Respon dua genotip kentang (Solanum tuberosum L.) dengan pemberian tiga sumber pupuk nitrogen di dataran medium

This study aimed to evaluate the growth and yield of two potato genotypes (S) due to three sources of nitrogen (G) fertilizer on medium plains. The study was arranged in a two-factor, randomized block design factorial and was repeated three times. The first factor is the source of N fertilizer, consisting of three levels: S1 = ZA ((NH4)2SO4), S2 = urea (CO(NH2)2), and S3 = ammonium nitrate (NH4NO3). The second factor was potato genotype, consisting of two levels G1 = MS 13 genotype and G2 = At 4 genotype. The data obtained were analyzed by F test at 5% level (ANOVA) to determine the effect of treatment and further LSD test was carried out to determine differences between treatments, and multiple regression analysis to determine the most influential factors on potato tuber starch content. The results showed that the highest starch content was obtained by the At 4 genotype of 18,50% and was suitable for medium plains. While the starch content of the MS 13 genotype was 17,53%. For fertilizing nitrogen sources, it is recommended to use ammonium nitrate, because it obtains the highest yield of 27,30 tons ha-1 from other nitrogen fertilizer sources.

Impact of gamma irradiation pretreatment on biochemical and molecular responses of potato growing under salt stress

Background Previous literatures revealed that gamma rays have an increasing effect on salt tolerance in different plants. In vitro experiment was conducted to study the effect of gamma rays (20 Gray) on salt tolerance of four potato cultivars (Lady Rosetta, Diamante, Gold, and Santana). Results Gamma-treated Santana plantlets were more tolerant to salinity as compared to other cultivars. It showed a significant increment of fresh weight (250% over the untreated). Gamma-treated plantlets of Lady Rosetta, Diamante, and Gold showed higher activity of peroxidase (POD) and polyphenol oxidase (PPO). Isoenzymes analysis showed an absence of POD 3, 4, and 5 in Gold plantlets. The dye of most PODs and PPOs bands were denser (more active) in gamma-treated plantlets of Santana as compared to other cultivars. Both gamma-treated and untreated plantlets showed the absence of PPO1 in Lady Rosetta and Diamante, and PPO 3, 4, and 5 in Gold plantlets. Genetic marker analysis using ISSR with six different primers showed obvious unique negative and positive bands with different base pairs in mutant plantlets as compared to the control, according to primer sequence and potato genotype. The 14A primer was an efficient genetic marker between mutated and unmutated potato genotypes. Santana had a unique fingerprint in the 1430-pb site, which can be a selectable marker for the cultivar. An increment in genetic distance between Gold cultivar and others proved that the mutation was induced because of gamma rays. Conclusion We assume that irradiation of potato callus by 20-Gy gamma rays is an effective process for inducing salt resistance. However, this finding should be verified under field conditions. Graphic Abstract

Potato Root-Associated Microbiomes Adapt to Combined Water and Nutrient Limitation and have a Plant Genotype-Specific Role for Plant Stress Mitigation

Background Due to climate change and reduced use of fertilizers combined stress scenarios are becoming increasingly frequent in crop production. In a field experiment we tested the effect of combined water and phosphorus limitation on the growth performance and plant traits of eight tetraploid and two diploid potato varieties as well as on root-associated microbiome diversity and functional potential. Microbiome and metagenome analysis targeted the diversity and potential functions of prokaryotes, fungi, plasmids and bacteriophages and was linked to plant traits like tuber yield or timing of canopy closure. Results The different potato genotypes responded differently to the combined stress and hosted distinct microbiota in the rhizosphere and the root endosphere. Proximity to the root, stress and potato genotype had significant effects on bacteria, whereas fungi were only mildly affected. To address the involvement of microbial functions, we investigated well and poorly performing potato genotypes (Stirling and Desirée, respectively) under stress conditions and executed a metagenome analysis of rhizosphere microbiomes subjected to stress and no stress conditions. Functions like ROS detoxification, aromatic amino acid and terpene metabolism were enriched and in synchrony with the metabolism of stressed plants. In Desirée, Pseudonocardiales had the genetic potential to take up assimilates produced in the fast-growing canopy and to reduce plant stress-sensing by degrading ethylene but overall yield losses were high. In Stirling, Xanthomonadales had the genetic potential to reduce oxidative stress and to produce biofilms, potentially around roots. Biofilm formation could be involved in drought resilience of Stirling and explain the recorded low yield losses. In the stressed rhizosphere the relative abundance of plasmids was reduced and the diversity of phages was enriched. Moreover, mobile elements like plasmids and phages were affected by combined stresses in a genotype-specific manner. Conclusion Our study gives new insights into the interconnectedness of root-associated microbiota and plant stress responses in the field. Functional genes in the metagenome, phylogenetic composition and mobile elements play a role in potato-stress adaption. In a poor and a well performing potato genotype grown under stressed conditions, distinct functional genes pinpoint to a distinct stress sensing, water availability and compounds in the rhizospheres.

Potential of Use of Potato Genotypes by the Industry

Aims: Evaluate four potato genotypes in terms of sprouting and coloring depending on the storage time at 8 °C and their potential for use by the potato processing industry.Study Design: The experiment was carried out in a completely randomized design, in a split-plot scheme with five replications, each replication consisting of two tubers.Place and Duration of Study: Tubers were obtained from the production area of Perdizes, Minas Gerais, Brazil (Latitude 19º 21’ 10’’ N and Longitude 47º 17’ 34’’ E and 1000 m).Methodology: The genotypes Alibaba, Arsenal, Antartica and Babylon were stored at 8° C for up to 180 days, with the analysis of sprouting, visual coloration before and after frying, parameters L*, b* and c*. Results: All potato genotypes were light colored before frying, category 1 (USDA). Babylon obtained the best parameters of b * and c *. Antartica and Babylon potato genotype showed low sprouting.Conclusion: The Arsenal and Antartica potato genotype have potential for use by the processing industry due to the color of the sticks before and after frying and low sprouting.The Alibaba potato genotype was darkly colored after frying. Babylon was the potato genotype with the best color of the sticks after frying and less germination.

Transcriptome analysis reveals that exogenous ethylene activates immune and defense responses in a high late blight resistant potato genotype

Ethylene (ET) is one of the many important signaling hormones that functions in regulating defense responses in plants. Gene expression profiling was conducted under exogenous ET application in the high late blight resistant potato genotype SD20 and the specific transcriptional responses to exogenous ET in SD20 were revealed. Analysis of differentially expressed genes (DEGs) generated a total of 1226 ET-specific DEGs, among which transcription factors, kinases, defense enzymes and disease resistance-related genes were significantly differentially expressed. GO enrichment and KEGG metabolic pathway analysis also revealed that numerous defense regulation-related genes and defense pathways were significantly enriched. These results were consistent with the interaction of SD20 and Phytophthora infestans in our previous study, indicating that exogenous ET stimulated the defense response and initiated a similar defense pathway compared to pathogen infection in SD20. Moreover, multiple signaling pathways including ET, salicylic acid, jasmonic acid, abscisic acid, auxin, cytokinin and gibberellin were involved in the response to exogenous ET, which indicates that many plant hormones work together to form a complex network to resist external stimuli in SD20. ET-induced gene expression profiling provides insights into the ET signaling transduction pathway and its potential mechanisms in disease defense systems in potato.

Physiological and molecular changes to short and prolonged heat in highlands China potato genotype

The authors have requested that this preprint be withdrawn due to author disagreement.

Transcriptome Profiling Reveals Effects of Drought Stress on Gene Expression in Diploid Potato Genotype P3-198

Potato (Solanum tuberosum L.) is one of the three most important food crops worldwide; however, it is strongly affected by drought stress. The precise molecular mechanisms of drought stress response in potato are not very well understood. The diploid potato genotype P3-198 has been verified to be highly resistant to drought stress. Here, a time-course experiment was performed to identify drought resistance response genes in P3-198 under polyethylene glycol (PEG)-induced stress using RNA-sequencing. A total of 1665 differentially expressed genes (DEGs) were specifically identified, and based on gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the transcription factor activity, protein kinase activity, and the plant hormone signal transduction process were significantly enriched. Annotation revealed that these DEGs mainly encode transcription factors, protein kinases, and proteins related to redox regulation, carbohydrate metabolism, and osmotic adjustment. In particular, genes encoding abscisic acid (ABA)-dependent signaling molecules were significantly differentially expressed, which revealed the important roles of the ABA-dependent signaling pathway in the early response of P3-198 to drought stress. Quantitative real-time PCR experimental verification confirmed the differential expression of genes in the drought resistance signaling pathway. Our results provide valuable information for understanding potato drought-resistance mechanisms, and also enrich the gene resources available for drought-resistant potato breeding.

Interference of Weeds in Sweet Potato Genotype Growth (Ipomoea batatas (L.) Lam.)

The experiment was carried out in the Experimental Area of ​​the Plant Genetic Improvement Sector of the Agricultural Sciences Center of the Federal University of Alagoas (SMGP-CECA-UFAL), in the year 2013, where periods of control and weed coexistence of sweet potatoes were evaluated. The experimental design was carried out in randomized blocks in the 3 x 14 factorial scheme with three replications, with three sweet potato genotypes in 14 periods of interference, and distributed in seven control periods (0, 10, 20, 30, 40, 50 and 60 days after planting - DAP), from which the weeds were controlled, and seven coexistence periods, from which the weeds coexisted with the crop. The evaluations consisted of sweet potato genotype shoot samplings at 30, 60, 90, and 120 days after planting (DAP), using one working area plant per plot in each evaluation stage. In the determination of the leaf area, a mechanical integrator was used, and to obtain the shoot dry mass, the material was taken to a forced air circulation oven at 65 ºC for 72 h, with subsequent weighing. According to the results, it can be observed that, in the coexisting treatments, there was a significant reduction in the shoot growth rates, in comparison to the treatments in which the weeds were controlled, especially the reduction of the leaf area at 120 DAP, where clone 6 and Sergipana showed a reduction of 89.0% and 88.0%, respectively. As for Clone 14, this reduction occurred at 90 DAP, at about 52.0%, which was less expressive, whereas in relation to the shoot dry mass, clones 6, 14, and the Sergipana variety showed a reduction at 120 DAP of 86%, 51%, and 46%, respectively.