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1.
Summary F1 hybrid true potato seed progenies with multiple sources of specific resistance to Pseudomonas solanacearum and adaptation were evaluated under tropical greenhouse conditions for resistance to a race 1 isolate of P. solanacearum. Results indicated that genes for adaptation are involved in conferring resistance to bacterial wilt. The effect of a particular resistant parent clone on the resistance level of its progeny depended on the resistance, adaptation or the combination of both characteristics of its mate. A heat tolerant parent gave a higher frequency of resistant offspring in combination with an ascertained source of resistance. Combining ability was an apparent feature of resistance to bacterial wilt and resistance was highest in the majority of the crosses that had a wide genetic background for both resistance and adaptation. The possible genetic nature of the resistance to bacterial wilt is discussed. 相似文献
2.
Inheritance of stalk rot resistance in cauliflower (Brassica oleracea var. Botrytis L.) 总被引：2，自引：0，他引：2
Summary The inheritance of resistance in cauliflower to stalk rot (Sclerotinia sclerotiorum (Lib.) de Bary) was investigated in population from six generations of six crosses. Disease incidence was recorded on 4 parents, 6 Fs
1, 6 Fs
2 and 12 back-crosses in a screenhouse under artificially created epiphytotic conditions. Resistance to stalk rot in this set of parents was found to be polygenic and under the control of recessive genes and due primarily to additive gene action. A breeding strategy emphasizing recurrent selection should lead to improvement in resistance. 相似文献
3.
Summary The inheritance of resistance to bacterial leaf streak or black chaff of wheat was studied under field conditions, with an artificial epidemic of Xanthomonas campestris pv. undulosa. A complete series of crosses between five parents, differing in reaction to X. c. pv. undulosa, was generated. Disease was recorded at two different stages of growth. No evidence of cytoplasmic effect was found from the comparison between reciprocal F1 crosses. The study of the F3 generations attested that five genes were involved in resistance to bacterial leaf streak. Separate analyses carried out for the two scoring dates were mutually consistent: genotypes, number of genes, and their action and relative importance were verified. The genes differed in strength of expression of resistance. One of the two strongest genes, Bls1, is present in all three superior parents, Pavon 76, Mochis T88 and Angostura F88. Resistance was not complete, and proved to be stable over the season. 相似文献
4.
Summary Monosomic analysis of resistance to stem rust, race 11 (isolate G 425) was carried out in the cultivar Almus (GDR) possessing a 1B/1R translocation. F2 progenies of monosomic and disomic F1 plants of Almus crossed with 21 monosomic lines of Chinese Spring were tested. Two lines (1B and 6B) differed significantly from the disomic segregation ratio by a higher number of resistant plants and two other lines (1D and 6A) by a lower number of resistant plants. The results fitted a hypothesis comprising the interaction of two genes for resistance and two inhibitors. 相似文献
5.
Summary Resistance to fusarium wilt, incited by Fusarium oxysporum (Schlecht.) f. sp. lycopersici (Sacc.) Snyder & Hansen race 3 in tomato (Lycopersicon esculentum Mill.) was discovered in LA 716, a L. pennellii accession. A resistant BC1F3 breeding line, E427, was developed from LA 716. E427 was crossed with the susceptible cv. Suncoast and F1, BCP1, BCP2 (to Fla 7155, a susceptible parent) F2, F3, and BCP2S1 seeds were obtained. Segregation for resistance following root dip inoculation over three experiments indicated a single dominant gene controlled resistance. Five of the 12 BCP1S1's segregated more susceptible plants, whereas one of the 12 segregated more resistant plants than expected (P<0.05). Three of 23 F3 lines segregated more susceptible plants than expected while 1 of the 23 had more resistant plants than expected (P<0.05). Segregation in all other lines fit expected ratios. Five of the 23 F3's were homozygous resistant which was an acceptable fit to expectations (P=0.1–0.5). The gene symbol I
3 is proposed for resistance to race 3 of the wilt pathogen. Deviations from expected ratios in data reported here and for other breeding lines indicate an effect of modifier genes and/or incomplete penetrance. Plant age at inoculation and seed dormancy did not affect results.Florida Agricultural Experiment Station Journal Series No. 8101. 相似文献
6.
Summary Inheritance of resistance to tomato leaf curl virus (TLCV) was studied in the progenies derived from interspecific crosses between TLCV resistant Lycopersicon hirsutum f. glabratum line B 6013 and five susceptible cultivars (HS 101, HS 102, HS 110, Pusa Ruby and Punjab Chhuhara) of L. esculentum. P1, P2, F1, F2, B1 and B2 progenies of the five crosses were artificially inoculated with local strains of TLCV by means of the vector whitefly, Bemisia tabaci (Genn.). and the disease reaction was studied in all the crosses. Reaction of parents, F1, F2 and backcrosses suggests that resistance derived from L. hirsutum f. glabratum B 6013 is based on two epistatic genes, one from the wild parent and one from the cultivated one, resulting in a 13:3 segragation in the F2. 相似文献
7.
Sunflower downy mildew caused by Plasmopara halstedii is an important disease of sunflower capable of causing losses of more than 80% of production. Races 100, 300, 310, 330,
710, 703, 730 and770 of the fungus have been identified in Spain. Race 703, of high virulence, has been identified frequently
in the northeast, while race 310 seems to occur over the south, the main sunflower growing region of the country. Oil sunflower
lines RHA-274 and DM4 were studied for their resistance to races 310(RHA-274 and DM4) and 703 (DM4). In each cross, only one
plant of the resistant parent was crossed to the inbred susceptible line HA-89 (or cmsHA-89).Plants from F2 and backcross(BC1F1 to susceptible parent)generations were evaluated for fungal sporulation on true leaves and/or cotyledons. The resistant-to-susceptible
ratios obtained in the F2 and BC1F1 progenies from the crosses cmsHA-89 × RHA-274 and HA-89 × DM4suggested that one major gene in each line is responsible for
resistance to race 703.The segregations of the progenies of the cross HA-89 × DM4 inoculated with race 703also fitted the
ratios 1:1 and 3:1 (for BC1F1 and F2, respectively)corresponding to control of resistance by a single dominant gene. In RHA-274, the gene for resistance to race
310 was designated Pl
9, whereas Pl
v is tentatively proposed to designate the gene in DM4 responsible for resistance to races310 and 703.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Wheat breeders in South Asia are attempting to develop wheat (Triticum aestivum L.) cultivars resistant to Helminthosporium leaf blight (HLB), which occurs mainly as a complex of spot blotch caused by Cochliobolus sativus (Ito & Kuribayashi) Drechs. ex Dastur, and tan spot caused by Pyrenophora tritici-repentis (Died.) Drechs. Information on the combining ability for HLB resistance in wheat cultivars of South Asia is not available. This study was undertaken to examine the resistance to HLB in nine genetically diverse wheat parents, and to evaluate their general combining ability (GCA) and specific combining ability (SCA) effects toward determining the genetic basis of disease resistance. Nine parents were crossed in a half-diallel mating design to produce 36 populations. The F1 and F2 progenies, and the parents were evaluated in replicated field tests at Rampur, Nepal. Multiple disease scores were recorded, and area under the disease progress curve (AUDPC) was calculated to measure disease severity over time. The combining ability analysis was performed using Griffing's Method 2, Model 1. The parents chosen showed wide variation for resistance to HLB. They and the F1 and F2 progenies differed significantly for AUDPC. GCA and SCA effects were significant in both generations suggesting that additive as well as non-additive genetic mechanisms were involved in the expression of resistance in these parents. Wheat genotypes 'SW89-5422', 'G 162', 'NL 781'and 'Chirya 7' had significantly negative GCA effects for AUDPC in both F1 and F2 generations, suggesting their prime suitability for use in wheat breeding programs to improve resistance to HLB. The estimate of narrow-sense heritability was 0.77 in both generations suggesting that selection for HLB resistance should be effective in these crosses. The results indicate a predominance of additive gene action in the inheritance of HLB resistance in spring wheat. 相似文献
9.
Summary The first backcross and F2 progenies from triploid F1 and tetraploid F1 hybrids between B. napus and 2x and 4x B. oleracea ssp. capitata (cabbage) were studied for their general morphology, resistance to race 2 of the clubroot pathogen, chromosome number and meiotic chromosome behavior. No linkage was apparent between resistance and the major morphological characters. Unreduced gametes played a large part in the successful formation of seed of the B1 and F2 progeny. B1 plants with low chromosome numbers were selected for use in recurrent backcrosses. The potential use of anther culture to extract gametic progenies from resistant B1 and F2 plants with higher chromosome numbers was suggested. The presence of homoeologous pairing observed in all the plants is considered advantageous for selecting suitable progeny in later generations. 相似文献
10.
Diallel analysis of resistance to head blight caused by Fusarium culmorum in winter wheat 总被引：1，自引：0，他引：1
C.H.A. Snijders 《Euphytica》1990,51(1):1-9
Summary Ten homozygous winter wheat genotypes representing different levels of resistance to Fusarium head blight were crossed in all possible combinations excluding reciprocals. Parents, F1 and F2 were inoculated with one pathogenic strain of Fusarium culmorum. Data for head blight, observed 21 days after first inoculation (OBS-2), and for the area under the disease progress curve, based on observations 14, 21 and 28 days after first inoculation (AUDPC), were analyzed. The contrast between parents and F1 crosses indicated dommance effects of the resistance genes. Diallel analysis according to Griffing's Method 4, Model 1 showed significant general combining ability (GCA) effects for both F1 and F2; specific combining ability effects were not significant. With the exception of one genotype for which general performance for Fusarium resistance was not in agreement with its GCA, the resistance to F. culmorum was uniformly transmitted to all offspring, and the parents can be described in terms of GCA. It is suggested that in the progenies with one of the awned lines as parent, one resistance gene was linked with the gene coding for presence of awns, located on chromosome 4B. A single observation date, taken at the right time, was as effective in assessing resistance as the AUDPC. 相似文献
11.
K. K. Nkongolo 《Euphytica》1996,90(3):337-344
Summary The Barley Yellow Dwarf Virus disease (BYDV) and the Russian wheat aphid (RWA) Diuraphis noxia (Mordvilko) have caused significant losses to wheat and barley in several areas of the world. Important sources of resistance to both BYDV and RWA have been found in Triticale. Different generations of interspecific wheat x Triticale crosses were produced and the progenies were screened for BYDV and RWA tolerance. Plants with equal chromosome numbers showed different levels of fertility. A significant correlation was observed between pollen fertility and seed set in primary florets (r=0.57). In generaL, pollen fertility, seed set and the number of euploid plants (2n=42) increased from one generation to the next. The expression of BYDV tolerance varied from population to population. Additive effects were predominant in F1 and some backcross populations. A dominant effect of rye tolerance genes was also observed in few populations. A monogenic trait or a quantitative (polygenic) character would not agree with the observed segregation patterns. The heritability of this oligogenic tolerance was quite different between populations and in many populations the tolerance genes were only partially expressed. Some transgressive segregation for tolerance and sensitivity was demonstrated. The genes controlling tolerance to RWA in Triticale lines, Muskox 658 and Nord Kivu were not expressed in advanced lines resistant to BYDV. This indicates that tolerance genes for BYDV and RWA in these lines are located on different chromosomes. 相似文献
12.
Summary In studies of the inheritance of resistance, pea seedlings of seven lines in which stems and leaves were both resistant to Mycosphaerella pinodes were crossed with a line in which they were both susceptible. With seven of the crosses resistance was dominant to susceptibility. When F2 progenies of five crosses were inoculated on either stems or leaves independently, phenotypes segregated in a ratio of 3 resistant: 1 susceptible indicating that a single dominant gene controlled resistance. F2 progenies of one other cross gave ratios with a better fit to 9 resistant: 7 susceptible indicating that two co-dominant genes controlled resistance. The F2 progeny of another cross segregated in complex ratios indicating multigene resistance.When resistant lines JI 97 and JI 1089 were crossed with a susceptible line and leaves and stems of each F2 plant were inoculated, resistance phenotypes segregated independently demonstrating that leaf and stem resistance were controlled by different genes. In two experiments where the F2 progeny of the cross JI 97×JI 1089 were tested for stem and leaf resistance separately, both characters segregated in a ratio of 15 resistant:1 susceptible indicating that these two resistant lines contain two non-allelic genes for stem resistance (designated Rmp1 and Rmp2) and two for leaf resistance (designated Rmp3 and Rmp4). Evidence that the gene for leaf resistance in JI 1089 is located in linkage group 4 of Pisum sativum is presented. 相似文献
13.
Summary Male meiosis of the interspecific hybrid between Allium roylei and A. cepa is undisturbed relative to its parents. Based on meiotic data, A. roylei is concluded to be a closer relative of A. cepa than A. fistulosum. Segregation ratios for downy mildew resistance among BC1 and F2 progenies from the F1 between A. roylei and A. cepa indicate the presence of two dominantly inherited, weakly linked nuclear resistance genes, Pd
1 and Pd
2, in A. roylei (recombination frequency 0.32±0.03). Presumably Pd
1 and Pd
2are the first genes described in Allium residing in one linkage group. The prospects of exploiting A. roylei in onion breeding seem very promising. 相似文献
14.
Reuben Tendo Ssali Andrew Kiggundu Jim Lorenzen Eldad Karamura Wilberforce Tushemereirwe Altus Viljoen 《Euphytica》2013,194(3):425-430
Fusarium wilt of bananas (also known as Panama disease), caused by the soil-borne fungus Fusarium oxysporum f. sp cubense (Foc), is a serious problem to banana production worldwide. Genetic resistance offers the most promising means to the control of Fusarium wilt of bananas. In this study, the inheritance of resistance in Musa to Foc race 1 was investigated in three F2 populations derived from a cross between ‘Sukali Ndizi’ and ‘TMB2X8075-7’. A total of 163 F2 progenies were evaluated for their response to Fusarium wilt in a screen house experiment. One hundred and fifteen progenies were susceptible and 48 were resistant. Mendelian segregation analysis for susceptible versus resistant progenies fits the segregation ratio of 3:1 (χ2 = 1.72, P = 0.81), suggesting that resistance to Fusarium wilt in Musa is conditioned by a single recessive gene. We propose panama disease 1 to be the name of the recessive gene conditioning resistance to Fusarium wilt in the diploid banana ‘TMB2X8075-7’. 相似文献
15.
Summary Tomato accessions (Lycopersicon sp.), along with commercial cultivars and breeding lines were grown in a field infested with the brown root rot (BRR) organism, Pyrenochaeta lycopersici and evaluated for resistance. Three L. esculentum Mill. accessions, P.I. 260397, P.I. 262906 and P.I. 203231, were resistant and were used as male parents in crosses designed to transfer resistance to tomatoes of fresh market type. Through analysis of parental generations and F1 and F2 progenies from three crosses the heritability of resistance in the broad sense was estimated to range from 25 to 43 percent. The minimum number of genes influencing resistance was estimated to be from 4 to 8.Florida Agricultural Experiment Stations Journal Series Paper no. 317. 相似文献
16.
Summary Genetics of rust resistance against stem rust race 122 in Chhoti Lerma was studied both by conventional and aneuploid analysis. Observations on F1, F2 and F2 backcross progenies revealed the operation of two recessive genes, controlling resistance in Chhoti Lerma. Monosomic analysis confirmed the operation of two recessive genes conferring resistance to race 122 located on chromosomes 1D and 7D. A minor gene or modifier was also located on chromosome 1B. This was concluded from the fact that F2 of mono's x Chhoti Lerma exhibited skewness in favour of resistant plants. 相似文献
17.
Summary Seven single-plant selections of wild emmer, with temperature-sensitive minor-effect genes for stripe rust resistance, were intercrossed in eight combinations. The resulting progenies were studied for a possible additive gene action.The transgressive segregation towards resistance in F2 observed in all the combinations indicates that additive gene action for resistance indeed occurs in wild emmer. The common occurrence of this phenomenon in random combinations suggests further that several minor-effect genes are involved.Following selection of the most resistant plants in F2, a marked shift towards resistance was noted in F3, which demonstrates a positive response to selection. In some instances, additive resistance selected for (in F2) at the high temperature-profile was expressed (in F3) also at the low temperature-profile. This kind of resistance, when utilized in breeding programmes, promises therefore to be effective over a range of temperatures. 相似文献
18.
19.
Summary Inheritance of the brown hypersensitive resistant (BHR), non-hypersensitive resistant (R) and susceptible (S) host reactions produced by three races of the bacterial pustule pathogen (Xanthomonas campestris pv. vignaeunguiculatae) was studied in 45 F1, F2 and testcross progenies, using the infiltration inoculation method BHR reaction was dominant over R and S reactions, and R was recessive to S reaction. Two genes appeared to be involved in BHR reaction; one governing BHR reaction to race 1 and the other to races 1 and 2. Both were ineffective against race 3. R reaction, effective against all the races, appeared to be controlled by one, two or three recessive genes. One cowpea line had one BHR gene and two duplicate recessive R genes. Reaction expression in the segregants was clear and as expected with races 2 and 3 but was modified with race 1, possibly due to interactions between dominant or recessive alleles of the BHR genes and the homozygous recessive allele of the R genes. Gene symbols Bp-1 and Bp-2 are proposed for the BHR genes and bp-3, bp-4 and bp-5 for the recessive R genes. The genes present in each of the differential cowpea line are suggested.Contribution from the International Institute of Tropical Agriculture, Ibadan, Nigeria and Crop Development Division, Ministry of Agriculture, P.O. Box 9071, Dar es Salaam Tanzania. 相似文献
20.
Phillip N. Miklas Dermot P. Coyne Kenneth F. Grafton Nedim Mutlu Jim Reiser Dale T. Lindgren Shree P. Singh 《Euphytica》2003,131(1):137-146
Knowledge of the evolutionary origin and sources of pest resistance genes will facilitate gene deployment and development
of crop cultivars with durable resistance. Our objective was to determine the source of common bacterial blight (CBB) resistance
in the common bean Great Northern Nebraska #1 (GN#1) and GN#1 Selection 27 (GN#1 Sel 27). Several great northern cultivars
including GN#1, GN#1 Sel 27, and Montana No.5 (the female parent of the common x tepary bean interspecific population from
which GN #1 and GN # 1 Sel 27 were derived) and known susceptible checks were evaluated for CBB reaction in field and greenhouse
environments. These genotypes and CBB resistant and susceptible tepary bean including Tepary #4, the male parent and presumed
contributor of CBB resistance toGN#1 and GN#1 Sel 27, were assayed for presence or absence of three SCAR markers tightly linked
with independent QTLs conditioning CBB resistance. The parents and F2 of Montana No. 5/GN #1 Sel 27 and Montana No.5/Othello(CBB susceptible) were screened for CBB reaction and SCAR markers.
CBB resistance in Montana No.5 was comparable to that of GN#1 and GN#1 Sel27. The SAP6 SCAR marker present in GN#1 and GN#1
Sel 27 was also present in Montana No.5, and it co-segregated (R
2 =35%) with the CBB resistance in the Montana No.5/Othello F2 population. Although a few CBB resistant and susceptible transgressive segregants were found in the F2 of MontanaNo.5/GN #1 Sel 27 and later confirmed by F3 progeny tests, SAP6 SCAR marker was present in all progenies. None of the tepary bean specific CBB resistance-linked SCAR
markers were present in GN#1, GN#1 Sel 27, or Montana No.5. A cluster analysis of 169 polymorphic PCR-based markers across
three common bean and Tepary #4 indicated that GN#1, GN#1 Sel 27, and Montana No.5 were closely related, and not related at
all with Tepary #4.Thus, these results clearly indicate Montana No.5, not Tepary #4, as the source of CBB resistance in GN#1
and GN#1 Sel 27.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献