抗稻瘿蚊品种多抗1的抗性遗传分析及抗性基因定位   总被引：9，自引：1，他引：9  

谭玉娟  张扬  黄炳超  徐炎康  赵丽霞  S. K. Katiyar  N. Huang  G. S. Khush  J. Bennett 《植物保护学报》1996,23(4):315-320

稻瘿蚊是亚洲稻区主要害虫,采用抗虫品种进行防治是最理想的方法。1993～1995年,广东省农科院与国际水稻研究所有关专家紧密合作,对能抗华南4个稻瘿蚊生物型的品种多抗1作进一步抗性遗传分析,确认多抗1对中国稻瘿蚊生物型1和4的抗性受显性单基因控制,这个基因暂定名为GM—6(t)。以多抗1×丰银占1组合的F3代160个家系作基因标记,据DNA库分离个体分析(BSA)原理,用随机扩增多态性DNA(RAPD)标记物OPM6(1.4kb),首次成功地标记了这个抗性基因。随后多态性扩增产物经~(32)p标记,用作探针,检测另一个参考作图群体IR64×Azucena,将这个抗性基因定位在水稻第4条染色体上,位于RG214和RG163两个DNA限制性片段长度多态性(RFLP)标记之间。应用这些分子标记辅助选择有可能不必通过稻瘿蚊的直接筛选,快速准确地选育抗稻瘿蚊品种或进行抗性基因累加。  相似文献   

The effect of phenylamide fungicides on the control of potato late-blight (Phytophthora infestans) in England and Wales from 1978 to 1992     

N. J. BRADSHAW  & T. B. VAUGHAN 《Plant pathology》1996,45(2):249-269

During the period 1978–1992, phenylamide fungicides in co-formulation with the dithiocarbamate fungicide mancozeb were tested for the control of potato late-blight in 51 separate field experiments in England and Wales. Whilst there was a general trend over all the experiments which indicated that foliage blight was less severe where the phenylamide + dithiocarbamate mixture had been used, the benefit was more marked in some than in others. Despite the detection of phenylamide resistance, at some sites the mixture gave better control of foliage blight than the dithiocarbamate alone. At one site where continuous data were available, the additional benefit of the phenylamide compound for control of foliage infection was lost after 1986 coinciding with a rise in phenylamide resistance from 31.7% in 1986 to 81% in 1987. Where foliar blight epidemics occurred, yield responses to fungicide programmes compared with unsprayed controls ranged from 0 to +118.5% with a mean response of +30.2%. This is equivalent to 30.8 and 12.92 t/ha respectively. Standardized yield differences were calculated to allow inter-trial and inter-year comparisons and showed no benefit from the phenylamide fungicide applied at 14-day intervals in 33 out of 38 experiments where foliar blight epidemics occurred. At one site, Cusum analysis of standardized yield differences following treatment with the phenylamide + dithiocarbamate mixture and the dithiocarbamate alone showed a mean benefit from the phenylamide mixture of 2.23 t/ha during the period 1978 to 1986. From 1987 to 1992, the yield benefit dropped to a mean level of 0.68 t/ha a decrease of 69.5%. In experiments where blight was not recorded, fungicide treatments had no deleterious effect on yields. Over all the trials, there was no effect of fungicide treatment on the incidence of tuber blight at harvest.  相似文献   

Production of syringomycins and syringopeptins by Pseudomonas syringae pv. atrofaciens   总被引：1，自引：0，他引：1  

V. VASSILEV  P. LAVERMICOCCA  D. DI GIORGIO  & N. S. IACOBELLIS 《Plant pathology》1996,45(2):316-322

All virulent strains of Pseudomonas syringae pv. atrofaciens produce in vitro substances with syringomycin-like features. All strains inhibited the growth of Geotrichum candidum in the plate assay although the extent of their growth inhibition was variable.
Purification of bioactive culture extracts of a highly virulent strain by ion exchange chromatography (Whatman CM52) yielded a main fraction which inhibited the growth of Rhodotorula pilimanae and Bacillus megaterium , and was phytotoxic to tobacco and wheat plants. In particular, the injection of this fraction in the culm of wheat plants caused phytotoxic symptoms on leaves similar to those caused in nature by the pathogen. The further purification by HPLC of the above fraction gave rise to four main bioactive substances which have been identified by spectroscopic methods (FAB-MS) and amino acid analysis as syringomycin E, syringomycin G, syringopeptin 25A and syringopeptin 25B, toxic lipodepsipeptides thus far recognized to be produced by most strains of P. syringae pv. syringae . The injection of both syringomycin E and syringopeptin 25A in wheat leaves caused necrotic symptoms; however, syringopeptin 25A was at least six times more active than syringomycin E. The possible role of the toxins in the disease development on cereals and the need for a careful examination of pathogenetic and biochemical features of P. syringae pv. atrofaciens to establish the relationships of the two pathovars in the 'syringae group' are discussed.  相似文献   

The potential for selecting wheat varieties strongly competitive against weeds   总被引：4，自引：1，他引：4  

D. LEMERLE  B. VERBEEK  R.D. COUSENS  N E COOMBES 《Weed Research》1996,36(6):505-513

The competitive abilities of a wide range of genotypes of wheat (Trilicvm aestivum L.) and durum wheat (Triticum durum Desf.) against Lolium rigidum Gaud, (annual ryegrass) were examined 1o determine the potential for breeders to select strongly competitive varieties, Considerable potential within the wheat genome to breed varieties with greater competitive ability was demonstrated. In 1993, 250 genotypes from around the world were screened and in 1994 a subset of 45 (mainly Australian) genotypes were further examined. A uniform density of L. rigidum reduced grain yield of wheat by up to about 80% in 1993 and to 50% in 1994, depending on wheat genotype. Reduction in grain yield was correlated with L. rigidum dry matter. Wheats varied in competitive ability with source, and durum wheats were less competitive than T. aestivum. The ‘old’ standard wheat varieties (released between 1880 and 1950) suppressed the weed more than all the current varieties, with the exception of eight F₁ hybrids. A doubling of the crop seeding rate of 10 of the genotypes in 1994 reduced the biomass of L. rigidum by an average of 25% compared with the standard seeding rate. Ranking of competitive ability of varieties at high density was consistent at both seeding rates. The strongly competitive genotypes had high early biomass accumulation, large numbers of tillers, and were tall with extensive leaf display. The potential for breeding enhanced competitive ability in wheat is discussed.  相似文献   

Ovipositional response ofHelicoverpa armigera to different cotton genotypes     

N. S. Butter  Surjit Singh 《Phytoparasitica》1996,24(2):97-102

The ovipositional response ofHelicoverpa armigera (Hübner) to different cotton varieties and species was studied under caged conditions. Maximum oviposition (51.6 eggs/female) was recorded on LH 900, a variety ofGossypium hirsutum, and minimum oviposition (3.0 eggs/female) on G 27, a variety ofG. arboreum. Oviposition, in general, was low (3 to 6.5 eggs/female) onarboreum cottons as compared withhirsutum. Of the number of factors found to affect the oviposition ofH. armigera, the trichome length on the upper surface of the leaf, rather than the density, was positively correlated (r = 0.687*). Among different months in the cropping season, oviposition was maximum (552.7) during April. Oviposition was higher on leaves than on other plant parts.  相似文献   

Parry's disease of pears is similar to pear decline and is associated with mycoplasma-like organisms transmitted by Cacopsylla pyricola   总被引：1，自引：1，他引：1  

D. L. DAVIES  C. M. GUISE  M. F. CLARK  A. N. ADAMS 《Plant pathology》1992,41(2):195-203

Mycoplasma-like organisms (MLOs) were detected by fluorescence microscopy in a number of pear cultivars and pear seedlings growing under a range of different conditions. In the cultivar Conference, MLOs were consistently associated with symptoms of Parry's disease, a decline-like disease of young trees with quince rootstocks. MLO-free pear seedlings rapidly became infected when they were planted outside. Experimental transmission of MLOs to pear seedlings and Conference trees was achieved using pear psyllids, caught outside or raised on infected plants under controlled conditions. Conference trees in an orchard trial remained free from the severe spring symptoms of Parry's disease when they were protected from feeding insects during spring of the previous year. MLOs were graft transmissible, but were not perpetuated by the standard propagation practices of budding or grafting when quince rootstocks were used. Parry's disease appears to be similar to pear decline, an MLO-induced disease well established in several other parts of the world. It is suggested that Parry's disease should be referred to as pear decline.  相似文献   

Variation in the resistance of Vicia faba to Ascochyta fabae in relation to disease development in field trials     

N. MAURIN  B. TIVOLI 《Plant pathology》1992,41(6):737-744

The epidemic development of Ascochyta fabae in artificially infected field trials was studied in order to define resistance criteria and assess the variation in resistance of infected lines of faba bean. Large differences were demonstrated among French winter lines during the 1985/86 and 1986/87 growing seasons. All the scoring systems allowed the differentiation of very susceptible and resistant material, but disease indices, which account for the number and intensity of lesions, were more precise. The different phases of the epidemic are described on the basis of the variation in disease incidence on foliage and on pods during the 1986/87 cropping season in Brittany. There were three phases in disease development: initiation, spread throughout foliage, and pod infection, and these were all influenced by host resistance. On a very susceptible line, the disease spread was seen as an increase in the number and size of lesions and rapidly developed up the plant. Low disease indices observed on the resistant line 29 H were due to the small size and low frequency of lesions, resulting in a reduced area of foliage affected.  相似文献   

3. Determination of the sensitivity of Phytophthora infestans to phenylamides: a semi-quantitative test method     

C. NUNINGER†  N. BOLTON  J. J. DE  WIJS† T. STAUB† 《EPPO Bulletin》1992,22(2):309-311

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Genetic engineering of insect viruses for insect biological control     

N. Chejanovsky  J. Tal 《Phytoparasitica》1992,20(Z1):S25-S31

Insect viruses can be exploited for the biological control of insect pests and serve as well as vehicles for the introduction of ‘foreign genes’ into insect cells and insects. The present work describes some of the molecular events that take place during the replication of theGalleria mellonella densonucleosis virus in the insect host. Viral RNA and protein synthesis were monitored. An understanding of the virus biology is essential for further implementation of these viruses for biological control purposes.  相似文献   

Molecular breeding for virus resistant potato plants     

Marianne J. Huisman  Erik Jongedijk  Dinie Posthumus-Lutke Willink  Frank Van Der Wilk  Ben J. C. Cornelissen 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):29-36

To engineer resistance against potato virus X (PVX), the viral coat protein (CP) gene has been introduced into two potato cultivars. Stable expression of the gene in transgenic clones throughout the growing season has been obtained and resulted in considerably increased virus resistance. With varying frequencies depending on the original cultivar used, true-to-type PVX resistant transgenic clones have been obtained. Since deviant light sprout characteristics were invariably associated with aberrations in plant phenotype, they can be used in procedures to early screen for deviations. Furthermore, it has been possible to unequivocally discriminate between the original untransformed and independent transgenic cultivars. Although no relation has been found between the presence, if any, of the CP of potato virus Y (PVY) or potato leafroll virus (PLRV) in CP gene transgenic potato, appreciable levels of resistance to these viruses has been obtained. This suggests that the mechanism by which a viral CP gene in the potato genome evokes resistance, differs amongst various viruses.  相似文献