油茶根际溶磷菌的分离、鉴定及溶磷能力研究

采用传统的微生物分离培养法,对油茶根际溶磷细菌进行了分离,共筛选得到17株溶磷细菌。利用透明圈法对油茶根际土壤中具有溶磷能力的细菌进行初筛;采用钼锑抗比色法测定发酵液的可溶性磷含量,对解磷菌株进行复筛,得出菌株6-Y-09溶磷活性最强。根据进行菌落形态特征、生理生化特征、16S r DNA序列和系统发育分析等研究,初步鉴定菌株6-Y-09为洋葱伯克霍尔德菌。该菌株在后续微生物菌肥研制中具有较大潜力,为通过生物途径改善油茶磷素供应,促进油茶生长提供了优良的菌株资源。     

Nicotine Production by Tobacco Callus Tissues and Effect of Plant Growth Regulators

Relationships between callus origin and the nicotine contents as well as conditions of nicotine production in tobacco tissue cultures were investigated. Nicotine contents of callus tissues were remarkably affected by plant growth regulators in the culture medium. Thus, nicotine production was promoted by the regulators at lower concentrations, but gradually inhibited when the concentrations increased over an optimal region which was different among several kinds of the regulators. The nicotine contents also considerably depended on conditions of the callus induction as well as organ from which they were derived, at least just after callus induction. The differences due to the induction conditions were considered to be gradually lost during successive cultures. Thus, the nicotine contents appeared gradually to change to a certain level which mainly depended on the concentration of the regulators added to the culture medium. When such stabilized callus tissues were transferred to a culture medium containing another regulator or different concentration of the regulator, their nicotine contents rapidly changed to a new level depending on the culture conditions during a few successive cultures. The stabilized callus tissues grown on a medium containing 0.1 ppm α-NAA contained 0.5% of nicotine or more, which was almost the same level in root of the intact plant.     

Phospholipids as Plant Growth Regulators

In this paper the potential to use phospholipids and lysophospholipids as plant growth regulators is discussed. Recent evidence shows that phospholipids and phospholipases play an important signalling role in the normal course of plant development and in the response of plants to abiotic and biotic stress. It is apparent that phospholipase A (PLA), C (PLC) and D (PLD), lysophospholipids, and phosphatidic acid (PA) are key components of plant lipid signalling pathways. By comparison, there is very little information available on the effect of exogenously applied phospholipids on plant growth and development. This paper serves to introduce phospholipids as a novel class of plant growth regulator for use in commercial plant production. The biochemistry and physiology of phospholipids is discussed in relation to studies in which phospholipids and lysophospholipids have been applied to plants and plant parts. Implicit in the observations is that phospholipids impact the hypersensitive response and systemic acquired resistance in plants to improve crop performance and product quality. Based on published data, a scheme outlining a possible mode of action of exogenously applied phospholipids is proposed.     

Studies on Plant Growth Regulators

The electronic structure of atropic acid and its β-alkyl and β,β-dimethyl derivatives is calculated by a molecular orbital method. Their plant growth activity is shown to be explained only by considering an electronic factor of the molecule derived by the calculation.     

Studies on Plant Growth Regulators

The auxin activities of the homologs of racemic and enantiomeric α-alkylphenylacetic acids were estimated by pea straight growth test. The α-methyl, -ethyl and -propyl acids were moderately active whereas the longer and branched alkyl chain were found to make the molecule inactive. The more active enantiomers were shown to have the same configuration as the more active enantiomers in the other series of the optical active synthetic auxins.

The auxin activities of the cyclic homologs of 1, 2, 3, 4-tetrahydro- and 3, 4-dihydro-1- naphthoic acids were determined by pea straight growth test. In the tetrahydro-acid series, it was observed that the alicyclic ring expansion from the 6-membered to the 7-membered made the molecule inactive. In the 3, 4-dihydro-acid series, on the other hand, the activity remained almost unchanged by such a structural change. Structure-activity relationships were discussed in terms of their molecular structures, in particular, the configuration of the carboxyl group.     

Production and utilization of aminoacids by various species of Rhizosphere Bacteria

Было выделено с поверхности корней и из почвы ризос?еры пшеницы и иденти?ицировано 11 видов микроорганизмов, растущих в минеральной среде с глюкозой и выделяющих в среду различные аминокислоты. Наиболее часто в ?ильтратах находились аспрагин, серин, аспарагиновая кислота, α-аланин и метионин (валин). В подобранных ?ильтратах, качественно различных по содержанию аминокислот, большая часть исследуемых микроорганизмов использовала эти амниокислоты для своего роста. Авторы полагают, что микроорганизмы споверхности корней и ризос?еры, растущие только в минеральной средес глюкозой и выделяюощие аминокислоты, могут иметь определенное значение в экологии микробных сообществ ризос?еры.     

Plant Growth Substances Produced by Micro-organisms of Soil and Rhizosphere

S ummary : Micro-organisms isolated from rhizospheres and rhizoplanes of wheat plants, and from root-free soil, produced growth regulating substances with the properties of gibberellins and indolyl-3-acetic acid (IAA). Substances inhibiting extensions of pea plant internodes and lettuce hypocotyls were also produced, especially by bacteria from the root region of seedlings 6 days old. Bacteria producing growth promoting substances were most abundant on roots of older plants. Seedlings grown aseptically with added gibberellic acid (GA₃) and IAA, or grown with a soil inoculum, developed similarly and differed in their morphology from those grown aseptically without additives.     

大豆根际土壤中氢氧化细菌促生效应研究

以大豆根际土壤样品为研究材料,采用一个气体循环培养体系(持续通氢气装置),在适当的H2、O2和CO2下以H2作为唯一能源分离氢氧化细菌,结果共分离出40余株细菌,对其进行耗氢能力测定,结果显示有20株菌具有氧化氢功能和自养生长能力。对20株氢氧化细菌进行小麦促生试验,筛选出11株具有促生效果的根际促生细菌。采用薄层层析法,对11株氢氧化细菌进行了ACC降解的分析,确定了菌株A06具有ACC脱氨酶活性,证实ACC脱氨酶是导致大豆根际土壤中氢氧化细菌促进小麦幼苗生长的原因之一。     

Benzaldehyde O-Alkyloximes as New Plant Growth Regulators

Fourty-two kinds of benzaldehyde O-alkyloximes derived from benzaldehydes were prepared and their biological activities were investigated. Introduction of a fluorine or bromine atom to the benzene ring of the oximes enhanced their phytotoxic activity. The O-alkyloximes with a fluorine atom at the 3 or 4 position of the benzene ring were more active than the other oximes in the GA₃-induced α-amylase induction inhibition test. In the transpiration test, 4-bromobenzaldehyde O-carboxylmethyloxime was the most active. The O-alkyloximes exhibited weak abscisic acid-like activity by inhibiting not only the germination, root growth and transpiration of higher plants but also GA₃-induced α-amylase induction in embryoless barley seeds.     

Studies on Herbicides and Plant Growth Regulators

With the aim of obtaining plant growth regulators, we have synthesized 1-aryloxyacylbenzimidazoles, 1-aryloxyacylindazoles, 2-aryloxyacyl-4,5,6,7-tetrahydroindazoles and 1-aryloxyacylbenzotriazoles by the acylation of azoles, and 1-aryloxyacyl-4,5,6,7-tetrahydroindazoles by the reaction of aryloxyacylhydrazines with 2-(hydroxymethylene)cyclohexanone. The structures of these compounds are discussed on the basis of nuclear magnetic resonance data.     

植物生长调节剂对鸡冠花愈伤组织生长及花色素苷积累的影响

通过不同种类和水平植物生长调节剂对鸡冠花愈伤组织生长及花色素苷积累的影响.试验实验结果表明:2,4-D0.2 BA1,2,4-D0.2 KT5,NAA2 BA1和IAA2 BA1为适合愈伤组织生长和花青素积累的几种组合,其中以2,4-D0.2 BA1组合的培养基效果最好,愈伤组织鲜重增长最快且花色素苷产量最高.     

解磷菌PSB-R全基因组测序鉴定及其解磷特性分析

采用生理生化指标结合分子生物学技术对解磷菌PSB-R进行分类学鉴定,确定为粘质沙雷氏菌（Serratia marcescens）,通过二代测序平台Illumina NovaSeq PE150对PSB-R进行全基因组测序,分析预测了与解磷能力相关基因及其他植物促生基因组成情况。通过响应面优化试验检测了PSB-R最大解磷能力为805.199 mg/L,连续培养10代后解磷能力稳定且对多种难溶性磷酸盐均具有溶解能力。本研究为解磷菌解磷机制的进一步研究提供了基因组数据基础,同时证实PSB-R具有应用于菌肥的潜力,为后续解磷菌肥的研制提供了研究基础。     

杨树根际解无机磷细菌Mp1-Ha4的鉴定及其解磷机理

解无机磷细菌能够溶解土壤中的难溶性磷酸盐,增加土壤有效磷含量,促进植物生长。以一株杨树根际土壤中筛选得到的解无机磷细菌Mp1-Ha4为研究对象,利用分子生物学的方法对该菌株进行鉴定,测定了其对磷酸钙、磷酸铝和磷酸铁的解磷能力,并对该菌株9 d内的磷酸钙溶解动力学进行了研究。结果表明,解无机磷细菌Mp1-Ha4为一株西地西菌Cedecea sp.,其对磷酸钙的溶解能力远强于对磷酸铝和磷酸铁的溶解能力。在NBRIP液体培养基中,该菌株对磷酸钙的溶解能力达到了497.4 mg/L,在其对磷酸钙解磷过程中,培养基pH及可滴定酸度与解磷量分别呈显著负、正相关。高效液相色谱分析显示,该菌株在解磷过程中分泌了大量有机酸,主要包括α-酮戊二酸,酒石酸和苹果酸。分泌有机酸,降低环境pH可能是解无机磷细菌西地西菌(Cedecea sp.)Mp1-Ha4溶解难溶性磷酸盐的主要机制,同时该菌株对磷酸钙的高效溶解作用使其具有较大的研究和应用前景。     

2种植物生长调节剂诱导烟草抗链格孢菌研究

以链格孢菌Alternaria alternata和烟草Nicotiana tabacum品种云烟87为试材,研究不同浓度茉莉酸甲酯(MeJA)和水杨酸(SA)处理下,链格孢菌菌丝生长情况以及成熟期烟叶防御酶活性与多酚含量变化,探讨植物生长调节剂对烟草抗链格孢菌的影响。结果表明,1 mmol·L^–1 MeJA对链格孢菌的抑制效果最好,抑菌率高达59%以上,其次是3.5 mmol·L^–1SA;MeJA和SA对链格孢菌的抑制效果随药剂浓度升高而增强;0.1 mmol·L^–1 MeJA和2.5 mmol·L^–1 SA能诱导烟草叶片SOD、POD、CAT等防御酶活性,并能降低H₂O₂活性氧含量,尤其以MeJA诱导效果较好。2种植物生长调节剂处理并接种链格孢菌能诱导提高烟叶多酚代谢相关酶PPO及PAL活性,但对烟草多酚类物质影响较小;成熟烟叶中含量较高的前3种多酚物质是绿原酸、芸香苷、隐绿原酸。     

Frequency and Biodiversity of 2,4-Diacetylphloroglucinol-Producing Bacteria Isolated from the Maize Rhizosphere at Different Stages of Plant Growth

A Pseudomonas 2,4-diacetylphloroglucinol (DAPG)-producing population that occurred naturally on the roots, in rhizosphere soil of Zea mays and in the nonrhizosphere soil was investigated in order to assess the microbial diversity at five stages of plant growth. A total of 1,716 isolates were obtained, and 188 of these isolates were able to produce DAPG. DAPG producers were isolated at each stage of plant growth, indicating that the maize rhizosphere is colonized by natural DAPG producers throughout development. The frequency of DAPG producers was very low in the first stage of plant growth and increased over time. An analysis of the level of biodiversity of the DAPG producers at the species level was performed by comparing the AluI restriction patterns of the 16S ribosomal DNAs (rDNAs) amplified by PCR from 167 isolates. This comparison allowed us to cluster the isolates into four amplified rDNA restriction analysis (ARDRA) groups, and the main group (ARDRA group 1) contained 89.8% of the isolates. The diversity of the 150 isolates belonging to ARDRA group 1 was analyzed by the random amplified polymorphic DNA (RAPD) technique. An analysis of RAPD patterns by a molecular variance method revealed that there was a high level of genetic diversity in this population and that the genetic diversity was related to plant age. Finally, we found that some of the DAPG producers, which originated from all stages of plant growth, had the same genotype. These DAPG producers could be exploited in future screening programs for biocontrol agents.     

Compatibility of Steinernema feltiae (Nematoda: Steinernematidae) with Pesticides and Plant Growth Regulators Used in Glasshouse Plant Production

Compatibility of the entomopathogenic nematode, Steinernema feltiae Filipjev with 17 different pesticides and three plant growth regulators, recommended for drench application in glasshouses, was evaluated. The products tested were two biofungicides, Streptomyces griseoviridis (Mycostop) and Trichoderma harzianum (Rootshield), nine chemical fungicides, iprodione (Chipco 26GT), thiophanate-methyl (Fungo Flo 4.5F), azoxystrobin (Heritage), fludioxonil (Medallion), flutolanil (Prostar), mefenoxam (SudDue Maxx 21.3ME), PCNB (Terraclor 400F), triflumizole (Terraguard), and etridiazole (Terrazole), two bioinsecticides, spinosad (Conserve SC) and Bacillus thuringiensis subsp. israelensis (Gnatrol), three chemical insecticides diflubenzuron (Adept IGR), acephate (Orthene), and fenoxycarb (Precision 25WP), one herbicide, clethodim (Envoy) and three plant growth regulators, ancymidol (A-Rest), paclobutrazol (Bonzi), and uniconazole-P (Sumagic). Infective juvenile nematodes were exposed to each product at the highest recommended concentration in 24-well plates at 22°C. Observations on the viability and infectivity of the nematodes were made at 4, 24, and 72 h after exposure. We found that S. feltiae is compatible with the majority of the tested formulations with no loss in viability and infectivity up to 24 h of exposure. The viability of S. feltiae was more than 80% in all the products even after 72 h of exposure. Three pesticide formulations, Prostar (1%), Gnatrol (9%), and Terrazole (10%) decreased the viability of S. feltiae significantly within 24 h compared to the controls. However, during the 24 to 72 hr incubation period, eight pesticides affected the viability of S. feltiae with Gnatrol and Terrazole causing the highest decrease (17% and 15%, respectively). Only Terrazole decreased the infectivity of S. feltiae to Galleria mellonella larvae compared to the control when tested after 24 h exposure. At 72 hr, Orthene and Terrazole caused significant decrease in the infectivity of S. feltiae (10% and 15%, respectively) and Gnatrol caused a significant increase in the infectivity (11%) compared to the control. Our results suggest that S. feltiae can be tank-mixed and applied in combination with all the tested formulations, except Terrazole.