首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 140 毫秒
1.
Traditional and doubled haploid (DH) genotypes of oilseed Brassica spp. resistant, partially resistant, moderately susceptible, and susceptible to Albugo candida were compared for phenotypic development of host‐pathogen interaction and histology of host‐pathogen interaction. The partially resistant genotype showed pinhead‐size pustules, mainly on the upper surface of cotyledonary leaves. Relatively less mycelium was observed in the partially resistant genotype compared with the susceptible genotype. In resistant B. napus genotypes, there was neither pustule development nor any mycelial growth. In the moderately susceptible genotype, the pustules were similar to those in the partially resistant genotype in being of pinhead‐size and occasionally coalescing. However, ample mycelial growth in the mesophyll tissue in the moderately susceptible genotype was similar to that in the susceptible control B. rapa cv. ‘Torch’. The susceptible genotype B. rapa cv. ‘Torch’ also showed large coalescing pustules. In the non‐host B. juncea cv. ‘Commercial Brown’, no pustules were formed although some mycelial growth was observed beneath the epidermal cell layer and in the mesophyll cell layer of the cotyledonary leaf tissue. For inheritance studies, two partially resistant B. napus genotypes were crossed with a resistant B. napus genotype. Various generations viz., F1, F1(reciprocal), F2, and DHs produced from the crosses were inoculated with a zoospore suspension of race 7v of A. candida. The partially resistant phenotype appeared to be controlled by a single recessive gene designated as wpr with variable expression. The simple inheritance of partial resistance has implications for disease resistance breeding against white rust, as this type of resistance can be easily incorporated into elite breeding lines through conventional and DH breeding methods.  相似文献   

2.
C. C. Su    J. Wan    H. Q. Zhai    C. M. Wang    L. H. Sun    H. Yasui  A. Yoshimura 《Plant Breeding》2005,124(1):93-95
The brown planthopper (BPH) is one of the most destructive insect pests of rice. Resistant varieties have proved to be one of the most economic and effective measures for BPH management. In this study, an indica rice ‘DV85’ showed resistance to biotype 2 of BPH by bulked seedling test, and a recombinant inbred line (RIL) population derived from a cross between a susceptible rice ‘Kinmaze’ and ‘DV85’ was phenotyped to map genetic factors conferring BPH resistance in ‘DV85′. Composite interval mapping revealed that one quantitative trait locus (QTL) with a LOD score of 10.1 was detected between XNpb202 and C1172 on chromosome 11. This QTL was designated as Qbph11. Qbph11 explained 68.4% of the phenotypic variance of BPH resistance in this population. The allele from the resistant parent ‘DV85’ at Qbph11 reduced the damage caused by BPH feeding and would be very useful in breeding resistant rice varieties via marker‐assisted selection.  相似文献   

3.
B. Saal    H. Brun    I. Glais  D. Struss 《Plant Breeding》2004,123(6):505-511
Screening of 212 spring type Brassica napus lines carrying B genome chromosome additions and introgressions from B. nigra, B. juncea and B. carinata resulted in the identification of one line segregating for resistance to Leptosphaeria maculans (anamorph Phoma lingam) at the seedling (cotyledon) stage. This line was derived from an interspecific hybrid containing the B genome of B. juncea. Trypan blue staining of cotyledons from resistant individuals demonstrated a hypersensitive response which is delayed in plants with intermediate lesion size. Genetic analysis supported the hypothesis of a monogenic recessive inheritance of resistance. The resistance gene, termed rjlm2, is effective in spring and winter type oilseed rape backgrounds against all tested virulent pathotypes, including two isolates which have been shown to overcome two dominant (race‐specific) B genome‐derived resistance genes in B. napus.  相似文献   

4.
Resistance responses of resynthesized Brassica napus lines to infection with Plasmodiophora brassicae were investigated. Lines that were derived from interspecific crosses between clubroot-resistant B. rapa and resistant B. oleracea exhibited very broad and effective resistance in both greenhouse and field tests. When clubroot resistance was introduced into resynthesized lines from the B. oleracea parent only, the plants were mainly susceptible. Interspecific hybrids from the most resistant parental genotypes, i.e. B. campestris ECD-04 and the B. oleracea cultivars ECD-15 or ‘Bohmerwaldkohf’, were used to initiate a B. napus resistance-breeding programme. These artificial rapeseed lines were resistant to isolates that were virulent on all B. napus differential lines and/or parental lines. Preliminary segregation analysis suggests that their resistance is due to at least two dominant and unlinked genes. In some cases progenies from selfed resynthesized plants exhibited resistance reactions that differed from those of the parental hybrid plant; this may have been the result of cytological instability.  相似文献   

5.
R. Wang    V. L. Ripley    G. Rakow 《Plant Breeding》2007,126(6):588-595
Pod shatter susceptibility was investigated in Brassica napus germplasm and shatter resistant species of B. juncea and Sinapis alba. The comparisons were made by measuring seed yield in field plots, detached pod rupture energy (RE) and the half‐life of pod‐opening. Pod shatter resistance was significantly greater in B. napus lines derived from interspecific hybridizations of B. napus with B. rapa, B. carinata and B. juncea, than common B. napus cultivars. While these lines exhibited no significant difference in resistance to pod shatter than B. juncea, an entry of S. alba had no yield loss caused by pod shatter. Resistance to pod shatter was characterized in the field as little or no yield loss after full maturity, delayed shattering in time, and stable yield performance under variable climatic conditions during pod maturity. Yield loss caused by pod shatter ranged from a low of 4% for the B. juncea cv. ‘AC Vulcan’ to a high of 61% for the black seeded B. napus line DH12075 in 2‐year field trials after 1 month maturity. Pod shatter resistance was not significantly associated with specific plant and pod morphological traits, except pod length (P = 0.005) in tested materials. Field visual scores of pod shatter through inspections of average pod shatter per plant within plots were highly correlated with plot yield loss. Indoor quantitative evaluations of pod strength using a pendulum machine to measure pod RE and random impact test to measure half‐life of pod‐opening resistance were highly correlated with field yield loss. Multiple evaluations of pod shatter in method and in time after pod maturity are recommended for reliable evaluation of pod shatter resistance.  相似文献   

6.
In the last decade, the cabbage seedpod weevil (Ceutorhynchus obstrictus (Marsham)) has become a major insect pest of canola (Brassica napus L.) in Canada reducing seed yields up to 35%. Therefore, the benefits of developing weevil resistant germplasm to canola breeders and the industry would reduce input costs, pesticide use, environmental degradation and increase yield. Yellow mustard (Sinapis alba L.) is resistant to C. obstrictus (CSPW), although the exact mechanism is not known (McCaffrey et al. 1999). A unique canola population was generated at the University of Guelph from a cross between B. napus and S. alba through embryo rescue and backcrossed to canola several times prior to double haploid (DH) production. Approximately one-half of this DH population had canola quality glucosinolate concentration (<16 μmol/g) and was used for further breeding. The hypothesis was that some DH progeny from this cross inherited resistance to CSPW from S. alba. Weevil infestation levels were assessed for the B. napus × S. alba BC2 and BC3 DH populations in the field over 7 years in Alberta where weevil pressure is strong to establish the resistant or susceptible status of these lines. The basic objectives for this study were to confirm field resistance in the B. napus × S. alba germplasm in Ontario and to identify any biochemical markers associated with resistance/susceptibility. Canola doubled haploid lines derived from BC2 or BC3 families were field screened for resistance (R) followed by chemical analysis of glucosinolates to detect biochemical polymorphisms correlated with CSPW resistance using High Performance Liquid Chromatography (HPLC). Two polymorphic peaks were found, one each, from extracts of upper cauline leaves and Stage 3 pod seed, with retention times of ~23 and 19 min, respectively. These HPLC peaks consistently correlated with larval infestation data and the peak differences between R and S DH lines were significant. Therefore, these two peaks can be considered as biochemical markers in this breeding germplasm and may play a role in rapid and early detection of CSPW resistance.  相似文献   

7.
Leptosphaeria maculans causes blackleg disease on Brassica napus, an economically important oilseed crop. Brassica juncea has high resistance to blackleg and is a source for the development of resistant B. napus varieties. To transfer the Rlm6 resistance gene from B. juncea into B. napus, an interspecific cross between B. napus “Topas DH16516” and B. juncea “Forge” was produced, followed by the development of F2 and F3 generations. Sequence characterized amplified region (SCAR) and cleaved amplified polymorphic sequence (CAPS) markers linked to the L. maculans resistance gene Rlm6 were developed. Segregation of SCAR and CAPS markers linked to Rlm6 were confirmed by genotyping of F2 and F3 progeny. Segregation of CAPS markers and phenotypes for blackleg disease severity in F2 plants had a Mendelian ratio of 3:1 in resistant vs. susceptible plants, respectively, supporting the assumption that genetic control of resistance was by a single dominant gene. The molecular markers developed in this study, which show linkage with the L. maculans resistance gene Rlm6, would facilitate marker‐assisted backcross breeding in a variety development programme.  相似文献   

8.
W. Rygulla    W. Friedt    F. Seyis    W. Lühs    C. Eynck    A. von Tiedemann    R. J. Snowdon 《Plant Breeding》2007,126(6):596-602
Resynthesized (RS) forms of rapeseed (Brassica napus L.; genome AACC, 2n = 38) generated from interspecific hybridization between suitable genotypes of its diploid progenitors Brassica rapa L. (syn. campestris; genome AA, 2n = 20) and Brassica oleracea L. (CC, 2n = 18) represent a potentially useful resource to introduce resistance against the fungal pathogen Verticillium longisporum into the gene pool of oilseed rape. Numerous cabbage (B. oleracea) accessions are known with resistance to V. longisporum; however, B. oleracea generally has high levels of erucic acid and glucosinolates in the seed, which reduces the suitability of resulting RS rapeseed lines for oilseed rape breeding. In this study resistance against V. longisporum was identified in the cabbage accession Kashirka 202 (B. oleracea convar. capitata), a zero erucic acid mutant, and RS rapeseed lines were generated by crossing the resistant genotype with two spring turnip rape accessions (B. rapa ssp. olerifera) with zero erucic acid. One of the resulting zero erucic acid RS rapeseed lines was found to have a high level of resistance to V. longisporum compared with both parental accessions and with B. napus controls. A number of other zero erucic acid RS lines showed resistance levels comparable to the parental accessions. In the most resistant RS lines the resistance and zero erucic acid traits were combined with variable seed glucosinolate contents. Erucic acid‐free RS rapeseed with moderate seed glucosinolate content represents an ideal basic material for introgression of quantitative V. longisporum resistance derived from B. oleracea and B. rapa into elite oilseed rape breeding lines.  相似文献   

9.
G. H. Jiang    C. G. Xu    J. M. Tu    X. H. Li    Y. Q. He  Q. F. Zhang 《Plant Breeding》2004,123(2):112-116
The wild‐rice‐derived dominant gene Xa21 conferring multi‐race resistance to bacterial blight and a fused Bt gene cry1Ab/cry1Ac conferring resistance to lepidopteran insects were individually introduced into the same genetic background of an elite indica cytoplasm male sterile (CMS) restorer line ‘Minghui 63′. The line showed the desirable insect‐ and disease‐resistant phenotypes. To maximize the effect, the two genes were also pyramided into the same recipient plant of ‘Minghui 63’ by marker‐assisted selection. After being subjected to natural infestation of leaf‐folders and yellow stem borers and inoculation of Xoo strain mixtures, the pyramiding line and its derived hybrids showed high levels of resistance against both insect damage and disease. Furthermore, data from field trials demonstrated that the hybrids made by crossing this pyramiding line with the CMS lines ‘Zhenshan 97A’ and ‘Maxie A’ retained a similar level of yield under conditions without chemical spray, indicating that the pyramiding genes have a yield‐stabilizing effect on the recipient line and its hybrids.  相似文献   

10.
Summary Asymmetric somatic hybrid plants between Brassica napus L. (oilseed rape genome AACC) and a transgenic line of Brassica nigra L. Koch (black mustard genome BB) were tested for their resistance against rapeseed pathogens Phoma lingam (black leg disease) and Plasmodiophora brassicae (club root disease). The transgenic B. nigra line used (hygromycin-resistant, donor) is highly resistant to both fungi, whereas B. napus (recipient) is highly susceptible. The asymmetric somatic hybrids were produced using the donor-recipient fusion method (with X-irradiation of donor protoplasts) reported by Zelcer et al. (1978) for the production of cybrids. Using hygromycin-B for selection, a total of 332 hybrid calli were obtained. Regenerants, resistant or susceptible to both diseases, were selected. Many hybrids expressed resistance to only one pathogen. Dot blot experiments showed that the asymmetric hybrid plants contained varying amounts of the donor genomic DNA. Furthermore, a correlation was detected between the radiation dose and the degree of donor DNA elimination.  相似文献   

11.
RNA干扰及其对昆虫抗药性相关基因的沉默研究   总被引：1，自引：0，他引：1  
唐涛  刘雪源  邱立红 《棉花学报》2010,22(6):617-624
以不同农药为主的防治策略对棉铃虫和小菜蛾等农业害虫的控制卓有成效,但易产生害虫抗药性问题。害虫抗药性与细胞色素P450酶系、酯酶、钙粘蛋白等酶或受体的生化与分子机理相关。RNA干扰(RNA in-terference,简称RNAi)作为分子生物学领域中功能基因及基因组研究的一种强有力工具,已逐渐用于昆虫抗药性相关基因的敲除研究并鉴定其功能。本文围绕RNAi的作用机理及其对昆虫抗药性相关基因的沉默研究展开综述,旨在为农业害虫及其抗药性治理提供新思路与新途径。  相似文献   

12.
Twenty Brassica breeding populations derived from mass selection or inter-specific hybridization were field screened for resistance to three separate isolates of Sclerotinia sclerotiorum, the cause of Sclerotinia stem rot (SSR). Variation due to S. sclerotiorum isolates (P ≤ 0.001) and host populations (P ≤ 0.001) were highly significant. Populations × isolate interactions were also significant. S. sclerotiorum isolates, MBRS1 and MBRS5 were the most pathogenic and almost similar in terms of population reactions, with WW3 clearly being distinct and having a much smaller range in lesion length across the populations. There were wide ranging and variable responses in terms of resistance against S. sclerotiorum in Brassica napus and B. juncea, with or without B. carinata introgression, among these breeding populations. In B napus, ZY006 (resistant check) and Line6 (HZAU) were the most resistant, closely followed by Line1 (HZAU), OCRI-3 and Line5 (HZAU). Line6 (HZAU) showed excellent resistance against the highly virulent isolates MBRS1 and MBRS5; while OCRI-1 appeared most resistant against isolate WW3. The B. juncea × B. carinata hybrid JC134 (PAU) was the most resistant against isolate MBRS5 and B. juncea RH9902 × JN026 the most resistant against isolate MBRS1. B. napus lines Line2 (HZAU), Line4 (HZAU), OCRI-3; and OCRI-4, and the B. napus × B. carinata hybrid Surpass4000 NCB4 (PAU), showed a significant degree of isolate-dependency in their reactions. In contrast, some other genotypes such as B. napus lines Line1 (HZAU), OCRI-5; Ding 110× Oscar and, particularly, Line5 (HZAU), were largely isolate-independent, making them ideal sources of resistance to target and exploit in developing new commercial cultivars with more effective resistance to SSR across multiple pathotypes of this pathogen. Cluster analysis allowed categorization of the test populations into five groups, based on their resistant responses. B. napus ZY006 was the sole genotype in the most resistant group. B. napus lines Line6 (HZAU), Ding 110 × Oscar (HAU) and Line4 (HZAU) clustered in another genetically distinct resistant group. That lines could be grouped into those with similar responses across the three different isolates of S. sclerotiorum will save breeders much time and expense by eliminating duplication of breeding efforts that occurs from using genotypes that are essentially similar in terms of host resistance against this serious pathogen. Further, that populations of similar levels of resistance but narrow variation in the resistance range could be identified is significant, as these are most likely to reliably provide breeders with advanced populations that not only consistently display the level of resistance expected but also reflect genetic diversity of resistance sources needed to successfully develop new more-resistant commercial varieties.  相似文献   

13.
Sesquiterpene carboxylic acids (SCA) from Lycopersicon hirsutum f. typicum Humb, & Bonpl, accession LA 1777 confer host‐plant resistance to Helicoverpa zea (Boddie) and Spodoptera exigua (Hübner), two Lepidopteran (Noctuidae) insect pests of the cultivated tomato. L. esculcntum Mill. Hybrids were made between LA 1777 and two accessions of insect‐susceptible tomatoes that do not produce SCA, L. hirsutum LA 1033 and the L. L. esculentum cultivar Chico III, F2 and backcross progeny of both crosses were evaluated for variation in amounts of total SCA in replicated field and greenhouse plantings. Analysis of variance of total SCA in a set of F2 plants of the cross LA 1033 × LA 1777 demonstrated significant variation in SCA attributable to genotype, environment and their interaction. Segregation for high levels of SCA in the populations suggests polygenic inheritance. Broad sense heritability was 0.84, which indicates that phenotypic selection for plants with high SCA is feasible in a backcross‐breeding programme for the introgression of SCA‐mediated insect resistance into tomato cultivars.  相似文献   

14.
Brown planthopper (BPH) is the most devastating insect pest in rice‐growing areas. Information on availability of BPH resistance alleles and their sources enhances BPH‐resistant breeding programmes. In this study, 260 highly diversified rice cultivars or breeding lines were screened for the presence of five major BPH resistance genes (Bph10, Bph13, Bph18, Bph20 and Bph21) using gene‐specific markers. The analysis revealed that 137 of the 260 cultivars possess at least one BPH resistance gene. Bph10 was predominant while Bph20 was the least distributed. Moreover, two and three different resistance gene combinations were found in the cultivars. Molecular markers play an important role in molecular breeding programmes. A tightly linked PCR‐based co‐dominant Bph18 marker was developed, which is cost effective and time effective and simpler than available Bph18 CAPS marker (7312.T4A). We strongly believe that the identified BPH‐resistant cultivars can be used as alternative resistance gene sources and also as resource for novel BPH resistance genes. The developed Bph18 marker will be highly useful in molecular breeding applications of BPH‐resistant breeding programmes.  相似文献   

15.
With the aim to transfer Phoma lingam resistance into rape, successful interspecific crosses were made between three oilseed rape varieties (Brassica napus) and the resistant species B. carinata and B. carinata. Although both hybrid types B. napus×B. juncea and B. napus×B. carinata showed the same high level of resistance as the respective resistant parent, the resistance could be only transferred from juncea crosses. After three backcross generations, lines morphologically undistinguishable from rape, fertile, and with a high degree of resistance were obtained. The resistance of B. carinata was practically lost in the first backcross. A possible explanation of this different behavior could be a higher recombination between the genomes B and C (juncea crosses) than between B and A (carinata crosses). The: applied embryo culture increased the yield of hybrids and first backcross plants and reduced considerably the generation time.  相似文献   

16.
Use of self‐incompatibility (SI) as a pollination control method for Brassica napus hybrid production requires the development of a sufficient number of S‐alleles that are expressed consistently in a range of B. napus lines. Self‐incompatibility (SI) alleles have been transferred from Brassica oleracea and Brassica rapa into B. napus var. oleifera. An understanding of expression of these alleles in B. napus is essential for their commercial use. Four SI B. napus doubled haploids containing the B. oleracea S‐alleles S2, S5, S13 and S24 were crossed to three B. napus cultivars to measure the B. napus genetic background effect on S‐allele expression. A line x tester analysis indicated that the largest source of variation in the expression rate of SI was the S‐allele itself. The B. napus genotypes tested contained modifier gene(s), some that enhanced SI expression and others that inhibited SI expression. The B. napus Canadian cultivar ‘Westar’ generally had a negative effect on SI expression while the European cultivar ‘Topas’ had a positive effect on the B. oleracea S‐allele expression. The B. oleracea S‐allele S24 was very similar in expression to the B. rapa allele W1. The application of these results for the use of B. oleracea S‐alleles for hybrid production in B. napus is discussed.  相似文献   

17.
Summary The possibilities to transfer important traits and in particular resistance to the beet cyst nematode (Heterodera schachtii, abbrev. BCN) from Raphanus sativus to Brassica napus were investigated. For these studies B. napus, R. sativus, the bridging hybrid ×Brassicoraphanus (Raparadish) as well as offspring of the cross ×Brassicoraphanus (Raparadish) ×B. napus were used. Reciprocal crosses between B. napus and R. sativus were unsuccessful, also with the use of embryo rescue. Crosses between ×Brassicoraphanus as female parent and B. napus resulted in a large number of F1 hybrids, whereas the reciprocal cross yielded mainly matromorphic plants. BC1, BC2 and BC3 plants were obtained from backcrosses with B. napus, which was used as the male parent. F1 hybrids and BC plants showed a large variation for morphology and male and female fertility. Cuttings of some F1 and BC1 plants, obtained from crosses involving resistant plants of ×Brassicoraphanus, were found to possess a level of resistance similar to that of the resistant parent. These results and indications for meiotic pairing between chromosomes of genome R with those of the genomes A and/or C suggest that introgression of the BCN-resistance of Raphanus into B. napus may be achieved.  相似文献   

18.
Two‐line hybrid rice technology is an effective way to increase rice production and improve rice quality. In this study, three bacterial blight (BB) resistance genes, Xa7, Xa21 and Xa23, were introgressed separately into C815S, a popular thermo‐sensitive genic male sterile (TGMS) line to develop five BB‐resistant lines (Hua1005S, Hua1002S, Hua1009S, Hua1006S and Hua1001S) to be resistant against seven races of Xanthomonas oryzae pv. oryzae (Xoo). The two‐line hybrids with heterozygous Xa23 were resistant against seven Xoo strains. But, the hybrids with heterozygous loci for both Xa7 and Xa21 were only resistant against three Xoo strains and were moderately susceptible to the other four strains indicating the role of modifiers influencing the poor expression of dominant BB resistance genes under heterozygous state. Among them, Hua1006S was found to be a promising TGMS line with its higher degree of disease resistance level on account of broad‐spectrum resistance gene Xa23 besides possessing better plant type and rice grain quality features.  相似文献   

19.
Greenbug and Russian wheat aphid (RWA) are two devastating pests of wheat. The first has a long history of new biotype emergence and recently. RWA resistance has just started to break down. Thus, it is necessary to find new sources of resistance that will broaden the genetic base against these pests in wheat. Seventy‐five doubled haploid recombinant (DHR) lines for chromosome 6A from the F1 of the cross between “Chinese Spring’ and the “Chinese Spring (Synthetic 6A) (Triticum dicoccoides × Aegilops tauschii)” substitution line were used as a mapping population for testing resistance to greenbug biotype C and to a new strain of RWA that appeared in Argentina in 2003. A quantitative trait locus (QTL) (br antixenosis to greenbug was significantly associated with the marker loci Xgwm1009 and Xgwm1185 located in the centromere region of chromosome 6A. Another QTL which accounted for most of the antixenosis against RWA was associated with the marker loci Xgwm1291 and Xiinni1150. both located on the long arm of chromosome 6A. This is the first report of greenbug and RWA resistance genes located on chromosome 6A. It is also the first report of antixenosis against the new strain of RWA. As most of the RWA resistance genes present in released cultivars have been located in [he D‐ genome, it is highly desirable to find new sources in other genomes to combine the existing resistance genes with new sources.  相似文献   

20.
The blackleg fungus, Leptosphaeria maculans, interacts with canola (Brassica napus) in a gene‐for‐gene manner. These major resistance genes are well characterized in the seedling stage of development, but not in other plant organs. Cotyledons, leaves, pods and stems of plants of two cultivars of B. napus, each harbouring a different major resistance gene (Rlm1 and Rlm4), were inoculated with two individual L. maculans isolates with different alleles of the corresponding avirulence genes (AvrLm1, avrLm4 and avrLm1, AvrLm4), and the disease phenotype in terms of lesion development was determined. Major gene resistance was expressed in cotyledons, all leaves and during pod set, but not in the stems of the adult plant. This is the first time major gene resistance has been shown to be effective in B. napus pods.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号