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1.
Summary Virulence of 12Fusarium oxysporum isolates was determined on three potato cultivars Late Harvest, BP1 and Kimberley Choice. The production of fusaric acid
by the 12F. oxysporum isolates was also determined. The aim of the study was to determine whether a correlation exists between fusaric acid production
and virulence ofF. oxysporum isolates. Late Harvest was the most tolerant and BP1 the most susceptible cultivar. Virulence ranking, order of theF. oxysporum isolates with the different cultivars corresponded with the mean of value of the ranking order for all three cultivars. A
correlation was found between virulence of isolates and fusaric acid production except for Late Harvest. Fusaric acid production
may play a major role in the development of dry rot in potato tubers. 相似文献
2.
Dry rot is a serious potato disease and causes significant losses in China. Research efforts on potato dry rot have been very limited as well as the attempts to characterize the pathogen in the major potato production regions of China. A total of 260 Fusarium isolates were identified in 698 potato tubers collected in six important potato production regions of northern China, out of which five different Fusarium species, Fusarium sambucinum, F. avenaceum, F. oxysporum, F. equiseti, and F. acuminatum, were isolated. The identification of each species was confirmed by sequencing analysis of ∼700 bp DNA fragment derived from the translation elongation factor-1 alpha gene. F. sambucinum was found to be the predominant species accounting for 56% of the isolates. Different pathogenicity was found to be associated with five most common Fusarium species. Sixty-seven clones used in China were identified as susceptible to F. sambucinum, indicating little scope for developing resistant cultivars using the currently available potato germplasm. 相似文献
3.
Ana Piedra-Buena José A. López-PérezMiguel Á. Díez-Rojo Lee RobertsonIván Castro-Lizazo Antonio Bello 《Crop Protection》2011,30(2):134-140
The susceptibility of three sweet potato cultivars (Ipomoea batatas L.) C4, TIS 3290 and TIS 9162 was evaluated against 156 isolates of Meloidogyne spp. with the aim to include resistant/tolerant sweet potato cultivars in a crop rotation scheme for the management of root-knot nematodes. The nematode isolates corresponded to races 1, 2 and 3 of Meloidogyne arenaria (n = 7), races 1, 2, 3 and 4 of M. incognita (n = 131) and Meloidogyne javanica (n = 18). Also, the isolates of M. incognita were differentiated in virulence groups: Pepper (n = 35), Pepper-Mi (n = 25), Tomato (n = 41) and Tomato-Mi (n = 30), depending on their ability to parasitize resistant pepper and tomato cultivars. The tested isolates of M. javanica parasitized C4 and TIS 3290, but not TIS 9162, whereas M. arenaria parasitized C4 and TIS 9162, but not TIS 3290, and M. incognita was able to parasitize the three sweet potato cultivars tested. C4 was the most susceptible cultivar to all nematode species tested, especially M. incognita, TIS 3290 was the most resistant and TIS 9162 was in between (7.2, 62.9 and 26.9% of resistant plants, respectively). Susceptibility of the sweet potato cultivars showed slight variations depending on the race or virulence group of M. incognita. The results suggest that sweet potato cultivars TIS 3290 and TIS 9162 may be used as rotation crops in fields where root-knot nematodes are present, their selection depending on the Meloidogyne isolates present. The use of resistant sweet potato cultivars would be preferably combined with other management practices to avoid virulence selection in nematode isolates. 相似文献
4.
Summary The severity of late blight tuber rot in five potato cultivars (Green Mountain, Sebago, Dorita, AC Brador and Island Sunshine)
resulting from inoculation with US-1/US-8 combinations of Canadian isolates ofPhytophthora infestans was evaluated. In addition, the potential for mixed (A1∶A2) inoculations to result in oospore formation was examined. In
studies conducted in 1996 and 1997, cv. Dorita (and Island Sunshine in 1997) developed the least amount of surface or internal
necrosis relative to the other cultivars following co-inoculation with US-1 and US-8 isolates ofP. infestans. Differences also were revealed among isolate combinations used for inoculation. The combination of a US-1 isolate from Prince
Edward Island with a US-8 isolate from New Brunswick consistently produced the least amount of necrosis in tubers of the various
cultivars. There was no evidence of oospore production in any of the tubers examined.
AAFC Contribution No. 919 相似文献
5.
Coloured potatoes (Solanum tuberosum L.) rich in anthocyanins are gaining increasing interest on the markets, mainly due to beneficial health effects. Potato
varieties containing colour pigments are therefore utilized more and more in actual breeding programmes. In this study, 10
purple-fleshed potato cultivars were compared in their resistance to soft rot caused by Pectobacterium carotovorum (Pc) with 10 white/yellow-fleshed potato cultivars. The results revealed that coloured potato cultivars exhibited on average
better resistance to soft rot than white/yellow-fleshed potato cultivars. On tuber halves of purple-fleshed cultivars, the
extent of rotting caused by Pc was on average 28.6% lower than on white/yellow-fleshed cultivars. The greater resistance of
coloured potatoes coincided with the presence of anthocyanins, higher concentrations of soluble phenols and elevated polyphenol
oxidase activity in tuber tissue. These three components were significantly correlated with the extent of rotting caused by
Pc. However, coloured and white/yellow-fleshed cultivars were not very different in phenylalanine ammonia-lyase and peroxidase
activity. There were also no significant differences in concentrations of dry matter, starch, crude protein and glycoalkaloids.
Key findings reveal that total soluble phenols and anthocyanins contributed crucially to resistance expression in tuber tissue
of coloured potato cultivars. 相似文献
6.
Summary A collection of 80 isolates ofPhytophthora infestans, representing multilocus genotypes of the pathogen found in Canada from 1994 to 1996, was screened on a series of nine differential
potato host cultivars to determine the physiological race of the isolates. A total of 28 pathotypes were found among the 11
genotypes present in the collection. There was a significant increase in the complexity of pathotypes from 1994 to 1996 which
reflected the displacement of the US-1 genotype (mean of 2.2 host differentials infected) by the US-8 genotype (mean of 8.1
host differentials infected). Eighteen of the US-8 isolates could overcome all nine of the resistance genes tested. Virulence
genes which overcame host resistance conferred by R8 were the rarest in the populations studied. The predominance of complex
populations ofP. infestans in Canada implies that the introduction of cultivars with specific R genes for resistance would be an ineffective control
measure.
AAFC Contribution No. 901 相似文献
7.
Summary Variation in aggressiveness to tubers among isolates ofPhytophthora infestans sampled from three potato growing regions in the Netherlands was compared. Variation in the ability to infect tubers of cv.
Bintje was found between isolates of each of the three regional populations. The most aggressive isolate of the old population
matched the average level of the new population in its ability to infect tubers. As a consequence, the commonly used reference
isolate VK 6C can no longer be considered to be representative of the present population ofP. infestans. Therefore it is recommended that testing tuber resistance for the official list of potato cultivars with this isolate should
be discontinued.
Tuber infection and subsequent spread of the fungus in the tuber tissues were not found to be correlated. The components of
tuber pathogenicity studied were not correlated to pathogenicity factors in the foliage, as measured under growth chamber
conditions. 相似文献
8.
New isolates of the necrotic strain of potato virus Y (PVYN) found recently in Poland 总被引:4,自引:0,他引:4
M. Chrzanowska 《Potato Research》1991,34(2):179-182
Summary In comparison to the previously known isolates of potato virus YN (PVYN), some isolates found in Poland since 1984 are more infectious to potato plants, reach faster a higher concentration and
induce milder disease symptoms.
Potato cultivars resistant to the standard type of PVYN may be susceptible to the new isolates whereas those that are extremely resistant to PVY remain extremely resistant to the
new isolates. The potato cultivar Elipsa is suitable for the differentiation of PVYN isolates. 相似文献
9.
Summary The symptomatology of Andean potato latent virus (APLV) was studied in several wild potato species and potato cultivars using
isolates Caj, Hu and Ay from Peru. In greenhouse tests, the virus was latent in most isolate/cultivar combinations with primary
infection but secondary infection commonly caused symptoms. Wild species infected with the different isolates normally reacted
with symptoms with either type of infection. The main symptoms were mosaics, chlorotic netting of minor leaf veins and, with
wild species, leaf deformation; the netting symptom was typical only with Caj. In infected cultivars growing in the field,
an additional symptom, rugosity, sometimes also developed and environmental conditions at high altitude seemed to enhance
symptom formation. Very severe symptoms were found in a cultivar jointly infected with APLV and Andean potato mottle virus.
Transmission of APLV from an infected plant to its tubers was erratic. 相似文献
10.
J. M. Parker H. D. Thurston M. J. Villarreal-Gonzalez W. E. Fry 《American Journal of Potato Research》1992,69(10):635-644
The interactions of four potato cultivars, with three isolates ofPhytophthora infestans were assessed in different environments and in different years. Preliminary tests with these cultivars and isolates were conducted in Toluca, Mexico, and Freeville, New York, U.S.A. in 1986 and 1987. Although data were available from only one year for cultivar Alpha, this cultivar had a dramatically different resistance ranking in Toluca, than that in Freeville — a result consistent with previous observations. The difference in resistance between two other cultivars also changed with site, but less dramatically and did not cause a change in resistance ranking. The resistance of the fourth cultivar appeared to be relatively unaffected by change in site. In both sites, all isolates ranked all cultivars in the same order. Although aggressiveness was slightly different in different locations and on different cultivars, variations were small and there were no consistent trends (consistent over all trials) concerning isolate aggressiveness. Thus, changes in location appeared to have different effects on the different cultivars but little or no effect on the isolates used. 相似文献
11.
12.
Summary The majority of isolates ofFusarium avenaceum caused dry rot on potato tubers; many were as pathogenic asF. coeruleum. Pathogenicity ofF. avenaceum was not related to the plant species from which the isolates originated. Tubers of potato cv. Cara were more susceptible
than those of cvs Romano or Maris Piper. Temperature (5–15° C) had no effect on lesion depth but lesions tended to be slightly
wider at the lowest temperature. Two isolates (of 61) from wheat and white lupin had a moderate level of resistance to thiabendazole.
The results are discussed in relation to the control of dry rot in stored potato tubers. 相似文献
13.
Summary 23 potato cultivars were grown in fields infested with potato mop-top virus and spraing was assessed on tubers at harvest
and after storage. Large differences in spraing susceptibility were found between cultivars. Compared with other countries,
spraing in Denmark is characterised by a high incidence at harvest, a low increase during storage and a very low proportion
of superficial spraing. Decrease in spraing during storage was recorded in two cultivars. DASELISA tests for PMTV in tubers
revealted a high reliability. Mapping of PMTV in important Danish potato growing areas showed that the virus is widespread.
Occurrence of spraing did not influence total yield or dry matter content. Soil acidity did not influence incidence of spraing
but it was more common on coarse-grained soil than on finer sandy soils. PMTV in viruliferous resting spores ofSpongospora subterranea was inactivated by heating to 90°C for 15 minutes. 相似文献
14.
15.
Kenneth L. Deahl Frances M. Perez Jonathan M. Thompson Caoimhe Fleming-Archibald Stephen Thompson Rosemary Collier Steven Kildea Louise R. Cooke 《Potato Research》2009,52(4):341-354
Potato production on the island of Jersey, in the English Channel, is dominated by Jersey Royal, a selection of the early
cultivar International Kidney. Jersey Royal is very susceptible to Phytophthora infestans, the cause of potato late blight, and Jersey’s climate is frequently conducive to infection. During 2004–2006, isolates of
P. infestans were obtained from Jersey Royal plant samples from 41 different sites (24 crops, one infected tuber, 16 volunteers) and from
five outdoor tomato crops and characterised by mating type, mtDNA haplotype, Gpi and Pep allozyme genotype, metalaxyl resistance and RG57 fingerprint. A subset of 17 isolates was additionally characterised by simple
sequence repeat (SSR). All but one isolate from potato belonged to a single A1 multilocus genotype or a variant. The five
isolates from tomato represented three distinct genotypes, none of which was found on potato and included one which was A2
mating type. The populations of P. infestans on potato and tomato in Jersey appear distinct, with that on potato being highly clonal. 相似文献
16.
Summary Available information has been reviewed on tuber resistance toP. infestans, its inheritance and breeding procedures used to obtain potato cultivars superior in this character.
P. infestans is worldwide the most destructive potato pathogen. Tuber resistance is an essential component of potato resistance as this
pathogen is often responsible for tuber rot in storage, and infected tubers of susceptible cultivars provide an important
way for its overwintering.
In Europe many cultivars and advanced breeders selections have been obtained with tuber resistance toP. infestans, but in the last decades no progress is noted in the mean level of this resistance in cultivars. The expression of tuber
resistance depends to a large extent on testing conditions and therefore it can be difficult to evaluate. Consequently making
progress in breeding is not easy, and also cultivar assessment data from various countries sometimes differ considerably.
It is concluded from published data that it should be easier to make progress in breeding potato cultivars with resistant
tubers if more attention is paid to combining the various types of resistance which are already known, and if the genetic
determination of durable resistance toP. infestans is better understood.
Professor Dr. K.M. Świeżyński passed away on 27th July 2000 相似文献
17.
The genetic resources available for the improvement of the cultivated potato (Solanum tuberosum) are reviewed along with progress in their utilisation. The conclusions are as follows. The wild and cultivated species of potato have been utilised in potato breeding to good effect, but only a very small sample of the available biodiversity has been exploited. New knowledge and technology will open possibilities for much greater use of these genetic resources in breeding. The strategy for utilising the cultivars native to Latin America will either be the introgression of desirable genes or the direct use of parents from improved populations, depending on how far modern S. tuberosum cultivars have genetically diverged from them and the extent to which S. tuberosum cultivars have been improved in the process. Molecular marker-assisted selection will be used for faster introgression of desirable genes from wild species, and the possibility exists of moving genes directly from wild species to cultivated potato with transgenic methods. New cultivars will continue to come from crosses between pairs of parents with complementary features but adapted to local growing conditions. However, increasingly these parents will possess desirable genes which have been introgressed from wild species and may also be from complementary groups of cultivated germplasm to exploit hybrid vigour. Successful cultivars may be genetically modified, if consumers see benefits in the use of the technology, to introduce genes not present in cultivated potatoes and their wild relatives to achieve novel biochemistry and further desirable improvements. 相似文献
18.
Incidence of potato leafroll virus (PLRV) and potato virus Y (PVY) was determined in seed potatoes (Solatium tuberosum) from Canada, Maine, Minnesota, New York, North Dakota, Nebraska, Pennsylvania, and Wisconsin used to plant the North Carolina crop in 1977, 1978 and 1979. Incidence of PLRV ranged from 0–5.2% (X = 0.57%) and for PVY from 0-5.6% (X = 0.62%) from all sources (112 seed lots). All PVY isolates (177) tested from potato caused a very mild veinbanding and mottling onNicotiana tabacum cultivars NC 95 and NC 2326. No serological difference was detected between these isolates and the common strain of PVY from tobacco in North Carolina. Essentially no spread of PVY occurred in three potato fields observed each year of the study. 相似文献
19.
Potato cultivars were assessed for their sensitivity to potato tuber necrotic ringspot disease (PTNRD) induced by two North American isolates (Tu619 and Tu660) of the tobacco veinal necrosis strain of potato virus Y (PVYN) and belonging to the tuber necrosis (PVYNTN) sub-group. Several widely grown cultivars (e.g. Norchip and Ranger Russet) were found to be highly sensitive to PTNRD, while others (e.g. Russet Burbank, Russet Norkotah and Shepody) were not. The foliage symptoms induced by these isolates were distinct from those reported to be produced by European isolates of PVYNTN, in that systemic necrotic rings and chlorophyll figures on the leaves were not produced. Instead, the symptoms were similar to those of normal strains of PVYN. The apparent correlation between resistance to the PVYO (common) strain group and cultivar sensitivity to PTNRD is discussed. 相似文献
20.
M. Koppel 《Potato Research》1993,36(3):183-188
Summary The susceptibility to soft rot caused byErwinia carotovora subsp.atroseptica of five potato cultivars and potato clones from the potato breeding programme at J?geva Plant Breeding Institute was assessed
in a laboratory test. Three test methods were used: a single site inoculation, vacuum infiltration and slice inoculation.
The severity of the disease varied widely with the different methods, which gave different cultivar rankings. 相似文献