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1.
We have evaluated the ability of two triazole growth regulators, viz. triadimefon (TDM) and hexaconazole (HEX), in the enhancement of tuber production and quality in cassava (Manihot esculenta Crantz) through their effects on carbohydrate metabolism. One litre of 20 mg(-1) TDM and 15 mg(-1) HEX solution per plant were used for the treatments and groundwater was given to control plants. Triazole treatments reduced plant height and leaf area, but increased fresh and dry weights. Plants treated with TDM showed an increased net assimilation rate, which is followed by HEX and control plants. Triazole compounds increased the relative growth rate of cassava after 200 DAP, i.e. in the phase of tuber enlargement. Triazole compounds increased the starch and other carbohydrate contents and carbohydrate metabolising enzyme activities. From the results of this study, it can be concluded that these triazoles can significantly enhance the tuber production and quality by affecting the starch metabolism, apart from their fungicidal properties.  相似文献   

2.
Cytokinin-like activity was assayed in stolons and tubers of Solanum tuberosum L. ssp. andigena (Juz. et Buk.) Hawkes cv. 165 grown in pots under controlled environment conditions. The plants were allowed to tuberise without the application of environmental or other external stimuli. The soluble sugar and starch contents of stolon tips and tubers were measured. Starch accumulation was a precise indicator of tuber initiation. Cytokinin-like activity began to increase in tubers with a diameter greater than 7.5 mm and, as assessed on a per tuber basis, was greatest in the largest size-category analysed. However, expressed as a function of fresh and dry weight, activity was greatest in tubers of 15–20 mm in diameter. Increases in cytokinin-like activity occurred subsequent to tuber formation, indicating that the tuberisation stimulus is unlikely to be cytokinin-like in nature.  相似文献   

3.
Proper priming techniques are among the most important methods for increasing seed germination and seedling growth. Three experiments were conducted to investigate the effects of plant hormone (500 and 1000 mg/L gibberellic acid (GA)), magnetic field (3, 15, 30 mili Tesla (mT)) and laser irradiation at 650 nm (200 mW) on the germination and the growth of Salvia officinalis. We examined the plumule and radical length, plumule and radical fresh weight, plumule and radical dry weight, germination percentage, germination rate and seed vigor. The two concentrations of GA significantly increased seed germination and seedling growth. The magnetic field at 15 mT significantly increased radical length. The effect of laser irradiation was also significant on plumule length, and fresh and dry weight, radicle fresh weight, germination percentage and rate and seed vigor. Such results may be of practical use in the field, especially in arid and semiarid areas, but more research must determine the response of medicinal sage, treated with the priming techniques tested in our experiments, under stress conditions.  相似文献   

4.
The present investigation was carried out with an aim to study the effects of two important fungicides/plant growth regulators, triadimefon (TDM) and hexaconazole (HEX) on white yam (Dioscorea rotundata Poir.). Each plant was treated with 1 l of aqueous solution containing 15 mg l-1 TDM and 10 mg l−1 HEX by soil drenching on 10, 20 and 30 days after planting (DAP). Starch and sugar contents, and the activities of α, β-amylases, sucrose phosphate synthase (SPS), sucrose synthase (SS) and acid invertase (AI) enzymes were estimated from leaf and tuber samples on 45, 60, 75 and 90 DAP. Results showed that TDM and HEX treatments inhibited the α, β-amylase and increased the fresh and dry weights, starch, sugar and sucrose contents and SPS, SS and AI activities in white yam. The data suggests that, the application of triazole fungicides may be a useful tool to increase the tuber quality as well as quantity in white yam plants, apart from their fungicidal properties.  相似文献   

5.
The effects of postharvest storage duration and temperature on endogenous cis -zeatin ( cis -Z) and cis -zeatin riboside ( cis -ZR) levels in potato ( Solanum tuberosum L.) tubers were determined in relation to tuber bud dormancy. The tubers used in these studies were completely dormant for at least 81 days of storage. Thereafter, tuber bud dormancy diminished gradually and after 165 days of postharvest storage, the tubers were completely non-dormant. Immediately after harvest, endogenous levels of cis- Z and cis -ZR were approximately 25 pmol (g fresh weight)−1 and 8 pmol (g fresh weight)−1, respectively. In tubers exiting dormancy but stored at a growth-inhibiting temperature (3°C), endogenous levels of cis -Z rose over threefold after 25 days of storage and remained elevated for the duration of the study. Levels of cis -ZR remained essentially constant during this same period. In tubers transferred to a growth permissive temperature (20°C) prior to use, the rise in endogenous cis -Z was less dramatic and more protracted; increasing twofold after 53 days of storage. No change in cis -Z riboside content was observed in these tubers during this period. Dose-response studies using either cis -Z or trans -Z demonstrated a time-dependent increase in cytokinin sensitivity during postharvest storage. Immediately after harvest, dormant tubers were insensitive to both zeatin isomers. Thereafter, tubers exhibited a dose-dependent increase in premature sprouting following injection with either cytokinin isomer. After injection into dormant tubers, cis -[8-14C]-zeatin was metabolized primarily to adenine/adenosine and cis -Z riboside. Seven days after injection, less than 10% of the recovered radioactivity was associated with trans -ZR. These results are consistent with a role for endogenous cis -Z (and its derivatives) in the regulation of potato tuber dormancy.  相似文献   

6.
张东向 《植物研究》2003,23(1):86-90
研究了不同培养条件对齿瓣延胡索(Corydalis remota)愈伤组织生长及延胡索乙素(THP)含量的影响。结果表明, 2, 4-D较NAA更有利于提高培养物鲜重,加速细胞增殖。培养基添加2.0 mg/L 2, 4-D和1.0 mg/L BA不仅有利于干物质积累,而且显著提高THP水平。蔗糖不仅可提高培养物鲜重,而且与半乳糖组合可显著促进干物质积累和THP水平的提高。水解酪蛋白和水解乳蛋白均有利于愈伤组织生长和THP含量的提高, 450mg/L的水解乳蛋白处理组THP含量最高。光照可提高培养物鲜重和THP含量。  相似文献   

7.
为了探究羧基化多壁碳纳米管(MWCNTs-COOH)复合镉(Cd)胁迫对植物生长生理的影响,采用液体培养方法,以水稻(Oryza sativa L.)为受试作物,测定了0~12.0 mg·L^-1MWCNTs-COOH、10μmol·L-1Cd单一和复合处理水稻幼苗21天后根生长、氧化损伤、抗氧化酶活性及根中Cd含量的变化。结果表明:(1)MWCNTs-COOH单一处理,根长、根鲜重均低于对照,并表现出先升高后降低的趋势,当其浓度达到12.0 mg·L^-1时,较对照分别下降了9.3%和15.2%,且低于10μmol·L^-1Cd单一处理;而复合处理组水稻幼苗根长、根鲜重、干重皆低于对应的单一处理;(2)MWCNTs-COOH单一胁迫下,水稻根的超氧自由基(O2-·)明显积累,并伴随着超氧化物歧化酶(SOD)及过氧化物酶(POD)活性升高,3.0和6.0mg·L^-1MWCNTs-COOH处理下,SOD、POD活性最高;(3)MWCNTs-COOH复合Cd胁迫下,水稻根的SOD、POD活性大均低于单一处理组,而丙二醛(MDA)及羰基化蛋白含量均显著高于单一处理;(4)MWCNTs-COOH复合Cd后,水稻幼苗根尖细胞死亡加剧,其中,10μmol·L-1Cd与12.0 mg·L^-1MWCNTs-COOH复合处理的根尖根冠区细胞伊文斯蓝染色最深;(5)1.5~6.0 mg·L^-1MWCNTs-COOH复合Cd处理水稻幼苗后,其根中Cd含量呈上升趋势,且在6.0 mg·L^-1浓度处理时达到最大值303.30μg·g-1;高浓度MWCNTs-COOH及其与Cd的复合均对水稻根产生毒性效应。  相似文献   

8.
Potato plants (Solanum tuberosum L.) were grown in water culture.About 14 d after tuber initiation no significant differenceswere found between apical and basal tuber parts in 14C-uptakeand partitioning into various fractions from 14C-labelled photosynthate.Thus, the fresh weight of these tubers could be used as a parameterfor the sink size. The 14C-content per tuber (sink strength)20 h after 14CO2-supply to the foliage was significantly correlatedwith the tuber fresh weight. No correlation was found betweenthe 14C-concentration of the tuber (sink activity; ct. ming fr. wt.) and tuber fresh weight. Consequently, tuberfresh weight (sink size) per se must have been a factor whichinfluenced sink strength. Stolon parameters characterizing theirgrowth prior to tuber initiation (e.g. stolon volume) and theircapacity for photosynthate transport (diameter, length) weremeasured at the time of tuber initiation. Significant correlationswere found between these stolon parameters and subsequent growthof individual tubers. Anatomical studies on the proportion ofvarious tissues in the cross sectional area of stolons supportthe idea of a negative relation between growth of individualtubers and transport resistance in the phloem of the stolons.It is concluded that in the initial phase of tuber growth, mainlyfactors outside of the tuber determine its growth rate. In laterstages of tuber growth, when the sink strength increases, thecompeting strength of individual tubers for photosynthate isdominated mainly by factors within the tuber itself, such astheir sink size and sink activity. Key words: Potato tuber, sink size, tuber initiation, transport resistance  相似文献   

9.
The effects of infection with potato leafroll virus (PLRV) on the four crop processes leading to tuber fresh weight yield were examined in field plots of four cultivars (Montana, Pentland Crown, Maris Piper and King Edward) differing in tolerance to infection. Averaged across cultivars, infection decreased yield by 50%. This decrease was equally due to less light (total solar radiation) being intercepted, a lower efficiency with which intercepted light was converted into dry weight, and a smaller proportion of dry weight being partitioned to tubers. Dry matter content of the tubers was also diminished but to a lesser extent. The main difference between the cultivars in their response to infection was in the partitioning of dry weight. In Montana and Pentland Crown, harvest index was decreased by 15% in infected plants, whereas in the less tolerant cultivars, Maris Piper and King Edward, it was decreased by 25%. The decline in photosynthetic performance of Montana, a cultivar with slightly earlier maturity than the other three, was delayed in PLRV-infected plants. Effects on number of daughter tubers essentially reflected those on yield to the extent that average tuber weight did not change in Maris Piper, was one third less in King Edward, and the change was intermediate in Montana and Pentland Crown.  相似文献   

10.
Triadimefon, potential fungicide cum plant-growth retardant was used in this study to investigate its effect on the growth and the photosynthetic pigment contents of two varieties of Catharanthus roseus (L.) G. Don. The plants of both varieties were subjected to 15 mg l(-1) triadimefon treatment by soil drenching 30, 45, 60, and 75 days after planting (DAP). Plants were uprooted on 90 DAP, and morphological parameters, like plant height, number of leaves, leaf area, root length and fresh and dry weights were determined. The photosynthetic pigments, like chlorophylls a and b, total chlorophyll, carotenoids, floral pigment, anthocyanin, were extracted and estimated. It was observed that plant height, number of leaves and leaf area were decreased and that root length, fresh and dry weights were increased under triadimefon treatment. The photosynthetic and floral pigments were increased under triadimefon treatment in both varieties. The results suggest that the application of this plant-growth retardant (triadimefon) has favourable effects on the reduction of plant height; it can thus be used for replacing manual hand pruning and for improving floral and vegetation colour in bedding plants like C. roseus.  相似文献   

11.
BIEMOND  H.; VOS  J. 《Annals of botany》1992,70(1):37-45
Potatoes (Solanum tuberosum L.) were planted in pots in a temperature-controlledglasshouse The treatments consisted of three levels of nitrogensupply, ie 25, 8 and 16 g N per pot (treatments called N1, N2and N3) The accumulation rates of dry matter and nitrogen showedan upper limit of response to nitrogen supply, N3 plants continuedto accumulate dry matter and N at a constant rate for a longerperiod of time than N2 and N1 plants The uptake of nitrogenslowed earlier in time than the rate of dry matter accumulationin all treatments. The proportion of the dry matter in tubersof mature plants was not affected by nitrogen treatment, butthe start of tuber bulking was delayed in the N3 plants Thefinal proportion of total plant nitrogen in the tubers was similarfor all treatments The concentration of nitrogen in the drymatter of mature plants increased with the level of N supplyMaximum haulm weight increased with the level of N supply Apicallateral branches of the first and second order made up largerproportions of the total haulm dry weight and total leaf areaas more nitrogen was supplied. Yet, the distribution of drymatter over stems and leaves was not different between nitrogentreatments Stems were the most responsive to N treatment interms of N concentrations In each of the component organs (stems, leaves, tubers) theconcentration of nitrogen declined with time Fairly strong associationswere observed between the concentrations of N in component organs.The concentration of nitrate in leaves usually increased initiallywith leaf age, peaked and declined. A substantial part of thedifferences between treatments in the concentrations of N inleaf dry matter were attributable to differences in nitrateconcentration Nitrate in stems and tubers fell virtually belowthe limit of detection at total nitrogen concentrations of lessthan 1%, but increased in proportion to total N above that threshold,especially in stems Potato, Solanum tuberosum L, dry matter production, dry matter distribution, nitrogen nutrition, nitrogen distribution, nitrogen concentration  相似文献   

12.
In many areas, decreases in the stratospheric ozone layer have resulted in an increase in ultraviolet-B (UV-B, 280-315 nm) radiation reaching the Earth's surface. The present study was conducted to evaluate the interactive effects of supplemental UV-B (sUV-B) and mineral nutrients on a tuber crop, potato (Solanum tuberosum L. var Kufri Badshah), under natural field conditions in a dry tropical environment. The nutrient treatments were the recommended dose of NPK (F(o)), 1.5 times the recommended dose of NPK (F(1)), 1.5 times the recommended dose of N (F(2)) and 1.5 times the recommended dose of K (F(3)). The response of potato plants to sUV-B varied with nutrient treatment and concentration. sUV-B adversely affected growth, yield and quality of tubers, causing an increase in reducing sugars in the tubers and thus reducing the economic value. Growth and fresh weight of tubers was maximal with sUV-B at 1.5 times recommended NPK, but the dry weight of tubers were highest with the recommended NPK dose. Reducing sugar content was lower in potato plants treated with sUV-B and the recommended NPK than with sUV-B and 1.5 times the recommended NPK. This study thus clearly shows that growing potato with 1.5 times the recommended NPK or 1.5 times the recommended dose of N/K does not alleviate the sUV-B induced changes in yield and quality of tubers compared to the recommended NPK dose.  相似文献   

13.
为了阐明纳米二氧化钛颗粒(TiO2NPs)对生菜(Lactuca sativa)生长的影响,采用自行设计的水培装置探究不同浓度TiO2NPs (300~1 200 mg/L)下,生菜生长和生理生化指标的变化。结果表明,300 mg/L TiO2NPs能促进生菜幼苗的根长、茎长、叶表面积、鲜重和干重;随着TiO2 NPs浓度增大,生菜的生长指标呈现下降趋势,但仍优于对照组。生菜体内的抗氧化酶(SOD、POD)在低TiO2 NPs浓度(300 mg/L)时,活性明显下降;随着TiO2 NPs浓度增大,这两种抗氧化酶活性逐渐增强。因此,生菜对TiO2NPs胁迫具有浓度依赖性,表现为“低促高抑”,且能够通过抗氧化酶系统来减轻TiO2NPs伤害。  相似文献   

14.
Weeds are one of the major constraints in oilseed Brassica production. Use of effective herbicides to control weeds in the fields is one of the major objectives of agronomists. To improve weed control efficacy and minimize the application costs, complex combinations of 5-aminolevulinic acid (ALA) and a new postemergence herbicide, propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), were used to investigate their combined effects in relation to seedling growth and development of oilseed rape (Brassica napus cv. ZS 758). Brassica seeds were treated with different concentrations of ZJ0273 [100 (normal dose for rape), 200, 500, and 1000 mg/L] and ALA (0.1, 1, 10, and 50 mg/L). ALA was applied as pre- and post-treatment alone and in combination with ZJ0273. We found that ZJ0273 stress imposed negative effects on rape seedling growth. Shoot fresh weight, shoot length, and root fresh weight were inhibited significantly under ZJ0273 stress, and the rate of decline increased consistently with increased ZJ0273 concentration. Root oxidizability was also inhibited significantly under ZJ0273 stress conditions, and the higher the concentration of the herbicide ZJ0273, the lower the oxidizability. Herbicide ZJ0273 treatment produced a gradual decrease in antioxidant enzymes (peroxidase, superoxide dismutase, and ascorbate peroxidase) and an increase in peroxidation substance (malondialdehyde accumulation). The increase and decrease were consistent with the ZJ0273 dosage. Our results indicated that pre- and post-treatments with a lower dosage of ALA (1 mg/L) improved rape seedling growth and root oxidizability parameters, whereas a higher concentration of ALA (50 mg/L) depressed growth. We also found that plants treated with 1 mg/L ALA produced the highest shoot fresh weights, shoot lengths, root fresh weights, and root oxidizability when the seeds were treated with different concentrations of ZJ0273. Lower dosages of ALA improved the activities of antioxidant enzymes, whereas the highest dosage of ALA increased the accumulation of peroxidation substance. These results indicate that ALA has promotive effects in the recovery of growth and development of rape seedlings under herbicide ZJ0273 toxicity stress.  相似文献   

15.
以种子萌发率、幼苗根长、幼苗株高和单株鲜质量以及菌落直径为指标,对碎米莎草(Cyperus iria L. )穗部总生物碱的化感活性及抑菌效果进行了初步研究.结果表明,不同质量浓度的总生物碱溶液对6种供试植物的种子萌发和幼苗生长均有不同程度的影响;质量浓度为500~4 000 mg·L~(-1)的总生物碱溶液对水稻(Oryza sativa L. )种子萌发率和幼苗的株高和单株鲜质量无显著影响(P>0.05),但4 000 mg·L~(-1)总生物碱溶液对水稻幼苗的根长有显著的抑制作用(P<0.05);总生物碱溶液对烟草(Nicotiana tabacum L. )、鳢肠[Eclipta prostrata (L. ) L. ]、千金子[Leptochloa chinensis (L. ) Nees]、三叶鬼针草(Bidens pilosa L. )及丁香蓼(Ludwigia prostrata Roxb. )的种子萌发和幼苗生长的抑制作用随质量浓度的提高而增强,且当质量浓度达到4 000 mg·L~(-1)时, 种子萌发率和幼苗的根长、株高和单株鲜质量均最低, 与对照差异显著(P<0.05). 碎米莎草穗部总生物碱溶液对6种供试植物病原真菌的抑菌效果有一定的差异, 但总体上随质量浓度(25~400 mg·L~(-1))的提高抑菌效果逐渐增强;当质量浓度达到400 mg·L~(-1)时,总生物碱溶液对苹果轮纹病病菌(Physalospora piricola Nose)、油菜菌核病病菌[Sclerotinia sclerotiorum (Lib. ) de Bary]、水稻稻瘟病病菌[Magnaporthe grisea (Hebert) Barr. ]、小麦赤霉病病菌(Fusarium graminearum Schw. )和番茄早疫病病菌(Alternaria solani Jones et Grout. )的抑菌率最高,分别达到74.05%、64.73%、43.54%、35.09%和32.56%,与对照差异显著(P<0.05);但25~400 mg·L~(-1)总生物碱溶液对杨树溃疡病病菌(Dothiorella gregaria Sacc. )无显著的抑菌作用(P>0.05).研究结果显示,碎米莎草穗部总生物碱具有被开发为稻田用生物源农药的潜力.  相似文献   

16.
Shen  Sisi  Liu  Yufeng  Wang  Fei  Yao  Guoxin  Xie  Lingli  Xu  Benbo 《Journal of Plant Growth Regulation》2019,38(1):241-248

Researchers have found that graphene oxide (GO) has significant effects on plant growth and development. The effects of GO on plants are variable and influenced by many factors, including GO concentration and genotype. Five rice varieties, Huanghuazhan (HHZ), Jinghuazhan (JHZ), Shenyou9521 (SY9521), Jingyouhuazhan (JYHZ), and Jingchuxiang (JCX), were treated with different concentrations of GO (0, 5, 15, 25, and 50 mg/L), and their physiological response was measured. The results demonstrate that GO had significant effects on the development of HHZ, JCX, JHZ, JYHZ, and SY9521 roots, but the effect varied by GO concentration and rice variety. The highest concentration of GO (50 mg/L) reduced the root length, fresh weight, and dry weight for all five rice species. The GO treatment also affected the levels of abscisic acid (ABA), indole-3-acetic acid (IAA), and malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) and catalase (CAT) enzymes. The correlation analysis indicates that GO could affect the IAA content to modulate rice root growth.

  相似文献   

17.
采用牛磺酸溶液培育小麦幼苗,测定10、100、500、1 000、5 000 mg/L的牛磺酸对小麦幼苗的光合作用PS Ⅱ光化学效率、细胞膜相对透性和膜脂过氧化以及生长的影响.结果表明,与对照组相比,适宜浓度的牛磺酸处理可促进小麦幼苗的生长,使其根长、株高、单株幼苗的干重和鲜重增加,并在一定程度上提高叶片的光化学效率,降低细胞膜相对透性和膜脂过氧化产物的含量;最适处理浓度约为500 mg/L.说明牛磺酸对小麦幼苗细胞膜有一定的保护作用.  相似文献   

18.
Shoot morphology at the emergence ofDioscorea japonica Thumb. could be classed into the following three types: (1) a seedling emergence with only one leaf (Se type), (2) a plant consisting of one stem and one leaf, which has emerged from a small tuber (rhizophore) or bulbil less than 50 mg in dry weight (S type) and (3) a twiner with many leaves, which has emerged from a tuber or a bulbil of more than 50 mg in dry weight (L type). The Se type failed to develop beyond the second leaf stage in 1.5% sunlight exposure. The effects of initial plant (seeds, bulbils and tubers) size and light intensity on plant growth were analyzed. The larger the initial plant size was, the greater the growth in height and leaf area was. The distribution ratio of assimilated substances in leaves was high in smaller plants at the early growth stage. The distribution ratio in the tubers of larger plants became high at the early stage of growth. In all three types at over 3% sunlight exposure, the switch-over from the vegetative to reproductive growth phase occurred simultaneously at a later growth stage, but the Se type at 1.5% sunlight exposure showed a very early switch-over in its development; this switch-over may be related to shade tolerance capacity. The L type showed shade avoidance by forming a large productive structure as a twiner  相似文献   

19.
When young radish ( Raphanus sativus L. cv, Novired RS) plants were exposed to low levels of ethylene, the fresh weight and dry weight of the tubers significantly increased. This was mainly because ethylene reduced the percentage of plants that hardly or not at all formed a tuber. Decaptated seedling cultured in vitro, were supplied with several plant growth regulators in order to determine a possible correlation between the induction of radial growth and the biosynthesis of ethylene in the hypocotyl. Indole-3-acetic acid, or in combination with 6-benzylaminopurine, induced growth of the hypocotyl and markedly enhanced ethylene biosynthesis. However, the application of a precursor and an inhibitor of ethylene biosynthesis revealed that there is no direct causal relationship between radial growth and ethylene evolution. It is suggested that ethylene favoured tuber growth in intact plants by changing the partitioning of assimilates in the plant, rather than by the induction of cambial activity.  相似文献   

20.
薯蓣皂素对油菜种子萌发及幼苗生长的影响   总被引:4,自引:0,他引:4  
薯蓣皂素对油菜种子萌发及幼苗生长的作用随处理浓度的不同而有差别。0.5mg/L对种子萌发和幼苗生长有明显的促进作用,处理后的油菜幼苗下胚轴伸长,干鲜重增加,并且子叶中可溶性蛋白、可溶性总糖、过氧化物酶和过氧化氢酶、Ca2 -ATP酶的活性都高于对照,这表明适度的薯蓣皂素有利于油菜生长和代谢。  相似文献   

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