Susceptibility Of Potatoes Research Articles

Commercial Potato Cultivars Exhibit Distinct Susceptibility to the Root Lesion Nematode Pratylenchus penetrans

The root lesion nematode Pratylenchus penetrans is an important plant-parasitic nematode of potato. In this study, the susceptibility of commercial potato cultivars to P. penetrans was assessed. Nematode penetration was evaluated in cultivars Agria, Camel, Kennebec, Laura, Royata, and Stemster at 1, 3, 7, and 15 days after inoculation (DAI) with 750 nematodes/plant, and an egression assay at 3 DAI with 1000 nematodes/plant. Reproduction assays of cultivars Agata, Agria, Camel, Désirée, Dirosso, Kennebec, Laura, Picasso, Royata, and Stemster were performed in 2 L pots inoculated with four P. penetrans/g soil and quantified at 60 DAI. Tenue or moderate root cell browning to advanced necrotic areas were observed after nematode penetration, and the number of nematodes/g of root gradually increased with time of infection. A lower number of deposited eggs and nematodes were observed within the roots of cultivar Laura in all assays comparatively to other cultivars. The susceptibility index (SI) was significantly lower in cultivar Laura (0.4–0.6), followed by cultivars Camel and Picasso (0.8–0.9). All remaining cultivars showed SI values above 1. Although the potato susceptibility to the nematode varied among cultivars, no differences on the average number or weight of tubers produced by each plant of inoculated versus non-inoculated plants were detected. Our data reveals that these cultivars have a distinct ability to support the reproduction of P. penetrans.

Yield and quality of potatoes depending on the application of microelements in the northern forest-steppe Ob in Novosibirsk

The aim of the work is to study the effectiveness of the use of trace elements on potatovarieties of different ripeness groups in the northern forest-steppe Ob in the Novosibirsk region.Experimental data were obtained on leached black soil of Novosibirsk region in 2017–2019. Thegenerally accepted technology of potato cultivation was used for the experiments. Since autumn,fertilizers at a dose of P90K90were applied as a general background for potatoes. Nitrogen fertilizers (60 kg / ha) were applied in the spring for pre-sowing cultivation. Foliar dressing with microelements(Cu, B, Zn) was used at the beginning of the budding phase of potato plants: copper – 20, boron –45, zinc – 50 g of active ingredient per 1 ha with a working fluid consumption of 300 l/ha. Traceelements increased the growth and development rates of potato varieties of three groups of ripeness.In varieties Liubava (early), Svitanok Kievsky (mid-early), Tuleevsky (mid-season), the use of traceelements contributed to an increase in the development indicators of the photosynthetic apparatus(maximum and average leaf area and plant productivity) by an average of 21%, especially againstthe background of boron and zinc. Foliar dressing of potatoes increased the yield parameters by anaverage of 24 % relative to the control (water). The increase in the marketability of tubers reached12 %. A greater effect was achieved against the background of boron use: a significant increase inyield, dry matter, starch, vitamin C. In variants with microelements, the susceptibility of potatoes byrhizoctonysis decreased.

Biological and molecular characterization of Potato yellow blotch virus, a new species of the genus Potyvirus

A new species of the genus Potyvirus infecting potatoes, with the proposed name Potato yellow blotch virus (PYBV), was discovered in a breeding line 99m‐022‐026 in Scotland. The infected plants show isolated yellow blotches on the leaves. The genome of PYBV contains a large open reading frame encoding a single polyprotein of 3054 amino acids. Sequence analysis shows that PYBV is closely related to Potato virus A (PVA), with an overall 72% identity at the nucleotide level for the whole genome. The least conserved P1 protease gene shares only 50% nucleotide identity with PVA. The host range of PYBV was comparable to PVA on solanaceaous and non‐solanaceous indicator plant species with the exception of Solanum demissum A and Y. Different symptoms were also observed for PYBV and PVA in Nicotiana benthamiana, Nicotiana hesperis and Nicotiana occidentalis P1. The susceptibility of potato (Solanum tuberosum) cultivars to PYBV and PVA was similar. In over 5 years of investigation, PYBV has not been found in commercial seed and ware potato crops in Scotland.

Evaluation of foliar and stem susceptibility of three cultivated Solanaceous crops to Phytophthora infestans

Late blight of potato, tomato and some members of Solanaceae is of wide occurrence in many parts of the world leading to crop damages and yield losses. Caused by Phytophthora infestans which has a wide host range, late blight disease offers severe challenges to the crop growers in geographic localities where climatic conditions favor spread of the disease. In this study, we evaluated the susceptibility of potato (Solanum tuberosum L.), tomato (Solanum lycopersicum L.) and eggplant (Solanum melongena L.) to P. infestans. The foliar resistance of intact leaves and detached stems of three species were determined by the disease severity, incubation period and lesion area caused by the pathogen. The three crops significantly varied in response to late blight infection; potato and tomato showed severe disease symptoms, lesion area and lower incubation period. Foliage sensitivity was more evident than stems. Among the evaluated crops, eggplant was the most resistant to foliar and stem late blight disease suggesting its role in potential breeding for resistance purposes.

Effect of immunomodulators on potato resistance and susceptibility to Phytophthora infestans

The mechanisms of induced resistance and susceptibility of potato (Solanum tuberosum L.) tubers to late blight agent (Phytophthora infestans Mont de Bary) were studied using an elicitor chitosan and an immunosuppressor laminarin. It was elucidated that treatment of disks from potato tubers with chitosan resulted in salicyclic acid (SA) accumulation due to activation of benzoate-2-hydroxylase and hydrolysis of SA conjugates. Such SA accumulation in potato tissues inhibited one of the antioxidant enzymes, catalase, inducing an oxidative burst and resistance development. The mechanisms of induced susceptibility to the late blight causal agent were studied using an unspecific immunosuppressor, laminarin, an analogue of natural specific suppressor of potato immune responses, β-1,3,β-1,6-glucan. It was established that the development of immunosuppression in tissues treated with laminarin did not affect the SA level in tissues. However, catalase sensitivity to SA reduced in laminarin-treated tissues, and the enzyme activity increased. In its turn, this might result in the reduced level of hydrogen peroxide in the cells and, as a sequence, in the increased potato susceptibility to late blight.

Effects of specific gravity and cultivar on susceptibility of potato (Solanum tuberosum) tubers to blackspot bruising and bacterial soft rot

Ten potato (Solanum tuberosum) cultivars were assessed for resistance to bacterial soft rot caused by Erwinia carotovora subsp. atroseptica, and to blackspot bruising. Specific gravities of individual potato tubers varied within each cultivar and between cultivars. Within all 10 cultivars tested, as tuber‐specific gravity increased, the severity of bacterial soft rot decreased, and the severity of bruising increased. Among the seven New Zealand‐bred cultivars, mean soft rot susceptibilities lay along a continuum, with cultivars having higher mean soft rot losses as mean specific gravity increased. Two of the three overseas cultivars exhibited very different responses from those bred in New Zealand. In contrast, for blackspot bruising, six of the New Zealand‐bred cultivars and two overseas cultivars lay approximately on a continuum of increasing mean bruise score as mean specific gravity increased, similar to the within‐cultivar relationships. The remaining New Zealand‐bred cultivar and the overseas cultivar ‘Fianna’ were quite different, having much lower mean bruise scores than predicted by the trend line of the other cultivars. ‘Fianna’ in particular exhibited both low bruising and low soft rot incidence in this experiment.

Susceptibility of potato (Solanum tuberosum) cultivars to powdery scab (caused by Spongospora subterranea f. sp. subterranea), and relationships between tuber and root infection

Ninety-nine potato (Solanum tuberosum) cultivars and 13 breeding lines were assessed in field trials for susceptibility to powdery scab (caused by Spongospora subterranea f. sp. subterranea). The trials wer e carried out over 11 growing seasons (each cultivar/line tested in at least two growing seasons) in soil inoculated with S. subterranea and regularly irrigated during crop growth. The cultivars and lines were categorised as ‘very resistant’ (21%). ‘moderately resistant’ (28%). ‘moderately susceptible’ (33%) or ‘very susceptible’ ( 19%). Scaled average severity scores for the cultivars and lines followed a continuum between very resistant and very susceptible, suggesting that resistance to powdery scab is quantitative. In a glasshouse experiment where small plants were inoculated with S. subterranea sporosori, 15 cultivars selected to cover the spectrum of field-assessed susceptibility were assessed for intensity of infection by S. subterranea zoosporangium in roots and for numbers of root galls on root systems. All of the cultivars developed zoosporangia and root galls (i.e. no cultivar was immune from infection), and root infection was usually related to tuber infection. Field-resistant cultivars (tuber infection) generally had low numbers of root zoosporangia and root galls in the glass house experiment, and cultivars that were very susceptible to tuber infection in the field had high levels of root infection in the glasshouse experiment. An exception was the early maturing cv. Swift, which had very low levels of tuber infection in the field, but had high numbers of root zoosporangia and root galls in the glasshouse. These results demonstrate the relative reaction of a large number of potato cultivars to powdery scab and reaffirm the potential for using plant resistance as a powdery scab management strategy. Development of S. subterranea in host roots, even in cultivars with resistance to tuber infection, is likely to be important in the epidemiology of powdery scab.

Plasma Membrane Receptors for Exopolysaccharides of the Ring Rot Causal Agent in Potato Cells

By means of differential centrifugation, microsomal fractions enriched in the plasma membrane were isolated from suspension cell cultures of two cultivars of potato (Solanum tuberosum L.) contrasting in their resistance to the causal agent of ring rot (Clavibacter michiganensis subsp. sepedonicus) (Cms). Electrophoresis of the fractions showed that they comprised a wide range of proteins from 15 to 75 kD. The protein bands were more brightly expressed in the microsomal membranes of the cells of susceptible cultivar. The proteins of 70 and 42 kD were present only in the cellular membranes of the resistant cultivar. In order to visualize the binding of exopolysaccharides (EPS) produced by Cms to the receptors of membrane fractions, a conjugate of EPS with a fluorescent marker was used. The membrane fraction isolated from the cells of the susceptible cultivar was found to be richer in receptors for EPS Cms than the membrane fraction from the resistant cultivar. It is supposed that numerous receptors for EPS present on the plasma membrane may partially account for potato susceptibility to Cms. These receptors may facilitate the binding of bacteria to the plant cells, the formation of colonies, and the development of the disease.

Effect of glucans from different races of Phytophthora infestans on defense reactions in potato tuber

It has been proposed that susceptibility of potato to Phytophthora infestanswould be a consequence of suppression and /or delaying of defense reactions by a soluble glucan which is released by compatible races of the fungus. In this report, the reaction of potato tuber slices ( Solanum tuberosum cv. Huinkul) infected with either race I (1,4,7,8,10,11) or C (1,4,10,11) of Phytophthora infestans was studied. Race C grew better on slices than race I. Glucans from both races were isolated and their effect on the accumulation of phytoalexins and glucanases in tuber slices was studied. The glucans from the less virulent race (I) did not affect the accumulation of phytoalexins and glucanases in tuber slices infected or elicited with eicosapentaenoic acid, whereas the glucans from race C produced 70% inhibition of phytoalexin accumulation and reduced by 50% the induction of glucanase activities. Purified glucanases from potato degraded the glucans from race C but not from race I. The results reported here show that, at least on this cultivar, glucans from both races affected defense responses in a different manner, which could reflect structural differences between these glucans. Abbreviations:EPA ‐ 5,8,11,14,17 eicosapentaenoic acid.

A simple and efficient method to assess susceptibility of potato to stem rot byErwinia carotovora subspecies

Limited development of blackleg resistant potato cultivars has been ascribed to the lack of an effective and reliable test for large scale blackleg resistance screening. A method using leaf petioles was developed for assessing susceptibility of potato stems to blackleg pathogens (Erwinia carotovora subspeciesatroseptica andE. c. subspeciescarotovora). Fifty grams of sterile autoclaved silica sand in Magenta jars (GA-7 vessel, Magenta Corp., Chicago, Illinois) was drenched with bacterial suspension, (17 ml, 2.6 × 10 to 2.6 × 107 cfu/ml) and freshly cut petioles from 5 to 6 week-old plants were inserted to about 5 mm into the sand. The Magenta jars with lids closed were kept on a laboratory bench (20 ±2 C, 16 hours light). The arrangement provided near ideal post-inoculation incubation environment of high humidity for pathogen multiplication and rot development in the petioles. Length of rot was recorded 72 hours after inoculation. Linear regression of rot development on inoculum concentration had R2 ≥ 0.80. The petioles inoculated and incubated by this method produced measurable rot lesions with a bacterial concentration as low as 2.6 × 104 cfu/ml and differentiated between the resistant cultivar Russet Burbank and the susceptible cultivar Sangre at all the inoculum concentrations used. Furthermore, susceptibility ranking of five cultivars obtained by this method agreed in general with their reported field reactions. The method is simple and sensitive, and could be used for large scale screening for stem rot resistance in wildSolanum species and early generation breeding populations.

The effect of tuber size on the susceptibility of potatoes to metoxuron

Field and pot experiments to determine whether the tuber size of volunteer potatoes affected their susceptibility to foliar applications of metoxuron are reported. The reduction in haulm weight of plants from small tubers (2–3 cm diameter) was greater than that of plants from large ones (4–5 cm diameter). This greater control was related to the lower vigour at spraying of the plants from the small tubers. It is suggested that these results could explain the variability in the level of control of volunteer potatoes achieved by metoxuron in carrot crops.

Rapid bruise development in potatoes with oxygen under pressure

Of a variety of methods tested in connection with the rapid assessment of bruise susceptibility of potatoes, oxygen under pressure (1. 4 kg/cm2) proved to be particularly effective on the grounds of time saved and authenticity of results. Time required for maximum pigmentation was regularly of the order of 2 h with oxygen compared with 8–12 h with compressed air at the same pressure and a minimum period of 3 days for the controls. From preliminary analysis carried out on the concentrations in potatoes of tyrosine, chlorogenic acid and ascorbic acid, no obvious relationship with susceptibility to bruising could be recognised.

Measurement of black spot susceptibility of potatoes

The black spot reaction was initiated by dropping plugs of varying weights from different heights onto the stem end of potatoes with known temperatures. The degree of discoloration was assessed in a scale from 0 to 5, the results were added and the sum was divided by the number of tubers.

CORRELATION OF PHOTOPERIOD WITH TUBERIZATION AND SUSCEPTIBILITY OF POTATO TO VERTICILLIUM ALBO-ATRUM

Photoperiod was found to control both initiation of tubers and susceptibility of potato to Verticillium wilt. Plants grown in a short-daily photoperiod (long dark period) formed tubers and such plants, when inoculated with Verticillium albo-atrum, developed moderate to severe wilt symptoms. Plants grown in a long-daily photoperiod did not form tubers and developed no disease symptoms when inoculated with Verticillium. When a 2-hour light period was interjected in the middle of the long dark period, no tubers were formed and plants developed no symptoms of disease when inoculated with Verticillium. The resistance to Verticillium exhibited by plants was not limited to the root but was present throughout the plant.

Internal sprouting of potatoes

1. Internal sprouting had been a problem in commercial storages with chipping potatoes prior to the use of CIPC. 2. Marginal dosages of CIPC did not increase the susceptibility of potatoes to internal sprouting. As the dosage of CIPC was increased, internal sprouting decreased. Check treatments always had the highest level of internal sprouting. Contaminated checks had less internal sprouting than non-contaminated checks indicating that even contamination levels of treatment tended to decrease the susceptibility. 3. The most important factor involved in internal sprouting was storage temperature. The same storage environment which leads to fast external sprouting and the need for an inhibitor is the same environment which gives most susceptibility to internal sprouting. 4. The phenomenon appears to be mechanically triggered. Whenever the pressure of a rosette eye or wall or adjoining tuber makes the line of least resistance for sprout growth through a tuber, there will be internal sprouting. Storage environmental factors which lead to one tuber indenting another accentuates internal sprouting problems.

Effects of environment on tuber production, potassium absorption, and susceptibility of potatoes to virus disease in Poland

1. The transfer of potatoes from optimal maritime conditions (Pomerania) to the Carpathian mountain, 300–1200 meters above sea level. resulted in a decrease in single plant yield, of 44 g for the variety Epoka and 59 g for the variety Ackersegen for each 100 meters increase in altitude. 2. A year to year increase of K in potato tubers planted in the Carpathians was found. Under our mountain conditions the content of K in potato tubers was correlated with a decrease in yield. 3. Transfer of potatoes from the mountains into the lowlands, irrespective of the kind of soil in which the plants had grown, caused a considerable increase in yield and a decrease of K in the tubers in the first year of cultivation. The most probable factor responsible for this phenomenon is temperature. The mean monthly temperature during the vegetative period decreases as elevation increases. The conditions under which parent and grandparent generations were grown affected the yield in the lowlands. When tubers produced at low temperatures in the mountains, were planted near Cracow, yield was increased, the K content of the tubers decreased, and there was little spread of leaf roll and streak. 4. Potatoes transferred from low lying mountain stations, below 400 meters above sea level, to the lowlands did not respond with increase in yield, nor did the K content in the tubers decrease. Also the plants were highly susceptible to streak and leaf roll.

The effect of fertilization on the susceptibility of potatoes to late blight

Experiments were conducted in the field and the greenhouse to study the effects of N, P and K nutritions on the incidence of late blight in potatoes. In the N experiments the results of the field and greenhouse were variable. In the field excessive amounts of N fertilizer had a marked tendency to increase the size of the late blight lesions on the potato leaves. In the greenhouse excessive use of N fertilizer did not increase the late blight lesions on the potato leaves. The amount of P applied in the fertilizer was the most significant factor in determining the size of the late blight lesions. Large applications of P decreased the size of the late blight lesions on the potato leaves, while the progress in the size of the late blight lesions was most rapid in leaves receiving no application of P. Significant decreases in the size of the late blight lesions resulted from the high applications of K fertilizers, but K was not as efficient as P in decreasing the size of the late blight lesions.

Varietal susceptibility of potatoes to internal black spot

1 Experiments were conducted to further test the correlation between black spot index and specific gravity, and to show the effect of field location on the relative response of various varieties to black spot and specific gravity. 2 A highly significant positive corelation of 933 was found between black spot index and specific gravity in 1949, using Long Island-grown Katahdin potatoes. We must conclude that there are other factors influencing blackening, but that there is an association between the specific gravity of the tuber and the black spot index. 3 The variety trials in 1949-1950 indicate that internal black spot is no longer just a Long Island problem, but is becoming increasingly prevalent throughout New York State. 4 The fact that location has an important effect on the incidence of black spot was demonstrated in the 1950–1951 trials. Several of the tested varieties reacted differently in blackening susceptibility when grown in certain counties. However, Ontario consistently blackened more than the other varieties in practically every location, whereas Ashworth, Pontiac and Kennebec showed the least susceptibility to discoloration of any of the varieties tested. 5 The most practical recommendations for the control of internal black spot are: (1) careful handling to avoid bruising, especially after very long storage and (2) the use of less susceptible potato varieties.

Varietal susceptibility of potatoes to fusarium wilt

Varietal susceptibility of potatoes to fusarium wilt