12:77-84, 2003 (Albugo bliti) 1,3 2 1 2 3 [email protected] +886-4-23321478 92 4 15 . 2003. (Albugo bliti) . 12:77-84. Albugo bliti (Amaranthus mangostanus) (A. mangostanus forma ruber) (A. lividus) 4 4 20 - 40 min 4hr 12-28 20-24 32 20 4hr 36 16 20 3.4% A. bliti 4 4hr Albugo bliti (Stramenopila) (Peronosporales) (6,10) (Amaranthus spp., edible amaranth) (zoosporangia) (zoospores) (Amaranthaceae) (oospores) (A. viridis L.) (A. lividus L.) (A. mangostanus (vesicle) L.) (A. mangostanus L. forma ruber Makino) (indirect germination) (A. hypochondriacus L., A. caudatus L.) (cyst) (18-23 ) (direct germination) (40 ) (8,11,13) (1,4) 22 - 30 Albugo bliti (8) (Biv.) Kuntze (white rust) (5) Pythium spp. (12) 8-12hr (damping-off) Rhizoctonia solani (haustoria) (9,12) (seedling blight) R. solani AG 2-2IIIB (foliage blight) (3) Albugo bliti (sori) A. bliti (2) 0% 70% 78 12 2 2003 4-5 24 2 24 2hr (lactophenol cotton blue) ( A-D) (%)=( ( A-C) / ) 100 4 100 Abw, Abr, Abl - 200 3 (analysis of variance, ANOVA) 1% 30 sec 1 min 50 30 11 cm3 24 4 ( 4 ) 4hr 24 4 hr 5-7 20 min 4hr ANOVA ( D) V (90 mm ) 24 1.5 ml 2hr Parafilm "M" (American National CanTM) (25 ) 5 min 8-36 ( 4 ) 4hr 4 100 - 200 1ml Mini-BeadbeaterTM (Biospec Products) 3000 rmp 1 min ( E, F) 1 105 (%) = ( / ) 100 V 3 Parafilm "M" 32 28 (Albugo bliti) 79 A D B E C F ( ) ( ) A. B. C. D. E. (A) (B) (C) F. (Albugo bliti) = 10 m (D) Fig. 2. Indirect germination of sporangia and direct Fig. 1. Symptoms of white rust occurred on various germination of zoospores of Albugo bliti. A. sporangia. B. amaranths (A) Amaranthus mangostanus, (B) A. mangostanus Protuberance on the tip of sporangium. C. Cytoplasm forma ruber, and (C) A. lividus caused by Albugo bliti in the squeezed from sporangium. D. Zoospores formed within the field. (D) Irregular, white protuberant sori on the infected leaf. vesicle outside the sporangium. E. Zoospores swimming around the empty sporangium. F. Cyst zoospores germinated and formed germ tube. Bar = 10 m. 32 (1 (mean standard 105 sporangia/ml) 32 4 24 hr deviation) 20 4hr 20 32 36 4 Abl 1.5 ml Parafilm 36 8hr Abl 2, 4 24 hr 58 20 4 18 %, 59 5 %, 65 6% ( ) 3 36 Abl 24 hr Abl 16 4 2 100 - 200 3 43.8 7.3% 4 66.2 4.4% 14 30.5 5.3% Y=30.35 + 9.92 X-0.71 X2, r2 = JMP version 5 (SAS Inc., Cary, NC, 0.92 Y X 1989-2002) ANOVA ( ) 10 t test Duncan's new multiple range test t 80 12 2 2003 20 min 10.7 2.9% - 12.1 11.3% 20 240 min Abl Abr Abw Abl Abr Abw (p < 0.05) ( ) Abl Abr Abw 80 min 4hr 56.8 17.4% 64.4 14.4% 39.5 7.0% 37.5 4.1% 32.4 8.6% 39.0 2.6% ANOVA 80 min 4hr 24 Abl Abr 12-20 4 24 hr Fig. 3. Zoospore discharge of sporangia of Albugo bliti 20-24 collected from Amaranthus lividus. Sproangial germination 32-36 was tested with two days intervals after sori formed. ( A) Sporangial germination in distilled water was recorded after incubation at 24 for 4 and 24 hr. (appressoria) ( ) Abl 12 4 hr 16-24 28 Abr 20-28 24-28 Abr 24 32 Abl, Abr Abw 32 4hr 24 hr 20 4hr (Abl) 32 24 hr 24 0, 2, 4, 6, 8, 12, 20 32 4hr 20 4hr 24 hr Fig. 4. Time required for the germination of mature sporangia Abr Abl Abw of Albugo bliti collected from Amaranthus lividus. Sporangial Abl, Abr Abw 32 4hr germination in distilled water was recorded after incubation 20 4hr 2.0 0.8 %, 1.0 1.4% at 24 for 2 to 24 hr with 2-hr intervals. 1.3 1.5% 69.2 1.5 %, 35.2 1.5% 40.8 2.6% 20 75.0 1.4 %, 12.9 3.8% test 24.8 2.9% (p < 0.002) ( 76 31% A) 32 24 hr 20 4hr 64 21% Abl, Abr Abw 1.3 1.5 %, 2.2 2.5% 1.8 1.5% 25.0 3.7 %, 30.5 2.5% 15.3 9.3% 20 83.5 2.6 %, 26.8 1.8% 44.5 1.7% Abr Abl Abw (p < 0.001) ( B) (Albugo bliti) 81 AP AP 4hr Abw, Abr Abl Fig. 5. Sporangial germination of Albugo bliti in distilled water incubated at 24 for 4 hr with 20-min intervals. Abw, Abr, and Abl were isolates of A. bliti collected from Amaranthus mangostanus, A. mangostanus forma ruber, A. 24 8hr lividus, respectively. (AP) =10 m Fig. 7. Appressorium (AP) formed on glass slide after zoospores in distilled water was incubated at 24 for 8 hr. Bar = 10 m. 36 Abl 36 1 4 20 4hr 41.0 6.9% 40.6 5.4% t test 10 22.6 5.0% 16 3.4 1.9% ( ) (blastic) (sporangial chain) (sporangiophore) (Abl) (Abr) (A) (B) 12% t test Fig. 6. Effect of temperatures on the sporangial (A) and zoospore (B) germination of Albugo bliti Abl and Abr isolates collected from Amaranthus lividus and A. mangostanus forma ruber, respectively. Sporangial germination in distilled water after 4 hr incubation at different temperatures. 82 12 2 2003 36 36 3 16 p=0.05 Fig. 9. Effect of 36 on the sporangia germination of Albugo bliti. Sporangia of A. bliti collected from Amaranthus lividus were maintained at 36 incubator for 16 days and germination was tested with 3-day intervals. The same letter above the bar was not differed significantly according to the Duncan's new multiple range test while p = 0.05. 32 Abl Abr Abw Duncan's multiple range test 20, 32 20 32 4hr 24 hr 80 min 24 hr 32 20 32 4hr 24 hr 20 4hr ( ) 80 20 32 20 32 p=0.05 min Fig. 8. Effect of 32 on the sporangial germination of Albugo bliti. Abl, Abr and Abw isolates were A. bliti collected from Amaranthus lividus, A. mangonstanus forma 24 ruber, and A. mangonstanus, respectively. 20, 32: sporangial Edie & Ho (8) (A. germination in distilled water was recorded after incubation ipomoeae-aquaticae) at 20 and 32 for 4 hr (A) and 24 hr (B), respectively. 32 25 20: sporangial germination in distilled water was recorded at 32 for 4 hr (A) and 24 hr (B), then transferring to 20 for further 4 hr to stimulate the sporangia germination. The same letter within the same isolate among the 20, 32 20 and (30 ) (5) 32 treatments, was not differed significantly according to (25 ) the Duncan's new multiple range test while p = 0.05. 24 2-4hr 4-5 4-6 Edie & Ho (8) (A. ipomoeae- ( ) aquatice) 15 (Phytophthora palmivora) 20 min (7) (Albugo bliti) 83 ( ) 1. 1996. 28: 14-17 2. 1998. 40: 439-440 ( ) 3. 2002. 11: 33-44 4. 1981. 12 - 28 16 - 28 ( ) . 21:88-105 16-24 5. 1922. (Suborder Peronosporineae) 32 4hr 24 hr 20 (Family Albuginaceae) (Genus Albugo). p. 22-27. 2 . 4hr 32 24 hr 2 . 173 pp Abr ( 6. Barr, D. J. S. 1992. Evolution and kingdoms of organisms B) 32 from the perspective of a mycologist. Mycologia 84:1-11. 36 7. Clerk, G. C. 1972. Germination of sporangia of ( ) 20 4hr Phytophthora palmivora (Butl.) Butl. Ann. Bot. 36:801- 807. 24 hr 32 8. Edie, H. H., and Ho, B. W. C. 1970. Factors affecting 20 20 sporangial germination in Albugo ipomoeae-aquaticae. 24 hr Trans. Br. Mycol. Soc. 55:205-216. 9. Kajornchaiyakul, P., and Brown, J. F. 1976. The infection process and factors affecting infection of sunflower by Albugo tragopogi. Trans. Br. Mycol. Soc. 66:91-95. 32 6hr 10. Patterson, D. J. 1989. Stramenopila: Chromophytes from 32 24 hr 4 a Protistan Perspective. Pages 357-379 in: The Chromophyte Algae: Problems and Perspectives. J. C 10 hr ( ) Green, B. S. C. Leadbeater, and W. L. Diver ed. Oxford Univ. Press, New York, 429 pp. 11. Petrie, G. A., and Verma, P. R. 1974. A simple method for germinating oospores of Albugo candida. Can. J. Plant Sci. 54: 595-596. 12. Verma, P. R., Harding, H., Petrie, G. A., and Williams, P. H. 1975. Infection and temporal development of mycelium of Albugo candida in cotyledons of four Brassica species. Can. J. Bot. 53: 1016-1020. 13. Verma, P. R., and Petrie, G. A. 1975. Germination of 90AS-1.2.2-PI-P4 oospores of Albugo candida. Can. J. Bot. 53: 836-842. 84 12 2 2003 ABSTRACT Lee, M. L. 1,3, and Hsieh, W. H. 2 2003. Effect of temperature on the sporangial germination of Albugo bliti. Plant Pathol. Bull. 12:77-84. (1. Department of Pesticide Application, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung hsien, Taiwan, R.O.C.; 2. Department of Plant Pathology, National Chung Hsing Univeristy, Taichung, Taiwan, R.O.C.; 3. Corresponding author, E-mail:[email protected], Fax:+886-4-23321478) The effect of temperature on the discharge of zoospores from sporangia of Albugo bliti (Biv.) Kuntze was studied. Sporangia of three isolates, Abw from Amaranthus mangostanus L., Abr from Am. mangostanus L. forma ruber Makino, and Abl from Am. lividus L. respectively, were used to inoculate on their original host plants. Sori formed on leaves 4 days after inoculation.