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1.
Summary Eye-bearing slices, cut from healthy potato tubers and placed between Parafilm membranes, were inoculated with potato leafroll
virus (PLRV) byMyzus persicae. PLRV was detected by ELISA and by transmission tests in tuber slices and in plants grown from the slices of the susceptible
cv. Désirée, but not in those of the resistant cv. Arkula. These results suggest that PLRV replication and transport within
tuber phloem is controlled by specific mechanisms of resistance.M. persicae was also able to acquire and transmit PLRV toPl floridana from slices cut from tubers of infected plants. The aphids effectively transmitted PLRV from slices cut from the sprouting
rose end but they failed to transmit it from slices cut from the heel end of tubers. 相似文献
2.
Summary Starch and pulp were isolated from three cultivars of potato tubers grown in four localities. The starch content in the pulp
was determined by an enzymatic method which is shown to be more accurate than a polarimetric method. On an average, 94% of
the starch was isolated and 5% remained in the pulp.
The change in low-molecular weight carbohydrates in the potato tubers during storage for 2, 4, 7 and 11 weeks at 9 C was studied.
Generally there was an increase of sucrose, glucose, fructose andmyo-inositol during the first 2–4 weeks of storage, followed by a diminishing decrease. 相似文献
3.
Mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl) sulfonyl] amino] phenyl] -acetamide}, a chemical with plant growth regulator properties, was applied to the foliage of potatoes (Solanum tuberosum L.) in field experiments to determine its effects on tuber development, maturity, and storage of the cultivars Russet Burbank and Norland. The rate of sucrose loss before harvest was reduced in mefluidide-treated plants. Total and marketable yields generally were lower in treated plants. Specific gravity tended to increase in Russet Burbank with application rates up to 1.0 kg ai/ha mefluidide. Preharvest treatments of mefluidide resulted in an increase in periderm thickness and russeting. However, weight loss during storage was greater in tubers from treated plants. Less sprouting occurred in storage in tubers from mefluidide-treated plants. Mefluidide resulted in a lower anthocyanin content and consequently an undesirable color change in Norland tubers. 相似文献
4.
Summary In measuring fructose 1,6-bisphosphatase (EC 3.1.3.11; FBPase) in potato tubers, we used anti PFP antibodies to ensure that
the assay was specific for FBPase and that PPi:fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90: PFP) did not contribute
to the production of fructose 6-phosphate (Fru-6-P). The involvement of cytosolic FBPase in cold sweetening was determined
by monitoring enzyme activity during storage ofSolanum tuberosum cv. Erntestolz tubers at 2 or 8°C. In contrast to the rapid increase in sucrose and reducing sugars, the specific activity
of FBPase showed no change and PFP rose slightly during storage at 2°C. Sugar concentrations and enzyme activities remained
virtually unchanged during storage at 8°C. These data allow the interconversion of fructose 1.6-bisphosphate (Fru-1,6-P2) to Fru-6-P and vice versa by FBPase and PFP, respectively, in potato tubers, but do not support a causal relationship between
coarse metabolic control of FBPase and cold-induced sweetening. 相似文献
5.
R. D. Toosey 《Potato Research》1962,5(1):23-27
Summary Experiments show that sprouting treatment, seed size and spacing affect the number and size of tubers produced. Early sprouting
gives fewer sprouts per set and hence plants per hill than late sprouting.
The number of tubers produced is directly related to the number of plants. Sets with few sprouts (plants) produce fewer tubers
than sets with many sprouts. Small seed produces fewer plants and hence tubers than large seed.
The size of the tubers is inversely related to tuber numbers. In 1960 unsprouted seed produced fewer and larger tubers than
pre-sprouted seed butPhytophthora infestans was not experienced. Early sprouting, small seed and wide spacing increased tuber size, but early sprouted seed planted closely
gives a higher yield of ware than late sprouted seed planted further apart. Pre-sprouting results in earlier emergence and
tuber set but does not necessarily increase the yield of ware. If early drought occurs, presprouting may increase the proportion
of mishapen tubers.
Zusammenfassung Versuche haben ergeben, dass Vorkeimung, Gr?sse der Saatknollen und Pflanzabstand die Anzehl und Gr?sse der erzeugten Knollen beeinflussen. Frühkeimung gibt weiiger Triebe je Pflanzknolle und somit Pflanzen je Staude als Sp?tkeimung. Die Anzahl der erzeugten Knollen steht in direktem Verh?ltnis zu der Zahl der Pflanzen, Pflanzknollen mit wenig Trieben (Pflanzen) liefern weniger Knollen als Saatgut mit vielen Trieben. Kleine Saatknollen ergeben weniger Pflanzen und somit Knollen als grosse Saatknollen. Die Gr?sse der Knollen steht in umgekehrtem Verh?ltnis zu der Knollenzahl. Im Jahre 1960 ergaben ungekeimte Saatknollen weniger und gr?ssere Knollen als vorgekeimte Saatknollen, jedoch kam kein Befall vonPhytophthora infestans vor. Durch Frühkeimung, kleine Saatknollen und weiten Pflanzabstand wurde die Knollengr?sse gesteigert; vorgekeimte Saatknollen bei enger Pflanzung ergaben jedoch einen h?heren Ertrag an Verbrauchskartoffeln als sp?tgekeimte, die in gr?sserem Abstand gepflanzt waren. Vorkeimen bewirkt früheren Aufgang und Knollenansatz, erh?ht jedoch nicht unbedingt den Ertrag an Verbrauchskartoffeln. Wenn früh Trockenheit eintritt, kann das Vorkeimen Ursache eines gr?sseren Anteils an missgebildeten Knollen sein.
Résumé Des essais ont démontré que la prégermination, la grosseur des plants et leur espacement influencent le nombre et la grosseur des tubercules récoltés. Une germination précoce donne moins de pousses par plant, c’est-à-dire moins de plantes par touffe qu’une germination tardive. Le nombre de tubercules obtenus est directement proportionnel au nombre de plantes. Les plants portant peu de pousses (peu de plantes) produisent moins de tubercules que les plants qui présentent des pousses nombreuses. Les petits plants donnent moins de plantes et donc moins de tubercules que les gros plants. La grosseur des tubercules obtenus est indirectement proportionnelle à leur nombre. En 1960, les plants non prégermés produisirent des tubercules moins nombreux et plus gros que les plants prégermés, mais il n’y eut pas d’attaque dePhytophtophthora infestans. La germination précoce, le petit format des plants et leur grand espacement faisaient augmenter la grosseur des tubercules, mais les plants prégermés et plantés et plantés serré donnaient un plus haut rendement en tubercules de consommation que les plants germés tard et espacés davantage. La prégermination occasionne une levée plus précoce et une tubérisation également plus précoce, mais n’augmente pas nécessairement le rendement en tubercules de consommation. En cas de sécheresse au début de saison, la prégermination peut accro?tre le nombre de tubercules difformes.相似文献
6.
L. Espen S. Morgutti A. Abruzzese N. Negrini A. Rivetta M. M. Quattrini M. Cocucci S. M. Cocucci 《Potato Research》1999,42(1):189-201
Summary In the last 30 d of potato (Solanum tuberosum L.) tuber growth metabolic activity decreased. Levels of glucose-6-P and sucrose in whole tuber tissues declined and in tuber
slices there was a decrease in the uptake from the medium and in the incorporation into macromolecules of [U-14C]sucrose. During storage at 23°C only the uptake of [U-14C]sucrose increased concomitant with tuber sprouting, indicating a possible involvement of the transport mechanisms in dormancy
breaking. At 3°C, levels of reducing sugars and sucrose increased in response to the low temperature and increased release
of K+ and malondialdehyde levels indicated cell membrane damage. The cell membrane functionality was restored at sprouting. The
sprouting potential of the tubers was evaluated using the sprouting ability of single-bud explants (“seedcores”) in response
to water, GA3 or ABA dips. This sprouting potential of tubers changed with stage of tuber growth and storage duration and temperature,
indicating that the tissue hormonal state changed strongly throughout tuber life, probably in relation with the “sink” to
“source” transition. 相似文献
7.
M. K. Van Ittersum 《Potato Research》1992,35(3):261-269
Summary The variation in duration of dormancy within a seed tuber lot was studied over three years by harvesting individual plants
of cvs Diamant and Désirée from field plots and by storing the tubers at 18°C. The variation in dormancy within a tuber lot
was large (especially for cv. Diamant) and was mainly caused by variation within plants.
For cv. Diamant there was a close negative relation between dormancy and the cube root of tuber weight, whereas for cv. Désirée
a relation with tuber weight was almost absent.
The duration of dormancy of a seed lot comprising tubers with a narrow range in weight can be well described by two parameters.
It is proposed to maintain the moment of 80% sprouting as the criterion for the end of dormancy of a tuber lot and to characterize
the spread in dormancy duration by the time lapse between 10% and 90% sprouting. 相似文献
8.
V. Vecchio S. Benedettelli Luisa Andrenelli E. Palchetti L. Espen 《Potato Research》2000,43(2):115-123
Summary The effect of growth conditions (medium and photoperiod) on in vitro tuberisation and microtuber dormancy of the cv. Désirée
(Solanum tuberosum subspeciestuberosum) and Imilla Negra (Solanum tuberosum subspeciesandigena) was evaluated. The short photoperiod and presence of CCC in the medium reduced the dry matter of plants as well as the size
of microtubers. The two cultivars showed a difference, in favour of Désirée, in the percentage of plants having more than
one tuber and in the average time of sprouting after storage. The average time of sprouting was more rapidly obtained under
long days and in a medium without CCC. The CCC and short days caused the same dormancy conditions and the same K+ quantity in the microtubers. The microtubers mineral composition is involved in the dormancy status. 相似文献
9.
Summary Wide differences in chemical composition occurred between potato tubers grown with nitrogen fertilizer rates of 60 and 200
kgN per hectare, respectively. The analyses were made in November–December The storage temperature was 6–8°C. It was found
that the tubers from plants grown at the higher nitrogen level contained less glucose. The varietiesBintje andFlora differed significantly as regards glucose. fructose and sucrose contents. The differences in these components between the
varietiesGiewont andEpoka were not significant.
Zusammenfassung Eine grosse Differenzierung der chemischen Zusammensetzung der Kartoffelknollen wurde durch verschiedene N-Gaben (60 und 200 kg N/ha) erzielt. Die chemische Analyse der Knollen wurde w?hrend der Ruheperiode (November, Dezember) durchgeführt. Die Lagertemperatur der Knollen betrug 6–8°C. Knollen mit gr?sseren Konzentrationen von Stickstoff haben einen geringeren Gehalt an Glukose und Fruktose (Tabelle 1). Es besteht eine Korrelation zwischen N-Konzentration und Glukosegehalt in Knollen (Tabelle 2). In tabelle 3 sind die Differenzierungsniveaus des Zuckergehaltes der analysierten Sorten zusammengestellt. BeiBintje undFlora konnten bezüglich des Gehalts an Glukose, Fruktose und Saccharose statistisch gesicherte Sortenunterschiede festgestellt werden. In den SortenGiewont undEpoka ist der Gehalt an Glukose, Fruktose und Saccharose ungef?hr gleich.
Résumé On a obtenu une grande variation de la composition chimique des tubercules par l'application de diverses doses d'engrais azoté-60 et 200 kg/ha. L'analyse chimique des tubercules fut effectuée pendant la période de repos, de novembre à décembre. La température de stockage était de 6 à 8°C. Les tubercules obtenus avec la plus forte concentration azotée montraient la plus faible teneur en glucose et fructose (tableau 1). Les données du tableau 2 révèlent l'existence d'une corrélation entre la concentration en azote et la teneur en glucose des tubercules. Les résultats de l'analyse de la variance des teneurs en sucres des différentes variétés figurent dans le tableau 3. Chez les variétésBintje etFlora, les teneurs en glucose, fructose et saccharose diffèrent essentiellement. Par contre chez les variétésGiewont etEpoka les teneurs sont à près identiques.相似文献
10.
Shmuel Wolf 《Potato Research》1993,36(3):253-262
Summary Photosynthetic characteristics, carbon allocation and partitioning of newly-fixed14C among the various carbohydrate fractions were studied in leaves of potato plants (Solanum tuberosum L. cv. Désirée) of different ages. The higher photosynthetic rate of young leaves was associated with higher levels of starch
and reducing sugars. After 24 hours, in young leaves the fixed14C had been partitioned mainly to the residue and starch fractions, while in older leaves there was an increase in partitioning
to sucrose and reducing sugars. The activities of the various sink organs were found to be dependent upon their distance from
the source leaf. Tuber activity, however, was affected similarly by all fully expanded leaves. Although young fully expanded
leaves are thought to be the major source of assimilates for tuber growth, it seems that a vast potential for contributing
to plant productivity and tuber yield lies also in the older leaves, which translocate most of their photoassimilates to the
tubers. 相似文献
11.
12.
The effect of low storage temperature (4 to 8 C) and maleic hydrazide (MH) treatment on sprouting, sucrose and reducing sugar (glucose and fructose) concentrations in tubers, and fry color-sugar relationships of Shepody were determined and compared to Russet Burbank. Sprouting of Shepody was delayed by 3 to 15 weeks when the temperature was lowered from 8 to 6 or 5 C, respectively. Shepody accumulated more sugars at all storage temperatures than Russet Burbank. The reducing sugars accumulated in Shepody at 5 and 6 C could be lowered to levels acceptable for processing for about 24 weeks after harvest by reconditioning at 18 C for at least two weeks. MH increased glucose in Shepody stored at 5 C compared to untreated tubers. Excessive sprouting (> 10 cm sprout length) of nonsprout inhibited Shepody occured late in storage with four weeks reconditioning. Although not statistically significant, MH tended to cause darker fry color per unit of reducing sugar in Shepody compared to tubers from untreated plants. Storage of Shepody tubers not treated with MH could be extended a few weeks by temperatures < 8 C only if there is precise control over temperature, sugars are closely monitored, and reconditioning is rapid to minimize sprouting. 相似文献
13.
Summary Two cDNAs, corresponding to genes differentially regulated during dormancy and sprouting in potato tubers, cultivar Désirée,
were isolated: i) G1-1 corresponded to a gene that was turned off during dormancy and turned on during early phases of sprouting;
ii) A2-1 corresponded to a gene activated during dormancy and strongly repressed during the transition from dormancy to sprouting.
When induced, both genes were expressed at low level. Full-length cDNAs and genomic clones were isolated and characterized.
G1-1 was a short gene, 452 bp long, containing an intronless open reading frame, coding for a putative protein of 64 aminoacids.
Sequence analysis showed that G1-1 was homologous to an expressed sequence tag (EST) ofArabidopsis thaliana. A2-1 full-length cDNA was 1577 bp long and contained an open reading frame coding for a putative protein of 383 aminoacids,
which contained a Walker box binding domain, common to a multifunctional family of intracellular ATPases. 相似文献
14.
S. Simmerman-Gries 《Potato Research》1964,7(2):112-118
Summary Hitherto unobserved symptoms were noted in tubers ofUp-to-Date in the summer of 1959. These consisted of slight damage to the eyes near the rose end and light grey to brown patches in
the internal tissue. No pathogenic fungi or bacteria were isolated from the lesions. This disease does not resemble internal
rust spot, but approximates to the heat necrosis described byBlodgett in North America. Varietal differences in susceptibility were observed.
The disease is considered to be due to high soil temperature before lifting rather than high temperatures at the time of lifting.
No difference in extent of damage due to storage conditions was observed. The sprouting capacity of affected tubers was reduced.
When affected sprouted tubers were planted the resulting stand in the field was lower than that obtained from normal tubers,
but the plants which did develop yielded normally in every respecti.e. in size, shape and weight of tubers.
Contribution from the National and University Institute of Agriculture, Rehovot, Israel, 1963. Series No. 613-E. Paper read to the Pathology Section at the Second Triennial Conference of the European Association for Potato Research—Italy, Sept. 1963 相似文献
Zusammenfassung Im Sommer 1959 wurden bis dahin nicht beobachtete Symptome an Knollen der SorteUp-to-Date festgestellt. Diese bestanden in leichten Sch?den an den nahe dem Kronenende gelegenen Augen (abb. 1) und in hellgrauen bis braunen Flecken im Gewebeinnern, die sich vom Kronenende gegen die Knollenmitte ausdehnten. An den befallenen Stellen bilden sich Hohlr?ume (abb. 2, 3). Die Symptome kommen gew?hnlich an Pflanzgut der SorteUp-to-Date vor, das Juni/Juli geerntet wird, doch erscheinen sie anfangs Juni auch an Knollen aus leicht sandigen sowie aus sehr kalkreichen B?den; Knollen aus lehmigen Tonb?den zeigen die Symptome selten um Ende Juni, h?ufiger dagegen um Ende Juli. Der Prozentsatz des Schaderns ist in Speisesortierung h?her als in Saatsortierung.Up-to-Date ist die empfindlichste Sorte;Ulster Dale undUlster Torch sind weniger.Avenir undPatrones sind nicht anf?llig. Unter verschiedenen Lagerungsbedingungen konnte kein deutlicher Unterschied im Umfang des Schadens beobachtet werden (tabelle). Die Triebkraft der befallenen Knollen war beeintr?chtigt. Wurden befallene, aber gekeimte Knollen ausgepflanzt, so entwickelten sie sich schlechter als unbesch?digte Knollen, der Unterschied war jedoch bei der Ernte in bezug auf Gr?sse, Form und Gewicht der Knollen nicht mehr festzustellen. Aus den besch?digten Stellen wurden keine pathogenen Pilze oder Bakterien isoliert. Diese Krankheit hat keine ?hnlichkeit mit Eisenfleckigkeit. Sie ist aber der vonBlodgett in Nordamerika beschriebenen Hitzenekrose ?hnlich, obwohl die Beobachtungen darauf hinweisen, dass sie vielmehr auf hohe Bodentemperatur vor der Ernte zurückzuführen ist als auf hohe Temperaturen zur Zeit der Ernte.
Résumé On a noté pendant l'été 1959 des sympt?mes inobservés jusqu'ici dans des tubercules de la variétéUp-to-Date. Ces sympt?mes consistent en légers dégats aux yeux près de la couronne (fig. 1) et en taches gris-clair à brunes dans le tissu interne qui progressent de la couronne vers le centre. Des cavités se forment dans les régions affectées (fig. 2, 3). Les sympt?mes sont fréquents sur les plantsUp-to-Date récoltés en juin-juillet; ils apparaissent au début de juin dans les récoltes provenant de sols légers sablonneux et dans les sols hautement calcareux; ils apparaissent rarement à la fin juin et plus fréquemment à la fin juillet dans les récoltes sur sols argilo-limoneux. Le pourcentage de dégat est plus élevé dans les tubercules de consommation que dans ceux de forme plants.Up-to-Date est la variété la plus susceptible;Ulster Dale etUlster Torch sont moins susceptibles etAvenir etPatrones ne le sont pas. On ne remarque aucune différence d'extension des dégats sous différentes conditions de stockage (tableau). La capacité germinative des tubercules affectés est réduite. Si l'on plante des tubercules atteints germés, le développement dans le champ est moindre qu'avec des tubercules normaux, mais les plantes qui se développent ont une production normale en forme, grosseur et poids des tubercules. On n'a isolé des lésions aucun champignon ni bactérie pathogènes. La maladie ne ressemble pas aux taches de rouille interne, mais se rapproche de la nécrose de chaleur décrite parBlodgett en Amérique du Nord, quoique les observations font supposer qu'elle est due à une température du sol élevée avant l'arrachage plut?t qu'à une température élevée au moment de l'arrachage.
Contribution from the National and University Institute of Agriculture, Rehovot, Israel, 1963. Series No. 613-E. Paper read to the Pathology Section at the Second Triennial Conference of the European Association for Potato Research—Italy, Sept. 1963 相似文献
15.
M. Susnoschi 《Potato Research》1981,24(4):381-388
Summary Locally grown seed tubers of nine varieties developing in spring or in autumn in a semi-arid region were examined for length
of dormancy and for sprouting response. In spring, high temperatures during the last part of tuber development markedly shortened
the dormant periods of tubers in comparison with tubers of the same varieties developing in autumn.
The sprouting behaviour of tubers indicated that it is a varietal characteristic influenced by the change in environmental
conditions during tuber development and storage. On tubers developing in spring and stored at high temperatures, three sprouting
patterns were defined: a) apical dominance, characterized by the evident development of the apical sprout and less than 10%
sprouting of the non-apical buds; b) apical influence, the apical sprout well developed and 10–20% sprouting of the non-apical
buds; and c) simultaneous sprouting of 3 or 4 sprouts of similar size per tuber.
It is suggested that apical dominance is a relative rather than an absolute phenomenon. The extent of dominance depends upon
the variety's response to the high temperatures during tuber growth and storage.
Contribution from the Agricultural Research Organization, Beit Dagan, Israel, 1979 Series, No 301. 相似文献
16.
Timothy J. Herrman Stephen L. Love Bahman Shafii Robert B. Dwelle 《American Journal of Potato Research》1996,73(9):411-425
Three potato cultivars (Russet Burbank, Norchip, and Gemchip) grown with nitrogen applied at three rates were stored at two temperature regimes (Treatment 1: 13 months at 10 CTreatment 2: 1 month at 10 C; followed by a 1 C decrease per week until tubers were 4 C; followed by 6 months at 4 C; followed by a 1 C increase per week until tubers were 10 C; followed by 3 months at 10 C). Tuber chemical components and potato chip appearance were measured at harvest and after 3, 6, 9, 11, 12, and 13 months; these measurements were performed within 24 hours of the time potatoes were removed from storage. Sugar responses (tuber glucose, fructose, sucrose) and potato chip appearance were affected by cultivar over time in both years and storage temperatures. Russet Burbank tubers displayed a significantly higher glucose forming potential and produced darker appearing chips, regardless of storage temperature or time in storage, compared to Norchip and Gemchip. Potatoes receiving a cold-storage treatment contained less sugar and produced lighter appearing chips after 12 months storage compared to tubers stored at a constant 10 C for 12 months. The linear association between tuber chemical components and potato chip appearance varied with storage temperature. 相似文献
17.
R. W. Gibson 《Potato Research》1991,34(2):205-210
Summary Field-grown potato plants of cvs King Edward, Record, Maris Piper and Désirée were inoculated on seven different dates during
the growing season of 1987 and 1988 with either potato virus YO (PVYO) or PVYN, using three viruliferous peach-potato aphids (Myzus persicae) per plant. In each cultivar, the proportion of progeny tubers infected with PVYO or PVYN was high in plants inoculated during the four weeks following emergence, the proportion declining to zero or close to zero
in the subsequent 4–6 wks. 相似文献
18.
Summary Between 1976 and 1981, healthy seed tubers were kept in five stores used for holding virustested stem cutting stocks. The
incidence ofPolyscytalum pustulans (skin spot) andPhoma exigua var.foveata (gangrene) was assessed after four months storage. The tubers were planted, often after various treatments, and the incidence
of the pathogens on their progeny tubers assessed after harvesting and further storage.
Seed tuber contamination byP. pustulans varied with the store and the differences were reflected in the incidences of contamination on their progeny tubers. Progeny
tuber contamination byP. pustulans was not affected by fumigation of the seed tuber with 2-aminobutane but was reduced by dipping seed tubers just prior to
planting in either a surface disinfectant or thiabendazole.
Seed and progeny tuber contamination byP. exigua var.foveata was not affected by storage site or by chemical treatment just prior to planting.
Zusammenfassung Zwischen 1976 und 1981 wurden gesunde Pflanzknollen in fünf L?gern gehalten, die zum Aufbewahren virusgetesteter ‘stem cutting”-Best?nde dienten. Nach viermonatiger Lagerung wurde das Auftreten vonPolyscytalum pustulans (Tüpfelfleckenkrankheit) undPhoma exigua var.foveata (Phoma-F?ule) ermittelt. Die Knollen wurden nach oft unterschiedlicher Behandlung angepflanzt und das Vorkommen der Pathogene an den Tochterknollen nach Ernte und weiterer Lagerung festgestellt. Die Versuche wurden mit Pflanzknollen durchgeführt, die in der ‘DAFS nuclear stock farm” erzeugt wurden. Die Pathogene wurden lediglich an den Knollen des Anbaus von 1977 nachgewiesen, und dies auch nur in sehr geringem Masse (Tabelle 1). Der Befall der Pflanzknollen war w?hrend der Lagersaison 1976/77 im Lager C am h?chsten und im Lager A am niedrigsten (Tabelle 2). In gleicher Weise variierte mit der Lagerung der Befall der Tochterknollen, wenn auch für die Sorte Kerr's Pink der Unterschied zwischen den L?gern B und C nicht signifikant war. Der Umfang desP. pustulans-Befalls war an den Tochterknollen signifikant (r=0,84; 22 d.f) bezogen zum Vorkommen der Tüpfelflecken. Zwei weitere Experimente best?tigten, dass der Knollenbefall mitP. pustulans mit dem Lager variierte (Tabelle 3). Die Kontamination der Tochterknollen wurde nicht durch die Begasung der Pflanzknollen mit 2-Aminobutan bei der Ernte beeinflusst. In zwei Versuchen wurde der Befall der Tochterknollen mitP. pustulans reduziert, in dem die Pflanzknollen aus Lager C entweder in Oberfl?chen-Desinfektionsmittel oder in ein Fungizid (Thiabendazol) getaucht wurden (Tabelle 4). Dieses Ergebnis best?tigte sich in zwei weiteren Versuchen, in denen Pflanzknollen der L?ger A, C und L verwendet wurden (Tabelle 5). Der Befallsumfang der Pflanz- und Tochterknollen mitP. exigua var.foveata wurde vom Lager, in dem sich die Knollen befanden, nicht beeinflusst (Tabellen 2 und 3). Die Kontamination der Tochterknollen wurde auch nicht durch die chemische Behandlung kurz vor dem Pflanzen berührt (Tabellen 4 und 5). Im Gegensatz zu diesen Versuchen, bewirkte das Best?uben der Pflanzknollen mit trockener, kontaminierter Lagererde einen h?heren Befallsgrad der Tochterknollen als das Best?uben mitP. exigua var.foveata freier Erde (Tabelle 6). Diese Ergebnisse wurden in Bezug zu einem luftbürtigen Inokulum diskutiert, das man von einem in Kartoffell?gern vorkommenden kontaminierten trockenen Boden erhielt (Carnegie et al., 1978).
Résumé Entre 1976 et 1981, des plants sains ont été conservés dans 5 locaux utilisés pour la conservation des stocks issus de boutures indemnes de virus. La fréquence dePolyscytalum pustulans (Oosporiose) et dePhoma exigua var.foveata (Gangrène) a été notée après 4 mois de conservation. Les tubercules ont été plantés, souvent après divers traitements, et l'incidence des parasites sur leur descendance évaluée après récolte puis après conservation. Les expériences ont été conduites en utilisant des plants en provenance de la station DAFS produisant le matériel de base. Les parasites n'ont été détectés que sur des tubercules de la récolte 1977, et à un niveau très bas (tableau 1). La contamination des plants parP. pustulans, pendant la période de conservation 1976–77 est la plus importante pour le magasin C et la plus faible pour le magasin A (tableau 2). La contamination des tubercules fils varie de la même fa?on, en fonction du local de stockage, bien que la différence entre les locaux B et C ne soit pas significative pour la variété Kerr's Pink. Sur les tubercules fils, la fréquence de la contamination parP. pustulans et la fréquence de l'Oosporiose sont significativement corrélés (r=0,84; 22 d.f.). Deux autres expériences confirment que la contamination des tubercules varie avec le local de stockage (tableau 3). La contamination des tubercules fils n'est pas modifiée par la fumigation des plants à la récolte par le 2 aminobutane. Dans deux essais, la fréquence de la contamination des tubercules fils parP. pustulans est réduite par le trempage des tubercules de semences venant du local C soit dans des désinfectants superficiels soit dans un fongicide, le thiabendazole (tableau 4). Ce résultat est confirmé par deux autres essais ultérieurs utilisant des plants provenant des locaux A, C et L (tableau 5). La fréquence de la contamination des plants et des tubercules fils parP. exigua var.foveata n'est pas modifiée par la nature du local dans lequel les plants ont été conservés (tableaux 2 et 3). Parallèlement, la contamination des tubercules fils n'est pas modifiée par un traitement chimique appliqué juste avant plantation (tableaux 4 et 5). Par opposition à ces données expérimentales, le saupoudrage des plants avec de la terre sèche contaminée prélevée dans un local, conduit à une augmentation de la contamination de la descendance, comparée à un saupoudrage effectué avec de la terre indemne deP. exigua var.foveata (tableau 6). Ces résultats sont discutés en se référant à l'inoculum aérien provenant de la terre sèche contaminée présent dans les locaux de stockage (Carnegie et al., 1978).相似文献
19.
W. G. Burton 《Potato Research》1965,8(2):80-91
Summary Immature tubers have a much higher content of sucrose than mature tubers. After harvest this sucrose is rapidly transformed
to hexose, which often then remains at a high level during storage. Mature tubers may have a very variable content of sugar
when harvested. During storage, apart from the sweetening which occurs at low temperatures, considerable sweetening occurs
after more than 10–15 weeks at 10 C and even more markedly at 20 C. The magnitude of this sweetening shows considerable varietal
differences, apparently correlated, in tubers which are allowed to sprout, with the vigour of sprout growth. It also occurs,
however, if sprout growth is suppressed chemically.
Zusammenfassung Unreife Knollen haben einen viel h?heren Gehalt an Saccharose als reife Knollen. Dies steht mit der anf?nglichen, aber kleiner werdenden Divergenz zwischen Verlagerung und Umwandlung von Saccharose in Hexose-Phosphate und schliesslich in St?rke im Zusammenhang. In einem angeführten Beispiel enthielten Knollen der SorteMajestic, die am 16.7.63 geerntet wurden, 1,01g Saccharose je 100 g Frischgewicht, w?hrend Knollen des gleichen Bestandes, die am 30.9.63 reif geerntet wurden, nur 0,06 g/100g enthielten. Nach der Ernte wird dieser hohe Gehalt an Saccharose in den unreifen Knollen rasch in Hexose umgewandelt (abb. 1) die dann w?hrend der Lagerung oftmals einen hohen Stand beibeh?lt (abb. 2). Reife Knollen k?nnen bei der Ernte einen sehr unterschiedlichen Zuckergehalt aufweisen. In dertabelle sind Ergebnisse von Analysen, die nach einer Woche Lagerung bei 10 C gemacht wurden, aufgeführt. Abgeschen vom Süsswerden, das bei niedrigen Temperaturen vorkommt (abb. 3), tritt nach mehr als 10 bis 15 Wochen Lagerung bei 10 C betr?chtliches, und bei 20 C sogar noch ausgepr?gteres Süsswerden ein. Das Ausmass dieses Süsswerdens zeigt bedeutende sortenbedingte Unterschiede (abb. 4), die, sofern die Knollen austreiben, mit der St?rke des Keimwachstums (abb. 6) offensichtlich korreliert sind. Süsswerden kommt jedoch auch vor, wenn das Keimwachstum durch Keimverhinderungsmittel unterdrückt wird.
Résumé Les tubercules non m?rs ont une teneur en sucrose beaucoup plus élevée que les tubercules m?rs, en raison du déséquilibre initial, bien que décroissant, dans sa translation et sa transformation en phosphates hexose et finalement en amidon. Dans un exemple chiffré, des tuberculesMajestic récoltés le 16 juillet 1963 contenaient 1,01g de sucrose par 100g de poids frais (1,01g/100g), tandis que les tubercules de la même récolte arrachés m?rs le 30 septembre 1963 contenaient seulement 0,06g/100g. Après la récolte cette haute teneur de sucrose des tubercules non m?rs est rapidement transformée en hexose (fig. 1), lequel, alors, reste souvent à un niveau élevé pendant la conservation (fig. 2). Les tubercules m?rs peuvent avoir une teneur très variable en sucres au moment de la récolte. Letableau mentionne les résultats d’analyses effectuées après une semaine à 10 C. Durant la conservation, indépendamment de l’affadissement qui appara?t à basse température (fig. 3), un affadissement considérable se produit après une conservation à 10 C pendant au moins 10 à 15 semaines, et même, d’une manière plus marquée, à 20 C. L’importance de cet affadissement montre des différences variétales considérables (fig. 4) qui, apparemment, sont en corrélation, chez les tubercules qui sont mis en germination, avec la vigueur de croissance du germe (fig. 6). Ce phénomène apparait également quand le développement du germe est supprimé par voie chimique.相似文献
20.
C. A. Braue R. L. Wample P. E. Kolattukudy B. B. Dean 《American Journal of Potato Research》1983,60(11):827-837
Potato (Solanum tuberosum L. cv. Russet Burbank) tuber periderm resistance to water loss was monitored during the harvest season. Periderm resistance of tubers from water-stressed plants was compared with tubers from unstressed plants throughout a six-week harvest period, in order to determine the effect of plant condition on tuber resistance to water loss. Tubers stored for ten days at 4°C immediately following harvest were also monitored to determine if storage enhanced periderm resistance and if any difference occurred between tubers from stressed vines compared with those from unstressed vines. During the harvest season, tuber resistance to water loss was positively correlated with plant water stress, as measured by leaf water potential and leaf diffusive resistance. Storage of tubers after harvest also caused an increase in periderm resistance. The commercial practice of vine killing, therefore, may have a positive effect on reducing weight loss in storage by enhancing the resistance of tuber periderm to water loss. 相似文献