Cultivars Agria Research Articles

CRISPR/Cas StNRL1 gene knockout increases resistance to late blight and susceptibility to early blight in potato.

With the development of genome editing technologies, editing susceptible genes is a promising method to modify plants for resistance to stress. NPH3/RPT2-LIKE1 protein (NRL1) interacts with effector Pi02860 of Phytophthora infestans and creates a protein complex, promoting the proteasome-mediated degradation of the guanine nucleotide exchange factor SWAP70. SWAP70, as a positive regulator, enhances cell death triggered by the perception of the P. infestans pathogen-associated molecular pattern (PAMP) INF1. Using a clustered regularly interspaced short palindrome repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, a construct was made to introduce four guide RNAs into the potato cultivar Agria. A total of 60 putative transgenic lines were regenerated, in which 10 transgenic lines with deletions were selected and analyzed. A mutant line with a four-allelic knockdown of StNRL1 gene was obtained, showing an ~90% reduction in StNRL1 expression level, resulting in enhanced resistance to P. infestans. Surprisingly, mutant lines were susceptible to Alternaria alternata, suggesting that StNRL1 may play a role as a resistance gene; hence, silencing StNRL1 enhances resistance to P. infestans.

Screening of endophytic bacteria from potato tubers and their antagonistic activity against soil-borne potato pathogens

In order to appraise the bacterial endophyte communities that help resist disease in potato tuber, the separation, the population density, biodiversity and the antagonistic activity of endophytic bacteria, from the tuber peel of potato cultivars (Fontan90, Agria, Sante’a and Jeli89), were examined in the Fars province in Iran. In this study, the bacterial endophyte Colony Forming Units (CFU) were counted based on the most suitable dilution in petri dishes and expressed per g of wet weight of tuber tissue. The presence of bacteria was found mostly in the outer layer. A wide variety of endophyte species biodiversity was in Agria cultivar. To estimate the antagonistic effect of potato associated endophytic bacteria, 115 bacterial isolates were evaluated by dual culture method against main soil-borne potato pathogens Fusarium oxysporum, Rhizoctonia solani, Verticillium dahliae, Streptomyces scabies and Ralstonia solanacearum. Endophyte strains were identified based on physiological, morphological and chemical characteristics and the 16S rRNA gene sequence analysis. The highest degree of the inhibitory activity in all layers of potato cultivars was related to Bacillus subtilis, Bacillus mojavensis and Klebsiella variicola. Antagonistic activity of endophytic bacteria against the pathogens was significantly higher (p<0.01) in the examined strains from the outermost layer of tuber peel and decreased progressively toward the center of the tuber. In this research, Klebsiella variicola was reported as endophyte bacteria in the four commercial potato cultivars mentioned above, for the first time.

Parameterizing the AquaCrop model for potato growth modeling in a semi-arid region

The AquaCrop model was used to model potato growth in a hot semi-arid environment under diverse irrigation managements including water saving irrigation treatments in two growing seasons of 2012 and 2013. The potato cultivars were Agria and Ramos in 2012, and Agria and Sante in 2013. The irrigation treatments were full irrigation and different static and dynamic deficit irrigation managements. The model was calibrated with the data of the cultivar Agria under full irrigation and static deficit irrigation in 2013. Validation was performed using the data from the other potato cultivars and growing seasons, by keeping the conservative crop parameters adjusted in calibration and changing those non-conservative parameters referring to the crop development. Analysis showed that biomass simulation was highly affected by the normalized water productivity (WP*). Unlike the previous studies on modeling with AquaCrop that assumed only one WP* for the whole growing period, we found that it is required to calibrate one WP* for the first half of the growing season until flowering, and then recalibrated WP* for the late growing season. One single WP* assumed for the whole growing season could not simulate the declining potato growth at the late growing season satisfactory, when potatoes were subject to water stress and high air temperature (heat stress). The simulations of the calibrated model showed that the model could simulate total soil water content, volumetric soil water content, and tuber dry yield satisfactory. In addition, the model showed excellent performance in simulation of the total actual evapotranspiration and end-season water productivity. The AquaCrop model was good in simulating the in-season biomass, though it showed fair simulation of biomass in the late growing season. Overall, the performance of the AquaCrop model was reasonable and satisfactory, and the model is a reliable analytical tool for irrigation water management and proper decision making in potato production under variable water resources in the hot semi-arid areas. • AquaCrop has been used for modeling potato growth in a hot and semi-arid region. • AquaCrop had satisfactory performance in simulating soil water content and tuber dry yield. • AquaCrop had excellent performance in simulating end-season actual evapotranspiration and water productivity. • Two WP* values were assumed to differentiate the effects of water and heat stresses on different growing periods. • The calibrated WP* was assigned 13 and 10 g m −2 during the early and late growing season, respectively.

Compost tea as a sustainable alternative to promote plant growth and resistance against Rhizoctonia solani in potato plants

Compost teas (CTs) are organic extracts originated by mixing mature compost with tap water under controlled conditions. The application of these extracts could constitute a biostimulant and eco-friendly alternative for sustainable agriculture. Thus, this study was proposed to verify the contribution of different doses and Trichoderma-fortified green waste based-CT in plant susceptibility against Rhizoctonia solani infection, as well as in plant growth and tuber quality in two potato cultivars (Agria and Hermes) grown under greenhouse and field conditions. The results showed that CT-treated plants displayed a higher resistance to Rhizoctonia solani, being Hermes the most susceptible cultivar. Moreover, CT-treated plants showed an enhancement in yield, shoot number, tuber weight and tuber size, as well as an advance in potato sprouting, especially in those plants treated with the highest CT dose. A similar trend was observed in both cultivars. Furthermore, to confirm the effect of CT on sprouting, an additional study in the laboratory was carried out with Agria cultivar, in which it was observed that the advance in the crop cycle is induced by CT supply. Subsequently, the fried-quality parameters of tubers coming from potato plants grown under the different treatments in field conditions were studied. The addition of CT to potato plants reduced fried defects, total soluble solids in tubers, while increasing moisture content. However, both cultivars displayed several differences under control conditions, since Agria displayed high fried defects, as well as a reduction in total soluble solids and in the slice puncture test. Therefore, the application of CT is a dose-dependent effective approach to decrease R. solani attack, advance potato cycle and promote plant growth, as well as to obtain a better fried-quality tuber that is highly valued by the agri-food industries.

Investigation of the Effect of Sulfonated Silicon Nutrient Solution With Elemental Sulfur S-8 on Agronomic Traits of New Potato Cultivars

This objective of this study is to optimize the farm management for improving tuber yield per unit area and improving the quality of potato tubers, which can play an effective role in ensuring food security. One of the most important factors in improving the quantity and quality of the product is the proper application of agricultural inputs such as nutrition and nutrient solution. In this study, the effect of sulfonated silicon nutrient solution with S-8 elemental sulfur on new potato cultivars was investigated in Ardabil Potato Research Station during 2021. This study was performed based on factorial experimental design in three replications. The first factor includes the use of nutrient solution in four levels: (1) spraying with a dose of 3 liter nutrient solution in 1000 liters of water in tuberization start, tuberization and tubers bulking stages; (2) treating with 2 kg per 200 liters of water per hectare in first, third, fifth and seventh irrigation stages; (3) foliar spraying with a dose of 3 per thousand in tuberization start, tuberization and tubers bulking stages and use of 2 kg per 200 liters of water per hectare in the first, third, fifth and seventh stages of irrigation; and (4) control. The second factor included five potato cultivars (Agria, Marfona, Rosa, Rona and Takta). During the growth period, plant height, number of main stems per plant, tuber number and weight per plant and tuber yield were measured. The results indicated that Takta, Rona and Agria cultivars had the highest amount in terms of tuber yield, tuber number and weight per plant, plant height and water use efficiency in foliar sprayed with a dose of 3 per thousand and treated with 2 kg per 200 liters of water. In this study, the use of sulfonated silicon nutrient solution with elemental sulfur S-8 in two forms of foliar spraying at a rate of 3 per thousand and use of 2 kg of solution in 200 liters of water increased tuber yield and water use efficiency.

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.

The Effect of Pars Humic (Ammonium humate) on Reducing Damage Caused by Potato Virus Y in Cultivars Agria

The Effect of Pars Humic (Ammonium humate) on Reducing Damage Caused by Potato Virus Y in Cultivars Agria

Comparing inoculation methods for in vitro evaluation of resistance to blackleg disease in potato cultivars

To find the best inoculation method for evaluation of the resistance in potato genotypes against bacterial blackleg caused by Pectobacterium atrosepticum under in vitro conditions, five inoculation methods were compared. In vitro grown explants of five potato genotypes were inoculated with different inoculation methods, then placed on MS solid medium and incubated at 23?C with 70% relative humidity under the light regime of 16 hours a day. After the appearance of symptoms, the efficiency of inoculation methods was then recorded based on the severity of disease symptoms in potato genotypes: Farmosa, Agria, Picaso, Marfona and a wild potato genotype ?Solanum phureja'. Plantlets inoculated by piercing the crown with sterile toothpick inoculated in bacterial suspension of 108 cfu/ml showed the most severe symptoms. Based on all experiments, cultivar Marfona showed higher resistance among all cultivars and, cultivar Agria was the most susceptible. Finally, after witnessing the reactions of different varieties to inoculation methods and comparing them with previous evaluations of resistance in greenhouse conditions, the crown treatment employing sterile toothpick after infection in 108 cfu/ml bacterial suspension was selected and introduced as the best evaluation method of in vitro potato explants against blackleg.

Determining the most stable potato hybrid using AMMI yield stability analysis method

Genotype-environment interaction (GEI) is very important for breeders. It is considered a complicated issue in breeding programs to obtain stable and high-yielding genotypes to release new genotypes. This study was conducted to achieve a stable high-yielding genotype that is adaptive to climatic conditions of potato-producing regions in Iran. A total of 20 potato breeding lines along with five commercial varieties (Savalan, Agria, Caesar, Luta and Satina) were evaluated in a randomized complete block design with three replicates in the Agricultural Research and Natural Resources Stations of five location (Ardabil, Razavi Khorasan, Karaj, Isfahan and Hamadan) in Iran, for two years (2016 and 2017). Combined ANOVA of yield data for studied genotypes and environments indicates significant differences among potato genotypes, environments, and GE interaction was significant. Thus, the AMMI method and its parameters were used to analyze yield stability. The results indicated that only four interaction principal components were significant (P<0.01), which accounted for 81.2% of the GEI sum of squares. Based on type 1 parameters (SIPC1, FA1, Za1, Dz1, EV1, and Da1), genotypes G7, G10, G14, G20 and G24 were identified as to be stable. Moreover, according to the results of type 2, 3 and 4 parameters, genotypes G2, G6, G7, G14, G15 and G20, as well as cultivars Agria (G24) and Luta (G23), were found to be stable. Genotypes G6, G7, G14, G15, G20, and G24 were stable according to the ASV parameter, and genotypes G6 and G7 were stable based on the MASV parameter. Amongst the stable genotypes identified by the AMMI parameters, while genotype G6 was high-yielding, G14 and G24 (Agria) were moderate-yielding.

Effects of highly concentrated KCl foliar spray for managing the occurrence of the internal brown spot, a physiological disorder of potato tubers

ABSTRACT Potato (Solanum tuberosum L.) under Mediterranean climate may be affected by internal brown spot, non-pathogenic disorder of flesh tissues leading to a dramatic depreciation of tubers. Its aetiology is still clarifying; however, some abiotic stressors, such as the high temperatures, heat and drought are noticed as crucial factors exacerbating the physiological decline. With the aim of escaping the potato growth stages most prone to the physiopathy, shortening cropping cycle by KCl-induced potato canopy desiccation was experimented on two field trials. Experimental field treatments were two consecutive KCl foliar applications, respectively at thirty and twenty days before harvesting, at 113 and 75 g L−1, that were compared to the water-sprayed control. Salt solution spraying injured above-ground parts ending potato’s growth early reducing incidence of tuber internal browning, on average, between 30% and 50% at low and high KCl concentration, respectively. The non-sensitive cultivar Agria proved the most productive, whereas Ricciona di Napoli resulted strongly defected by the physiopathy. Under low-irrigation regime, IBS occurrence was reduced of about 39%. The reduction of the transpiration flow and growth cycle likely decreased internal brown spot under KCl vine desiccation, as well as the role of KCl on tuber ripening dynamics cannot be overlooked.

Effect of Phosphate Fertilizer Type and Nitrogen Application Method on Tuber Yield and Growth Indices of Three Potato (Solanum tuberosum L.) Cultivars

Nitrogen and phosphorus are essential nutrients in growth of plants. In addition, the type and method of fertilizer application play an important role in the efficient absorption of nutrients and reduce fertilizer use. Therefore, an experiment was conducted in a randomized complete block design with three replications in the Bahar city in 2017: phosphorus fertilizer was three levels (no application, triple superphosphate and diammonium phosphate), nitrogen fertilizer with two levels (placement and no-placement) and potato cultivar with three levels (Agria, Banba and Sante). The highest leaf area index (5.27), crop growth rate (13.22 g.m-2) and total dry matter (582.86 g.m-2) were obtained from diammonium phosphate along with nitrogen placement in by using Agria cultivar. The results also showed that under conditions phosphorus deficiency, nitrogen application method did not affect leaf area index, crop growth rate and total dry matter: However, tuber yield of Agria under phosphorus deficiency increased by nitrogen placement treatment. In this study, the use of diammonium phosphate, compared to triple superphosphate, increased leaf area index, crop growth rate, relative growth rate and total dry matter. The effect of nitrogen placement along with triple superphosphate was higher than that of nitrogen with diammonium phosphate. Chlorophyll index was not affected by nitrogen placement when using diammonium phosphate, whereas, nitrogen placement increased chlorophyll index by 6.5% with triple superphosphate. The results also showed that the tuber yield increased by 25.4% when nitrogen used by placement combined with triple superphosphate fertilizer. As a whole, highest tuber yields of all three cultivars, especially in Agria and Banba, were increased under nitrogen placement treatment along with diammonium phosphate.

EFFECT OF SALINITY ON PHOTOSYNTHETIC AND ENZYMATIC ACTIVITIES AND TUBERIZATION YIELD IN THE GENOTYPE OF POTATO CULTIVAR AGRIA UNDER IN VITRO CONDITIONS

The aim of this study aimed to investigate the effect of salinity levels on physiological and biochemical properties and tuberization yield of potato, cultivar Agria, in MS culture medium. After preparation and cultivation of tuber, the lateral aerial buds were removed after a few months and cultured in MS medium. After that, healthy samples were prepared and induced at the above-mentioned salinity stress level and transferred to the culture medium. Two weeks later, an air sample was taken, and the physiological and biochemical properties studied in this study (photosynthetic pigments, proline, soluble sugars, anthocyanins, phenolic compounds, and the activity of some antioxidant enzymes) were measured. Finally, salinity stress assessment was evaluated and studied in a fluid environment. The effects of stress on different stages of seedling growth in vitro conditions and the activity of photosynthetic and enzymatic pigments were investigated using spectrophotometric measurements and in accordance with their protocols. Data analysis of variance showed that salinity reduces photosynthetic pigments and salinity to a concentration of 50 mM, it is resistant to the addition of compounds such as soluble sugars, proline and antioxidant activity but at higher concentrations (75 and 100 mM), the plant is likely to be severely damaged due to excessive growth in active oxygen species. Therefore, due to the increase in antioxidant activity, it indicates an increase in the removal of active oxygen species, this feature is often used as an indicator to increase salinity tolerance. Research on the different ecological conditions in Iran, research is needed on other potato cultivars and molecular studies.

Chlorogenic acid content in potato tubers with colored flesh as affected by a genotype, location and long-term storage

In three-year field experiments, the effect of genotype, flesh color, site conditions and storage on chlorogenic acid content (CAC) in tubers of potato cultivars with purple or red flesh was compared to yellow-fleshed cv. Agria. The results confirmed the significant effect of genotype on CAC. The highest CAC was characteristic on a three-year mean for the purple-fleshed cv. Vitelotte (769.5 mg/kg fresh weight (FW)), i.e. 1.19−2.6 times higher than in the other cultivars. In regard to the effect of flesh color, significantly higher mean CAC levels have been shown for the red-fleshed (2.8 times) and purple-fleshed (3.16 times) cultivars in comparison with cv. Agria (148 mg/kg FW). At the Uhříněves location with a warmer climate and frequent dry periods as compared to the second Valečov location, a higher CAC (1.18 times) was found. Cold storage (4°C, 6 months) resulted in a significant CAC increase varying from 33.2% in the Blaue St. Galler cultivar to 210.6% in the Vitelotte cultivar among all eight evaluated color-fleshed cultivars. On the other hand, the effect of storage on CAC was not evident in the yellow-fleshed Agria cultivar (inconclusive difference against CAC after harvest).

Uticaj sorte i porekla biljaka na proizvodnju bezvirusnih mini krtola krompira u aeroponik sistemu gajenja

The effects of variety and origin of planting material were examined in the aeroponic growing system. The potato cultivars 'Cleopatra', 'Kennebec' and 'Agria' were used for the experimental purposes, originating both in vitro and from minitubers of the previous season's crops. Plants originating from minitubers were found to be simpler and cheaper to prepare for the aeroponic system of cultivation compared to plants obtained in vitro. The first harvest of the 'Cleopatra' minitubers began 43 days after planting in aeroponics, whereas the harvest of the 'Kennebec' and 'Agria' minitubers occurred 20 days later. The 'Cleopatra' cultivar yielded an average of 14.37 minitubers, followed by the 'Kennebec' cultivar and Agria cultivar with 16.91 and 19.43 minitubers on average, respectively. In the 'Cleopatra' and 'Kennebec' cultivars, the plant of the in vitro origin had a significantly larger number of tubers per plant than the plants originating from previous vegetation minitubers. In the 'Agria' cultivar, the in vitro created plants had a larger number of minitubers. The average mass of minitubers of all the cultivars under consideration was significantly higher in the plants originating from minitubers. A successive harvest of minitubers allows them to reach the desired size with dominant minitubers weighing over 8 g, which are considered large.

Parametrization of Cropsyst model for the simulation of a potato crop in a Mediterranean environment

Data from a two-year field experiment were used to calibrate (2011) and validate (2012) the parameters required by the CropSyst model for simulating the growth of a potato crop (Agria cultivar) in a semiarid area of Spain. The primary variables analysed during the parameterization model were leaf area index, canopy cover, total dry matter, total biomass at harvest, soil moisture balance, and evapotranspiration, being the potato crop subjected to four irrigation treatments (120%, 100%, 80%, and 60% of the crop water requirements “CWR”) under a center pivot system. The results showed that the CropSyst model attained a suitable goodness of fit with regards to the simulated and observed values (Willmott’s index close to 1 and errors around ±10%). Although the model includes a reduction coefficient for taking into account the effect of both water and temperature stress on the reference harvest index, yields at harvest were not properly simulated by the model. According to the results, the calibrated and validated CropSyst model showed that the 100% and the 80% CWR treatments are the most interesting ones for the farmers in the study area (both reached a suitable rate between high yield and high efficiency in the use of water).

In vitro propagation, microtuberization, and molecular characterization of three potato cultivars

Sprouts of potato tubers were excised from the three potato cultivars Agria, Hermes, and Spunta, sterilized and subjected to shoot formation and propagation on Murashige and Skoog (MS) medium supplemented with 1 mg dm-3 6-benzylaminopurine (BAP) + 0.5 mg dm-3 gibberellic acid. Shoots were rooted on MS medium supplemented with 1 mg dm-3 indole-3-butyric acid. To increase shoot vigour prior tuber formation, shoots were subcultured on MS medium supplemented with 0.56 mg dm-3 BAP, 0.11 mg dm-3 2,4-dichlorophenoxyacetic acid, and 0.96 mg dm-3 naphthaleneacetic acid. Under dark, microtuberization on MS media supplemented with 4 mg dm-3 of both BAP and kinetin was better than 4 mg dm-3 BAP alone, where they induced higher number of microtubers per shoot and/or the percentage of shoots that formed microtubers. The highest frequency of microtuber formation was achieved when sucrose at high concentration (8 %) was used as carbon source in culture media. Glucose ranked at the second position whereas fructose reduced the microtuber formation frequency when it was used alone or in combination with glucose. Under the applied culture conditions, cvs. Agria and Hermes showed better micropropagation and microtuberization in comparison to cv. Spunta. In addition, isozyme and RAPD techniques revealed that Agria and Hermes are closer to each other when compared with the third cultivar.

Effect of RNAi-mediated gene silencing of starch phosphorylase L and starch-associated R1 on cold-induced sweetening in potato

ABSTRACTTo decrease the accumulation of reducing and non-reducing sugars in potato tubers stored at low temperature, a multiple gene-silencing vector pBIPhLSAR1-IR possessing a part of starch phosphorylase L and starch-associated R1 genes was constructed and transformed into potato (Solanum tuberosum L.) cultivars Agria and Marfona. Polymerase chain reaction (PCR) and southern blotting indicated that the RNAi construct was transformed successfully into the genome. Real-time reverse transcription PCR (RT-PCR) analysis showed that the expression level of starch phosphorylase L and starch-associated R1 genes was reduced in transgenic microtubers in relation to the non-transgenic plants. The accumulation of total and reducing sugars in transgenic microtubers was significantly decreased (up to 58% in line AM6) compared to the control. Repression of these genes decreased the phosphate content of starch and increased starch content in transgenic microtubers, implying that silencing of starch phosphorylase L and starch-associated R1 genes reduced starch breakdown during cold storage conditions.

A First Approach of Using Ultrasound as an Alternative for Blanching in Vacuum-Packaged Potato Strips

The effect of ultrasound (US) (40 kHz, 200 W, 3 min), blanching (85 °C, 3.5 min), and the combination of both methods was evaluated on the quality of vacuum-packaged potato strips stored at 3 ± 1 °C for up to 10 days. For this study, two cultivars of potatoes were assessed. For blanched Agata samples, the lightness (L*) decreased over 12 % (p < 0.05). Moreover, their hue increased up to 100, obtaining lesser yellow potato strips. In contrast, US did not affect the hue values. The losses of firmness of blanched potato strips were notable (35 % for Agata and 51 % for Agria), whereas US did not change this property (p < 0.05). Nevertheless, no significant differences were found in the total starch content at 10 days. Agata and Agria showed different metabolic behaviors of sucrose in the refrigerated storage. Therefore, Agria cultivar retained better color after frying. These results suggest that US had less impact on color and improve the firmness in vacuum-packaged potato strips with no added chemicals.

Evaluation of Aquacrop model for a potato crop under different irrigation conditions

The processes of calibration and validation of the Aquacrop model for the simulation of the growth and development of a potato crop (Agria cultivar) that was irrigated with a center pivot system are described in this study. The field experiments were conducted during 2011 (calibration) and 2012 (validation) in a semiarid region in southeastern Spain. The potatoes were irrigated with four treatments (120%, 100%, 80%, and 60% of the water requirement). The Aquacrop model was suitable for the simulation of the growth and development of potatoes in the climatic conditions of the study area. The canopy cover, total dry matter, dry matter of tubers and evapotranspiration were the primary variables analyzed. An acceptable goodness of fit was found between observed and simulated values. So, statistical indicators such as the Willmott index of agreement (d) and the coefficient of determination (R2) showed good values (d and R2>0.90) for the primary variables analyzed. Both the model and the observed data found that 80% and 60% of the water requirements were the treatments that were most efficient in the use of water. A high temperature stress coefficient affecting the harvest index is recommended to be incorporated in the model for avoiding overestimations of yield.

Influence of the frying process and potato cultivar on acrylamide formation in French fries

Acrylamide formation during the production of French fries is attributed to Maillard reactions from reducing sugars and asparagine and is dependent on the frying temperature. Low reducing sugars content in potatoes has been recommended to produce fried potato products. However, the influence of the complexity of the potato medium in the chemical reactions that promote the acrylamide formation during deep frying are not well understood. In this study, three potato cultivars (Kennebec, Red Pontiac and Agria) commonly used for fried potato products were evaluated to determine the relationships between the precursors of acrylamide in the fresh potato tubers and the properties of the fried potato strips with the acrylamide content after frying. Frying experiments were conducted at three conditions (time-temperature) to obtain French fries of similar visual colour. Acrylamide formation increased with frying temperature but different behaviour was observed between cultivars. For Red Pontiac, a remarkably increase in acrylamide content was found at 170 °C (∼40%) together with the increase in colour. However, lower oil uptake and higher moisture content was obtained as temperature increase. Significant positive correlations were observed between the acrylamide level and the reducing sugars and sucrose content on fresh potatoes (0.652, 0.699, p ≤ 0.01, respectively). The acrylamide content obtained in Agria cultivar may be obtained from the hydrolysis of sucrose during the frying process. In fried potato strips, positive significant correlation was found between the shear force and acrylamide (0.749, p ≤ 0.01). The significant correlations obtained between colour, and texture, colour and oil uptake and texture and acrylamide content indicate the intrinsic relationship between the properties of the fried potato strips and the acrylamide content.