 B (VIII) and 2 D (XX), respectively. These results combined with those of Hurd and McGinnis (1958) justify the conclusion that in hexaploid wheat a locus of a dwarfing gene occurs on each of the chromosomes 2 A (XIII), 4 B (VIII) and 2 D (XX).  相似文献   

12.
肥料与修剪高度对深圳高尔夫球场果岭草坪的影响   总被引:1,自引:0,他引:1  
费凌  干友民  刘媛 《中国农学通报》2006,22(10):267-267
分别对深圳高尔夫球场两个练习果岭分别施播两种粒径和化合技术均不同的缓释肥后,对其草坪草生长速度、绿叶率变化、灼烧斑点的测定和比较,结果表明IBDU缓释肥粒径大,显效速度快,但肥效期短,可适用于北方或气候冷凉地区的高尔夫球场;UF缓释肥粒径小,显效速度稍慢,但肥效期长,缓释性高,适宜深圳及周边地区高尔夫球场果岭施用。而对6个果岭分别在留茬高度4.2mm,4.5mm,5mm下测速发现,在平常比赛中推荐使用留茬高度4.5mm的果岭,锦标赛中建议果岭留茬高度保留至4.2mm。  相似文献   

13.
Summary Chromosme numbers were determined for 56 Hemarthria altissima (Poir.) Stapf et C. E. Hubb. introduction, forty of these were diploid (2n=18) and 16 were tetraploid (2n=36). These results, combined with previous findings, show that all but three of the tetraploids in the USDA Hemarthria altissima collection originated north of 20 S latitude. All other introductions collected throughout southern Africa were diploid. Meiosis was regular in a hexaploid, 6 tetraploid and 32 diploid introductions but a low frequency of quadrivalents was found in the teraploids. H. uncinata R. Br. and H. uncinata var. spathacea (Domin) Vickery were found to have 2n=36 chromosomes H. compressa (L.f.) R. Br., introduced from Japan, had 2n=54 chromosomes. No major cytological abnormalities exist in these Hemarthria species. Significant variation exists among the ploidy levels for cold tolerance and in vitro organic matter digestion to provide the basis for a forage improvement program.Joint contribution from the Department of agronomy. Institute of food and Agric. Sciences (IFAS), Univ. of Florida. Gainesville, Fl and, Plant Genetics and Germplasm Institute, USDA, Beltsville, MD Published as IFAS Journal Series No. 2849.  相似文献   

14.
G. Bremer 《Euphytica》1961,10(1):59-78
In this article a survey is given on sugar cane breeding, as it was performed in Java during a period of about fifty years. When in the eighties of the nineteenth century sugar cane was heavily affected by the sereh disease it was Soltwedel, the first director of the Sugar Experiment Station Midden Java, who tried to obtain sereh resistant cane varieties by species hybridization, until his early death intervened. The first species hybrids were obtained in 1893 by Wakker, who crossed noble sugar cane, Saccharum officinarum, with Kassoer, considered by him as a wild species. In later years it appeared from morphological investigations by Jeswiet (1916) and from cytological investigations by Bremer (1921) that Kassoer is to be considered as a spontaneous hybrid between S. officinarum and S. spontaneum, the wild glagah. In 1895 Kobus imported the Indian sugar cane Chunnee in Java. Chunnee, not belonging to S. officinarum, was crossed with noble sugar cane (for the first time) in 1897. From this cross many clones were obtained which appeared to be resistant against the sereh disease but were highly susceptible to mosaic. The continued crossing between noble sugar cane and Kassoer, however, was very successful. Many clones were obtained, which as commercial varieties, showed a high degree of resistance against sereh disease and mosaic and moreover gave a much higher sugar production than the susceptible varieties of noble sugar cane.The following terms are introduced: first, second and third nobilisation of the wild S. spontaneum. Kassoer cane itself is a product of the first nobilisation, the direct cross between noble sugar cane and wild cane. The back cross between Kassoer and noble sugar cane is called the second nobilisation. When cane varieties belonging to the second nobilisation are crossed again with noble sugar cane, the third nobilisation of S. spontaneum is said to take place. The well-known sugar cane variety 2878 P.O.J. belongs to the third nobilisation.In all clones investigated Saccharum officinarum has 2n=80 chromosomes. Within S. spontaneum types occur which in chromosome number vary from 2n=48 to 2n=128. The Java glagah has 2n=112 chromosomes.Clones of the first glagah nobilisation S. officinarum (n=40) x S. spontaneum (n=56) did not have 2n=40+56 chromosomes, but 2n=40+40+56=136 chromosomes.In relation to the taxonomy of Saccharum many other cytological details are given. Within S. officinarum the basic chromosome number x=10. About S. spontaneum opinions are divided. The author supposes that x=6,8 and 10 are basic numbers of S. spontaneum.  相似文献   

15.
Summary Dihaploids were produced from tetraploids resistant to potato cyst nematode (Globodera pallida (Stone)). High levels of resistance were found in the dihaploids and three were used to produce tetraploid progenies by crossing them with susceptible tetraploid cultivars. One dihaploid, PDH505, produced more highly resistant offspring than the other two, PDHs 417 and 418. The latter gave progenies whose levels of resistance were similar to those obtained from susceptible dihaploids crossed with resistant tetraploids.The differences between the progenies of the resistant dihaploids were probably due to different modes of unreduced gamete formation (PDH505 producing gametes by first division restitution (FDR) and PDHs 417 and 418 by second division restitution (SDR)) although cytological studies would be necessary to confirm this. The methods by which dihaploids could be utilised in a tetraploid potato breeding programme are discussed in relation to the mode of unreduced gamete formation.  相似文献   

16.
S. Tokumasu 《Euphytica》1976,25(1):463-470
Summary Amphidiploids (Brassicoraphanus) were produced by means of colchicine treatment of F1 hybrids between Brassica japonica Sieb. and Raphanus sativus L. The cytology of the amphidiploids was studied from F1 to F3 generations. Some plants had the euploid chromosome number 2n=38, whereas others had the aneuploid number 2n=37. One or two of either quadrivalents or trivalents, as well as some univalents, were seen in most of the plants examined. All the plants showed a low seed fertility. In F3 generation there arose some yellow-flowered plants, all of which showed a higher seed fertility than normal white-flowered plants. It is postulated that the change of flower colour might originate in the segmental exchange of only partially homologous chromosomes following multivalent formation. A gene causing white flower colour was perhaps closely linked to a gene causing sterility, and both genes were probably excluded together through the segmental exchange of the chromosomes. Therefore, it can be said that the increase of fertility was induced by cytological irregularity.  相似文献   

17.
Summary The problem of mutagen-induced sterility has been especially studied in barley by Gaul, and in Arabidopsis by Müller and by van der Veen. Their results and conclusions are essentially confirmed and extended by the present Arabidopsis experiment, which compares EMS with X-rays.For a given treatment, M2-fertility is correlated with M1-fertility, but mutant frequency in M2 is equal for the different M1-fertility classes. It follows that efficiency in mutation breeding can be increased by pre-selection for fertility in M1, and by using doses which do not make fully fertile M1-sectors too rare.EMS is more efficient than X-rays by a factor 4 at equal M1-fertility, and a factor 3 at equal M2-fertility. As a result of difference in fertility spectrum, fertility improvement from M1 to M2 is better for X-rays than for EMS.A considerable load of diplontic sterility and of embryonic lethals (non-germinating seeds) is simply the toll one has to pay for the higher mutant frequency after EMS.Fortunately, part of the diplontic sterility can be pre-selected against in M1, and maternally conditioned embryonic lethals can be selected against by discarding seedlots from individual M1-sectors which show reduced germination. (M2-line selection may also be practised against recessive embryonic lethals and seedling lethals.)  相似文献   

18.
J. W. Lackamp 《Euphytica》1966,15(3):291-296
Although the polycross methods developed by Tysdal, Frandsen and Wellensiek are mostly considered, also by the authors themselves, to be practically the same, those applied by Tysdal and Frandsen essentially differ from the method of Wellensiek. The former authors try to find combining ability while the latter attempts to detect genetic differences. Imperfections in the logical conception, combined with practical difficulties which have to be faced, while carrying out an ideal program, are often responsible for a less successful result of the polycross method in looking for the best combining ability. There are no such imperfections in the conception of Wellensiek's method. Possibilities are being explored to develop a method ensuring a good determination of combining ability of a grass clone by means of an I1-generation derived from one individual through self-pollination.  相似文献   

19.
F. Bakos    É. Darkó    G. Ascough  L. Gáspár    H. Ambrus    B. Barnabás 《Plant Breeding》2008,127(3):235-240
The in vitro selection of microspores and microspore‐derived structures under Al stress is one way to improve the Al tolerance of crops. In our study, cytological alterations caused by Al were examined in anther cultures of a commercial wheat (Triticum aestivum L.) variety ‘Mv Pálma’, and the efficiency of in vitro selection was demonstrated. Although the anther walls retarded the appearance of toxicity symptoms, cytological changes similar to those observed in root cells (inhibition of cell division, intense vacuolisation, occurrence of micronuclei and cell wall thickening) were detected in the microspores. The severity of Al toxicity and the efficiency of selection depended on the Al concentration and the mode of treatment. Single Al treatments (0.6 and especially 1.6 mM) allowed DH lines with increased Al tolerance to be selected. Repeated Al treatment severely inhibited the cell division of the microspores and it was lethal even at a concentration as low as 0.6 mM. The results show that microspore embryogenesis can be exploited for studying the cytological effect of Al and for increasing the Al tolerance of wheat.  相似文献   

20.
R. C. Hardwick 《Euphytica》1981,30(1):217-221
Summary This paper offers an interpretation for a recent finding of Phillips et al., that the value of the Finlay & Wilkinson regression coefficient for each genotype was correlated with the genotypic effect. Attention is drawn to a number of other findings of such a correlation. It is shown that the condition for the correlation to occur is that the Finlay & Wilkinson regressions should be concurrent, and pass through a common point. In biological terms this implies that in certain environments the differences in performance between genotypes must disappear. In natural populations this can be accounted for in terms of the operation of natural selection. Where the data concern performance of a plant pest (as in Phillips et al.'s data), concurrent regression lines predict the existence of an environment which reduces the performance of the pest to zeroon every genotype of plant.  相似文献   

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