The English term fungus (pl. fungi) should be translated into Chinese in two ways, according to its definite meaning when applied to different cases. One is pronounced zhenjun (真菌) for true fungi which is of strict sense, usually for those belonging to Eumycota while the other is of broad sense, pronounced junwu (菌物) for organisms including true fungi, pseudofungi, fungus like protozoa and symbiontic fungi such as lichens and mycorrhyza. So far the term fungi in the 8th edition (1995) of Ainsworth & Bisby's DICTIONART OF FUNGI is of broad sense, therefore the Chinese term junwu (菌物) should be used.

ifferentiation of the resistance in wheat cultivars to stripe rust (Puccinia striiformis) was tested with wild type physiological race CYR29-1 and its 7 mutants. The results indicated that the populations of Suwon 11, Kang yin 655, and Beardless Zhong 4 differentiated in their resistance to these stripe race and mutants. So were some sources of resistance, commercial cultivars and candidate cultivars, with different ratios of R:S or R:MR individuals. All these indicates that the populations of these accessions are heterogeneous in their resistance to stripe rust. The cause of the differentiation of the resistance of wheat cultivars to stripe rust was also discussed, and the improvement on the screening and utilization of sources of resistance suggested.

Resistance to eighty four isolates of Blumeria graminis f. sp. tritici was identified in Haynaldia villosa (2n=14, VV), five amphiploids (2n=42, AABBVV), TH1, TH1W, TH2W, TH3, and TH3W, derived from crossing Triticum durum (2n=28,AABB) with H.villosa, and hexaploid substitute wheat lines 6D/6V, pm93064 (DH₂), derived from H. villoas. The results showed that the H. villosa and its derived wheat lines were immune or high resistant to all tested isolates from America, Germany and China. The resistance was more effective than any other resistance gene lines from pm1 to pm20, and the resistance gene has been transfered effectively to tetraploid and hexaploid wheat from H. villosa, and also was inherited to the progenies.

This paper analyses the field epiemic dynamics of wheat sharp eyespot, using the method of Fuzzy clustering. The results show:the field epidemic dynamics of the disease can be divided into 5~6 stages, namely the occurrence stage before winter, winter steady stage, turning green rising stage, jointing evil stage and white ear showing illness stage. The field distribution and expanding of wheat sharp eyespot can be described with several parameters, such as X1, X2, X3, X4. Fuzzy clustering analysis describes the condition of the field distribution of wheat sharp eyespot, of both horizontal expanding and vertical directions. That is, it describes the changing of the disease in time and space. The results provide the reliable basis for forecast and integrated control of wheat sharp eyespot.

In 1985~1995, 1394 samples of maize stalk rot were isolated from 16 provinces in China. of which, 63.8% were Pythium, 36.4% were Fusarirm. Isolation frequency of these fungi were, however, different among these provinces. Results of further research showed that the frequency were directly influenced by several factors, such as culture medium, isolation position, degree of stalk rot, as well as season when the sample was collected.

The present paper deals with studies on the ultrastructure of syncytia in roots of resistant soybean varieties, Huipizhiheidou and Yuanboheidou,and susceptible control, Ludou No.1 at 4, 9, 14 days after inoculation. The results showed that there were bigger syncytium component cells, formation of all ingrowths and a lot of various organelles, especially with more and bigger smooth endoplasmic reticula in susceptible roots; whereas the syncytia in resistant roots were with smaller syncytium component cells, and there were more ribosomes, and less and smaller rough endoplasmic reticula,and more lipidlike droplets in their cytoplasm.It was also observed that the separation of plasmalmma from cell wall and the early degeneration of cytoplasm in resistant roots also occurred.

The variations of cytokinin and auxin levels in the sweet potato associated with MLO were measured by using HPLC in the whole growing season. It was indicated that the cytokinin level of diseased sweet potato was much higher than that of healthy ones, and as to the auxin level, the diseased plants had drasticly lower concentration of auxin than healthy plants in the bud bursting stage. The auxin level in both healthy and diseased plants became almost the same as the sweet potato growing up. The cytokinin to auxin ratio during the growing season was calculated and itsèffect on the witches' broom symptoms was discussed.

The sensitivities of Sclerotinia spp. isolates from different hosts infected by Coniothyrium minitans were tested in laboratory. The effects of soil factors,such as soil temperature,soil related water content and soil type on C. minitans parasitizing sclerotia of Sclerotinia sclerotiorum were examined. The activity and colonization of C. minitans in soil were also detected by measuring the respiratory rate of soil when C. minitans was inoculated in laboratory. The results showed that the sclerotia of all Sclerotinia spp. isolates tested were high sensitive to C. minitans rather than to S. minor which showed moderate sensitivity. The optimum soil temperatrue and soil related water content (RWC) for parasitism were 20℃ and 50~60% RWC respectively. The sclerotia carried spores of C. minitans were rotten after two months in all kinds of soil so far supplied,but the soil type could influence the speed of sclerotial rot.The activity and colonization of C. minitans in soil were related closely with the existence of sclerotia or extract of sclerotia of S. sclerotiorum. According to the ecological characteristics of C. minitans, it suggested that C. minitans has a great potential for controlling sclerotinia wilt of various crops.

Biology and serological comparison between ToMV tomato isolate (ToMV-To-S1) and TMV broad bean isolate (TMV-B935A) was made. Both ToMV-To-S1 and TMV-B935A could infected 14 plant species in 3 families when 20 plant species in 6 families were tested. The difference was found in Nicotiana tabacum (N. tabacum-White Burley, N. tabacum-Huang Miaoyu), ToMV-To-S1 induced local lesions in these plant species, while TMV-B935A produced systemic mosaic symptoms. In double-diffusion tests, spur formation was observed between ToMV-To-S1 and TMV-B935A, and the results of intragel cross-absorption tests agreed with the doublediffusion tests results. Specific primers corresponding to the coat protein gene and 3' non coding region were designed. When ToMV-To-S1 cDNA templete were used, a specific band could be amplified with ToMV primers by PCR, No band was found when we used TMV primers. With TMV-B935A templete, only TMV primers could produce a specific band. So it is easy to distinguish ToMV-To-S1 and TMV-B935A with ToMV and TMV specific primers.

The results of this study indicated that the optimal stage of tomato seedling inoculated by root dipping for resistance identification to Fusarum oxysporum is at 2-true-leaf stage, when the fibrous roots are numerous and liable to be hurt. Thus resulted in high inoculation rate by root dipping. The occurrence of Fusarium wilt showed no significant difference when inoculated plants were re-planted at once or at 2, 5, 10 minutes after dipping. With an inoculum concentration of 10 spores per milliliter and at 28℃~30℃ in a greenhouse,resistance of tomato varieties to Fusarium oxysporum can be determined and screened accurately.

The experiment utilized two induced nonpathogenic fungi to inject in the stem of cucumber plant. The results shown that the active resistance and against ability to downy mildew were improved. All the foliages sugar and lignin content of the induced plants were higher than the contrast plant. The sugar were 11.21%, 10.66% and 9.58%, respectively. The lignin were 8.4%, 7.8% and 6.9%, respectively. These data indicated the induced-resistance caused by induced fungi related to the contents of soluble sugar and lignin, but also demonstrated that the contents of soluble sugar and lignin in cucumber plants were a part of mechanism of inducing resistance.

Spathiphyllum pallas Hort.is a new introduced flower plant in South China in recent years. The brown rot occured seriously in the autunm of 1995. The pathogen has been identified as Cylindrocladium spathiphylli Schoulties et al. according to its morphology, cultural characters and pathogenicity. A series of experiments on diseased soil and various media of planting flower plants showed that this fungus spread to Mainland from Taiwan province with the seedlings and their media in 1995. It is proposed that roots of plant and media must be quarantined strictly during introducing these new plants.

Indexing tests were done in seeds of Guotoucheng orange for citrus tristeza-stem pitting virus with double antibody sandwish enzyme-linked immunosorbent assay (DAS-ELISA). The results showed that seeds collected from Guotoucheng orange seedling infected with stem pitting disease were positive for CTV-SP. The consistency of CTV in inner seed-coat was higher than that in peeled seed. It remained positive after one to two years' storage of seeds in refrigerator at 4℃, but the consistency of CTV was reduced. External seed-coat was negative. Young tissues collected from some of the seedlings propagated from infected seeds, as well as Mexican lime grafted on Guotoucheng orange seedlings were positive for CTV by DAS-ELISA test. More than 100 of 2 years-old Guotoucheng orange seedlings planted in insect-proof screenhouse were grafted with buds of healthy Mexican lime, and no symtoms were observed for two years.

Three endogenous hormone contents of banana plants infected by BBTV, including gibberellic acid (GAs), isopentenyladenine group (iPAs) and abscisic acid (ABA), were detected by enzyme-linked immunosorbent assay (ELISA) in this test. The results showed that the GAs contents of inoculated plants at different infecting periods were all lower than that of healthy plants, in spite of increasing slightly during infection. The iPAs contents of infected plants decreased significantly after 14th day of BBTV inoculation and kept in lower level during infection. ABA was greatly induced and accumulated in banana plants infected by BBTV. The ABA content of infected plants tested in 35th day of BBTV inoculation was highest and was 3.34 times of the control. The movement of BBTV in infected banana plants was determined in the same time in this test. The BBTV contents in inoculated leaves and in top leaves detected by indirect-ELISA respectively indicated that BBTV particles replicated greatly both in inoculated leaves and top leaves after 21th day of inoculation. However, the symptom of infected banana plants appeared in top leaves after 35th day of inoculation. All these results indicated that the symptom of banana bunchy top disease may be closely related to the unbalance of endogenous hormones of infected plants, but indirectly related to the BBTV movement within plant.

Pseudomonas sp., Fusarium solani, Alternaria tenuis and Rhabditis elegans were isolated from root rot of Panax notoginseng (Sanqi) at different developmental stages. In inoculation test, Pseudomonas sp. showed the strongest pathogenicity, while Fusarium solani and Alternaria tenuis were weak, Rhabditis elegans was non-pathogenic. With the three formers as inocula, the root rot rates of mixed inoculations were all higher than that of their individual inoculations. The combined inoculation of the three pathogens showed the highest pathogenicity. With new multiple range test, root rot rates among 3 combined inoculations and their individual inoculation resulted in significant diffenence (P=0.05). The present experiments reveals the fact that the bacteria played an important role in the combination infection with other fungous and nematode pathogens.

The present papaer deals with the accurate meaning of the Chinese translation of some technical terms in plantpathology and its related sciences. The writer inter prets some of the published Chinese terms with their accurate meanings and points out the proper selection in use of them. The terms mentioned and discussed are as the following:fungi, virus, virion, particle, toxin, mechanism, principle, infection, infection cycle, life cycle, nucleoside, mycoplasma, mycoplasma-like organisms, phytoplasma, bacte-ria-like organisms, antagonism, syner-gism and Cynophyta or green bacteria, and nucleocapsid.

276 accessions from 80 species of 16 genera in Triticeae were screened for resistance to head scab with single-floret and multi-floret injection inoculation methods respectively. The results showed that great difference in resistance existed between genera or species. Roegneria species with high resistance to initial infection and high resistance to pathogen spread were the most resistant ones in all tested species. Elytrigia, Pseudoroegeria, Psathyrostachys and perennial species of Hordeum were susceptible to initial infection, but were highly resistant to pathogen spread. Elymus, Kengyilia and Agropyron showed moderate resistance to initial infection and high resistance to pathogen spread. Aegilops, Crithopsis, Eremopyrum, Heteranthelium, Henrardia, Haynaldia, Teaniatherum and annual wild species of Hordeum showed high susceptibility to head scab.

Four winter wheat varieties were inoculated with conidia suspension of Fusarium graminearum Schw. JF-12, and conc. of ascorbic acid (AsA) and the activities of AsA oxidase and AsA peroxidase in the head tissues sampled 2~22 d after inoculation were assayed. The results showed that susceptible and moderately susceptible varieties (Ning No.6, Yangmai No.3 and Ning 8026) showed higher conc. of AsA and lower activities of AsA oxidase and AsA peroxidase, while resistant variety (Wangshuibai) showed lower conc. of AsA and higher activities of AsA oxidase and AsA peroxidase in the inoculated heads than those in the check heads (inoculated with water). It was also observed that AsA stimulated the germination of conidia and the extension of the germ tubes of the pathogenic fungus at the conc. of 1~5mg AsA·10ml^-1. AsA showed no obvious effects on the growth of the pathogen at the conc. of ≤ 15mg·L^-1 but suppressed the fungal growth at the conc. of 30~60 mg·L^-1. The conc. of AsA on which the fungus grown gave no effect on the conc. of AsA within the fungal mycelia. The relationship between wheat resistance/susceptibility to scab and AsA conc. in the heads tissues was discussed and it was suggested that higher AsA contents might be related to wheat susceptibility to scab.

The rice seedling disease causal agents:Fusarium equiseti, F. oxysporum, F. graminearum and Rhizoctonia solani isolated from paddy rice soil and diseased rice seedlings, were used to inoculate the Immunization of Rice Nursery (IRN) seedlings and Paddy Soil Land Nursery (PSLN) seedlings (control). It was indicated that the disease resistance of IRN seedlings was 95.5~97.8% higher than that of PSLN seedlings. By testing the dynamics defensive enzyme systems in both IRN and PSLN seedlings after inoculation with the causal agents, the results showed that under the elicitment by the causal agents the enzyme activity peaks of peroxidase (PO) and superoxide dismutase (SOD) in IRN seedlings appeared 36 hrs and 4 hrs earlier than those in PSLN seedlings, respectively, and that the ratio activity of phinylalaminase in IRN seedlings was 2 times more than that in PSLN seedlings. In addition, IRN seedlings metabolized faster and showed higher physiological activity. The physiological traits of IRN seedlings were as follows:(1) the higher amount of chlorophyll (3.12mg/ml), strong photosynthetic ability (887.0 mol O₂/g.hr), thus dry matter accumulation was much faster. (2) Dense root system (11.5 roots per plant), there was 3.9 roots per plant more than that of control. (3) The α Naphthylamine oxidation was 60.0 μg/g.hr which was 30% higher than that of control.

Callus induction and bud and root differentiation of leaf culture in vitro from soybean plant inoculated with soybean mosaic virus strains Sa and Sg were studied. The induction rate and its results showed that there appeared no significant difference of callus morphological characteristics between those inoculated and non-inoculated with SMV. The frequency of bud differentiation for those inoculated with Sa strain was lower than those non-inoculated, while the situation was vise versa for those of Sg. The root differentiation ability was decreased after inoculation of Sa and Sg, but with less influence on resistant varieties in comparison with susceptible varietes.

Soybean cultivars and lines 861387-10, Ludou No 4, 8205, RN-9, 861003, Peking were selected as differential hosts for pathogenicity tests. 37 isolates of soybean root rot pathogen (Fusarium solani) collected from Shandong, Anhui, Henan and Jingsu provinces were divided into 10 groups based on the virulence on 6 differentials.

The inhibiting action of ZHONGSHENGMYCIN on gram postive bacteria, gram negative bacteria and filamentous fungi showed that ZHONGSHENGMYCIN was a wide-spectrum agricultural antibiotics. It had no effect on permeability of cell membrane of bacteria, but it could result in condensation of the plasma of some cells of E. carotovora subsp. carotovora on high concentration 100 ppm. The incorporation experiment of precursor labelled by radio-active isotope showed that ZHONGSHENGMYCIN had little effect on the synthesis of DNA and RNA of E. carotovora subsp. carotovora on 15.6 ppm, while it had strong inhibiting action on the synthesis of protein. Similar results to precursor incorporation experiment was gained by quantity analysis the amount of the macromolecules of Bacillus subtilis 6633. The studies showed the mode of action of ZHONGSHENGMYCIN is the inhibiting action on the synthesis of protein.

The Biolog identification system (Biolog Inc. USA, BIS) with MicroStation^TM V3.5 software were used for the rapid identification of bean wilt bacterium (C. f. pv. flaccumfaciens, Cff) and related plant coryneform bacteria. The results showed that 23 of 24 isolates of Cff and related pathovars (pv.) were correctly identified to species level, one to genus level; and 13 out of 24 isolates to pv. level with an accuracy of 95.8% being identified to species level. Two isolates of Clavibacter michiganensis subsp. michiganensis and two isolates of C.m. subsp. insidiosus were also correctly identified to pv.level. Cluster analysis using MLClust program showed that Cff and related coryneform bacteria isolates seperated into two divisions and supported the classification of Clavibacter and Curtobacterium at both species and genus level.We concluded that the BIS is a useful tool for the rapid identification of Cff and meets the requirements of our port plant quarantine because of its rapid, accurate and high standards.

An invastigation on the relation between bark senescing process and susceptibility to Valsa invasion was conducted. The number of circles of phloem fiber bundles is corresponding to the age of apple, bark growth. During the senescing process of bark, the disturbance and disorganization of the end part of phloem rays in the outer old bark tissues is closely related to susceptible performance of the bark. Characteristic standard of "strong tree" was suggested and verified in field trials. Artificial renewal of senescent bark was helpful for enhancing resistance to fungal invasion and therefore prevention of disease incidence.