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1.
Summary Evaluation of forage germplasm digestibility is an important factor in screening programmes. The major problems involve the relevance of estimations made in spaced plants to plot performance, the effect of maturity, leaf: stem ratio and the choice of plant organ to be analysed. The use of stems of reproductive tiller proved successful in Lolium multiflorum. In the present experiment the effect of dates of sampling (date 1=28/6; date 2=5/7; date 3=12/7/83) and of plant densities (spaced plants and plots) on the digestibility of reproductive tillers of L. perenne cv. Marta 23 days after ear emergence was evaluated. After harvesting, the following characters were recorded on each tiller: tiller length and diameter, and spike and flag leaf length. Leaf blades and sheaths were then removed, the tillers dried and milled individually, and the in vitro digestibility assessed. The data were analysed by Analysis of Variance, Principal Components Analysis and Numerical Classification followed by a study of how the variables contributed to the derived group structure. Results: I-Plots: digestibility values were 63.4, 60.3 and 56.6% (P<0.01), respectively, for the sampling dates 1, 2 and 3. The Cramer Value (0.41) shows some correlation between tiller size and digestibility. Tillers from date 3 tend to be smaller than the others but the separation is not very clear. II-Spaced plants: digestibility values were 63.2, 60.0 and 60.8%, respectively, for dates 1, 2 and 3. Analysis of variance showed differences (P<0.01) between dates and also between genotypes. The Cramer Value (0.23) shows less correlation between tiller size and digestibility: however, tillers from dates 1 and 3 are clearly separated on the basis of size. Tillers from date 3 being smaller, date 2 tillers are located in between those from dates 1 and 3. III-Plots and single plants combined: Tillers from plots are larger than tillers from spaced plants in sampling dates 2 and 3. The Cramer Value for digestibility (0.14) is the lowest one. The results indicate differences in size and digestibility of reproductive tillers of L. perenne when contrasting situations are being compared, which suggest influence of environmental conditions upon the characters evaluated in the experiment. The differences are sufficiently high so that the use of this technique, when populations of L. perenne with wide variation in flowering dates are being evaluated, is not recommended. 相似文献
2.
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
3.
Sharma R. C. Duveiller E. Gyawali S. Shrestha S. M. Chaudhary N. K. Bhatta M. R. 《Euphytica》2004,139(1):33-44
Helminthosporium leaf blight (HLB), caused by a complex of Cochliobolus sativus (Ito & Kurib.) Drechsler ex Dastur and Pyrenophora tritici-repentis Died, is a serious disease of wheat (Triticum aestivum L.) in the warm lowlands of South Asia. Wheat cultivars grown in the area are either susceptible to HLB or possess low levels of resistance to it. A replicated field study was conducted in 1999 and 2000 at two sites in Nepal to determine the level of HLB resistance and other desirable traits in 60 wheat genotypes of diverse origin. The test genotypes were planted in main strips divided into two strips one of which was sprayed four times with Tilt (a.i. propiconazole) @ 125 g of a.i. ha–1. Four readings of HLB were recorded to calculate the area under the disease progress curve (AUDPC). Other traits under investigation included biomass yield (BY), grain yield (GY), 1000-kernel weight (TKW), harvest index (HI), days to heading (DH) and maturity (DM), plant height (PHT), and effective tiller number (ETN). Wheat genotypes differed significantly for all traits. Mean AUDPC values ranged from 45 to 1268. A few exotic genotypes were highly resistant to HLB. Losses in GY due to HLB ranged from 2 to 26%, and TKW was reduced by up to 33%. A few genotypes showed HLB tolerance, i.e., relatively smaller GY and TKW reductions despite high levels of HLB. In general, medium to late maturity and higher levels of HLB resistance and low to high GY and TKW characterized genotypes exotic to South Asia. Biplot analysis identified several genotypes that were HLB-resistant and agronomically superior. Results suggest it is possible to improve HLB resistance of local wheat cultivars based on selective breeding using this pool of germplasm. 相似文献
4.
Rosario Linacero Marisa G. López-Bilbao Concepción Romero David A. Laurie Ana M. Vázquez 《Euphytica》1996,89(3):345-348
Summary In the course of experiments performed to obtain haploid wheat plants in which 2,4-dichlorophenoxyacetic acid (2,4-D) was applied to developing spikes, it was found that three cultivars showed a different ability to produce polyembryos (Thatcher 20.19%, Chris 7.06%, Dollar 0%). This behaviour was related to their capacity to form somatic embryos. Diploid immature embryos cultured in vitro after 2,4-D treatment, gave a higher frequency of embryogenic callus in Thatcher and Chris than in Dollar. As the common factor in both experiments was the 2,4-D treatment we propose that the three cultivars showed a differential sensitivity to 2,4-D. 相似文献
5.
Scutellum and inflorescence explants of four genotypes of durum wheat(Triticum turgidum var. durum Desf.) were used to define culture conditions to obtain high frequencies of embryogenesis and plant regeneration in vitro. Under all conditions tested, scutellum cultures gave higher frequencies of embryogenesis and plant regeneration than inflorescence
cultures. Two different auxins, 2,4-D(2,4-dichlorophenoxyacetic acid) and picloram(4-amino-3,5,6-trichloropicolinic acid),
were compared for their effect on scutellum and inflorescence explant response in vitro. Picloram was found to significantly increase the frequency of plant regeneration from both explants. When cultures were
grown on regeneration medium containing zeatin for two three-week passages, the frequency of plant regeneration increased
by between 20–30% compared with cultures exposed to hormones for a single three-week passage. Finally, the addition of 1 mg/l
6-BAP (6-benzyl aminopurine) to the plantlet growth medium was found to enhance tiller production in regenerants. The optimized
culture conditions were applicable to the four genotypes tested and frequencies of plant regeneration varied between 97% to
100% for scutellum cultures (2 mg/l picloram in induction medium) and between45% and 80% for inflorescence cultures (4 mg/l
picloram in induction medium). The number of plants regenerated per explant was improved over previous procedures, with means
of 34 plants per scutellum, and 16 plants per inflorescence explant.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Effect of in vitro propagation methods on field performance of two strawberry cultivars 总被引：2，自引：0，他引：2
Summary Strawberry cultivars, Redcoat and Veestar, propagated by meristem culture (MC), callus culture (CC) and direct shoot regeneration (DR) from leaf disks were compared for their vegetative and reproductive characters with standard runner (SR) propagated plants under field conditions. In the planting year, in vitro propagated plants of both cultivars had the same number of leaves as SR plants, but in vitro propagated Redcoat produced fewer stolons per plant than SR plants. However, in the following year, in vitro propagated mother plants of both cultivars had more leaves and higher runner production than SR mother plants. Flowering and fruiting behaviour of Veestar was not appreciably influenced by in vitro propagation methods. However, in vitro propagated plants of Redcoat flowered earlier and produced more flowers and fruits than SR plants, but still maintained normal berry weight. Among in vitro propagated plants, DR plants of Redcoat were the earliest to flower, whereas MC plants produced more flowers and fruits. The field performance of the first daughter plants derived from the in vitro propagated plants was consistent with their respective mother plants. Leaf shape of both cultivars was not altered by in vitro propagation. Phenotypic abnormalities were mainly confined to occurrence of yellow leaf variants in MC and CC plants and occasional appearance of plants with irregular flowering and growth habit among CC plants.NRCC No. 38004 相似文献
7.
Kuzumitsu Matsumoto Milena Luz Barbosa Luiz Augusto Copati Souza João Batista Teixeira 《Euphytica》1995,84(1):67-71
Summary The selection of tolerant variants to race 1 fusarium wilt of banana was carried out through the effects of fusaric acid onin vitro banana multiple bud clumps (MBCs). The MBCs of Maçã cultivar (Musa sp., AAB, Silk), which is susceptible to the race 1 fusarium wilt, were used. And, Nanicão cultivar (AAA, Cavendish subgroup) was used in the tolerant tests as control of a disease tolerant variety. Firstly, to aim at determining an appropriate concentration of the toxin for the tolerant selection, the MBCs were cultured on the Modified Murashige & Skoog medium supplemented with 0.05 to 1.6 mM fusaric acid. The growth on both cultivars was completely inhibited on the medium containing 0.1 mM fusaric acid.Tolerant variants of Maçã were, then, selected with 0.1 mM fusaric acid after chemical mutagen treatment. The results showed an increased tolerance of the selected Maçã plants to the race 1 fungus in greenhouse tests.
In vitro selection by fusaric acid is a very useful method for obtaining fusarium disease tolerance, although the tolerance mechanism of the selected plants may be different from that of existing tolerant cultivars. 相似文献
8.
Doubled haploid production in winter wheat and triticale genotypes,using the Hordeum bulbosum system 总被引：1，自引：0，他引：1
Summary An attempt was made to produce doubled haploids on 16 winter wheat and six spring and winter triticale genotypes thought to carry genes for interspecific incompatibility. The potential for haploid production was maximized by the use of Hordeum bulbosum genotypes selected for high crossability on crossable wheat genotypes, the use of two post-pollination applications of gibberellic acid and by the pollination of immature florets.A low frequency of seed was set on both the wheat and the triticale genotypes, having mean seed sets of 0.20 per cent and 0.27 per cent respectively. Although the frequency of embryos (seed quality) was high, doubled haploid production was further limited by poor embryo differentiation and regeneration. Haploid plantlets were obtained from the wheat cultivars Moulin and Renard, although successful chromosome doubling and doubled haploid production was achieved in Moulin only. 相似文献
9.
Summary Plant regeneration from cultured immature inflorescence segments of Eleusine coracana was obtained by direct shoot development and somatic embryogenesis. Direct development of shoots from cultured inflorescence segments occurred on MS medium supplemented with 2,4-D in combination with zeatin. Inflorescences with well developed spikelets differentiated at a low frequency (<5%) from callus cultures initiated on media supplemented with 2,4-D in combination with zeatin or coconut water or picloram + kinetin. Somatic embryogenesis was also induced in callus cultures growing on MS + picloram + kinetin at the end of four passages. Supplementation of the media with different concentrations of sucrose showed 3% sucrose as the best concentration for plant differentiation from somatic embryos. The majority of the regenerated plants showed the diploid chromosome constitution in their root tips. The regenerants were in general shorter with an increased number of tillers compared to the control.Abbreviations CW
Coconut water
- 2,4-D
2,4-dichloro phenoxyacetic acid
- Kn
Kinetin
- Z
Zeatin 相似文献
10.
Summary Callus cultures were initiated from inflorescence explants of wheat, rye and triticale on MS medium supplemented with 2 mgl-1 2,4-D+5% CW or 2 mgl-1 2,4-D+0.5 mgl-1 BA. On transfer of the cultures to medium supplemented with 15% CW+0.2 mgl-1 NAA or 1 mgl-1 BA+0.1 mgl-1 IAA, shoot buds and embryoids were produced. Full fledged plantlets obtained on MS medium supplemented with NAA were transferred to the field. Cytological analysis showed the plants to be diploid. However, the regenerated plantlets were shorter, produced fewer tillers and had lower fertility compared to the control.Abbreviations BA
Benzyladenine
- CW
coconut water
- IAA
indoleacetic acid
- NAA
-naphthaleneacetic acid
- 2,4-D
2,4-dichlorophenoxyacetic acid 相似文献
11.
Relationship between cold resistance,heading traits and ear primordia development of wheat cultivars
Summary For breeding early heading wheat cultivars with resistance to frost damage which are well adapted to dry areas of West Asia and North Africa, the relationships between winter hardiness, ear primordia development and heading traits, i.e. veernalization requirement, photoperiodic response and narrow-sense earliness, were assessed using a total of 30 genotypes of wheat (Triticum aestivum L.) grown in an experiment in Syria. The results of artificial freezing tests indicated that cultivars with good winter hardiness were to be found only in the winter wheat cultivars which required 50 or more days of vernalization treatment. These winter wheat cultivars did not initiate internode elongation without vernalization even at 95 days after planting. Thus their ear primordia were still underground and were protected from frost injury at this stage. Photoperiodic response and narrow-sense earliness were not associated with winter hardiness and earliness of internode elongation, but were related to the number of days to heading after planting. This indicated the possibility for breeding early heading cultivars with winter hardiness and tiller frost avoidance by combining high vernalization requirement, short narrow-sense earliness and neutral response to photoperiod. 相似文献
12.
Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
13.
Ricardo Tadeu de Faria Deonisio Destro João Carlos Bespalhok Filho Rolf Dieter Illg 《Euphytica》2002,124(1):59-63
The goal of this research was to study the introgression of the high regeneration capacity of Lycopersicon pimpinellifolium Mill line WV-700, in recalcitrant tomato cultivars (L. esculentum Mill cvs. Petomech, Santa Rita and VFN-8) using backcrossing. Hypocotyl explants of in vitro germinated seeds were cultivated in half strength MS medium supplemented with 5mg/l 6-BA to assess their shoot regeneration
capacity. The apical shoot of the in vitro germinated seeds were cultured on a separate medium. Apical shoots from genotypes showing high regeneration rates were acclimated
in a glasshouse and used as pollen donors for the next backcrossing. After four backcrossings, the material showed a similar
mean fruit weight for the cultivated tomato and a high regeneration capacity similar to the wild species. It is shown that
L. pimpinellifolium can be used with success as donor parent to introgress in vitro regeneration capacity to recalcitrant tomato cultivars.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
Brent Tisserat 《Euphytica》1982,31(1):201-214
Summary A discussion of a suitable procedure to rapidly propagate free-living date palms (Phoenix dactylifera L.) from callus cultures is presented. Embryogenic callus derived from lateral bud explants was subjected to various auxin treatments in liquid and agar media including p-chlorophenoxyacetic acid. -naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid at 0.0, 0.1, 1.0 and 10.0 mg/l concentrations in order to obtain optimum growth. Subsequent plantlet initiation from callus was found to be related to initial auxin pretreatments upon subculture to medium devoid of hormones. Plantlet production from callus subcultured from media containing 0.0, 1.0 and 10.0 mg/l auxin concentrations was notably lower than from callus precultured on the 0.1 mg/l auxin levels. In order to improve in vitro adventitious rooting isolated plantlets were cultured on media containing 0.0, 0.1, 1.0 and 10.0 mg/l concentrations of indole-3-acetic acid or -naphthaleneacetic acid in various physical environments. Optimum adventitious rooting responses and survival in free-living conditions were obtained by culturing plantlets in medium containing 0.1 mg/l for 8–16 weeks prior to transplanting to soil. Axillary shoot outgrowths (offshoots) were found to be common in plantlets cultured on a variety of media once an adequate root-shoot system was developed. Mention of a trademark name or proprietary product does not constitute a guarantee or warranty of the product by the US. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable. 相似文献
15.
A.F. Stelmakh 《Euphytica》1992,65(1):53-60
Summary The Vrn1, Vrn2 and Vrn3 genes have different values of effects on heading date and related yield components. The genetic background and environment do not affect the ranking of Vrn genotypes according to earliness within near-isogenic line sets; however, they do influence the level of differences between heading dates of particular genotypes and between effect values, respectively. The frequencies of defined Vrn genotypes in the global set of spring bread wheat cultivars are associated with grain weight per plant predicted on the basis of Vrn gene effects averaged over backgrounds and over environments. Peculiarities of backgrounds and environments alter the grain yield ranges of Vrn genotypes. For early photoperiod-insensitive wheats, planted in stress conditions at grain filling, the highest yield was predicted for double dominant Vrn genotypes with Vrn3. This gene is rarely used by the breeders in middle latitudes and its wider adoption is encouraged. 相似文献
16.
Summary To provide a truly genotype-independent transformation system, it is necessary to be able to transform a wide range of potato genotypes. The ability to regenerate shoots in vitro was determined for 34 potato varieties using tuber disc explants. Following a culture regime used extensively in previous studies with the variety Desiree, half of the varieties could be regenerated from tuber discs and half could not. From a sample of varieties that could be regenerated from tuber discs, all but one variety gave transgenic plants. Twelve varieties were evaluated for the capacity to regenerate shoots from leaf and internode explants excised from in vitro grown plants. All of the varieties tested regenerated adventitious shoots. Leaf and internode explants from 5 varieties were subsequently used for transformation, and transgenic plants were produced from two potato varieties that did not give transgenic plants from tuber disc explants. Some varieties could not be transformed by either method, and will require modification of the in vitro regeneration and transformation system to be successful.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- GA3
gibberellic acid
- IAA
indole-3-acetic acid 相似文献
17.
Summary
In vitro hybridization between Gossypium hirsutum, and G. arboreum was carried out. Hybrid seedlings were obtained after successive use of the following five kinds of media: 1) pollen grain germination medium, 2) double-fertilization medium, 3) embryo development medium, 4) seedlings formation medium, 5) green seedlings growth medium. The factors affecting in vitro interspecific fertilization, embryogenesis and seedling formation were studied. The key factors were temperature and relative humidity (RH). The optimum RH for in vitro interspecific fertilization was 65%, and a suitable temperature range was 26–30°C. Pollen grain germination ratio decreased rapidly at a RH of 80%. When the temperature and the RH were higher than 32°C and 80%, respectively, the fertilization rate decreased to zero.Effects of petals and calyces of the maternal flowers on in vitro interspecific fertilization and ovule growth were identified. Even though the petals or calyces were excised, hybrid plantlets were also obtained after media were improved and a shake culture was used. In addition, the process of double-fertilization and embryo development were studied cytologically. The developmental characteristics of the hybrid embryos derived from in vitro interspecific fertilization were a later occurrence of the double-fertilization process and a much lesser division of endosperm cells. But the embryo development was not affected by these characteristics, and young hybrid embryos can develop to their cotyledon stage finally on artificial media. 相似文献
18.
G. Spangenberg Z. Y. Wang G. Legris P. Montavon T. Takamizo R. Pérez-Vicente M. P. Vallés J. Nagel I. Potrykus 《Euphytica》1955,85(1-3):235-245
Summary Intergeneric symmetric and asymmetric somatic hybrids have been obtained by fusion of metabolically inactivated protoplasts from embryogenic suspension cultures of tall fescue (Festuca arundinacea Schreb.) and unirradiated or 10–500 Gy-irradiated protoplasts from non-morphogenic cell suspensions of Italian ryegrass (Lolium multiflorum Lam.). Genotypically and phenotypically different somatic hybrid Festulolium mature flowering plants were regenerated.Species-specific sequences from F. arundinacea and L. multiflorum being dispersed and evenly-represented in the corresponding genomes were isolated and used for the molecular characterization of the nuclear make-up of the intergeneric, somatic Festulolium plants recovered. The irradiation of Italian ryegrass protoplasts with 250 Gy X-rays prior to fusogenic treatment favoured the unidirectional elimination of most or part of the donor chromosomes. Irradiation of L. multiflorum protoplasts with 500 Gy produced highly asymmetric (over 80% donor genome elimination) nuclear hybrids and clones showing a complete loss of donor chromosomes.The RFLP analysis of the organellar composition in symmetric and asymmetric tall fescue (+) Italian ryegrass regenerants confirmed their somatic hybrid character and revealed a bias towards recipient-type organelles when extensive donor nuclear genome elimination had occurred.Approaches aimed at improving persistence of ryegrasses based on asymmetric somatic hybridization with largely sexually-incompatible grass species (F. rubra and Alopecurus pratensis), and at transferring the cytoplasmic male sterility trait by intra- and inter-specific hybridization in L. multiflorum and L. perenne, have been undertaken.Abbreviations cpDNA
chloroplast DNA
- CMS
cytoplasmic male sterility
- 2,4-D
2,4-dichlorophenoxy-acetic acid
- IOA
iodoacetamide
- mtDNA
mitochondrial DNA
- RFLP
restriction fragment length polymorphism 相似文献
19.
Summary Protocols for plant regeneration from cotyledon explant and anther cultures of Sinapis alba have been developed for creating doubled-haploids and somaclonal variation. Among the several cultivars tested in this study, only Arda responded well to in vitro plant regeneration both from anther-as well as cotyledoncultures. Multiple shoot formation in cotyledon explants, which always followed a brief callusing phase, was found to be the best on MS medium with ZEA (1.0mg/l) and NAA (0.1mg/l). Regeneration frequency declined sharply in the absence of auxin or presence of other cytokinins and/or auxin. The frequency of shoot regeneration also declined with reduction in the photoperiod to 16h. On MS + BAP (1.0mg/l) + NAA (1.0mg/l) medium, cotyledonary explants showed profuse callusing, which could regenerate shoots on high ZEA + low NAA/IAA medium. However, it declined with progressing time in culture. Anthers, excised from fresh as well as cold pretreated buds, cultured on 10% sucrose containing MS media with different hormonal constitution, developed calli and/or embryos. Initial culture temperature was important with embryogenesis occurring only in anthers cultured at 30°C for 3 weeks. A high temperature (35°C) treatment was lethal for both callus as well as embryo formation. While BAP + NAA and ZEA + NAA/IAA supported embryogenesis, further plant regeneration from anther-or embryo-callus could be achieved in ZEA + NAA/IAA media. Some of the regenerants flowered already in vitro and had small and sterile flowers. Cytological examination of some of the root differentiating calli indicated the presence of haploid as well as diploid cells. Shoots were rooted during prolonged incubation on the same medium or on transfer to MS (reduced)/ B5 + ZEA + NAA media. 相似文献
20.
Summary Early flowering carnation cultivars, responding to artificial long days, can assist the grower to plant the onset of flowering and achieve a better distribution of flower production over the year.A comparative trial is described of 20 carnation genotypes (cultivars and backcrosses of interspecific hybrids), representing a wide variation in flowering time and response to long days. The trial was planted in September in a phytotron under a winter light intensity of 15 W/m2 for eight hours per day. In one half of the trial, daylength was increased to 24 hours for 25 days in December-January. At the end of February the plants were transferred to a glasshouse where they were observed until all primary shoots had flowered. The main purpose of the experiment was to analyse the genetic factors responsible for the large differences in flowering behaviour between genotypes. Average flowering dates varied from 132 days from pinching in a Dianthus chinensis hybrid to 181 days in the mediterranean cultivar Raggio di Sole. LD response was most pronounced in the earliest flowering Diantini selections and least in the traditional commercial cultivars. In the former the LD effect was evident in all shoots of a plant, but mostly so in the lower (older) shoots; in the traditional cultivars only the higher placed shoots responded to LD. As a result, the proportion of the shoots actually responding to LD varied from 28% in the traditional cultivars to 54% in the Diantini x D. Allwoodii cv Doris group of genotypes. 相似文献