Temperature Effects on Tuber Production and Carbohydrates Partitioning in Different Cultivars During Consecutive Stages of Potato (Solanum tuberosum L.) Growth

The main objective of this study was to assess responses of mid-early (Spunta) and mid-late (Bellini) potato cultivars to different temperature regimes during subsequent stages of potato growth. The impact of high temperature (25/22°C day/night), low temperature (18/16°C day/night) and intermediate temperature (20/18°C day/night) was evaluated for different growth stages. Data were obtained for photosynthesis, carbohydrates in leaves, stems and tubers as well as production parameters. Enzyme activities were determined for sucrose-phosphate synthase in leaves, acid invertase in stems and acid and neutral invertases in tubers. Gene expression levels of relevant sugar metabolizing enzymes was quantified.A detailed correlation analysis revealed a strong impact of the expression level of sugar metabolizing enzymes in leaves on the final number of tubers per plant.Whereas total tuber yield increases with temperature, the number of tubers per plant was highest under low temperature conditions. Our data suggest an important role of the temperature on the length of the different growth stages.

Potato (Solanum tuberosum L.) Growth in Response to Foliar Silicon Application

As silicon induces abiotic stress tolerance in crop plants, it was hypothesized that foliar silicon application could improve potato growth in an early crop culture. The effect of dosage (0.25 dm3∙ha–1 or 0.50 dm3∙ha–1) and time (the leaf development stage, BBCH 14–16, tuber initiation stage, BBCH 40–41, or both the leaf development stage and tuber initiation stage) of application of the silicon-based biostimulant Optysil (200 g SiO2 and 24 g Fe in 1 dm3) on potato growth was investigated. Optysil caused an increase in plant height and above-ground plant biomass, enlarged leaf area and decreased leaf weight ratio (LWR), and, as a result, increased tuber number and tuber weight per plant. The effect of Optysil depended on a water deficit during potato growth. The average tuber weight per plant in the cultivation treated with Optysil was higher by 23% under periodic water deficits during potato growth, and by 13% under drought conditions, than in the cultivation without the biostimulant. Dosage of Optysil had a significant effect on above-ground plant biomass and leaf area in the warm and arid growing season. Under drought stress, Optysil at 0.50 dm3∙ha–1 stimulated potato growth more than at 0.25 dm3∙ha–1. Under periodic water deficits during potato growth, the time of Optysil application affected potato growth more than the biostimulant dosage. The plants produced greater above-ground biomass and had a larger leaf area with two Optysil applications; one in the initial plant growth period (BBCH 14–16), and a repeated treatment in the tuber initiation stage (BBCH 40–41). The tuber weight per plant was positively correlated with the plant height, above-ground plant biomass, leaf area, and LWR.

Temporal and spatial variation characteristics of soil mechanical composition after aeolian soil improvement by soft rock in Mu Us sandy land

Based on the field experiment of compound soil with volume mixing ratio of soft rock and sand of 1 : 1, 1 : 2, 1 : 5 from 2010 to 2018, the spatio-temporal characteristics and development trend of the mechanical composition of the compound soil with different proportions were studied. The driving factors of the good development of potato growth-compound soil mechanical composition were also explored. Results showed that there was a significant positive correlation between silt-clay mass fraction and cultivation years, the annual variation rates of silt-clay mass fraction were 3.02, 3.90 and 4.11% in 1 : 1, 1 : 2, and 1 : 5 of compound soil. At the initial stage of mixing, clay and silt contents of the compound soil in different proportions were 1 : 1 > 1 : 2 > 1 : 5, and 9 years after planting, clay and silt contents were 1 : 5 > 1 : 2 > 1 : 1, potato growth promoted the development of 1 : 5 compound soil mechanical composition more significantly. The downward migration of silt and clay content in the 0-30 cm surface soil made a relatively dense argic horizon in the 30-40 cm soil layer, which effectively prevented water and fertilizer downward movement and the migration of fine particles in the surface soil. After years of planting, the thickness of the sandy land plow layer has increased to 45 cm, and the three-proportion compound soil mechanical composition developed to a good condition suitable for crop growth, and did not need to be compounded again after many years. Bangladesh J. Bot. 50(3): 865-872, 2021 (September) Special

Rhizosphere Microbiomes of Potato Cultivated under Bacillus subtilis Treatment Influence the Quality of Potato Tubers

Plants serve as a niche for the growth and proliferation of a diversity of microorganisms. Soil microorganisms, which closely interact with plants, are increasingly being recognized as factors important to plant health. In this study, we explored the use of high-throughput DNA sequencing of the fungal ITS and bacterial 16S for characterization of the fungal and bacterial microbiomes following biocontrol treatment (DT) with Bacillus subtilis strain Bv17 relative to treatments without biocontrol (DC) during the potato growth cycle at three time points. A total of 5631 operational taxonomic units (OTUs) were identified from the 16S data, and 2236 OTUs were identified from the ITS data. The number of bacterial and fungal OTU in DT was higher than in DC and gradually increased during potato growth. In addition, indices such as Ace, Chao, Shannon, and Simpson were higher in DT than in DC, indicating greater richness and community diversity in soil following the biocontrol treatment. Additionally, the potato tuber yields improved without a measurable change in the bacterial communities following the B. subtilis strain Bv17 treatment. These results suggest that soil microbial communities in the rhizosphere are differentially affected by the biocontrol treatment while improving potato yield, providing a strong basis for biocontrol utilization in crop production.

Differential growth and yield responses of local potato cultivars from basic seed tubers

ABSTRACT Potato quality of seed tubers is a determinant factor that allows obtaining high yields, and its use must be a priority for a country or a producing region. Lack of information about how local cultivars perform differentially according to the environment has been identified in order to support potential seeds production programs. The research was carried out in 2018 at the Obonuco Research Center of Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), with the aim of analyzing the growth and yield of basic tuber seeds of five potato (Solanum tuberosum spp. andigena) cultivars. 1,080 seed tubers from each cultivar (treatments) were planted in a completely randomized block design and three replications. Mean comparison Tukey-Kramer (p≤0.05) test was performed for the yield analysis. From emergency to final harvest, destructive sampling was carried out every fifteen days in order to calculate dry matter and leaf area and establish growth models based on the accumulated degree-days (DD). The yield and proportion of seed tubers per plant were determined according to local resolution for seed certification in Colombia. Growth variables fitted better with the Hoerl, Gaussian, and third-degree polynomial models. The leaf area index of the potato cultivars reached the maximum value at 876 DD, with values ranging from 2.91 to 6.11 DD. The highest yield per plant was obtained by the Ica Única cultivar (2.73 kg plant-1). However, this cultivar showed the lowest percentage of seed tubers, with 50.59% compared to the others, which ranged between 80.82 and 87.40%. Differential potato growth responses through models based on the DD would explain the differences in final yield and seeds tuber production.

Potato growth, photosynthesis, yield, and quality response to regulated deficit drip irrigation under film mulching in a cold and arid environment

The effects of the amount and timing of regulated deficit drip irrigation under plastic film on potato (‘Qingshu 168’) growth, photosynthesis, yield, water use efficiency, and quality were examined from 2017 to 2019 in cold and arid northwestern China. In the four stages of potato growth (seedling, tuber initiation, tuber bulking, starch accumulation), eight treatments were designed, with a mild deficit was in treatments WD1 (seedling), WD2 (tuber initiation), WD3 (tuber bulking), and WD4 (starch accumulation); and a moderate deficit in WD5 (seedling), WD6 (tuber initiation), WD7 (tuber bulking), and WD8 (starch accumulation). The net photosynthetic rate, stomatal conductance, and transpiration rate decreased significantly under water deficit in the tuber formation and starch accumulation stages. Although water deficit reduced potato yields, a mild deficit in the seedling stage resulted in the highest yield and water use efficiency at 43,961.91 kg ha−1 and 8.67 kg m−3, respectively. The highest overall quality was in potatoes subjected to mild and moderate water deficit in the seedling stage. Principal component analysis identified mild water stress in the seedling stage as the optimum regulated deficit irrigation regime. The results of this study provide theoretical and technical references for efficient water-saving cultivation and industrialization of potato in northwestern China.

Phytohormones: plant switchers in developmental and growth stages in potato

Background Potato is one of the most important food crops worldwide, contributing key nutrients to the human diet. Plant hormones act as vital switchers in the regulation of various aspects of developmental and growth stages in potato. Due to the broad impacts of hormones on many developmental processes, their role in potato growth and developmental stages has been investigated. Main body of the abstract This review presents a description of hormonal basic pathways, various interconnections between hormonal network and reciprocal relationships, and clarification of molecular events underlying potato growth. In the last decade, new findings have emerged regarding their function during sprout development, vegetative growth, tuber initiation, tuber development, and maturation in potato. Hormones can control the regulation of various aspects of growth and development in potato, either individually or in combination with other hormones. The molecular characterization of interplay between cytokinins (CKs), abscisic acid (ABA), and auxin and/or gibberellins (GAs) during tuber formation requires further undertaking. Recently, new evidences regarding the relative functions of hormones during various stages and an intricate network of several hormones controlling potato tuber formation are emerging. Although some aspects of their functions are widely covered, remarkable breaks in our knowledge and insights yet exist in the regulation of hormonal networks and their interactions during different stages of growth and various aspects of tuber formation. Short conclusion The present review focuses on the relative roles of hormones during various developmental stages with a view to recognize their mechanisms of function in potato tuber development. For better insight, relevant evidences available on hormonal interaction during tuber development in other species are also described. We predict that the present review highlights some of the conceptual developments in the interplay of hormones and their associated downstream events influencing tuber formation.