Effect of Heat Treatment Combined with Shoot Tip Culture on the Virus-Free of Arena Strawberry

With Arena strawberry as experimental materials, heat treatments combined with shoot tip culture were used to explore their detoxification effects. The results indicated that if not heated, splitting shoot tips directly could not completely remove viruses. On the other hand, it will be obviously improved after shoot tips are heated. Incubators heat treatment （inconstant temperature） with shoot tip culture, constant temperature water bath incubation process with meristem-tip culture, hot air treatment （constant temperature） with apical meristem culture were three methods tested in searching for virus-free of Arena strawberry in this experiment. And their virus-free rates were 78.9%, 86.0% and 50.0% respectively. Of the three methods, the second, constant temperature water bath process with shoot tip culture, with 78.7% survival, is the best. Thus, it can be inferred that constant temperature water bath treatment combined with shoot tip culture might be the most appropriate method to remove viruses of Arena strawberry.

Standardized Production Technology of Virus-free Seed Potato

The research reviewed standardized production technology of virus-free seed potato, including stem tip isolation, tissue culture seedling production, breeder＇s seed and protospecies production, and standard potato tubers＇ production, and concluded a set of standardized production technology for virus-free seed potato, in order to provide theoretical references for improving potato yield.

Evaluation of the Characteristics of Virus-free Sweetpotato and Its Use in Hybridization

Application of virus-free sweetpotato is a breakthrough of sweetpotato production. Several popular varieties were adopted to study their yield increase potential and their use in breeding in this research. The results showed that after virus-elimination, all varieties had a yield increase ranging from 14.95% - 91. 61% and marketable quality improvement, despite the changes in location and season. The changes of dry matter content and disease resistance were not significant. Virus-free sweetpotato performed vigorous vine growth and strong dry matter assimilation ability. Virus-free parents had a slightly high seed setting percentage, but its flowering ability and performance of off-springs were similar to that of its check plants.

Establishment of Three Breeding System of Virus-free Strawberry Plantlet in Infantry Regiment of the Twelve Division

Shoot-tip culture of strawberry is the most important way to get virus-free plants.Moreover,detoxification and rapid propagation are the key techniques for producing high-quality seeds and seedlings massively and rapidly and achieving the high-quality,high-yield and high-efficiency development of strawberry industry.We have recently produced virus-free strawberry seedlings by combing tissue culture technology and stolon-reproduction method and this technology has been widely used.In addition,a relatively perfect three breeding system of virus-free strawberry seedlings was established after production practices,guaranteeing the supply of high-quality seeds and seedlings and technical support for strawberry industry in corps.

Detection of Ratoon Stunting Disease in Virus-free Seedcane via Real-time Fluorescence Quantitative PCR

This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease （RSD） in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture sam- pies. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37 - 39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.

Rapid Propagation of Virus-free Sugarcane Plantlets via Temporary Immersion Bioreactor System

By employing temporary immersion bioreactor system(TIBs),we studied virus-free culture of seedlings from sugarcane varieties ROC16 and ROC22,from medium recipe,inoculation amount,sucrose concentration,and variety difference. The results showed,using this method,that proliferation rate of ROC16 improved by 40 times,per flask generated about 800 plantlets; of ROC22 improved by 30 times,per flask generated about 400-600 plantlets. The results provided basis for using TIBs in rapid propagation of plantlets via tissue culture.

A Preliminary Study on Tissue Culture and Rapid Propagation of Virus-free Plantlets of Benihoppe Strawberry

[ Objective] This study aimed to investigate the tissue culture and rapid propagation techniques of Benihoppe strawberry. [ Method] Shoot tips of new stolons of Benihoppe strawberry were used as experimental materials to analyze the effects of media type, cytokinin type and concentration, carbon source type and concentration, and light intensity on tissue culture and propagation of Benihoppe strawberry. [ Result] MS was the optimal media for plantlet propagation. In the media containing 1.2 ing/L BA （with addition of 0.1 mg/L NAA）, fresh weight, dry weight and propagation coefficient of strawberry plantlets reached the maxi- mum, which were 2.259 g, 0. 221 g and 12.4, respectively. The optimal carbon source was 30 g/L sucrose, and the optimal light intensity was 1 600 lx. [ Conclu- sion] The best media for tissue culture and rapid propagation of Benihoppe strawberry was MS ＋ BA 1.2 mg/L ＋ NAA 0. 1 mg/L ＋ sucrose 30 g/L ＋ agar 8 g/L. This study provided scientific basis for large-scale production of Benihoppe strawberry.

Detection of Ratoon Stunting Disease in Virus-free Seedcane of Saccharum officinarum by PCR

[Objective]The study was carried out for providing good method to detect ratoon stunting disease（RSD）in virus-free seedcane of Saccharum officinarum.[Method]PCR method was used for the detection of RSD in virus-free seedcane of sugarcane.[Result]During the different growth stages of healthy virus-free seedling including proliferation stage,rooting stage,sand culture stage and temporary planting stage,the RSD detection results were negative.PCR detection sensitivity in the present study showed that PCR could detect RSD pathogen in the solution with bacterium concentration 10-3.[Conclusion]PCR method showed a good specificity and higher sensitivity,so it was suitable for the batch detection in the production of healthy virus-free seedlings of sugarcane.

Expression of Invertase Genes in Virus-free Sugarcane

Virus-free sugarcane seedlings have improved biomass and sucrose content compared with ordinary seedlings, and sucrose invertases are key enzymes regulating sugarcane growth and sucrose accumulation. In this study, the differences in the expression levels of 3 invertase genes, CWI, SAI and NI, between virus- free and ordinary sugarcane seedlings were analyzed. Compared with ordinary sugarcane plants, the expression of CWI was mainly up-regulated in immature leaves and stems at elongation stage and leaves and immature internodes at maturation stage, and especially, greatly up-regulated in immature interuedes at maturation stage of virus-free plants. The expression of SAI and NI were mainly up-regnlated in leaves and immature internedes of virus-free plants at maturation stage, which might be beneficial to sugar accumulation and rapid utilization of monosaccharide in the stalks of virus-free plants. It is further indicated that virus-free treatment could significantly improve the expression of sucrose invertases at late growth period, and might facilitate the increase of plant biomass.

Study on Virus-free Breeding Technology of Potato Microtuber

It is the simplest,fastest and effective way to improve the yield level of potato by selecting high quality virus-free seed potato for field production and maintaining the original characters of virus-free minituber. Microtuber is featured by small volume,no pathogen,convenient storage and transportation,which can be induced in summer with high temperature and humidity,and overcome a series of problems such as poor survival rate of transplanted test-tube plantlets,and easy pollution of cutting tips. Therefore,it can replace conventional test-tube plantlets directly for reproduction. Meantime,if minitubers are sown ahead of time using cold frame,the growth stage of potato minituber will avoid the occurrence period of aphids. The use of gauze cover for insect prevention has good effect on maintaining the excellent characters of microtuber. The yield and quality of virus-free potato are greatly improved by means of virus-free culture of shoot tip seedlings,subculture propagation of virus-free seedlings,induction of microtubers by dark culture,cultivation of breeder’s seeds in greenhouse and screenhouse to preserve the characters of potato.

Correlations between delayed fluorescence of chlorophyll, metabolism and yield of plants. III. Influence of viral infection on field plants and new technology of clone selection of virus-free planting potato

At the end of potato plants vegetation virus in-fection induced both decrease in maximum amplitude of delayed fluorescence maximal amplitude and increase half time of its decrease, as well as reduction in the amount of stems, plants’ height and assimilation area surface, yield, acceleration of plants development and their early die-off. The differences of DF pa-rameters and yields between strongly and weakly infected plants increase in case of a combined virus infection. In industrial test of the selection of virus-free planting potato by the use of DF parameter, a rise in the yield and de-crease degree of viral infection of crops was obtained.

Steps To ward HIV Cure Two more HIV-infected patients appear to be virus-free after bone-marrow transplants

THIS year＇s International AIDS Society Conference on HIV Pathogenesis, Treatment and Preven-／tion, held in Kuala Lumpur, Malaysia, made major headlines when Timothy Hendch, an American doctor, announced that two more cancer patients may have been cured of HIV after receiving bone-marrow transplants to treat lymphoma. Both patients had been taking retroviral medication, and continued to do so after the transplants as their viral levels sank until doctors were unable to find any traces of HIV in the patients＇ blood.

Design and experiment of conical diversion virus-free potato minituber precision seed-metering device

In order to accelerate the development of sowing mechanization of virus-free potato minituber,a conical diversion virus-free potato minituber precision seed-metering Device was designed according to the structural characteristics and agronomic requirements of virus-free potato minituber.The device is mainly composed of conical turntable,transmission shaft,outer baffle of seed-metering Device,baffle,seed outlet,seed cleaning device,type hole,etc.The working principle of conical diversion precision seed-metering device for virus-free potato minituber was expounded,and the stress analysis of virus-free potato minituber in each region was carried out.By EDEM discrete element simulation software,the structure of the type hole is optimized to determine the optimal structure of the type hole and according to the physical characteristics of virus-free potato minituber,the single factor experiments of the effects of length of type hole,cone disc speed and cone disc angle on seed filling performance were completed.The orthogonal regression test was carried out with the length of type hole,cone disc speed,and cone disc angle as the test objects,and the leakage rate and qualified rate as the response indexes.The regression models of leakage rate,replay rate,and qualified rate were established,and the parameters of the regression model were optimized.The optimal parameter combination is that the length of type hole is 33.61 mm,the cone disc speed is 6.35 r/min,and the cone disc angle is 26.59°.Bench test was carried out under the optimal conditions,the leakage rate was 3.80%,the replay rate was 0.80%,and the qualified rate was 95.40%,which was basically consistent with the prediction results of the regression model,and met the requirements of precision sowing of virus-free potato minituber.

连翘酯苷药理活性研究进展

连翘酯苷作为中草药连翘中一个主要的有效成分,具有广泛的药理学活性。连翘酯苷不仅能抑制引起感染的各种革兰氏阳性菌和阴性菌,而且还具有较强的抗病毒作用。连翘酯苷通过调控各种细胞因子,发挥免疫调节作用,同时通过清除体内的自由基,发挥抗氧化作用。作者针对连翘酯苷药理学活性进行了综述。

通过茎尖分生组织离体培养获得马铃薯脱毒试管苗

通过发芽块茎热处理（３７℃）、茎尖（０．１～０．５ｍｍ，带１～２个原基）生长点剥离、分生组织培养（２～６个月）技术，配合血清学、电镜技术检测筛选，获得了６个马铃薯品种无ＰＶＸ、ＰＶＹ、ＰＬＲＶ等主要病毒的脱毒试管苗。本法可用于马铃薯脱毒快繁供种体系扩繁应用或研究。

甘薯茎尖培养

报道了甘薯茎尖培养的实验工作,证明在MS附加IAA mg/L+BA 0.1mg/L+GA_3 0.05mg/L的条件下能促进茎尖生长,但基部形成愈伤组织,因此必须适时转入无激素的MS培养基上,停止愈伤组织的继续生长,以加速成苗过程,成苗度可达80％左右。甘薯的基因型显著影响培养茎尖的成苗率,脱毒植株进行单节茎段微型快速繁殖,每月繁殖系数为4～5。

热处理茎尖组织培养法快速繁育苹果无病毒苗木研究

对热处理茎尖组织培养法繁育苹果无病毒苗木进行实验研究。北斗、王林等5个苹果品种的盆栽苗经38℃±1℃恒温处理21～35天,取处理苗茎尖灭菌后,切取0.10～0.15cm长的生长点置MS+1.5ppm6-BA+0.2ppmIBA培养基中,培养40天后,剪取分化苗转入各品种适宜的生长分化培养基中,继代培养2～3次,可获足量的试管苗。取少量组培苗研磨成汁,用酶联免疫吸附法(ELISA)和摩擦接种草本指示植物进行病毒检测,北斗、王林、红乔纳金和高岭4品种均不带苹果褪绿叶斑病毒(ACLSV)和苹果茎沟病毒(ASGV),早富士品种仍带有茎沟病毒(ASGV)。剪取组织培养苗,用100ppmIBA处理12小时后,置1/2MS+0.1ppmGA+1.5ppmIAA+0.5g/L活性炭各品种皆适宜的生根培养基中培养,生根率达72％～98％。生根苗在5～30℃的温室内自然光下闭口驯化4周,开口驯化1周,植入普通腐质土中,成活率达90％～100％。

苹果潜隐病毒的研究——Ⅱ.苹果茎沟槽病毒对苹果生理生化的影响

用金冠、富士二品种幼苗接种茎沟槽病毒(SGV)后,分期测定蛋白质、核酸、DNA、总氮、氨基酸、可溶性糖、铁和锌含量。结果表明:受SGV侵染的植株,核酸、蛋白质含量下降;DNA、总氮、游离氨基酸含量增加;铁含量增加,锌含量减少,可溶性糖含量增加。

湖南省柑桔良种的脱毒与检测研究

1989～1992年经高温预热处理——微芽茎尖嫁接获得30个柑桔优良单株的79株茎尖嫁接试管苗.有10个单株的18株茎尖苗经指示植物、电镜及双向聚丙烯酰胺凝胶电泳检测证明不带裂皮病、碎叶病、衰退病和黄龙病,确定为无毒茎尖苗.另有10个单株的23株茎尖苗已初步检测不带上述各种病害.电镜检测20个单株母本树中,有10个观察到衰退病毒,4个观察到碎叶病毒,分别为供检单株的50%和20%.在双向聚丙烯酰胺凝胶电泳法检测的25个单株母本树中,有8个带有裂皮类病毒,占供检单株的32%.指示植物嫩枝嫁接或边劈可提高检测效率.

苹果潜隐病毒的研究——Ⅲ.茎沟槽病毒对苹果内源激素的影响

用LC—6A高效液相色谱仪测试富士二年生苹果苗的三种内源激素。结果表明:受茎沟槽病毒侵染植株GA_3、CTK及IAA,三种内源激素的含量均较对照(无毒植株)低。GA_3降低最显著,比无毒植株低111.18％,CTK比无毒株低19.66％,IAA比无毒株低17.69％。