The Effect of Plant Growth Regulators on Physico-Chemical Properties of Safflower (Carthamus tinctorius L.) Derived Biodiesel

Global concerns about the environmental impact of combustion emissions from petroleum fuels influence new research to seek for alternative energy sources. The current study investigates the possibility of using safflower (Carthamus tinctorius L.) as an alternative biodiesel raw material. Four plant growth regulators (PGR) were used to boost the production of safflower. Thirteen treatments were constituted from the four plant regulators and applied to the safflower crop arranged in completely randomised design, repeated three times. The results show that the effect of plant growth regulators was not more than that of the control. More studies have to be channelled towards the relationship between safflower and plant growth regulators.

Combining ectomycorrhizal fungi and plant growth-promoting rhizobacteria to enhance salt tolerance of Metasequoia glyptostroboides

Plant growth and productivity are negatively affected by soil salinity.This study investigated the effects of the rhizosphere-promoting bacterium,Bacillus paramycoides JYZ-SD5,and the ectomycorrhizal fungus,Schizophyllum commune Be,on the growth of Metasequoia glyptostroboides under salt stress.Changes in biomass,root growth,root ion distribution and in vivo enzyme activities were determined under different treatments(Be,JYZ-SD5,and Be+JYZ-SD5).The results show that all inoculations increased chlorophyll content,shoot length and root diameter with or without salt stress,and the effect of Be+JYZ-SD5was the strongest.JYZ-SD5 and Be+JYZ-SD5 treatments significantly increased root length,surface area,bifurcation number,tip number,main root length and diameter under salt stress.Normal chloroplast structures developed under both single and double inoculations.Relative to the control,root activities of M.glyptostroboides in the Be,JYZSD5,and Be+JYZ-SD5 treatments increased by 31.3%,17.2%,and 33.7%.All treatments increased the activities of superoxide dismutase(SOD),peroxidase(POD),Na^(+)-K^(+)-ATPase and Ca^(2+)-Mg^(2+)-ATPase.The strongest effect was by Be+JYZ-SD5.Analysis of root ion distribution showed that,under salt stress,Na^(+)and K^(+)decreased and were concentrated in the epidermis or cortex.Na/K ratios also decreased.The Be+JYZ-SD5 treatment increased betaine by 130.3%and 97.9%under 50 mM and 100 mM salt stress,respectively.Together,these changes result in the activation of physiological and biochemical processes involved in the mitigation of salinity-induced stress in M.glyptostroboides.

Influence of Plant Growth Regulators on Pollen Germination and Growth of Xinjiang Apricots

[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in solid media supplemented with five plant growth regulators （GA3 , NAA, 2, 4-D, 6-BA, IAA）. Then the rate of pollen germination and the length of pollen tube were respectively measured. [Result] In a certain concentration range, GA3 most significantly promoted the pollen germination and the pollen tube growth of Shushanggan, Kalayulvke, Dayoujia, Yiliakeyulvke and Kabakehuanna; NNA had the strongest improvement function on Kumaiti’s pollen germination and pollen tube growth. [Conclusion] All the five plant growth regulators promoted the pollen germination and the pollen tube growth of apricots at low concentration but inhibited them at high concentration.

Research Progress of Mechanism of Action of Plant Growth Promoting Rhizobacteria

The paper first introduces the definition and classification of plant growth promoting rhizobacteria （PGPR）, then reviews the research achievements on the mechanism of action of plant growth promoting rhizobacteria, including growth pro-moting mechanism and bio-control mechanism, subsequently lists the use of excel-lent plant growth promoting rhizobacteria strains in recent years, especial y Pseu-domonas and Bacil us strains, and final y discusses problems existing in this area and points out issues requiring further exploration, including PGPR screening meth-ods, preservation methods, mechanism of action, in order to commercialize PGPR as soon as possible and practical y realize its application to production.

Effects of Plant Growth Regulator on Absorption,Circulation and Contents of Potassium in Flue-cured Tobacco

[Objective] This study was to investigate the effects of plant growth regulator on accumulation and circulation of potassium in flue-cured tobacco.[Methods] Hydroponics experiment was adopted to study the effects of plant growth regulator（NAA,GA3,BR） on accumulation and circulation of potassium in flue-cured tobacco.[Results] The BR treatment increased the absorption of potassium,calcium and magnesium in flue-cured tobacco,reduced the potassium emission from the root,enhanced the accumulation and contents and promoted the circulation of potassium in the tobacco plants.There was no statistical difference between the NAA and GA3 treatment.And BR treatment was 0.52%,0.30%,0.28% higher than NAA treatment in enhancing potassium content in tobacco plants at 2,7,12 d after topping.In a word,the results showed that BR treatment was the most.[Conclusion] BR treatment could effectively enhance potassium content in tobacco plants after topping.

Dwarfing effects of plant growth regulators on narcissi

The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.

Influences of Carbon Sources and Plant Growth Regulators on Anther Culture Efficiency of Pepper

[Objective]In order to increase anther culture efficiency of pepper.[Method]MS culture media and Bolajiaohong were used in this experiment to study the influences of carbon sources and concentrations on anther callus induction of pepper.Jiayu was taken as a material to study influences of plant growth regulators and concentrations on anther callus induction of pepper according to L16（4^5） orthogonal design.[Result]The average callus and embryoid induction rates of maltose at all concentrations were higher than these of sucrose but the difference was not significant.Taking maltose or sucrose as a carbon source,3% to 6% concentration was good for increasing induction frequencies of calli and embryoids.However,If the concentration was over 6%,the induction rates were declined dramatically with the increase of sugar concentration.The influences of growth regulators on induction rate of calli were listed as 2,4-D﹥ZT﹥NAA﹥KT﹥6-BA;the influences on induction rates of embryoids were listed as 2,4-D﹥NAA﹥ZT﹥KT﹥6-BA.The 2,4-D,ZT,NAA and KT had signficant or extremely significant influences on induction rates of calli and embryoids.2,4-D,ZT at 1.0 mg/L and NNA,KT at 0.5 mg/L had the best effects.The influences of ZT on calli and embryoids were better than those of KT and 6-BA.1.0 mg/L 2,4-D ＋1.0 mg/L ZT ＋0.5 mg/L KT ＋0.5 mg/L 6-BA was the best regulator combination for induction culture of Jiayu anther.[Conclusion]The experiment provided research basis for anther culture of pepper.

Effect of vernalization and plant growth regulators on flowering of Onithogalum ‘Chesapeake Snowflake’

The effect of vernalization and two growth regulators Fascination^TM and Pro-Gibb^R on the growth, inflorescence development and flowering of Omithogalurrt Chesapeake Snowflake＇ was studied. Regardless of growth regulator treatment, chilling bulbs for 3 weeks at 10℃ before planting accelerated flowering of the first inflorescence by 5 to 6 days, elongated floral stem length by 1.5 to 2 cm and shortened leaf length by 4 to 5 cm as compared with non-chilled bulbs. When bulbs were chilled 3 weeks at 10℃ before planting, Fascination 2% and Pro-Gibb accelerated flowering of the first inflorescence by 2 to 6 days respectively as compared with the control. When bulbs were not chilled before planting, Fascination 2% and Pro-Gibb accelerated flowering of the first inflorescence by 6 to12 days respectively as compared with the control. The lengths of the leaves and the inflorescences were not affected by PGR treatment. Higher rates of Pro-Gibb （100 mg.L^-1 and 200 mg.L^-1） and more amount of Fascination 2%（100 μL and 200 μL） can cause abortion of inflorescence.

Effects of Plant Growth Regulators on the Contents of Reducing Sugar and Starch in Potato(Solanum tuberosum L.)

[Objective] The aim was to investigate the effects of plant growth regulators on contents of reducing sugar and starch in potato（Solanum tuberosum L.）.[Method]A potato cultivar named ＇Holand-212＇ with three treatments by spraying Diethyl aminoethyl hexanoate（DTA-6）,Uniconazole（S3307）and SOD mimics（SODM）were employed to compare differences of the contents of reducing sugar and starch in potato leaves,stolons and tubers in a field experiment.[Result]DTA-6 treatment could significantly reduce the contents of starch and reducing sugar in potato stolons in the period of 100-110 d after seeding,and it could also reduce the content of reducing sugar in tubers,but there is an opposite result in leaves in the same period,significantly.S3307 could extremely significantly increase the content of starch,and can promote the transfer of starch in stolons,in addition,it also could reduce the content of reducing sugar in tubers,and extremely significantly increase the content of starch in leaves at the 110 d after sowing.Moreover,there is a similar effect between SODM and S3307.[Conclusion]The research results are significant for understanding mechanisms of plant growth regulators and promoting application of plant growth regulator in potato.

Functions of Plant Growth Substances in the Growth of Dendrobium officinale Kimura et Migo

[Objectives] To study the effects of plant growth substance on the growth and development of Dendrobium officinale Kimura et Migo. [Methods] Comparative methods were applied to study the effects of plant growth substance on the growth and development of D. officinale Kimura et Migo. [Results] Plant growth regulators play an important role in the process of tissue culture rapid propagation of D. officinale Kimura et Migo,and the main regulatory pathways are as follows.( i) Plant growth regulators promote the growth and development of D. officinale Kimura et Migo through regulating the changes of its endogenous hormones.( ii) Plant growth regulators affect the accumulation of polysaccharide content in D. officinale Kimura et Migo through regulating the changes in chlorophyll content and enzymes involved in sucrose metabolism.( iii) Plant growth regulators can increase the activity of antioxidant enzymes of D. officinale Kimura et Migo,to increase its stress resistance. [Conclusions]Using molecular biology techniques,combined with the changes of plant hormones in D. officinale Kimura et Migo,and analysis on key enzyme in the synthesis of plant hormones and gene expression,it is feasible to study the rules o changes in the content of active content of D. officinale Kimura et Migo.

Plant growth and their root development after inoculation of arbuscular mycorrhizal fungi in coal mine subsided areas

Coal mining often cause serious land degradation, soil erosion, and desertification affecting growth of the local vegetation, especially the roots. Arbuscular mycorrhizal fungi （AMF） inoculation is considered a potential biotechnological tool for mined soil remediation because mycorrhizal fungi could improve plant growth environment, especially under adverse conditions due to their good symbiosis. A field experiment was conducted to study the ecological effects of AMF （Funneliformis mosseae, Rhizophagus intraradices） on the growth of Amygdalus pedunculata Pall. and their root development in the regenerated mining subsidence sandy land. The reclamation experiment included four treatments： inoculation of Funneliformis mosseae （F.m）, inoculation of Rhizophagus intraradices （R.i）, combined inoculation of F.m and R.i and non-inoculated treatment. Root mycorrhizal colonization, plant height, crown width, soil moisture, root morphology and certain soil properties were assessed. The results showed that AMF improved the shoot and root growth of Amygdalus pedunculata Pall., and significantly increased root colonization after 1 year of inoculation. Available phosphorus content, activities of phosphatase as well as electrical conductivity in soil rhizosphere of all the three inoculation treatments were higher than that of the non-inoculated treatment. AMF increased the quantity of bacteria and fungi in soil rhizosphere compared with the non-inoculated treatment. Our study indicates that revegetation with AMF inoculum could influence plant growth and root development as well as soil properties, suggesting that AMF inoculation can be effective method for further ecological restoration in coal mine subsided areas.

Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice(Oryza sativa L.)

Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the wholeplant growth duration salt tolerance（ST） was genetically dissected by phenotyping two sets of BC2F5 introgression lines（ILs） for four yield traits under severe natural salt stress and non-stress filed conditions using SSR markers and the methods of advanced backcross QTL（AB-QTL） analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and nonstress conditions were identified, most（〉90%） of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan（HHZ） ILs with favorable donor alleles at multiple QTLs and significantly improved yield traits under salt stress and non-stress conditions were identified, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection（MAS） or genome selection.

A meta-analysis of experimental warming effects on woody plant growth and photosynthesis in forests

Increasing field experiments have been conducted in forests to better understand the response of plant growth and photosynthesis to climatic warming. However,it is still unknown whether there is a general pattern in relation to how and to what extent warming impacts woody plants in forests. In this study, a meta-analysis was conducted to investigate the warming effects. When temperatures increased between 0.3 and 10 ℃, specific leaf area(SLA) was significantly increased by 5.9%, plant height by 7.8%, biomass by 21.9%, foliar calcium(Ca) and manganese(Mn) concentrations by 20.7% and 39.6% and net photosynthetic rate(Pn) by 9.9%. Enhanced growth and Pn may have a relationship with changing SLA, efficiency of PSⅡ(photosystem Ⅱ), photosynthetic pigment concentrations and foliar nutrients. The results will be useful to understand the underlying mechanisms of forests responding to global warming.

Effect of Arbuscular Mycorrhizal Inoculation on Plant Growth and Phthalic Ester Degradation in Two Contaminated Soils

A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorrhizal inoculation on plant growth and degradation of DEHP in two contaminated soils, a yellow-brown soil and a red soil. The air-dried soils were uniformly sprayed with different concentrations of DEHP, inoculated or left uninoculated with an arbuscular mycorrhizal (AM) fungus, and planted with…

Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth

Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons(PAHs)from contaminated sandy soil for a remediation purpose,with some of the oil remaining in the soil.Although most of the PAHs were removed,the risk of residue oil in the soil was not known.The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soil properties after soil extraction for a better understanding of the soil remediation.Addition of sunflower oil and column ex...

Effects of plant growth regulators, carbon sources and pH values on callus induction in Aquilaria malaccensis leaf explants and characteristics of the resultant calli

The endangered tropical tree, Aquilaria malaccensis, produces agarwood for use in fragrance and medicines. Efforts are currently un-derway to produce valuable agarwood compoundsn tissue culture. The purpose of this study was to develop an optimal growth medium, specif-ically, the best hormone combination for callus suspension culture. Using nursery-grown A. malaccensis, sterilized leaf explants were first incu-bated on basic Murashige and Skoog （MS） gel medium containing 15g/L sucrose and at pH 5.7. Different auxin types including 1-naphthaleneacetic acid （NAA）, 2,4-dichlorophenoxyacetic acid （2,4-D）, and indole-3-butyric acid （IBA）, were tested at various concentrations （0.55, 1.1 and 1.65 μM） using the basic medium. Leaf explants were incubated for 30 days in the dark. Callus induced by 1.1 μM NAA had the highest biomass dry weight （DW） of 17.3 mg;however the callus was of a compact type. This auxin concentration was then combined with either 6-benzylaminopurine （BAP） or kinetin at 0.55, 1.1, 2.2 or 3.3 μM to induce growth of friable callus. The 1.1μM NAA＋2.2μM BAP com-bination produced friable callus with the highest biomass （93.3mg DW）. When testing the different carbon sources and pHs, sucrose at 15g/L and pH at 5.7 yielded highest biomasses at 87.7mg and 83mg DW, respec-tively. Microscopic observations revealed the arrangement of the friable cells as loosely packed with relatively large cells, while for the compact callus, the cells were small and densely packed. We concluded that MS medium containing 15 g/L sucrose, 1.1 μM NAA ＋ 2.2 μM BAP hor-mone combination, and a pH of 5.7 was highly effective for inducing friable callus from leaf explants of A. malaccensis for the purpose of establishing cell suspension culture.

Research Progress on Nitrogen Use and Plant Growth

The application of nitrogen （N） fertilizers in agriculture has been increasing dramatically since 1970s. However, the over-fertilization causes could cause environmental problems, as well as low N use efficiency （NUE）. Promoting NUE in plants and minimizing the environmental impacts of N fertilizers had been the focus of the current research. We reviewed the importance of N, N metabolism and plant growth, plant N physiology and the molecular aspect of N metabolism in this paper. The future development of N use and NUE of plants was also discussed.

Effect of Different Plant Growth Regulators on Callus Induction and in vitro Rapid Propagation of Wild Petunia Juss.

In this study,the seeds of wild Petunia Juss.were used as explants to investigate the optimal condition for tissue culture.Several different kinds and concentrations of growth regulators were adopted to produce more multiple bud clumps,callus or roots in this study.The experiments may provide experimental foundation for the rapid propagation technology and establishment of tissue culture system for wild Petunia Juss.

Effects of different plant growth inhibitors on growth and flowering of narcissus

This study was conducted to determine effects of four plant growth inhibitors viz. PP333,Het,CCC and B9 with different concentrations on growth and flowering of narcissus.The results indicated that the narcissus treated with certain concentration inhibitors could grow shorter plants with shorter scapes of flower and smaller leaves than the check, and the compact,straight and coordinate plants improve the decorative value obviously.

Utilizing the γ-Irradiated Sodium Alginate as a Plant Growth Promoter for Enhancing the Growth,Physiological Activities,and Alkaloids Production in Catharanthus roseus L.

Sodium alginate is a polysaccharide that is largely obtained from the brown algae （Sargassum sp.）.It has been used as a wonderful growth promoting substance in its depolymerized form for various plants.The aim of this study was to find out the effects of various concentrations of γ-irradiated sodium alginate （ISA）,viz.,deionized water （control,T0）,20 （T1）,40 （T2）,60 （T3）,80 （T4）,and 100 ppm （T5） on the agricultural performance of Catharanthus roseus L.（Rosea） in terms of growth attributes,photosynthesis,physiological activities,and alkaloid production.The present work revealed that ISA applied as leaf-sprays at concentrations from 20 to 100 ppm might improve growth,photosynthesis,physiological activities,and alkaloid production in C.roseus L.significantly.Of the various ISA concentrations,80 ppm proved to be the best one compared to other concentrations applied.