Tuber Sprouts Research Articles

Effect of essential oil of seven medicinal plants on longevity, nongermination, qualitative and quantitative traits of Solanum tuberosum cv. Agria

There is increasing interest in the application of natural plant extracts for the postharvest management of food crops. This study investigates the potential for hydro-distilled natural essential oils to inhibit the germination of potato tubers in storage. Four completely randomized design experiments were undertaken with extracts of seven medicinal plants [(Zataria multiflora L.), peppermint (Mentha piperita L.), fennel (Foeniculum vulgare L.), summer savory (Satureja hortensis L.), cloves (Eugenia caryophylium L.), lavender (Lavandula officinalis L.), and black cumin (Bunium persicum L.)], at four concentrations (0, 150, 300, and 450 μl/L) and three replications. Tubers were treated with essential oil vapor and then stored for 6 months at 8°C in the dark. Peppermint and fennel essential oils, at a concentration of 300 μl/L, completely inhibited tuber germination. In pregermination experiments, the dimensional and mass weight of tubers before germination increased by 18.4% and 21.11%, respectively, in the control treatment compared with the treated tubers with a concentration of 150 μl/L. However, the highest rate for the mentioned parameters in postgermination experiments was observed at a concentration of 300 μl/L fennel treatments. Peppermint and fennel essential oil with a concentration of 300 μl/L completely inhibited germination and tubers had acceptable volume, mass, dry matter, protein, and potassium. Also, the highest concentration of sugar (44.44 mg/g) occurred in tubers treated with fennel (300 μl/L), but the starch levels were lower than in tubers treated with the other essential oils. From these results, peppermint essential oil was identified as the best treatment and it is recommended for use in commercial harvests. Novelty impact statement Plant essential oils are safe substances for the environment and human health. Therefore, for the first time, these essential oils with different concentrations were evaluated for an Iranian potato cultivar. The innovation of this article was the use of a range of concentrations and diversity of important plant essential oils to provide a novel solution for Iranian farmers in controlling potato germination and storage conditions.

Integrated Analysis of Transcriptome and Metabolome Reveals the Mechanism of Chlorine Dioxide Repressed Potato (Solanum tuberosum L.) Tuber Sprouting.

Sprouting is an irreversible deterioration of potato quality, which not only causes loss in their commercial value but also produces harmful toxins. As a popular disinfectant, ClO2 can inhibit the sprouting of potato tubers. Using transcriptomic and metabolomic approaches to understand the repressive mechanism of ClO2 in potato sprouting is yet to be reported. Sequencing the transcriptome and metabolome of potatoes treated with ClO2 in this study revealed a total of 3,119 differentially expressed genes, with 1,247 and 1,872 genes showing down- and upregulated expression, respectively. The majority of the downregulated genes were associated with plant hormone signal transduction, whereas upregulated differential genes were associated primarily with biological processes, such as phenylpropanoid biosynthesis and the mitogen-activated protein kinase (MAPK) signaling pathway. Metabonomic assays identified a total of 932 metabolites, with 33 and 52 metabolites being down- and upregulated, respectively. Downregulated metabolites were mostly alkaloids, amino acids, and their derivatives, whereas upregulated metabolites were composed mainly of flavonoids and coumarins. Integrated transcriptomic and metabolomic analyses showed that many different metabolites were regulated by several different genes, forming a complex regulatory network. These results provide new insights for understanding the mechanism of ClO2-mediated repression of potato sprouting.

Snakin-2 interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenase 1 to inhibit sprout growth in potato tubers.

The potato tuber is the main nutrient supply and reproductive organ; however, tuber sprouting can reduce its commercial value. Snakin-2 (StSN2) was first reported as an antimicrobial peptide that positively regulates potato disease resistance. Our recent study suggested StSN2 overexpression inhibited sprout growth, while the sprouting process was accelerated in StSN2 RNAi lines. Cytoplasmic glyceraldehyde-3- phosphate dehydrogenase 1 (StGAPC1) was identified as a candidate protein that interacts with StSN2 by coimmunoprecipitation/mass spectrometry (CoIP/MS) experiments. Here, we report that the expression levels of StSN2 and StGAPC1 decreased during sprouting compared with dormancy. Coexpression of StSN2 and StGAPC1 in bud eyes and apical buds was verified by immunofluorescence analysis of paraffin sections. In addition, interaction of StSN2 and StGAPC1 was confirmed by yeast two-hybrid, coimmunoprecipitation and split luciferase complementation assays. Overexpression of StGAPC1 depressed sprout growth, which is similar to the function of StSN2, and StSN2- and StGAPC1-overexpressing lines showed decreased glucose, fructose and galactose content. The interaction of StSN2 and StGAPC1 enhanced StGAPC1 activity and decreased its oxidative modification to inhibit sprout growth. Our results suggest that StSN2 plays a regulatory role in tuber sprout growth through interaction with StGAPC1.

Yield and quality of potatoes depending on the use of biological preparations

In biologized agricultural production, together with minimized chemical agents, promising preparations based on various subspecies of spore-forming bacteria are widely used. The aim of the study was to determine the effectiveness of the use of biological preparations of Kartofin (based on the Bacillus subtilis strain I5-12/23) and BisolbiSan, (based on the Bacillus subtilis strain h-13) according to the following indicators: – germination of tubers, plant growth and development, prevalence and development of diseases on plants, crop weight and its marketability. The results of the studies showed that pre-planting treatment of seed tubers with Kartofin and BisolbiSan biologics had a positive effect on the germination of potato tubers, increasing it by 6.3 – 8.7% compared to the control. Under field conditions they showed high biological effectiveness against pathogens of fungal diseases of potatoes: late blight (from 37.5% to 100%). Accounting for the total yield showed that the highest yield indicators were noted on the variant with the use of the biological preparation BisolbiSan – 38.4 t/ha (20.5% higher than the control variant).

The effectiveness of the use of biological preparations in the production of potatoes on the soils of North Ossetia

The use of biological preparations in the protection of agricultural plants from diseases is of great importance. This issue is especially relevant in the production of potatoes. The research results showed that the pre-planting treatment of seed tubers with biological products Kartofin and BisolbiSan had a positive effect on the germination of potato tubers, increasing it in comparison with the control by 6.3-8.7%. In the field, they showed high biological effectiveness against pathogens of fungal diseases of potatoes: late blight, rhizoctonia (from 37.5 to 100%). The counts of the total yield showed that the highest yield indicators were observed in the variant with the use of the biological product BisolbiSan - 38.4 t / ha (20.5% higher than the control variant).

The influence of agrotechnical methods on the formation of the harvest of potatoes of the early variety

The article presents the results of research on agrotechnical methods of growing potatoes of the early Meteor variety in the conditions of the Non-Chernozem zone. To obtain products in the early stages, the following were used: covering materials of various density and light transmission (white and black) 17 g-m-2 and 30 g-m-2, germination of tubers, the influence of the fraction of the planting material on the formation of the crop. The Moscow region is characterized by extreme weather conditions in the early spring period, which often leads to a delay in the development and formation of the harvest of early potato production. For the implementation of research tasks, an early potato variety “Meteor” for table use was used - with good taste and recommended for obtaining ultra-early products. The variety has a high declared yield, resistance to diseases widespread in research conditions. The aim of the research was to obtain an increase in yields without the use of growth stimulants and chemical fertilizers, which is important for the modern buyer. According to the research results, we noted the effect of the covering material in combination with the germination of tubers on the early emergence of seedlings and a long growing season before the first and second harvesting. The maximum difference in yield was noted at 15.07 in relation to the control in variants with a covering material of 17 g-m-2 and 30 g-m -2 in combination with germination, as well as in the variant: tubers of a large fraction in combination with germination that amounted to 27 … 25%. The average increase for the first harvest was noted in variants with a covering material without germination of tubers that amounted to 8 … 11% in relation to the control. When cleaning, the gap between control and options decreased by 2 … 3% compared to the first harvest, and the total yield increased by 5 … 8% in all variants of the experiment in relation to the first harvest.

Growing methods that promote the production of early potato products of the Udacha variety

The scientific article presents the results of five-year research on an effective method of growing potatoes of the early variety Udacha, for obtaining products in the second decade of July in the conditions of the Moscow region of the Russian Federation. For the formation of the potato yield, various methods were used to optimize the conditions for the growth and development of plants in the early spring and summer periods, for the experiments used (pre-planting glauconite sands 10, 20 and 30 g/plant, the effect of drip irrigation on the formation of early production the use of a covering material during germination of potato tubers, light germination of tubers). In the studies, observations were made of the early ripening potatoes of the Luck variety. Our research is aimed at increasing early potato yield through environmentally friendly practices. Thus, according to the results of the study, the following data were obtained: the interphase period of seedling-harvesting had a difference of 5 … 7 days, depending on the variant of the experiment, this period was 46 … 56 days, which corresponds to the length of the growing season for early-maturing varieties grown under optimal conditions. The average mass of tubers per plant for all variants as of July 15 was 787.1 grams, which is not a bad indicator for the Moscow region. The maximum early yield was achieved in the variants with the use of drip irrigation with the introduction of glauconite sands at a dose of 20 and 30 g/plant and in the variant with light germination in combination with a covering material of 17 g/m2.

Characterization of C-26 aminotransferase, indispensable for steroidal glycoalkaloid biosynthesis.

Steroidal glycoalkaloids (SGAs) are toxic specialized metabolites found in members of the Solanaceae, such as Solanum tuberosum (potato) and Solanum lycopersicum (tomato). The major potato SGAs are α-solanine and α-chaconine, which are biosynthesized from cholesterol. Previously, we have characterized two cytochrome P450 monooxygenases and a 2-oxoglutarate-dependent dioxygenase that function in hydroxylation at the C-22, C-26 and C-16α positions, but the aminotransferase responsible for the introduction of a nitrogen moiety into the steroidal skeleton remains uncharacterized. Here, we show that PGA4 encoding a putative γ-aminobutyrate aminotransferase is involved in SGA biosynthesis in potatoes. The PGA4 transcript was expressed at high levels in tuber sprouts, in which SGAs are abundant. Silencing the PGA4 gene decreased potato SGA levels and instead caused the accumulation of furostanol saponins. Analysis of the tomato PGA4 ortholog, GAME12, essentially provided the same results. Recombinant PGA4 protein exhibited catalysis of transamination at the C-26 position of 22-hydroxy-26-oxocholesterol using γ-aminobutyric acid as an amino donor. Solanum stipuloideum (PI498120), a tuber-bearing wild potato species lacking SGA, was found to have a defective PGA4 gene expressing the truncated transcripts, and transformation of PI498120 with functional PGA4 resulted in the complementation of SGA production. These findings indicate that PGA4 is a key enzyme for transamination in SGA biosynthesis. The disruption of PGA4 function by genome editing will be a viable approach for accumulating valuable steroidal saponins in SGA-free potatoes.

Combining conventional QTL analysis and whole-exome capture-based bulk-segregant analysis provides new genetic insights into tuber sprout elongation and dormancy release in a diploid potato population

Tuber dormancy and sprouting are commercially important potato traits as long-term tuber storage is necessary to ensure year-round availability. Premature dormancy release and sprout growth in tubers during storage can result in a significant deterioration in product quality. In addition, the main chemical sprout suppressant chlorpropham has been withdrawn in Europe, necessitating alternative approaches for controlling sprouting. Breeding potato cultivars with longer dormancy and slower sprout growth is a desirable goal, although this must be tempered by the needs of the seed potato industry, where dormancy break and sprout vigour are required for rapid emergence. We have performed a detailed genetic analysis of tuber sprout growth using a diploid potato population derived from two highly heterozygous parents. A dual approach employing conventional QTL analysis allied to a combined bulk-segregant analysis (BSA) using a novel potato whole-exome capture (WEC) platform was evaluated. Tubers were assessed for sprout growth in storage at six time-points over two consecutive growing seasons. Genetic analysis revealed the presence of main QTL on five chromosomes, several of which were consistent across two growing seasons. In addition, phenotypic bulks displaying extreme sprout growth phenotypes were subjected to WEC sequencing for performing BSA. The combined BSA and WEC approach corroborated QTL locations and served to narrow the associated genomic regions, while also identifying new QTL for further investigation. Overall, our findings reveal a very complex genetic architecture for tuber sprouting and sprout growth, which has implications both for potato and other root, bulb and tuber crops where long-term storage is essential.

Postharvest application of growth regulators on Dioscorea alata (L.) and Dioscorea rotundata (Poir.)

Yam is a tuber that sees high demand and consumption in Colombia, whose post-harvest quality losses during storage have been a challenge for farmers. At the Universidad de Cordoba-Colombia, Agronomy Engineering program, between March and August of 2019, a trial was established to estimate the effect of two growth regulators on the variables: tuber weight loss (TWL), tuber sprouting (TS), starch on a dry basis (SD), and reducing sugars (RS) during storage for 120 days, with evaluations every 30 days. A completely randomized design with a 4×2 factorial arrangement plus two additional treatments with three replications was used. Four concentrations of abscisic acid (ABA) were tested: 0, 10, 15, and 20 mg L-1 in the species D. alata and D. rotundata, plus paclobutrazol (PBZ): 15 mL kg-1, for a total of 10 treatments. Each experiment unit consisted of 12 tubers that were preserved in darkness at 23°C and 53% relative humidity on average. ABA and PBZ exerted effective control over the sprouting and weight loss of the tubers during the first 90 days of storage in both species, which averaged 24.4%, i.e. approximately 488 g, favoring high starch contents, and did not influence the reducing sugar content.

ОБ ЭФФЕКТИВНОСТИ ОБРАБОТКИ СЕМЕННЫХ КЛУБНЕЙ КАРТОФЕЛЯ ЭТИЛЕНОМ

Potato (Solanum tuberosum L.) is one of the most important agricultural crops in Russia. Potato tubers contain protein of high biological value, starch and vitamins necessary for humans. There are various ways to increase the yield of the crop, currently, it is mainly due to application of mineral fertilizers. However, this method has limitations, since an increase in doses of fertilizers is associated with deterioration of consumer quality and culinary indicators of tubers. One possible alternative is the gassing of seed tubers with ethylene. This phytohormone is widely used on various crops, but its effect on potatoes has not yet been fully studied. It is known that depending on the treatment modes it can act as both a stimulator and an inhibitor of tuber germination. We have developed a new method for increasing potato yield based on the property of phytohormone ethylene to suppress apical dominance at the beginning of tuber germination and thereby promote the formation of a larger number of lateral sprouts from which additional stems are formed. The aim of the research was to determine the effect of seed potato tubers treatment with ethylene on their biochemical parameters, as well as on the growth, development and tuber yield of the crop. The experiments were conducted on the basis of storage facilities of JSC Ozyory (Ozyorsky District, Moscow Province). For gassing, the adapted technology of the company «Restrain Company Ltd» (Great Britain) was used. The storage temperature for seed potatoes was 4 °С; the period of ethylene gassing was from November to the end of April. The treatment with ethylene was stopped 3-5 days before planting. Ethylene-treated potatoes were planted in 2015-2017 on the territory of the Moscow region. A two-factor small-plot field trial was conducted in the Lyuberetsky District at the Korenevo experimental base, the soil was sod-podzolic sandy loam. Seed tubers of potato varieties Lady Claire (early), Gala (mid-early) and Saturna (mid-late) were treated with ethylene. In the control, ethylene was not applied. A three-factor large-scale (40 ha) field trial was performed during commercial potato growing of the same varieties (JSC Ozyory, Ozyorsky District, Moscow Province, sod-podzolic loamy soil). We used the same treatment as in experiment 1 added with 2-3 irrigation (200 m3/ha). In both experiments, the potatoes were planted in the first decade of May (45 thousand tubers per hectare, row spacing width of 75 cm; N60P120K120 applied locally). Biochemical, biometric parameters, and potato yield were measured.It was found that the treatment of potato seed tubers with ethylene at 4 °С changes their biochemical parameters, i.e., dry matter content decreases by 0.2-0.5 % while sucrose increases by 0.03-0.08 %, which indicates the breakdown of tubers’ dormancy. There was a suppression of apical dominance and the formation of more lateral sprouts on tubers, a greater number of stems per plant (by 19.9-36.0 %), and an increase in number of tubers per plant (by 6.3-19.0 %, especially in the Gala variety). Potato yield increased by 9.9-19.0 % depending on the variety, growing area and irrigation. The produced potato tubers were more uniform and marketable. Depending on the common agricultural level and the technology used at a farm, a differentiated approach is proposed in choosing the planting rate. If low agricultural technology and no irrigation, the planting rate of ethylene-treated tubers reduced by 10-15 % allows for the same yield as that for high technology and irrigation.

EFFICIENCY OF ETHYLENE APPLICATION ON SEED POTATO TUBERS

Potato (Solanum tuberosum L.) is one of the most important agricultural crops in Russia. Potato tubers contain protein of high biological value, starch and vitamins necessary for humans. There are various ways to increase the yield of the crop, currently, it is mainly due to application of mineral fertilizers. However, this method has limitations, since an increase in doses of fertilizers is associated with deterioration of consumer quality and culinary indicators of tubers. One possible alternative is the gassing of seed tubers with ethylene. This phytohormone is widely used on various crops, but its effect on potatoes has not yet been fully studied. It is known that depending on the treatment modes it can act as both a stimulator and an inhibitor of tuber germination. We have developed a new method for increasing potato yield based on the property of phytohormone ethylene to suppress apical dominance at the beginning of tuber germination and thereby promote the formation of a larger number of lateral sprouts from which additional stems are formed. The aim of the research was to determine the effect of seed potato tubers treatment with ethylene on their biochemical parameters, as well as on the growth, development and tuber yield of the crop. The experiments were conducted on the basis of storage facilities of JSC Ozyory (Ozyorsky District, Moscow Province). For gassing, the adapted technology of the company «Restrain Company Ltd» (Great Britain) was used. The storage temperature for seed potatoes was 4 °С; the period of ethylene gassing was from November to the end of April. The treatment with ethylene was stopped 3-5 days before planting. Ethylene-treated potatoes were planted in 2015-2017 on the territory of the Moscow region. A two-factor small-plot field trial was conducted in the Lyuberetsky District at the Korenevo experimental base, the soil was sod-podzolic sandy loam. Seed tubers of potato varieties Lady Claire (early), Gala (mid-early) and Saturna (mid-late) were treated with ethylene. In the control, ethylene was not applied. A three-factor large-scale (40 ha) field trial was performed during commercial potato growing of the same varieties (JSC Ozyory, Ozyorsky District, Moscow Province, sod-podzolic loamy soil). We used the same treatment as in experiment 1 added with 2-3 irrigation (200 m3/ha). In both experiments, the potatoes were planted in the first decade of May (45 thousand tubers per hectare, row spacing width of 75 cm; N60P120K120 applied locally). Biochemical, biometric parameters, and potato yield were measured.It was found that the treatment of potato seed tubers with ethylene at 4 °С changes their biochemical parameters, i.e., dry matter content decreases by 0.2-0.5 % while sucrose increases by 0.03-0.08 %, which indicates the breakdown of tubers’ dormancy. There was a suppression of apical dominance and the formation of more lateral sprouts on tubers, a greater number of stems per plant (by 19.9-36.0 %), and an increase in number of tubers per plant (by 6.3-19.0 %, especially in the Gala variety). Potato yield increased by 9.9-19.0 % depending on the variety, growing area and irrigation. The produced potato tubers were more uniform and marketable. Depending on the common agricultural level and the technology used at a farm, a differentiated approach is proposed in choosing the planting rate. If low agricultural technology and no irrigation, the planting rate of ethylene-treated tubers reduced by 10-15 % allows for the same yield as that for high technology and irrigation.

The Cultivation of Early Potatoes in the Conditions of Climate Change

Climate change is becoming increasingly dangerous for agricultural regions. Nevertheless, it gives some advantages for cultivating early potatoes. Potato is a ductile crop ubiquitously grown in Russia. In the Moscow region, it is possible to obtain two early potato crops due to various technological methods, e.g., light germination and large fractions of tubers for the first sowing. The first planting was carried out by the germination of tubers Red Scarlet, Meteor, and Lady Claire. The second planting was carried out with the middle fraction of the same array. The obtained crops of early potatoes show the possibility to get two crops in the Moscow region. It is better to carry out the first planting with a large fraction, which is physiologically older since it is more resistant to various growing conditions and has more nutrients in early planting. Thus, the tubers germinate faster, and the development phases pass faster, which allows one to get the crop by July 15. Such products are sold at higher prices and are economically feasible for any farm. The second landing was carried out on July 15. The received products are in demand among the population and restaurateurs in the fall, indicating the appropriateness of this cultivation technology. Therefore, climate change allows obtaining two early potato crops in the conditions of the Moscow Region.

New nano-geroprotectors application in seed potato production

This study was conducted during 2007 to 2019 at the Lorch Potato Research Institute, Moscow region, Russia to study the effect of the application of new specific antioxidants (Skulachev ions) in order to counteract the ROS accumulation and physiological ageing of potato grown for seed production. The results of years of research on the use of Skulachev ions with geroprotective properties at various stages of original seed potato production represented. In vitro when adding SkQ1 preparation (2.5 nM) in an artificial nutrient medium there was an increased survival rate of tissue explants varieties with a shorter vegetation period by 16 to 43% and varieties with longer vegetation period by 7 to 13%. Simultaneously, the output of stem cuttings after the first grafting of regenerants grew in 1.9 to 2.7 times, and the number of cultivated micro plants was doubled after 5 to 7 passages in culture. Studies have shown that the use of Skulachev ions (SkQ1) counteracts the accumulation of ROS in cells, which confirmed by a corresponding decrease in the activity of peroxidase in the sprouts of tubers and leaves of potato plants. The result was a stabilizing effect on the growth, development and productivity of potato plants. In the field treatment of seed tubers with Skulachev ions (25 nM) and followed by spraying of plantings in the phase of budding - beginning of flowering (2,5nM) promoted more intense development of vegetative mass of plants (1.5 times the height and 1.7 to 2.1 of leaf area and increased the length of growing season. As a result of getting a reliable increase in yield of the studied varieties was 1.4 to 1.5 times.

Performance of bioproduct Albit on potatoes

This article summarizes the data of field trials and practical application of biostimulant Albit on potatoes. It was shown that Albit increases the tuber germination, accelerates the emergence of shoots and maturation, improves the quality and marketability of the potato crop, and on an average increases the yield of potato up to 28%. When applied together with chemical pesticides, Albit relieves their phytotoxic effect acting as antidote. Immunizing effect of Albit against late blight and other diseases was also demonstrated.

Effect of Storage Temperature and Postharvest Tuber Treatment with Chemical and Biorational Inhibitors on Suppression of Sprouts During Potato Storage

Abstract Consumption of ware potatoes in the tropics may be enhanced by storage under conditions that inhibit sprouting, most important of which is the temperature. The effects of storage temperatures (10 °C and 23 °C) and two alternatives to the chlorpropham (CIPC): 1,4-dimethylnaphthalene (DMN) and peppermint oil (PMO), a biorational inhibitor, were evaluated for tuber sprout suppression at postharvest. Tubers of three cultivars – ‘Asante’, ‘Kenya Mpya’, and ‘Shangi’ – with different dormancy lengths were assessed. Storage temperatures and suppressant effects on tuber sprouting, sprout length and sprout numbers per tuber were investigated in replicated storage experiments. Significant differences in sprout inhibition were observed between the two temperatures with suppressive effects higher at 10 °C than in 23 °C. CIPC had the greatest suppressive effect on tuber sprout inhibition at both temperatures. After 24 weeks of storage, the suppressive effects of CIPC at 10 °C was 100% on the three cultivars, whereas all the nontreated tubers sprouted after six (‘Shangi’), twelve (‘Asante’), fourteen (‘Kenya Mpya’) weeks of storage. At 23 °C, the effectiveness of CIPC followed the dormancy period of the cultivars, with ‘Shangi’ recording significantly more sprouted tubers followed by ‘Asante’ and ‘Kenya Mpya’. The inhibition of sprouting by DMN and PMO varied with storage temperatures and cultivars, but were significantly greater than the nontreated tubers. At 10 °C, the effectiveness of DMN treatment was equal to that of CIPC for ‘Kenya Mpya’ resulting in 100% inhibition. In the PMO treatments, complete inhibition of sprouting was observed for 18 weeks on cultivars ‘Asante’, ‘Kenya Mpya’ and 14 weeks on ‘Shangi’. At 23 °C, PMO suppressed sprouts for 14 weeks on ‘Asante’ and ‘Kenya Mpya’ and on ‘Shangi’ for 8 weeks. Storage temperature effects on sprout length and numbers varied with inhibitor type and cultivar. These findings showed that in potato tuber storage, inhibitors can replace low temperature but to an extent depending on the cultivar dormancy character and storage length, thus enabling greater consumption of potatoes in tropical regions.

Factors on seed germination, tuber sprout and plant growth of <i>Vallisneria </i> species in China

由于人类生产生活对众多淡水水体的扰动、污染，我国苦草属（Vallisneria）植物的种群规模出现了严重的退化.明确苦草属植物萌发和生长的影响因素，阐明苦草属植物退化的原因，是保护和恢复该属植物亟需解决的科学问题.通过对已发表的文献进行收集和分析，总结了影响苦草属植物萌发和生长的主要因素，并通过挖掘文献中的数据，对重要环境因子与苦草属植物萌发和生长参数的关系进行了分析.结果表明：（1）涉及苦草（V.natans（Lour.）Hara）的研究较多，而涉及刺苦草（V.spinulosa Yan）和密刺苦草（V.denseserrulata Makino）的研究较少；（2）苦草属植物种子的萌发受到温度、光照强度、水深、掩埋深度、基质情况和储存方式等因素的影响；（3）苦草属植物生长受到光照强度、水深、水体营养水平、底泥营养水平、底泥有机质和动物牧食等因素的影响；（4）其他条件适宜时，苦草和刺苦草种子在20~30℃都保持较高的萌发率（均值> 50%）；（5）苦草种子萌发率随着掩埋深度的增加而快速下降；（6）苦草的相对生长率随光照强度的增加而升高，随水深增加而下降；（7）苦草的相对生长率随着氨氮浓度增加而下降；（8）水体和底泥中高含量的总氮和总磷对苦草属植物生长的抑制作用主要是通过促进浮游植物和附着藻生长导致的遮光，而不是直接毒害作用.未来需要进一步加强苦草属植物萌发、生长参数与环境因子关系的定量研究，更好地服务于该属植物的保护和恢复.

Effect of Treatment with Gibberellic Acid on the Dormancy and Sprouting of Tubers of Some Potato Varieties

Effect of Treatment with Gibberellic Acid on the Dormancy and Sprouting of Tubers of Some Potato Varieties

Effect of Treatment with Licorice Solution on the Dormancy and Sprouting of Tubers of Some Potato Varieties

Effect of Treatment with Licorice Solution on the Dormancy and Sprouting of Tubers of Some Potato Varieties

Influence of Treatment with Different Levels and Periods of Temperature on Dormancy and Sprouting of Tubers of Some Potato Varieties

Influence of Treatment with Different Levels and Periods of Temperature on Dormancy and Sprouting of Tubers of Some Potato Varieties