Plant growth regulators and electric current break tuber dormancy by modulating antioxidant activities of potato (original) (raw)
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Regulation of potato tuber dormancy: A review
Australian Journal of Crop Science
Dormancy is one aspect of tuber physiological age that begins with potato tuber initiation. During dormancy, biochemical and physiological processes do occur but they do not trigger immediate morphological changes, yet these processes are relevant for the number of sprouts produced after breaking of the dormancy and for the growth vigour of the seed tuber. This review article reports that dormancy is a complex process that depends on genetic background, stage of tuber development, environmental and management conditions during tuber growth and storage. Temperature, water supply, soil fertility and the photoperiod during plant growth are important environmental factors that regulate the sprouting behaviour. Storage temperature and gas composition regulate dormancy breaking. Endogenous as well as exogenous phytohormones are also important. When seed tubers are needed before natural sprouting occurs, it may be necessary to break the dormancy using chemical agents.
Physiological mechanisms for potato dormancy release and sprouting: A review
2014
Potato (Solanum tuberosum L.) tubers undergo a period of dormancy, during which visible bud growth is inhibited. The length of the dormancy is determined by environmental, physiological and hormonal control mechanisms. Dormancy is the final stage of tuber life, which serves to preserve tubers as organs of vegetative reproduction under unfavourable growth conditions. Since the duration of potato tuber dormancy and sprouting time bear significant economic importance, this review considers the regulation of dormancy and sprouting of potato by phytohormones and reactive oxygen species. Two phytohormones, ABA and ethylene suppress tuber sprouting; however, the exact role of ethylene remains to be elucidated. Cytokinins and gibberellins are required for bud breaking and sprout growth, respectively. The auxin seems to play a role in vascular development. Thus, tuber dormancy and sprouting can be controlled in potato by manipulation of Reactive Oxygen Species (ROS), especially H2O2 metabol...
2017
Potato is grown under, subtropical, tropical and temperate conditions. It is essentially a cool weather crop, with temperature being the important limiting factor for production. Tuber growth is sharply inhibited at temperatures below 10°C and above 30°C while optimum yields are obtained where means daily temperatures are in the range of 18°C to 20°C. More than 90% of Indian potato production is done during cold weather season and quite a significant portion (45-50%) is stored and consumed over entire year. For that reason, potato is planted in early spring in temperate zones and late winter in warmer regions, and grown during coolest months of the year in hot tropical climates. In some sub-tropical highlands, mild temperatures and high solar radiation allow farmers to grow potatoes throughout the year, and harvest tubers within 90 days of sowing. In recent years rapid multiplication of disease-free clones using micro-propagation along with conventional multiplication methods has no...
Pakistan Journal of Botany, 2017
Photoperiod is one of the environmental factors which affect the tuberization of potatoes. In order to determine the effects of photoperiod on tuberization of two potato cultivars, the effects of long (14 hours) and short (8 hours) days on the growth and production of mini-tubers in two potato cultivars (Agria and Savalan) were evaluated under controlled conditions. The results showed that plants grown under short-day conditions produced more mini-tubers, and these tubers were superior in terms of diameter compared to tubers grown in long days. Agria allocated more assimilates to shoots but lower assimilates to underground in long days which is economically more important. Savalan produced more tubers than Agria in short photoperiods, while, long photoperiod led to increase in shoot and decrease in root weight in this cultivar, still it was significantly higher than Agria. Chlorophyll content of both cultivars decreased under short photoperiod conditions. Irrespective to the cultivar, the number and length of stolon decreased under short photoperiod conditions, but the number of tubers per plant increased under such conditions. Savalan showed lower sensitivity to photoperiod than Agria. Therefore, in the photoperiod sensitive potato cultivars, production of mini-tubers in short days may be recommended, but in the long term, introduction of potato cultivars with lower sensitivity to photoperiod through plant breeding may increase potato yield in short days by maintaining sink and source balance.
ScienceAsia, 2020
Magnetic field (MF) treatment improves the germination of seeds and enhances the performance of various crops. In this study, the effects of different MF strengths (0-control, 75, 150, and 300 mT) and exposure time periods (0-control, 24, 48, and 72 h) on sprouting of dormant seed potato tubers, vegetative growth (emergence time and plant height), tuber formation (tuber number per plant and mean tuber weight), and total chlorophyll content in 2 potato (Solanum tuberosum L.) cultivars ('Necta' and 'Banba') were investigated in all parameters examined in both cultivars, the worst results were recorded in control treatment where no MF strength was used. Emergence times of sprouts were reduced significantly when seed potato tubers were exposed to 150 mT MF strength for 72 h in both cultivars. The fastest emergence times were recorded as 14.0 days in cv. 'Nectar' and 17.0 days in cv. 'Banba' when seed tubers were exposed to 150 mT MF strength for 72 h. In control treatment, emergence time of sprouts was noted as 31.8 days in cv. 'Nectar' and 39.5 days in cv. 'Banba'. The best results in other parameters (plant height, total chlorophyll content, tuber number per plant and mean tuber weight) were again obtained from seed tubers treated with 150 mT MF strength for 72 h whereas the worst results were noted in control treatment in both cultivars. Thus, MF pre-treatment can compensate for the negative effects of dormancy in seed potato tubers.
Increased Phytochrome B Alleviates Density Effects on Tuber Yield of Field Potato Crops
PLANT PHYSIOLOGY, 2003
The possibility that reduced photomorphogenic responses could increase field crop yield has been suggested often, but experimental support is still lacking. Here, we report that ectopic expression of the Arabidopsis PHYB (phytochrome B) gene, a photoreceptor involved in detecting red to far-red light ratio associated with plant density, can increase tuber yield in field-grown transgenic potato (Solanum tuberosum) crops. Surprisingly, this effect was larger at very high densities, despite the intense reduction in the red to far-red light ratios and the concomitant narrowed differences in active phytochrome B levels between wild type and transgenics at these densities. Increased PHYB expression not only altered the ability of plants to respond to light signals, but they also modified the light environment itself. This combination resulted in larger effects of enhanced PHYB expression on tuber number and crop photosynthesis at high planting densities. The PHYB transgenics showed higher maximum photosynthesis in leaves of all strata of the canopy, and this effect was largely due to increased leaf stomatal conductance. We propose that enhanced PHYB expression could be used in breeding programs to shift optimum planting densities to higher levels. fax 5411-4514 -8730.
The control of source to sink carbon flux during tuber development in potato
The Plant Journal, 1998
We have used top-down metabolic control analysis to investigate the control of carbon flux through potato (Solanum tuberosum) plants during tuberisation. The metabolism of the potato plant was divided into two blocks of reactions (the source and sink blocks) that communicate through the leaf apoplastic sucrose pool. Flux was measured as the transfer of 14 C from CO 2 to the tuber. Flux and apoplastic sucrose concentration were varied either by changing the light intensity or using transgenic manipulations that specifically affect the source or sink blocks, and elasticity coefficients were measured. We have provided evidence in support of our assumption that apoplastic sucrose is the only communicating metabolite between the source and sink blocks. The elasticity coefficients were used to calculate the flux control coefficients of the source and sink blocks, which were 0.8 and 0.2, respectively. This work suggests that the best strategy for the manipulation of tuber yield in potato will involve increases in photosynthetic capacity, rather than sink metabolism. A 'top-down' approach to the determination of control coefficients in metabolic control theory. Eur. J. Biochem. 188, 321-325. Collins, W.B. (1976) Effect of carbon dioxide enrichment on growth of the potato plant. Hort. Sci. 11, 467-469. Engels, C. and Marschner, H. (1986a) Allocation of photosynthate to individual tubers of Solanum tuberosum L. I. Relationship between tuber growth rate and enzyme activities of the starch metabolism. J. Exp. Bot. 37, 1795-1803. Engels, C. and Marschner, H. (1986b) Allocation of photosynthate to individual tubers of Solanum tuberosum L. III. Relationship between growth rate of individual tubers, tuber weight and stolon growth prior to tuber initiation. J. Exp. Bot. 37, 1813-1822. Entwistle, G. and ap Rees, T. (1990) Lack of fructose-1,6bisphosphatase in a range of higher plants that store starch.
Plants
Most cultivated potatoes are tetraploid, and the tuber is the main economic part that is consumed due to its calorific and nutritional values. Recent trends in climate change led to the frequent occurrence of heat and drought stress in major potato-growing regions worldwide. The optimum temperature for tuber production is 15–20 °C. High-temperature and water-deficient conditions during the growing season result in several morphological, physiological, biochemical, and molecular alterations. The morphological changes under stress conditions may affect the process of stolon formation, tuberization, and bulking, ultimately affecting the tuber yield. This condition also affects the physiological responses, including an imbalance in the allocation of photoassimilates, respiration, water use efficiency, transpiration, carbon partitioning, and the source–sink relationship. The biochemical responses under stress conditions involve maintaining ionic homeostasis, synthesizing heat shock prote...
Asian journal of advances in agricultural research, 2023
Tuber dormancy is an important phenomenon in potato seed production cycle and its duration can positively affect the number of crops and crop performance during the seed production. The present study was conducted to evaluate the effect of different factors which include potato genotypes (Roko and SM kaghan varieties), chemical treatments i.e GA3, thiourea, Thiourea+GA3 and sugar under light and dark storage conditions. It was found that between varieties, Roko responded better than SM kaghan to various chemical treatments regarding number of days to dormancy breaking. It was found that the growth hormone GA3 (gibberellic acid) in combination with thiourea can significantly increase sprouting percentage to 100% under dark conditions after 31 days of application. However, it was observed that after planting of the treated tubers the emergence percentage, and minituber yield did not show any significant effect of the three
Agronomy
Potatoes—a global food security and staple crop—is threatened by dry spells in drought-prone areas. The use of physiological thresholds to save water while maintaining a reasonable tuber yield has been proposed, but their effects on physiological performances and usefulness under different irrigation methods are yet to be evaluated. In this study, photosynthetic traits were monitored to assess the effect of water restriction and rewatering under drip (DI) and furrow (FI) irrigations. The treatments consisted of two maximum light-saturated stomatal conductance (g s _ m a x ) irrigation thresholds (T2: 0.15 and T3: 0.05 mol H 2 O m − 2 s − 1 ) compared with a fully irrigated control (g s _ m a x > 0.3 mol H 2 O m − 2 s − 1 ). DI used less water than FI but promoted early senescence and low percentage of maximum assimilation rate (PMA) at late developmental stages. FI caused no yield penalization in T2 and higher recovery of carbon isotope discrimination and PMA than DI. It is sugge...