824 research outputs found
An unusual adenomatoid odontogenic tumor in the mandible resembling a cyst - a case report
No full textActivation of Peroxisome Proliferator Activating Receptor ?? by some compounds and extracts from food materials
No full textHigher expressions of p53 and proliferating cell nuclear antigen (PCNA) in atrophic oral lichen planus and patients with areca quid chewing
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Thickness dependence of microstructures and magnetic properties for CoPt/Ag nanocomposite thin films
No full textEffect of Ag Underlayer on Microstructures and Perpendicular Magnetic Properties of CoPt Nanocomposite Thin Films
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Multi-Rate Throughput Optimization with Fairness Constraints in Wireless Local Area Networks
No full textAn investigation on cotton nematodes of Taiwan and a preliminary study on. the effects of reniform nematode, root-knot nematode and stubby-root nematode on cotton
No full text本項試驗以本省南部九個主要植棉區為線蟲調查對象，並就三種主要植物寄生性線蟲進行玻璃室病原性接種試驗，旨在明瞭本省棉作主要寄生性線蟲之種煩及其分佈情形，以及與棉黃化矮、提早落葉等現象之關係。試驗結果得知本省棉田土中之植物寄生性線蟲計有Rotylenchulus sp., Helicotylenchus sp., Tylenchorhynchus sp., Mel oiclogyne sp., Aphelenchoides sp., Praitylerzchus sp., Triholors sp., Hoplolaimus sp., Criconemoides sp., Tylenchus sp., Xiphiflema sp., Longidorus sp.,及Hirschmanniella sp. 等13屬，其中6屬已鑑定種名者為腎形線蟲(R. renifomis)，根瘤線蟲(M. incognita)，螺旋線蟲(H.exdlus)，殘根線蟲(T. christiei)，刺線蟲(T. cylinciricus )及根腐線蟲(P. minyus)等。
棉寄生性線蟲之種類及密度因棉栽培地區及生育時期而有差別。在老棉區如義竹、朴子等鄉鎮棉田寄生性線蟲種類較多，共育10~11屬，但在其他地區則僅有5~6屬，少者2~3屬(圖2)，然而都以R. reniformis發生蟲數最多，次為根瘤線蟲(M. incognita)或為螺旋線蟲(H. exallus)。棉生育初期主要寄生性線蟲以R. reniformis蟲數最多，H. exallus次之，再次為M. incognita。生育後期亦是以H. reniformis居首位，次為M. incognita，再次為T. cylindricus，並有Longidorus sp. 之出現。
以腎形線蟲(R. reniforlnis)，根瘤線蟲(M. incornita)及殘根線蟲(T. christiei）進行玻璃室接種試驗結果，顯示此等寄生性線蟲均具有高度病原性，可使棉株生育受阻，產生矮小、根群生育不良葉片黃化等病徵。接種後30日以T. christiei病象最明顯，但接種60日後則R. reniformis病徵最嚴重。田間調查矮小黃化、提早落葉等現象之棉株根圈土壤結果，發現含有高密度之腎形線蟲(R. reniformis)，根瘤線蟲(M. incognita)，螺旋線蟲(H. exallus)，刺線蟲(T. cylindrichus)，殘根線蟲(T. chrstiei)，根腐線蟲(P. minyus)及Tylenchus sp.等。
Several plant parasitic nematodes were found associated with cotton rhizosphere, the most predominant of which were reniform nematode (Rotylenchulus sp.), spiral nematode (Helcotylenchs sp.), stunt nematode (Tylenchorhvnchus sp.), root-knot nernatode (Meloidgyne sp.), lesion nematode (Pratylenchus sp.), stubby-root nematode (Trichodoys sp.), lance nematode (Hoplolaimus sp.), ring nernatode (Criconemoides sp.) dagger nematode (Xiphiema sp.), needle nematode (Longidorus sp.), rice-root neinatode (Hirschimanniella sp), Aphelenchoide. sp., and Tylenchus sp. Among them six were idertified to species, they were reniform nematode (R. reniformis), root-knot nematode (M. incognita), spiral nematode (H. exa1lis), stubby-root nernatode (T. christiei), stunt nematode (T. cylindricus). and lesion nematode (P. mmnyzes).
The genera of nematode discovered were found to be different among cotton-growing areas. The older cotton-growing areas, such as Pn-tzu and I-tsu, harbored more plant parasitic nernatocles with 10 to 11 genera; but the newly established or well roated cotton-growing areas were found containing comparatively lesser nernatodes with 5-6 genera or even only 2-3 genera.
Reniform nematode was probably the most important plant parasitic nematode of cotton in Taiwan. This nernatode was found heavily associated with cotton root throughout the growing season. Great numbers of root-knot and stunt nematodes also fed on both young and mature cotton plants, Spiral nematode was generally found in the rhizosphere of cotton seedling, but was found less frequently from the soil of mature cotton plant. Populations of reniforin, root-knot, spiral, stunt, stubby-root, and lesion nernatocies, and Tylenchus sp. were generally higher on sites exhibiting poor growth (stunting and yellowing) of cotton.
In greenhouse tests, reniform, root-knot, and stubby-root nematodes all caused considerable root damage and inhibiting top growth cotton. Stubby-root nematodes were more destiuctive than renjforrn and root-knot nematodes in the first 30 days after inoculation. However, the damages caused by reniform nematodes were more pronounced than the other two nmatodes after they fed longer on cotton roots
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