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 265 毫秒
1.
Developing disease resistant cultivars is one of the major objectives for a potato (Solanum tuberosum L.) breeding program, but many resistant clones have not achieved commercial acceptance because of late maturity and non-marketable tuber characteristics. Selection for tuber quality should have greater emphasis inbreeding disease resistant cultivars. The objectives of this study were 1) to evaluate the ability of late blight (Phytophthora infestans (Mont.) de Bary) resistant parents to transmit chip-processing (tuber appearance, specificgravity, and chip-color) or tablestock (tuber appearance) quality to the offspring and 2) to compare selecting for tuber quality in single-hill versus eight-hill generations. We made crosses among eight unadapted potato cultivars (B0718-3,Bertita, Bzura, Greta, Libertas, Stobrawa, Tollocan, and Zarevo) with reported late blight resistance with adapted susceptible cultivars/breeding clones to generate 95populations (4,750 seedlings). Approximately 10% of the progeny from each cross were selected from single-hill plots based on tuber appearance, number, shape, and internal defects. These selected clones (408) were evaluated for tuber appearance, specific gravity, and chip-color. The same evaluations in the following year were made on tuber samples from eight-hill plots. Libertas and Tollocan were the best parents for transmitting chip-color; B0718-3, Zarevo, and Tollocan for transmitting tuber appearance; and Bzura, Libertas, and Zarevo for transmitting high specific gravity to the highest percentage of the offspring. Overall, 50% and 56% of the clones based on single- and eight-hill generation, respectively, were considered to possess chip-processing quality; over 90% of the clones had acceptable tablestock quality. A total of 71% of the clones possessing acceptable chip-processing and 95% of the clones possessing acceptable tablestock quality selected in both generations were identified in single-hill plots. The evaluation of tuber quality characteristics in single-hill generation not only permitted the identification of clones with acceptable chip-processing and tablestock, but also increased the amount of clonal information for the following generation of selection. In crosses between late blight resistant and susceptible clones, selection for tuber quality traits can be initiated in single-hill generation using a moderate selection intensity and precede late blight testing. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

2.
Summary Degeneration of seed tubers caused by viruses is a major constraint to potato cultivation in many warm tropical areas. Cultivars resistant to the most important viruses present a promising solution to such a problem. In a breeding study conducted at the International Potato Center (CIP), ten cultivars resistant to PLRV were crossed to five clones immune to PVX and PVY, as well as to a susceptible control. The resulting progenies were screened for PVX and PVY immunity. Afterwards, the resistant genotypes were fieldexposed to a PLRV-viruliferous aphid population. One tuber was harvested from each plant and used to assess, using ELISA serology, the presence of leafroll virus. The cultivars Serrana and Pentland Crown gave the best progenies in terms of percentage of healthy plants, with values of 47.4 and 33.3 respectively. The presence of joint infection of PLRV and PVY or PVX in the progenies of the susceptible control resulted in an increased susceptibility to leafroll.  相似文献   

3.
Summary Seven wild diploid potato species, Series Tuberosa, representing 1023 clones were screened for resistance to the potato cyst nematode, Globodera pallida. Over 25% of the clones were resistant to pathotype P4A and almost 30% were resistant to pathotype P5A. The resistance in hybrid progenies of these and other resistant species with cultivated potatoes was evaluated, and over 2200 seedlings were screened. High frequencies of resistance (>50%) to P4A were found in progenies with Solanum leptophyes, S. vernei, S. gourlayi and S. capsicibaccatum, whereas resistance to P5A was found in these species as well as S. sparsipilum. The importance of nematode resistant wild species for potato breeding is discussed.  相似文献   

4.
Summary Potato virus Y (PVY) infects most Solanaceous crops grown in Mediterranean countries in open fields and in greenhouses. Necrogenic strains, which have been isolated from diseased tomatoes in France since the 1980's, seriously cause yield and quality loss of tomato fruits. Lycopersicon hirsutum PI 247087 was found to be resistant to PVY. Virus could not be detected in inoculated leaves by ELISA and/or by back-inoculation on susceptible plants. This resistance was efficient against the 16 tested isolates or strains. Temperature and inoculum concentration did not affect its expression. All the F1 plants of (Momor × PI 247087), (PI 134417 × PI 247087) and (PI 247087 × PI 134417) had symptom scores and ELISA values similar to those of the susceptible parents. The mechanism of resistance could be immunity-like or inhibition of virus migration from cell to cell. The resistance of L. hirsutum PI 247087 appeared to be governed by two independent recessive genes. In a few F2 plants of (PI 134417 × PI 247087) and F2 (Momor × PI 247087), virus was able to multiply in the inoculated leaves but could not establish a systemic infection. This finding may suggest a mechanism which interfers with the long distance migration of the virus in the plant.  相似文献   

5.
The Rysto gene from Solanum stoloniferum introduced into potato cultivars (Solanum tuberosum L. ssp. tuberosum) confers resistance to potato virus A, potato virus V and potato virus Y (PVY). In addition to PVY, tobacco etch virus (TEV) and a TEV construct that encodes β‐glucuronidase (TEV‐GUS) were inoculated to determine the inheritance of resistance to these viruses in progenies obtained from potato cultivars containing the Rysto gene. While cultivars ‘Karlena’ and ‘Delikat’ were susceptible, ‘Bettina’ and clone 927eY were resistant to PVY, TEV and TEV‐GUS, as determined by enzyme linked immunosorbent assay, biotest and GUS assay, respectively. The segregation ratios obtained from the progenies of ‘Bettina’בDelikat’ and 816eY בKarlena’ indicate that resistances to PVY and TEV are governed by one dominant gene or two genes tightly linked in coupling phase. Evidently, Rysto confers broad spectrum resistance to potyviruses. TEV resistance could be reliably detected 4 days after inoculation with the TEV‐GUS construct by GUS assay. Therefore, the GUS‐tagged TEV construct can be used for early selection for resistances based on the gene Rysto or closely linked genes.  相似文献   

6.
Summary Traditional potato breeding is a laborious process in which, by intercrossing, valuable traits from different parental clones are combined in a progeny genotype. Depending on the availability of genes, molecular techniques can be used to add specific genes to existing cultivars that, although otherwise satisfactory, lack a lew commercially important traits. For virus resistance the gene for the coat protein of a given virus transplanted into the genome of the plant renders the plant resistant to that virus. In conferring such resistance to potato varieties it proved to be possible to preserve their intrinsic properties.  相似文献   

7.
Summary Potato plantlets derived from in vitro propagation of three cultivars known for their field resistance (Cruza 148 and BR-63.65) or susceptibility (Désirée) to Pseudomonas solanacearum E.F. Smith were artificially inoculated under controlled conditions. The aim of this work was to determine the optimal inoculum concentration and the best observation period in which the cultivars would show different reactions to bacterial infection as expected on the basis of their field performance.A suitable statistical analysis of disease indices is proposed to distinguish between resistant and susceptible responses, with a particular care for the applicative needs and a univocal interpretation of the results. In order to evaluate the significance of sources of variation related to the observed mean differences, the analysis of variance and a convenient clustering procedure of disease index means were applied.The statistical analysis revealed that, under our conditions, an inoculum concentration of 5×106 cfu/plant was suitable for separating resistant from susceptible responses, in accordance with the reactions already observed in field experiments by other authors. Also, differences among the three cultivars were best observed nine to twelve days after inoculation with the pathogen.  相似文献   

8.
Summary A total of 934 potato cultivars and clones from different breeding programmes across the world were tested for their reaction to early blight (Alternaria solani) in Brasilia-DF, Brazil. This field trial was set up in order to identify tetraploid potato genotypes with useful levels of resistance to early blight (EB) that were not correlated with late maturity or lateness. Artificial inoculation (spread ofA. solani infected leaves over plant canopy) was employed even though EB occurs naturally at epidemic levels in the test area. Four disease assessments were made every 10 days, beginning 45 days after planting. Based on the evaluation made 65 days after planting, only 27 clones were identified that had less lesioned leaf area than the resistant standard (cv. Aracy). Area under disease progress curve (AUDPC) was also used as a criterion of resistance. Using AUDPC as a parameter, 22 genotypes were identified presenting values lower than or identical to cv. Aracy. Differences in the commercial yield were recorded in genotypes with identical response to EB, suggesting that distinct levels of tolerance to EB also exist. In spite of the strong correlation between EB resistance and late maturity, some genotypes derived from the parental materials NDD 277-2, Kufri Jyoti, CIP 377888-7, Maine-28, and the clones CFS 69.1 and I-853 were identified as having good levels of EB field resistance not linked with the negative phenotypic trait of lateness. These materials presented medium to medium-early maturity with a vegetative cycle of around 90–95 days. Some selected genotypes presented more acceptable agronomic characteristics including resistance toPhytophthora infestans, potato leaf roll luteovirus (PLRV) and potato virus Y (PVY). The EB resistance sources identified in this work can be recommended as parental materials for widening the genetic base for EB disease resistance in breeding programmes for highland tropical and subtropical areas.  相似文献   

9.
Summary Resistance toMeliodogyne chitwoodi races 1 (MC1) and 2 (MC2) andM. hapla (MH) derived fromSolanum bulbocastanum was introduced into the cultivated potato gene pool through somatic fusion. The initial F1 hybrids showed resistance to the three nematodes. Resistance to reproduction on roots by MC1 was accompanied by resistance to tuber damage in F1 clones. Tuber damage sometimes occurred, however, in hybrids of BC1 progeny resistant to reproduction on roots when MC2 and MH were the challenging nematodes. Resistance to reproduction was transferred into BC1 individuals, but a greater proportion of BC1 progeny was resistant to MC1 than to MC2 or MH. Resistance to MC1 appears to be dominant and discretely inherited. F1 and BC1 progeny were pollen sterile, but seed were produced from crosses using cultivated tetraploid pollen sources. Approximately 11 and 33 per cent of pollinations produced berries on F1 and BC1 pistillate parents, respectively. Seed yield increased fourfold overall in crosses with F1 compared to BC1 individuals.Abbreviations MC1 Meloidogyne chitwoodi race 1 - MC2 Meloidogyne chitwoodi race 2 - MH Meloidogyne hapla - Rf Reproductive factor  相似文献   

10.
J. Bae  S. H. Jansky  D. I. Rouse 《Euphytica》2008,164(2):385-393
Verticillium wilt (VW) of potato, caused primarily by the fungus Verticillium dahliae, results in yield loss and is therefore an important soil-borne disease. Resistance to VW exists in potato germplasm and is used by breeders during cultivar development. Breeders could make more rapid progress toward the development of VW resistant clones if they had an effective early generation selection strategy. The purpose of this study was to determine whether selection for VW resistance could be carried out in the first tuber generation on single hills. One hundred and fifty-two clones from 19 families were planted as single hills on a V. dahliae-infested field. Each plant was scored for vine maturity, VW symptom expression, yield, stem colonization (colony forming units (cfu), in dried basal stem segments) and incidence (percent infected stems). In the second clonal generation, which consisted of replicated four-hill plots, stem colonization scores and incidence values were used to identify clones which were more resistant than a moderately resistant cultivar and others which were more susceptible than a susceptible cultivar. The efficiency and reliability of the single-hill selection strategy, based on symptoms and yield, was then determined by comparison to the four-hill results. We determined that the best single-hill selection strategy was negative selection (discard clones with the lowest performance) with low stringency, based on yield.  相似文献   

11.
Summary Tuber characteristics of potato clones (Solanum tuberosum L.) regenerated from cultured leaf, rachis or stem pieces of cv. Desiree were assessed in field trails over three years. In the first two seasons, when the crop was grown for seed potato production, tuber numbers and the tuber yields were normally distributed and the population means of the clones were about the same as those of the controls. When 78 of the clones were grown as a ware crop in a replicated field trial there were statistically significant differences between most clones and the controls in total yield (generally lower) and ware yield (generally higher), brought about by alterations of the size distributions of tubers. In all years the population of clones had fewer scab (Streptomyces scabies) lesions than the controls. Clones with consistent differences in flesh colour and eye depth were also observed. Two out of 78 clones, in 1984, had significantly higher dry matter content. No stable decrease in susceptibility to the cyst nematode Globodera pallida was observed amongst 167 clones tested. These potato plants regenerated from explants clearly show that somaclonal variation can include agronomically relevant changes.  相似文献   

12.
J. Brown 《Euphytica》1987,36(3):711-718
Summary The efficiency of single plant selection in the initial selection stage of a potato breeding programme was examined. A random sample of potato clones was grown in single plant plots and also in tworeplicates of five plant plots. After harvest, each plot was visually assessed by three potato breeders; total tuber weight and number of tubers per plant were also recorded, from which mean tuber weight was calculated. The error variances of the single plant plots were found to be significantly greater than from the five plant plots for total tuber weight, mean tuber weight and number of tubers per plant, but not significantly different for breeders' preference. Coefficients of correlation between single and five plants plots were significantly greater than zero for all traits examined, but they were lower than the corresponding correlations between the two replicates of five plant plots. Although a random sample of clones was examined, each clone had been assessed for breeders' preference the previous year. When the clones were grouped according to the previous years preference scores, it was found that the correlation coefficients between single and five plant plots for breeders' preference were inversely related, in magnitude, to the mean preference score of each group. It was concluded that single plant selection was generally ineffective, particularly when only the better clones, from the previous years assessment, are examined.  相似文献   

13.
Summary Resistance to potato leafroll virus (PLRV) was detected in an accession of Solanum chacoense. Inoculations with viruliferous aphids and subsequent graft challenges using Datura tatula and potato as PLRV sources determined that resistance appears to be of an extreme type. Virus was not detectable using enzyme-linked immunosorbent assay (ELISA) in S. chacoense, and in resistant F1 and BC1 progenies after attempts to transmit the virus through grafting. The segregation ratios of BC1 progenies for positive and negative ELISA tests are consistent with simple dominant inheritance.  相似文献   

14.
Summary Using an amylose-free (amf)mutant of diploid potato (Solanum tuberosum), diploid and tetraploid clones with different genotypes at the amf-locus were produced. In order to make use of the diploid material in analytic breeding of amf-potatoes, clones were selected that produced a considerable frequencies of 2n-pollen and 2n-eggs. Successful attempts were made to select normal synaptic as well as desynaptic clones producing 2n-gametes. Based on the phenotype of starch in the microspores, tetraploid clones with nulliplex, simplex and duplex genotypes at the amf-locus were selected. Prospects of using this material in conventional as well as in analytic breeding of potato are discussed.  相似文献   

15.
The objectives of this study were to evaluate the use of potato (Solanum tuberosum L.) late blight (Phytophthora infestans (Mont.) de Bary) resistant parents in cultivar development and identify superior clones possessing moderate to high late blight resistance combined with acceptable maturity and tuber quality. Ninety-five crosses were made between eight unadapted parents with reported late blight resistance (B0718-3, Bertita, Bzura, Greta, Libertas, Stobrawa, Tollocan and Zarevo) and susceptible parents (cultivars or advanced breeding clones) adapted to North American growing conditions. A total of 408 field selected clones were assessed for late blight resistance in the greenhouse and in the field using a mixture of US8 P. infestans isolates (A2 mating type, metalaxyl resistant) that overcame all known R-genes except R8 and R9. Clones with ≤ 10% infected foliar area in the greenhouse test or ≤ 0.30 RAUDPC (relative area under the disease progress curve) value in the field in 1998 were re-tested in 1999. A total of 118 (29% of 408) putative late blight resistant clones were selected. The eight late blight resistant parents differed in both the ability to transmit late blight resistance and in the level of resistance transmitted to the progeny. The Tollocan and B0718-3 families (half-sib progeny) had the greatest degree of resistance and frequency of resistant clones. Scott-Knott cluster analysis ranked 79 clones (67% of 118) in the high and moderate late blight resistant groups. Among these 79 clones, 19 clones had vine maturity equal to or earlier than mid-season combined with acceptable tuber quality. Further selection in 2000 resulted in eight advanced selected clones (six from Tollocan and two from B0718-3 families) with the same level of resistance as the parent combined with vine maturity and tuber quality equivalent to Atlantic, a standard cultivar for chip processing in North America. The results indicate that this breeding approach can be used to select parents for late blight resistance breeding and to identify superior clones with high levels of late blight resistance and marketable vine maturity and tuber quality. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
Summary The potato tuber moth, Phthorimaea operculella (Zeller) is an important pest of potatoes in the field and in stores in warm environments throughout the world. In this study genetic resistance to potato tuber moth was identified in clones of Solanum sparsipilum (coded MBN) originally developed for resistance to bacterial wilt and root-knot nematode. Resistance to this pest in S. sucrense and S. tarijense as well as S. sparsipilum was exploited in wide crosses with diploid and tetraploid cultivated potatoes, and haploids derived from S. tuberosum; hybrid progenies were produced. Crosses between resistant S. pinnatisectum or S. commersonii and cultivated potatoes failed completely, although S. commersonii did hybridise with two bridging species S. lignicaule and S. capsicibaccatum which are slightly compatible with cultivated potatoes. Resistance to potato tuber moth was transferred to all progenies except those in which S. tarijense was the resistant parent. The development of potatoes resistant to potato tuber moth is discussed in the context of population breeding for the lowland tropics.  相似文献   

17.
B. Maris 《Euphytica》1986,35(2):465-482
Summary Fifty-five populations from crosses of three Solanum tuberosum ssp. tuberosum cultivars and seven selected S. tuberosum ssp. andigena clones adapted to the northern temperate zone have been studied in the seedling and the first and second clonal generation. This paper only deals with the effect of seed tuber weight on various important agronomic characters which are selected for in early clonal generations, independently of the type of crosses.The results showed that a distinction has to be made between the effects of differences in seed tuber weight within and between seedlings, i.e. genotypes. The effects on the first clonal generation of differences in weight of the tubers within seedlings and those of the first heaviest tubers between seedlings were similar and comparable to seed tuber weight effects within cultivars. In contrast to the within seedlings effects the between seedlings effects proved to be heritable. This is concluded from the fact that, on average, independent of seed tuber weight seedlings with larger first heaviest tubers performed better in the second clonal generation than those with smaller ones. Notably plant height, general impression, date of maturity and particularly tuber yield and mean tuber weight in the second clonal generation were related to the weight of the first heaviest tubers of the seedlings. The potentialities of these findings for an early generation selection are discussed.  相似文献   

18.
Summary Selection of diploid potato genotypes that produce high frequencies of 2n-pollen grains in different environments is an important requirement for analytic breeding as well as for true potato seed production. In this context, quantitative estimates of 2n-pollen formation were made in two type of diploid potato populations. One population set consisted of the progeny from diallel crosses of five well-known diploid potato clones (A=US-W 5293.3, B=US-W 5295.7, C=US-W 5337.3, D=US-W 7589.2 and E=772102-37). Another population set was obtained by pollinating three genotypes of Solanum phureja, IvP35, IvP48 and IvP101 with clones A, C and E. It was observed that the behaviour of the parental clones with respect to 2n-pollen grains formation in different environments, such as in Europe and China, was stable. The correlation coefficient between means of 2n-pollen grains frequency of combinations and percentage of genotypes with more than 5% 2n-pollen grains in a given combination were estimated and that between mean and maximum frequency of 2n-pollen grains formation in each combination. The results showed that the former coefficients were significant wheareas the latter were not. The combining ability analysis revealed variation in 2n-pollen grains formation between families. Specific combining ability (SCA) effects contributed much more than general combining ability (GCA) to the variation in 2n-pollen grains formation. The broad-sense heritability of 2n-pollen grains formation was estimated to vary between 0.45 and 0.53 and the narrow-sense heritability was calculated to be 0.15 and 0.20 in the two types of populations. This means that additive variance was relatively low. Two to four genes were estimated to control the inheritance of 2n-pollen grains formation.  相似文献   

19.
Summary A number of previously selected hydroxyproline (hyp) resistant cell lines of a diploid potato (Solanum tuberosum L., clone H2578, 2n=2x=24) could be regenerated into plants which were further analysed. Hyp resistance, although lower than in the originally selected calli, was still present in regenerated shoots and in callus initiated from these shoots and it was not lost upon (mini)tuber propagation. Regenerated shoots showed a wide range of phenotypic variation. The chromosome number, analysed in 4 clones, appeared to be hypotetraploid (44 or 45). Tuber-propagated regenerants generally showed increased frost tolerance both at the plant and the cell level. In leaves this seemed to be associated with increased levels of both proline and total amino acid content. However, in callus only the total amino acid content but not proline was still elevated. In the wild type the frost tolerance of the tubers appeared to be lower than that of the leaves. Between tubers of wild type and the hyp resistant regenerants no differences in frost tolerance were found, although proline and total amino acid content tended to be higher in tubers from the regenerants.  相似文献   

20.
Tomato mosaic virus (ToMV) is a limiting factor for the success of pepino (Solarium muricatum) as a new crop. The effects of ToMV infection on total and marketable yield, fruit weight, length/width ratio and soluble solids content (SSC) have been studied in two commercial clones (`Sweet Long' and `Sweet Round'). ToMV infection depressed total yield in infected plants of `Sweet Long' (43.1%), while it had no effect on this trait in `Sweet Round' . Marketable yield was dramatically reduced by ToMV infection in both clones, 94% in `Sweet Long' and 100% in `Sweet Round'. Infected plants of clone `Sweet Long' had a lower weight than healthy plants. Although no differences in fruit weight were detected in `Sweet Round' between ToMV infected and healthy plants, many fruits from infected plants showed deformities. Changes in fruit length/width ratio and SSC as a result of ToMV infection were not relevant, but fruit quality was lower in infected fruits, most of which had corky-like flesh. Forty-two clones from cultivated (S. muricatum), wild (S. caripense and S. tabanoense) and interspecific hybrids were tested for ToMV resistance. All but seven clones (four from S. muricatum and three from interspecific hybrids S. muricatum × S. caripense) were susceptible. Non-susceptible clones showed variable degrees of resistance and developed hypersensitive local lesions. Among these clones the most promising as sources of variation for resistance to ToMV are those belonging to the cultivated species. Although no immunity was found, plants from these clones remained asymptomatic and absorbance values resulting from the DAS-ELISA tests in these plants were always lower than those of the susceptible control (cv. `Sweet Round'). These sources of resistance may be of great utility in developing commercial clones resistant to this severe disease affecting pepino. This revised version was published online in July 2006 with corrections to the Cover Date.  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