Lu YU

Xinjiang Production and Construction Corp，Agricultural Technology Extension Station，Urumqi 830011，China

Popularization and Application of Haidaosu（5% Amino-oligosaccharin）as a Plant lmmunity lnducer in Main Crops Cultured by Corps

Lu YU*

Xinjiang Production and Construction Corp，Agricultural Technology Extension Station，Urumqi 830011，China

The plant immunity inducer，amino-oligosaccharin，has remarkable effects in disease resistance，cold tolerance，growth promotion，yield increase and quality improvement.This paper introduced the action mechanism of amino-oligosaccharin，its main application effects on crops and application techniques.In 2013-2014，experiments were conducted on a variety of crops at multiple locations by Xinjiang Corps as well as popularization and application in 2013-2014，and it was shown by the popularization and application that the application of amino-oligosaccharin could promote plant growth，reduce the incidence of crop diseases and improve crop yield and product quality.

Plant immunity inducer；Action mechanism；Popularization and application

P lant immunity inducers use the self-defense ability of plants to gives full play to the potential of disease resistance in plants，and they induce broad-spectrum disease resistance with long duration time without inducing specific resistance in plants after repeated induction，and meanwhile，pathogens could not develop drug resistance.Haidaosu is a novelmarine oligosaccharide type plant immunity inducer，which is a kind of novel biopesticide developed in recentyears，containing 5% aminooligosaccharin aqueous solution as a main component.It is a novel plant fungicide synthesized from marine chitosan as a raw material through catalytic hydrolysis，and also is a biological pesticide product mainly generalized by the Department of Agriculture and The National Agro-Tech Extension and Service Center（NATESC）and a green prevention and control technique for crop diseases and pests，and under the guidance and organization by NATESC，more than 500 experiments have been conducted on more than 40 crops nationwide（including corps）.A plenty of experiment results illustrated that oligosaccharide type plant immunity inducer could induce plants to improve its own disease resistance and stress tolerance，regulate metabolic balance of plants and improve quality of agricultural products as well as alleviating disease.The writer of this paper conducted experiments and demonstration on aminooligosaccharin product with a number of crops in different areas，and further understood that the product has the effects of increasing yield，improving quality and enhancing stress tolerance，and is safe to ecological environment due to no residues.Furthermore，the amounts ofagricultural chemicals could be reduced when using this product which is thus deemed to be a green prevention and control technique and a pesticide-reduction measure for large-area popularization and application in crops culture by Corps.

Action Mechanism of Amino-oligosaccharin

In order to adapt the changes innatural environment and resist the invasion by pathogenic microorganisms，plants have developed their own immune system capable of secreting a variety of immune function materials in long evolutionary process［1］.This immunoreaction of plants first identifies the microorganisms which may be harmful to them and activate their main defense mechanism［2］.The generation of induced plant defense reaction begins with identification of fragmental substances-the elicitor on cell walls of microorganisms，which is the general term of the special compounds that could induce defense reaction of host plants［3］，and also could be called as plant resistance inducer.Plant immunity inducers could be classified into biotic and abiotic types.The elicitors from pathogen，other microorganism，host plants and host-pathogen interaction were called biotic elicitors，while the chemicals having induction function and physical effects were called abiotic elicitors.

The first chemical inducer is the product registered as thiabendazole in Japan.Hereafter，more chemical and biological elicitors were developed，including benzothiadiazole （Bion and Actigard，Syngenta），Milsana（extacted by Reynoutriasacalinensis，KHH biologicalscience），ELEXA （oligochitosan，Safe Science），and messenger（harpin，Plant Health Care）.With continuous research on induced resistance，many factors capable of inducing resistance to various crop pathogens have been proved.There were literatures reported that there have been 23 effective plant resistance inducers published internationally since 2010，and they were applied on 27 crops［4］.

Amino-oligosaccharin is the common name of oligochitosan in agricultural field，and the research on its action mechanism mainly focus on signal transduction and physiologicaland biochemicalmechanism.Oligosaccharide as the immunity activator of plants was found and studied by agricultural specialists since the 1960s.In 2006，Jones and Dangl published on“Nature”“The plant immune system”，which systematically summarized the concept of plant immunity，greatly promoting the development of plant immunology［5］.Functional sugars including amino-oligosaccharides and glucooligosaccharides induce plants to produce bio-enzymes and sugar signals to improve their immunity，to thereby realize crop disease resistance，harm reduction and yield increase.By applying amino-oligosaccharin，crops could be induced to produce signal substances including salicylic acid，jasmonic acid，ethylene and nitric oxide，under the action of which crops were stimulated to produce systemic enzymes（phenylalnine ammonialyase，β-1，3-glucanase，chitinase and peroxidase）and phytoalexin，lignin and pathogenesis-related proteins for resisting diseases and external harsh environment（diseases and pests，drought，phytotoxicity，growth inhibition，nutritional deficiency），i.e.，crops resist diseases and pests and adversity stress and recover growth through improving and enhancing their immune system，thereby achieving the effects of preventing diseases and pests，resistance stress，increasing yield and improving quality［6］.

Main Application Effects of Amino-oligosaccharin on Agricultural Crops

In recent years， outstanding progress has been made in the development of plant immunity inducers in ourcountry，such as5% aminooligosaccharide aqueous solution（Haidaosu）of oligosaccharides and 6%oligosaccharin aqueous solution. Under the guidance and organization by NATESC，Xinjiang Production and Construction Corp，Agricultural Technology Extension Station conducted experiments as well as popularization and application of 5%amino-oligosaccharin aqueous solution（Haidaosu）on cotton，grape，red date，prepared dry pepper and processed tomato of more than 50 regiment farms of 13 divisions including the first division and the second division in 2013-2014，the popularized area accumulated in the two years was more than 6.667×104hm2，and it was verified that the application of 5%amino-oligosaccharin aqueous solution （Haidaosu）exhibited the effects of promoting root and seedling growth，increasing yield and accelerating growth stage，and could induce crops including red date and grape to generate stress resistance such as resistance to freezing （late spring coldness）and drought. The aminooligosaccharin aqueous solution had remarkable effects ofaccelerating branch development and leaf growth，increasing yield，treating yellowing and improving fruit quality on grape and red date，and also had the effects of preventing diseases and reducing the amount of chemical pesticides.The outstanding effects of amino-oligosaccharin presented in 5 aspects.

lnduction of stress resistance in crops

By regulating the physiological and biochemical functions under stress conditions including cold and drought，the injury by stress to crops could be greatly reduced，thereby reducing the effects of harmful environmental factors to crops［7］.The fourth division of Xinjiang Corps reduced desiccation in main trunks of grape（or Xiayan）by 30%-50% and increased yield by 80%by adopting amino-oligosaccharin to prevent late spring coldness in 2014.

lnduction of disease resistance in crops

By inducing crops to produce immune-related factors in large quantities，the infection by pathogens including viruses，fungi and bacteria was prevented，thereby reducing diseases.

The experiments conducted by 83thand 106thregiments in 2013 showed that applying amino-oligosaccharin could remarkably decrease the incidences ofdowny mildew and powdery mildew，and reduced pesticide application by 1-2 times.The incidence of downy mildew in the grape cultured by 106thregiment decreased by 45.5%，and the disease index was lower than the control by 0.02.The eighth regiment of the first division applied amino-oligosaccharin to red date in 2013，and reduced the incidence of fruit shrink disease by 60%.College of PlantScience and Technology of Tarim University applied Haidaosu to red date and reduced the incidences of black spot，fruit shrink disease and fruit cracking by 50%.

Promotion of crop growth

By regulating metabolic balancesin crops，the absorption of water by roots could be promoted，chlorophyll metabolic level could be improved，resulting in improved photosynthetic efficiency of plants，and the growth of crops is thus promoted.

The 143th，147th，148th，129th，130thand 12thregiments and the Communist Youth League of Xinjiang Corps applied amino-oligosaccharin to cotton，and the results showed that it could facilitate steady growth of cotton seedlings，and brought forward the mature stage by 3-7 d，cotton leaves were 0.5-1 leaf more than the control，the root system was well developed with thick and strong main root，and fibrous roots increased by 20%compared with the control.The experiment for freezing protection and growth promotion ofred date conducted by Hongxingyichang showed that the red date treated with Haidaosu had the flower bud more plump than those of the control，its branch and leaf development was earlier than the control by 3-4 d，the inflorescence was improved by 13.1%compared with the control，there are more branches，and the leaves were deep green.The experiments carried out on grape by 83thand 106thregiments indicated thatthe grape treated with Haidaosu had its branches and leaves developed earlier than the control by 2-3 d，and it grew vigorously with deep green leaves and was free of etiolation.

lmprovement of product quality

Amino-oligosaccharin could improve the contents of plant chlorophyll content，vitamin C and total soluble sugar，and could reduce titratable acid content. After applying aminooligosaccharin to the grape of the 106thregiment，83thregiment，Shihezi Head Farm and 70th regiment，fruit clusters were lengthened obviously，and fruit inflated fast，had their color changed earlier than the control by 5-7 d，and showed the advantages of good color，high sugar content and the percentage of first class fruit improved by 26%-30%.By application together with zinc fertilizer，uneven fruit sizes and etiolation were obviously reduced.Application of Haidaosu to korla pear showed that the fruit obtained after applying Haidaosu had thin peel and less sclereids，was even in size and tasted good，there were more female pears，and the fist class fruit was improved by more than one time；and after applying on red date，total sugar content and vitamin C content both were improved.

Promotion of yield increase

By reducing the influences and hazards from diseases and stress，the effects of improving plant photosynthetic efficiency and promoting plant organ differentiation and nutrient accumulation were achieved，thereby improving crops yield.

The yields per unit area of Xinjiang grape，red date，cotton and greenhouse tomato increased by 20%，30%，5%-15%and 1.05%-9.7%，respectively.

Discussion of Application Techniques for Aminooligosaccharin

As a novel biopesticide，aminooligosaccharin has the advantages of environmental friendliness and less dosage，and has broad application prospect in inducing disease resistance and cold tolerance，increasing yield and improving quality.There are many aspects to be discussed due to the characteristics of immunity induction technique.Currently，the technical solutions for the field application techniques of amino-oligosaccharin should be determined according to different crops，different action sites，etc.，and matched with other green prevention and control techniques.

Application of amino-oligosaccharin in conjunction with fungicide

The experiment in the two years indicated that the effect achieved by applying amino-oligosaccharin alone was higher than or equal to that of conventional fungicide in early stage or preliminary stage of crop diseases，but was inferior to that of conventional fungicide in the case of severe diseases，while the combination of amino-oligosaccharin and fungicide could reduce the application of fungicide as well as obtaining good disease prevention effect.Currently，it is importantto determine the dosagesof amino-oligosaccharin and the fungicide in conjunction with it，and the a good deal of experiments are required to obtain data support.Therefore，It is necessary to improve the application technique combingamino-oligosaccharin and fungicide in production continuously，including the initial application time，time interval and dosages of the immunity inducer and conventional fungicides as well as application times and time.

Different action mode of aminooligosaccharin

The action mode of immunity inducers is plant leaf spraying or root treatment at present，and the effect obtained by applying to seeds is also very remarkable.By seed dressing experiments carried out on cotton in the two years at partial experiment points for the Corps，the emergence rate increased by 7.2%-9.2%，and the yield per unit area increased by 2.3%-4.3%，and the incidence of cotton verticillium wilt decreased by 12.7%.It was thus clear that application of amino-oligosaccharin to seed could protect crop seedlings at their weak stage，and such protection was persistent and showed no correlation with growth declination of crops.Therefore，amino-oligosaccharide plays an important role in inducing crop resistance through seed treatment，especially for those crops who are susceptible to diseases in early growth stage［8］.In production，the action mode of aminooligosaccharin should be researched continuously while taking crop objects and action sites into consideration，to select the action mode most effective for giving full play to induced resistance.

In conclusion，to exert the continuous and high effectiveness of aminooligosaccharin in crop production，the characteristics amino-oligosaccharin should be considered.The action characteristics of amino-oligosaccharin could be deduced by systematically summarizingexperimentaldata，to obtain a matched application technique system for large-area popularization and application in Corps.

Conclusions

Haidaosu is a typical plant immunity inducer in our country currently.It is different with traditional pesticides in that it realizes the change from disease treatment to disease preventionin disease control.Its popularization and application will reduce the usage amounts of other chemical pesticides，and thus reduce soil and water pollution and improve environment and food safety，satisfying the requirements of plant protection and ecological civilization construction.

With the application of plant immunity induction technique in promoting crop stress resistance，increasing yield and ensuring quality and safety of agricultural products，continuous improvement of green prevention and control matching techniques and the understanding of the technique by farmers，the technique will play its due role under the environment of“scientific plant protection，public plant protection，green plant protection”and“developing modern agriculture，serving modern agriculture”，and make significant contributions to yield increase and quality and environment safety of agriculture in Corps and realization of agricultural modernization in northwest region in 2018.

［1］YANG PY（楊普云），ZHAO ZH（趙中華）. Green prevention and control technique handbookfor crop diseases and pests: application techniques for plant immunity inducer（農(nóng)作物病蟲害綠色防控技術(shù)指南:植物免疫誘抗劑應(yīng)用技術(shù)）［M］. Beijing:China Agricultural Press（北京:中國農(nóng)業(yè)出版社），2012.

［2］SADIK T，ELIXABETH B.Multigenic and induced systemic resistance in plants［D］.Berlin:Springer Science+Business Media Inc，2006.

［3］ZHAO JH（趙繼紅），SUN SJ（孫淑君），LI JZ（李建中）.A progress on the study of plant induced resistance and elicitors（植物誘導(dǎo)抗病性與誘抗劑研究進(jìn)展）. Plant Protection（植物保護(hù)），2003，29（4）:7-10.

［4］WALTERS DR，RATSEP J，HAVIS ND. Controlling crop diseases using induced resistance:challenges for the future［J］. Journal of Experimental Botany，2013，64（5）:3-18.

［5］JONES JDG，DANGL JL.The plant immune system ［J］.Nature，2006，444: 323-329.

［6］ZHAO XM （趙小明）.Preliminary study on the oligochitosan induced plant resistance and its mechanism （氨基寡糖素誘導(dǎo)植物抗病性及其誘抗的初步研究 ）［D］.Dalian:Dalian Institute of Chemical Physics（大連:大連化學(xué)物理研究所），2006.

［7］LI P（李萍），YANG PY（楊普云），ZHANG SX（張善學(xué)）.Action mechanism of plant immunity inducer amino-oligosaccharin and its popularization and application（植物免疫誘抗劑氨基寡糖素的作用機理及其推廣應(yīng)用）［J］.Pesticide Science and Administration （農(nóng)藥科學(xué)與管理）. 2013k，34:1-7.

［8］WORRALL D，HOLRYD GH，MOORE JP，et al.Treating seeds with activators of plant defence generates longlasting priming ofresistance to pests and pathogens［J］.New Phytologist，2012，193:770-778.

Responsible editor：Yingzhi GUANG

Responsible proofreader：Xiaoyan WU

綠色防控技術(shù)植物誘導(dǎo)免疫劑海島素（5%氨基寡糖素）在兵團(tuán)主要作物上的推廣應(yīng)用

余 璐*（新疆兵團(tuán)農(nóng)業(yè)技術(shù)推廣總站，新疆烏魯木齊 830011）

植物誘導(dǎo)免疫劑——氨基寡糖素，在誘導(dǎo)農(nóng)作物抗病、抗寒、促生長、增產(chǎn)及改善品質(zhì)等方面具有明顯作用。該文介紹了氨基寡糖素的作用機理，在農(nóng)作物上的主要應(yīng)用效果以及應(yīng)用技術(shù)探討。2013～2014年在新疆兵團(tuán)進(jìn)行了多作物多點試驗與大面積推廣應(yīng)用，通過推廣應(yīng)用表明：使用氨基寡糖素可促進(jìn)作物生長，降低作物發(fā)病率，提高作物產(chǎn)量和改善產(chǎn)品品質(zhì)。

植物誘導(dǎo)免疫劑；作用機理；推廣應(yīng)用

余璐（1975-），女，河南汝南人，高級農(nóng)藝師，主要從事植物保護(hù)和農(nóng)藥管理工作，E-mail：yulu930@163.com。*通訊作者。

2015-07-18

*Corresponding author.E-mail:yulu930@163.com

Received:July 18，2015 Accepted:November 9，2015

修回日期 2015-11-09