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1.
Summary When nodal explants from sprouts grown from virus-free tubers of ten cultivars were propagated on half-strength Murashige
and Skoog medium, cvs Arsy, Nicola, Kennebec and Spunta grew best. Rooted plantlets, 5–8 cm tall, were transplanted from culture
vessels into pots containing soil, vermiculite and sand. They were weaned by growing in a glasshouse for about three weeks.
Over 90% of the plantlets survived and these were then planted in the field and protected against aphids by a double screen
(a large tunnel covering four adjacent small tunnels) and chemical treatments. Prebasic seed tubers thus obtained were virus-free
and production ranged from 49.9 t.ha−1 (‘Monalisa’) to 27.1 t.ha−1 (‘Majestic’).
A survey showed that ‘elite’ (near virus-free) seed could be produced from prebasic seed by early planting and early haulm
killing regardless of location, but late planting on the plains and normal planting dates on the mountains resulted in 1 to
5% virus infection levels acceptable only for certified seed. 相似文献
2.
J. Marinus 《Potato Research》1993,36(1):63-69
Summary In three experiments seed tubers of cvs Jaerla, Bintje and Alpha, stored at 12 °C in the dark, were planted in glasshouses
on various dates at soil temperatures varying from 8 °C to 28 °C to study the phenomenon of ‘non-emergence’ with ageing seed
tubers. In general the tubers were desprouted before planting. At all plantings cv. Alpha produced normal plants. The cvs
Jaerla and Bintje, however, showed high proportions of the ‘little potato’ phenomenon when planted in cold soil, and high
proportions of decayed tubers more frequently in warm soil. When using physiologically older seed at later planting dates,
both the range of soil temperatures became wider and the proportions of seed tubers experiencing both ‘little potato’ and
decay increased. 相似文献
3.
T. Bjor 《Potato Research》1987,30(3):517-524
Summary For laboratory screening for resistance to gangrene andFusarium dry rot, the ‘scrape and paint’ method was compared to a ‘prick and paint’ method. In the latter method the potatoes were
wounded before inoculation by rolling them over a group of nail points. The disease scores increased when the length of the
nail points was increased from 2 to 6 mm, but the scores were lower than for scraped potatoes. For the 10 cultivars used,
the results for the pricked and the scraped potatoes correlated equally well with the results from a ‘field inoculation’ method.
The two laboratory methods discriminated equally well between resistant and susceptible cultivars. However, pricking is much
less laborious than scraping.
In routine tests with the ‘prick and paint’ method, differences between cultivars were highly significant over three years
for resistance to gangrene but less significant forFusarium dry rot.
Zusammenfassung Für die Laborprüfung auf Resistenz gegenPhoma-Faule (Phoma exigua var.foveata) undFusarium-Trockenf?ule (Fusarium solani var.coeruleum) wurde die ‘scrape and paint’-Methode von Wiersema (1977a) mit einer ‘prick and paint’-Methode verglichen, wobei Kartoffeln vor Inokulation durch Rollen über eine Gruppe von Nagelspitzen, 1 cm auseinander und von einer h?lzernen Basis aufw?rtsweisend, besch?digt wurden. Für beide Krankheiten stieg der Krankheitsindex an, wenn die L?nge der Nagelspitzen von 2 auf 4 und 6 mm anstieg, war im Ganzen jedoch niedriger als bei geschürften Kartoffeln (Tabellen 2 und 4). Für die zehn für jeden Erreger in den Versuchen verwendeten Sorten korrelierten die Ergebnisse bei ‘prick’ (Rollen über Nagelspitzen) und ‘scrape’ (Schürfen) gleichermassen mit einem vermutlich besser zu verwirklichendem Feld-Inokulationstest (Bjor, 1980), dessen Ergebnisse in Tabelle 1 dargestellt sind. Die Unterscheidung von Sorten unterschiedlicher Resistenz war mindestens so deutlich beim ‘prick’ — wie beim ‘scrape’-Test, wie die F-Werte für Sorten in der Varianzanalyse zeigen (Tabellen 2 und 4). Darüberhinaus ist die ‘prick’-Methode betr?chtlich weniger arbeitsaufwendig als die ‘scrape’-Methode. Die ‘prick and paint’-Methode mit 4 mm-Nagelspitzen ergab Unterschiede zwischen 14 Standard-Sorten in Routinetests aus drei verschiedenen Jahren beiPhoma-F?ule, aber nicht so gut beiFusarium-Trockenf?ule (Tabelle 6). Die Korrelation zwischen den Ergebnissen nach der ‘prick and paint’-Methode und dem Feld-Inokulationstest bei den 14 Sorten warr=0,86 undr=0,71 beiPhoma-bzw.Fusarium-F?ule. Allerdings war die Variation innerhalb der Sorten bei Resistenz gegenPhoma-F?ule betr?chtlich gr?sser als die bei Resistenz gegenFusarium-Trockenf?ule.
Résumé Le criblage au laboratoire pour la résistance à la gangrène (Phoma exigua var.foveata) et à la pourriture sèche fusarienne (Fusarium solani var.coeruleum) est réalisé selon deux méthodes. La méthode du ‘grattage et du badigeonnage’ est comparée à celle de la ‘piq?re et du badigeonnage’ où les pommes de terre sont blessées avant l'inoculation en les faisant passer sur un groupe de 10 clous distants de 1 cm, orientés vers le haut et fixés sur un support de bois. Pour les deux maladies, la note de maladie augmente quand la longueur de la pointe des clous passe de 2 à 4 et 6 mm, mais les tubercules blessés par piq?res sont moins malades que ceux ayant subi des égratignures (tableaux 2 et 4). Pour les 10 cultivars inclus dans les expériences pour chacune des maladies, les résultats des tubercules blessés par chacune des 2 méthodes sont également corrélés avec ceux d'un test ‘inoculation au champ’, plus s?r (Bjor, 1980) figurant au tableau 1. Le classement des cultivars de différents niveau de résistance est aussi clair à partir des tubercules blessés par piq?re que ceux blessés par grattage comme le montre la valeur du F pour les cultivars, des analyses de variance (tableaux 2 et 4). De plus, la méthode des piq?res est beaucoup moins fastidieuse que la méthode par égratignures. La méthode des piq?res avec des pointes de clous de 4 mm reproduit les différences entre 14 cultivars de référence inclus dans des tests de routine depuis 3 ans pour la gangrène, mais de fa?on moins nette pour la fusariose (tableau 6). La corrélation entre les résultats obtenus avec la méthode des piq?res et le test ‘d'inoculation au champ’ pour les 14 cultivars estr=0,86 etr=0,71, respectivement pour la gangrène et la fusariose. En outre, la variabilité des cultivars pour la résistance à la gangrène est considérablement plus grande que celle vis-à-vis de la fusariose (Figure 1).相似文献
4.
Summary Single leaf cuttings with their subtended axillary buds proved to be useful models to study maturation and senescence in potato
(Solanum tuberosum L.). Senescence was more rapid if the cultivar was early maturing or if plants were exposed to short days before cuttings
were taken. Rooting was decreased by short days before cutting; excision of the buried bud only partially overcame the effects
on senescence and rooting. High rates of N to mother plants in the field delayed senescence of cuttings in a way analogous
to the delayed senescence of field plants. The tuberization of cuttings from late maturing cultivars was decreased by high
rates of N. The color of crisps made from bud tubers was positively correlated with the color of crisps made from ordinary
tubers of the same cultivars. Sugar concentrations in bud tubers decreased as cuttings became more senescent and increased
after cold storage. Bud tubers harvested while ‘immature’ had greater concentrations of reducing sugars after 90 d at 10°C
than did ‘mature’ bud tubers.
Paper No. 878, Department of Vegetable Crops, Cornell University. This research was supported through HATCH project NYS161414,
a contributing project to Regional Project NC150, and through HATCH project NYS161407. 相似文献
5.
Summary Potato tuber dormancy is usually defined as lasting from tuber initiation until a sprout of 2 mm long has been formed under
storage conditions optimal for sprouting. We tried to find out whether there is a period during which buds of seed tubers
do not grow and whether different batches of seed take the same time to grow sprouts 2 mm long.
We measured changes in number of leaf primordia and length of tuber buds of cvs Diamant and Désirée over two years. After
early haulm pulling, buds did not grow for at least 60 days (‘Diamant’) or 95 days (‘Désirée’).
Buds in both cultivars and two tuber weights of ‘Diamant’ took about 20 days from the estimated onset of sprouting to grow
2 mm long. We question whether this period is always similar and thus whether the moment sprouts 2 mm long have formed is
a good criterion for the end of dormancy. 相似文献
6.
The effect of a seaweed concentrate on the in vitro growth and acclimatization of potato plantlets 总被引：2，自引：0，他引：2
Summary The seaweed concentrate ‘Kelpak’ is used commercially in the greenhouse and field to improve plant quality. ‘Kelpak’ was added
to the in vitro culture medium of potato cv. ‘BP1’ and also applied as a leaf/soil drench immediately after transplanting.
The addition of 0.25% seaweed concentrate to the medium improved plantlet quality and led to better establishment in the greenhouse.
No beneficial effect of seaweed concentrate in the tissue culture medium was observed if a second cutting was part of the
micropropagation process. Additional application of 0.5% seaweed concentrate in the greenhouse to plantlet cuttings derived
from tissue culture was not beneficial. 相似文献
7.
Summary Soil in a potato field naturally infested with black dot (Colletotrichum coccodes) was fumigated with methyl bromide at 126 g m−2 or left unfumigated. Potato seed tubers (cv. BP1) uninfected, lightly infected (1–25% surface affected), severely infected
(26–100% surface affected) and severely infected withC. coccodes but dusted with prochloraz manganese chloride as Octave 2.5% DP at 750 g per 100 kg seed were planted in fumigated and unfumigated
soil. When harvested, the incidence of black dot on the progeny of infected seed planted in unfumigated soil was twice that
of progeny in fumigated soil, with progeny of uninfected seed having a 68.5 times higher disease incidence in unfumigated
soil. Black dot on progeny tubers was reduced by pre-treatment of seed with prochloraz in fumigated soil only. With black
dot infested fields, planting disease-free seed or treating seed with fungicides would not decrease disease on progeny tubers. 相似文献
8.
Antje Moll 《Potato Research》1992,35(3):279-285
Zusammenfassung Die Pflanzgutvorbehandlung beeinflu?te die Stengelzahl signifikant. Abgekeimtes Pflanzgut der Sorten ‘Adretta’ und ‘Mariella’
entwickelte weniger Stengel und Knollen pro Pflanze jedoch mehr Knollen pro Stengel als vorgekeimtes und keimgestimmtes Pflanzgut.
Die st?rker negativen Korrelationen zwischen Stengelzahl pro Pflanze und Knollenzahl pro Stengel sowie die h?here Reduktionsrate
der angelegten Knollen bei der Sorte ‘Adretta’ weisen auf Sortenunterschiede in der Sch?rfe der Konkurrenz zwischen den Stengeln
und innerhalb der Knollenanlagen eines Stengels hin. Die Ernteknollenzahl wurde bei ‘Mariella’ wesentlich durch die Zahl der
Knollenanlagen, bei ‘Adretta’ hingegen st?rker durch die Reduktionsrate bestimmt.
Summary Three different seed treatments and two cultivars were studied over seven years of field experiments (Table 1). Differences were detected between the cultivars in all characteristics studied: numbers of stems, maximum number of tubers (tuber initials), the number of harvestable tubers (>3 cm) at maturity per plant and per stem, and tuber reduction (percentage of initiated tubers that did not develop). Apart from the number of harvestable tubers, there were also differences between seed treatments (Tables 2, 3 and 4). Chitted seed of ‘Mariella’ and sprouted seed of ‘Adretta’ gave the greatest number of tubers per plant (Tables 3 and 4). In both cases desprouting reduced the numbers of stems and tubers per plant but increased the number of harvestable tubers per stem. Chitted seed set the most tubers per plant and per stem but had the highest levels of tuber reduction (Table 4). Due to intra- and inter-stem competition in both cultivars the percentage tuber reduction is significantly correlated with the number of tuber initials (maximum tuber number, Table 5). Smaller numbers of tubers per stem (Table 3) and significantly negative correlations between the number of stems and the maximum and harvestable number of tubers per stem (Table 5) highlight the effect of strong inter-stem competition in ‘Adretta’. Moreover, in this cultivar intra-stem competition seems to play an important role too. The rate of tuber reduction was significantly higher than in ‘Mariella’ (Table 3), and the final number of tubers significantly depended on the percentage of tuber reduction during the period of tuber growth (r=0,57*, Table 5). In contrast, the number of harvestable tubers per plant in ‘Mariella’ was significantly correlated with the maximum tuber number during the period of tuber set (r=0,61*, Table 5).相似文献
9.
Hong Y Lin S Jiang Y Ashraf M 《Plant foods for human nutrition (Dordrecht, Netherlands)》2008,63(4):200-204
Eriobotrya plants are known to have significant amounts of phenolics and flavonoids, and exhibit a strong antioxidant activity. Experiments
were conducted to examine variation in the contents of total phenolics and flavonoids, and antioxidant activities in the leaves
of 11 Eriobotrya species (Tibet loquat, Daduhe loquat, Hengchun loquat, Taiwan loquat, Oak leaf loquat, Bengal loquat, Fragrant loquat, Guangxi
loquat, Obovate loquat, Big flower loquat, and common loquat, the last species include two materials, one is a cultivar ‘Zaozhong
6’, another is a wild tree). In these species, ‘Zaozhong 6′ loquat is a cultivar. The leaf extracts of ‘Tibet’, ‘Obovate’,
‘Taiwan’, ‘Bengal’ and ‘Hengchun’ loquats exhibited significantly higher contents of total flavonoids and total phenolics,
compared with those of other species. Of these 11 species, the highest contents of total phenolics and total flavonoids were
observed in ‘Tibet’ and ‘Obovatae’ loquats, respectively. The significantly stronger antioxidant abilities assessed by the
DPPH radical scavenging activity and reducing power were obtained in the leaf extracts of ‘Taiwan’, ‘Tibet’, ‘Bengal’, ‘Oak
leaf’, ‘Hengchun’ and ‘Obovate’ loquats, compared with the other species. In addition, significant correlations were found
between the contents of total phenolics or flavonoids and DPPH radical scavenging activity/reducing power. This work indicates
that the leaf extracts of the wild Eriobotrya species, ‘Tibet’, ‘Obovatae’, ‘Taiwan’, ‘Bengal’, ‘Oak leaf’ and ‘Hengchun’ loquats, exhibited significantly higher levels
of total phenolics and flavonoids, and significantly stronger antioxidant activities, compared with the cultivated species,
‘Zaozhong 6′ loquat, which suggests that these wild species have a better utilization value. 相似文献
10.
J. Marinus 《Potato Research》1992,35(4):343-354
Summary Young seed tubers of several cultivars were exposed to storage temperatures of 4–24°C in light and dark intended to optimise
their growth vigour following early plantings. In five experiments during four autumn and winter periods, the effects of storage
conditions on subsequent initial plant development in the glasshouse were studied. Storage of seed potatoes for 2 months at
temperatures of 12°C or higher greatly increased early plant development of five cultivars following early plantings. Light
during storage had a favourable effect, but desprouting before planting was greatly disadvantageous. 相似文献
11.
Summary In five field trials with the cultivars Gloria (early), Bintje (mid-early) Désirée (mid-late) and Morene (late), crops grown
from conventional 28–35 or 35–45 mm seed were compared with crops grown from microtubers, of various sizes and from various
sources, that had been producedin vitro. The following means to quicken initial crop development from the micropropagated material were tested: large microtubers,
plastic soil cover, and transplanting of plantlets grown from microtubers pre-planted in a glasshouse. Crops grown from microtubers
weighing less than half a gram yielded much less than crops grown from conventional seed crops but their yields were increased
by each treatment. With the later-maturing cultivars, which generally produce few tubers per plant, the yields within seed
grades from plants grown from transplanted microtuber plants were comparable with those of conventional crops. Reasons are
given, why direct planting of microtubers, with or without plastic foil, is not a practical option. 相似文献
12.
Lílian da Silva Fialho Valéria Monteze Guimarães Everaldo Gonçalves de Barros Maurilio Alves Moreira Luiz Antônio dos Santos Dias Maria Goreti de Almeida Oliveira Inês Chamel José Sebastião Tavares de Rezende 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(2):83-85
Common beans have a high nutritional value, but contain galactooligosaccharides (GO), which cause flatulence and intestinal discomfort in humans. The biochemical composition of ten bean cultivars was determined to select those of high protein and low GO contents. The cultivars varied in carbohydrate (47.02–60.17%), GO (3.12 – 5.71%), protein (22.17–33.50%), lipid (1.13–1.81%), moisture (11.42–12.93%) and ash contents (4.08–5.61%). ‘Mexico 222’ presented the highest α-galactosidase activity. Protein and GO contents were positively correlated. ‘Perry Marrow’ combined high protein and low GO concentrations, indicating it can be used in improvement programs aiming at high-quality cultivars for human consumption. 相似文献
13.
M. K. Van Ittersum 《Potato Research》1992,35(4):355-364
Summary The duration of dormancy of seed potatoes varies between years and between origins. Therefore, the effects of conditions during
crop growth on dormancy of progeny tubers were studied. The effect of nitrogen during tuber bulking on the duration of dormancy
was investigated in three field experiments with two cultivars. In addition to an application of 125 kg N/ha at planting,
top dressings of 0–150 kg N/ha were given about 2 weeks after tuber initiation. Haulm was pulled about 4 weeks later. The
effect of nitrogen rate at planting was also examined in one experiment.
Nitrogen top dressings shortened dormancy in all experiments by 5–8 days. An increased nitrogen rate at planting resulted
in a shorter dormancy when the duration of dormancy was expressed in days after tuber initiation, but not when it was expressed
in days after haulm pulling, probably because extra nitrogen also delayed tuber initiation. 相似文献
14.
Cesonienė L Daubaras R Jasutienė I Venclovienė J Miliauskienė I 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(3):238-244
Benzoic acid, total anthocyanins, soluble solids, titratable acidity, and colour properties in juice of the American cranberry
Vaccinium macrocarpon and the European cranberry Vaccinium oxycoccos were investigated. Berry juices of V. macrocarpon cultivars were distinguished by their higher total anthocyanin and benzoic acid amounts. These cultivars accumulated on average
43.11 mg/l of benzoic acid and 92.45 mg/l of total anthocyanins. The levels of benzoic acid and total anthocyanins in V. oxycoccos cultivars were 17.52 mg/l and 42.54 mg/l, respectively. The V. macrocarpon cultivars ‘Franklin’, ‘Le Munyon’, ‘Searles’, and ‘Early Richard’ were selected as the best according to the enhanced total
anthocyanins and benzoic acid amounts. The separation of anthocyanins by HPLC-UV-VIS revealed the presence of six anthocyanins,
with peonidin-3-galactoside being the most prevalent. Galactoside together with glucoside conjugates comprised the largest
percentage of total anthocyanins in the juices of V. macrocarpon and V. oxycoccos cultivars. 相似文献
15.
Summary The resistance to common scab of nine cultivars and eight advanced breeding lines of potatoes, fiveSolanum andigenum Juz. et Buk. clones, and three potato breeding lines selected for resistance to common scab, was investigated in a field
and a pot trial. In the pot trial potaroes were planted in inoculated coarse river sand in plastic pots (150 mm in diameter)
placed on irrigated subsoil in a glassfibre house. In a field trial potatoes were planted in an artificially infested field.
The harvested tubers were scored individually for scab incidence according to two scales, viz. a 1–5 point scale for percentage
surface covered with scab and a 1–3 point scale for lesion type. A scab index value was calculated for each tuber. A significant
correlation coefficient of 0.82 was obtained for the results of the two tests. 相似文献
16.
Gülay Tuncer 《Potato Research》2002,45(2-4):153-161
Summary Powdery scab, caused by the fungusSpongospora subterranea, has developed in the Cappodocia region of Turkey because of changes in agronomic practices, such as excessive irrigation
and nitrogen fertilizer use and growth of highly susceptible cultivars. The most suitable irrigation and nitrogen application
levels were established to maintain powdery scab at minimum levels without affecting potato yield. Three irrigation levels
were used in 1998 (673, 897, 1121 mm) and five in 1999 (329, 494, 658, 823, 987 mm). Nitrogen levels were applied 150, 300,
450, 600 kg N ha−1. In 1998, least powdery scab occurred with 673 mm irrigation, which yielded 41 t ha−1 potatoes. The lowest disease severity occurred in 1999 with 494 mm irrigation and 150 kg N ha−1. At these levels, tuber yield was 34 t ha−1 which was not significantly different from the highest yield measured. In 1999 and at two of the three irrigation levels
inl998, nitrogen increased disease severity. 相似文献
17.
Summary Incidence of silver scurf (Helminthosporium solani) was assessed macroscopically (silver scurf lesions) or microscopically (H. solani infection of tuber eyes) on seed tubers, on progeny tubers during growth or at harvest, and on stored tubers, from up to
26 commercial crops·cv. King Edward in each of 5 years, and up to 13 crops grown from ‘healthier’ seed in 4 years.
Infection of eyes was frequent on seed in all years, scace on progeny tubers during growth, but had increased by harvest.
Silver scurf was prevalent in stored tubers, except in 1975, and more developed at 10°C than at 3 °C.
Infection of tubers during growth, at harvest, or after storage, was not related to incidence of eye infection on seed. In
3 years, infection at harvest was significantly related to infection during growth, but only in 1975 was infection at harvest
related to silver scurf in store.
In 2 years amounts of silver scurf on crops grown from seed derived from stem cuttings (‘healthier’ seed) were positively
correlated with disease incidence in commercial crops grown on the same fields.
Zusammenfassung Zwischen 1971 und 1975 wurde in bis zu 26 Proben von Marktware der Sorte King Edward das Auftreten von Silberschorf an gelagerten Kartoffelknollen untersucht sowie die Infektion mitHelminthosporium solani von Knollenaugen des Pflanzgutes, von Tochterknollen w?hrend des Wachstums und zur Ernte (Adams et al., 1980). Zwischen 1972 und 1975 wurden diese Erhebungen auch an Erntegut aus ‘gesünderem’ Pflanzgut (das von Stecklingen abstammte) das benachbart zur Marktware aufwuchs, gemacht. Das durchschnittliche Auftreten von Infektion oder Krankheitsbesatz auf Marktware (Tab. 1) zeigte, das in allen Jahren die Infektion der Knollenaugen des Pflanzgutes h?ufig war, seltener an den Tochterknollen w?hrend des Wachstums, aber vorallem 1971 zur Ernte wieder verst?rkt war. Ausser 1975 trat Silberschorf h?ufig auf gelagerten Knollen auf, und entwickelte sich bei 10°C mehr als bei 3°C. Eine Wundheilung von 2 Wochen bei 15°C hatte keinen Einfluss auf diese Krankheit. Bei ‘gesünderem’ Pflanzgut waren weniger Augen infiziert als im Durchschnitt der Marktware, aber w?hrend des Wachstums und zur Ernte war der Befall der Augen genau so gross oder gr?sser als von Marktware (Tab. 2). Die Signifikanz der Regressionen zwischen den Feststellungen des Krankheitsbesatzes oder der Infektion, die zu verschiedenen Zeiten gemacht wurden (Tab. 3) zeigte, dass die Bonitur der Infektion des Pflanzgutes im allgemeinen mit den folgenden Bonituren nicht in Beziehung stand. In drei Jahren war das Auftreten von Augeninfektionen zur Ernte mit dem w?hrend des Wachstums verbunden (Abb. 1). 1975 wurden Pflanzkartoffeln und geerntete Knollen unter feuchten Bedingungen inkubiert und die Sporulation vonH. solani nach dem Waschen und dem Zentrifugieren der Flüssigkeit untersucht. Die Sporulation war abh?ngig vom Auftreten von Augeninfektionen des Pflanzgutes (Abb. 2c). Untersuchungen des Inokulums vonH. solani bei denen Schalenstückchen, ausgenommen Augen, verwendet wurden, ergaben Beziehungen zum Ergebnis von Augenstückchen des Pflanzgutes (Abb. 2b) und zur Sporulation auf geerntetem Nachbau (Abb. 2d). Das Auftreten von Silberschorf nach der Lagerung war mit allen verschiedenen Messungen des Inokulums verbunden und am besten mit den Ergebnissen der Sporulation (Abb. 2e). Ein Vergleich der Ergebnisse ‘gesünderer’ Ernte mit den Ergebnissen benachbarter Marktware ergaben nur wenig signifikante Beziehungen. 1975 waren jedoch das Ausmass der Augeninfektion zur Ernte (Abb. 3a) und des Krankheitsbesatzes nach der Lagerung (Abb. 3b) verbunden, was auf eine allgemeine Quelle des Inokulums, eine Verbreitung zwischen benachbarten Ernten oder die Bedeutung der allgemeinen Bodenbedingungen hinweist
Résumé L'incidence de la gale argentée sur les tubercules en conservation et l'infection parHelminthosporium solani des yeux des tubercules de semence et des tubercules-fils durant la croissance et à la récolte, ont été notées, de 1971 à 1975, dans 26 cultures issues de lots de semence du commerce de la variété King Edward (Adams et al., 1980a). Entre 1972 et 1975, des évaluations ont également été faites sur des lots issus de semences ‘plus saines’ (dérivées de boutures) cultivées près de certains lots commerciaux. L'incidence moyenne de la contamination ou de la maladie sur les lots commerciaux (tableau 1) montre que la contamination des yeux a été fréquente sur les semences tous les ans, rare sur les tubercules-fils en végétation mais plus fréquente à la récolte, surtout en 1971. La gale argentée est apparue fréquemment en conservation, sauf en 1975, et s'est plus développée à 10 °C qu'à 3°C. La cicatrisation des blessures pendant deux semaines à 15°C n'a pas eu d'effet marqué sur l'incidence de la maladie. Les semences ‘plus saines’ avaient moins d'yeux atteints que la moyenne des semences des autres lots, mais la contamination des yeux en végétation et à la récolte atteignait ou dépassait celle des tubercules des autres lots (tableau 2). La signification des régressions entre les notations de maladie ou d'infection réalisées à différentes époques (tableau 3) a montré que les notations de contamination des tubercules de semence n'étaient pas généralement en relation avec les suivantes. Pour 3 années, l'incidence de l'infection des yeux à la récolte était en relation avec celle notée durant la croissance (Fig. 1). En 1975, on a aussi placé les tubercules de semence et la récolte en conditions humides et on a contr?lé la sporulation deH. solani après lavage et centrifugation du liquide. La sporulation était liée à l'incidence de l'infection des yeux des tubercules de semence (Fig. 2a) et celle des tubercules-fils récoltés. Des analyses d'inoculum deH. solani sur des fragments de peau sans yeux se sont montrés corrélées aux résultats obtenus sur les yeux des tubercules de semence (Fig. 2b) et à l'importance de la sporulation sur la récolte (Fig. 2d). L'incidence de la gale argentée en conservation s'est montrée liée à toutes les différentes mesures d'inoculum effectuées sur la récolte et en particulier aux mesures de sporulation (Fig. 2e). La comparaison entre les notations sur les cultures ‘plus saines’ et leurs homologues de la série commerciale n'a révélé que peu de relations significatives. Cependant, en 1975, il y avait relation entre la contamination des yeux à la récolte (Fig. 3a) et la maladie après conservation (Fig. 3b) sont liées, laissant supposer soit une source commune d'inoculum, soit une propagation d'une culture à l'autre, soit l'importance des conditions habituelles de sol.相似文献
18.
Summary Tests for systemic induced resistance (SIR) to late blight were performed with different potato cultivars in field trials
and in growth chamber experiments.
The non-pathogenPhytophthora cryptogea (Pc) and salicylic acid (Sa) were used as inducer agents. In the field, plants were naturally infected byPhytophthora infestans while the indoor plants were inoculated. The degree of SIR obtained varied with the cultivar used and also with the type
of inducer. For example in the field the susceptible cv. St. Cecilia had enhanced resistance with Pc whereas Sa caused increased
susceptibility. Inbred resistant cvs acquired increased resistance after treatment with Sa.
In a separate pilot experiment in a growth chamber, Sa at two different concentrations was injected into potato seed tubers
before planting. The higher Sa concentration increased resistance in genetically resistant cultivars while the lower Sa concentration
brought about increased susceptibility. 相似文献
19.
Potato stolbur is a phytoplasmal disease that seriously affects yield and tuber quality in South Eastern Europe, Russia and
the Mediterranean areas. In 2007 and 2008, field experiments were carried out to determine stolbur resistance of processing
potato cultivars at Sannicolau Mare (Romania) by determining consistency and concentration of reducing sugars (fructose and
glucose), sucrose and phytoplasmas in potato tubers. In both years, non-symptomatic potato tubers showed sucrose levels in
the range of 3,000 mg kg−1 fresh weight (FW). In contrast, sucrose concentrations were up to 11,820 mg kg−1 FW in 2007 and 19,560 mg kg−1 FW in 2008 in tubers showing severe symptoms. These high values severely affect suitability of tubers for processing as sucrose
serves as substrate for the formation of reducing sugars that are the limiting factor in fried potato production for Maillard-related
discolouration. The cultivars examined differed considerably in susceptibility to stolbur disease. Whereas cvs. ‘Courage’
and ‘Lady Rosetta’ showed high numbers of diseased tubers and high sucrose concentrations, ‘Lady Claire’ had a lower incidence
of symptomatic tubers and lower sucrose concentrations. However, fully resistant cultivars were not observed. Across all cultivars
examined, phytoplasmal concentration was significantly higher in symptomatic tubers than in non-symptomatic ones. 相似文献
20.
Summary Diploid potato clones (dihaploid x wild species hybrids) and their colchicine doubled, tetraploid counterparts were compared
for resistance to eelworm (Globodera rostochiensis andG. pallida) and for pollen ‘stainability’ as an indicator of viability. The responses due to doubling were not uniform. For eelworm
resistance, three of the five clone pairs showed no differences; in one pair the tetraploid was significantly more susceptible
to one pathotype but not to two others and in the remaining pair, the tetraploid was significantly more susceptible to both
pathotypes used. In eleven of fourteen pairs tested for pollen ‘stainability’, the tetraploid had significantly less ‘good’
pollen. In one case, the tetraploid had significantly more ‘good’ pollen. Generally there was sufficient ‘good’ pollen to
allow further crossing at the tetraploid level.
Zusammenfassung Fünf diploide Kartoffelklone, Kreuzungen zwischen anf?lligen Dihaploiden und nematodenresistenten Vermehrungen vonSolanum spegazzinii, S. vernei und einer nicht-beschriebenen, mitS. sparsipilum verwandten peruanischen Art, wurden hinsichtlich ihrer Resistenz mit ihren Colchicin-verdoppelten Gegenstükken verglichen. Tabelle 1 zeigt die verwendeten Nematoden-Populationen (Globodera rostochiensis undG. pallida) zusammen mit der Anzahl gebildeter Zysten. Die Reaktionen gegenüber Verdopplung waren nicht einheitlich; drei der fünf Klonpaare zeigten keine Unterschiede, bei einem der Paare war der tetraploide Teil signifikant anf?lliger gegen einen der Pathotypen, aber nicht gegen zwei andere, und beim letzten Paar war der tetraploide Teil gegen beide verwendeten Pathotypen signifikant anf?lliger. Obwohl die tetraploiden Pflanzen generell ein etwas gr?sseres Wurzelsystem entwickelten als die diploiden und eine gr?ssere Oberfl?che für die Einwirkung der Nematodenlarven boten, liess sich der Schluss ziehen, dass dies nur geringe Auswirkung auf die Feststellbarkeit von Unterschieden zwischen Vertretern der Ploidiepaare hatte. Die Zahl der Eier pro Zyste wurde durch die Resistenz der Pflanzen im Testmaterial nicht beeinflusst. Die Ergebnisse deuten auf gleiche oder niedrigere Grade der Nematodenresistenz durch die Colchicin-Verdopplung. Allerdings deutet die Uneinheitlichkeit der Reaktion darauf hin, dass die Produktion einiger ‘verdoppelter’ Klone mit erh?hter Resistenz doch nicht ganz auszuschliessen ist. Colchicinverdoppelte Klone mit Resistenz im Duplex-Stadium dürften hohen potentiellen Wert als Eltern für weitere Züchtungen auf tetraploidem Niveau haben, vorausgesetzt sie behalten ausreichende Fertilit?t bei. Pollen-‘F?rbbarkeit’ als Indikator der m?nnlichen Fertilit?t wurde in einem gr?sseren Umfang bei Ploidiepaaren, von denen die meistenS. acaule und/oderS. stoloniferum in der Elternschaft hatten, untersucht. Die Ergebnisse zeigt Tabelle 2. In 11 von 14 Paaren hatten die Tetraploiden signifikant weniger ‘gute’ Pollen, in einem Falle signifikant mehr. Generell waren ausreichend ‘gute’ Pollen vorhanden, um weitere Kreuzungen auf tetraploider Ebene zu gestatten. Die Rückkehr auf die tetraploide Ebene via Colchicin-Verdopplung l?sst deshalb einen hohen Anteil verwertbarer Elternlinien für die Erzeugung nematodenresistenter St?mme erwarten.
Résumé Cinq cl?nes diplo?des obtenus par croisement entre dihaplo?des sensibles aux nématodes et résistants, issus deS. spegazzinii, S. vernei et d'une espèce péruvienne non décrite associée àS. sparsipilum, ont été comparés, pour leur résistance, avec leurs homologues tétraplo?des. Les populations de nématodes (Globodera rostochiensis etG. pallida) qui ont été utilisés sont présentées dans le tableau 1 avec le nombre de kystes nouvellement formés. La réponse donnée par le doublement des chromosomes n'a pas été uniforme; trois des cinq cl?nes n'ont pas montré de différences avec leurs homologues diplo?des; dans un cas le tétraplo?de a été significativement plus sensible à un pathotype mais pas aux deux autres et dans le dernier cas, le tétraplo?de a été significativement plus sensible aux deux pathotypes utilisés. Bien que les plantes tétraplo?des développent généralement un système radiculaire légèrement plus important et présentent une plus grande surface à l'infection par les larves de nématodes que les diplo?des, on conclut que cela a eu peu d'effet au niveau des différences observées entre les deux types de plo?die. Le nombre d'oeufs par kyste n'a pas été affecté sur les plantes résistantes, dans le matériel testé. Ces résultats suggèrent que des degrés similaires ou moindre de résistance aux nématodes peuvent résulter du doublement chromosomique d? à l'effet de la colchicine. Cependant, la non uniformité des réponses fait en sorte que la création de quelques cl?nes tétraplo?des résistants aux nématodes pourrait se faire. De tels cl?nes, ayant des gènes de résistance au niveau duplex, auraient une grande valeur potentielle comme parents pour les hybridations futures au stade tétraplo?de s'ils gardent une fertilité suffisante. La coloration du pollen comme indicateur de fertilité male a été étudiée sur une large gamme de plo?die doublée ayantS. acaule et/ouS. stoloniferum dans la parenté. Les résultats de ces tests sont donnés dans le tableau 2. Dans onze des quatorze paires comparées le tétraplo?de a eu un pollen significativement moins bon que le diplo?de. Dans un cas le tétraplo?de a présenté un pollen significativement meilleur. Cela parait suffisant pour prendre en considération le croisement au niveau tétraplo?de. Par le retour au state tétraplo?de sous l'effet de la colchicine ont peut s'attendre à obtenir de fortes proportions de géniteur valables pour la création de variétés résistantes aux nématodes.相似文献