土壤理化性質對水稻徒長病發生之影響

近年來由Fusarium fujikuroi Nirenberg引起的水稻徒長病(bakanae disease of rice)在台灣各地有逐漸嚴重的趨勢，本試驗於農業試驗所溫室內利用8個不同類型土壤以及3個不同接種病原菌之方法進行研究。8個試驗土壤分別採自於彰化縣芬園鄉、屏東縣萬巒鄉、彰化縣和美鎮、彰化縣線西鄉、彰化縣竹塘鄉、彰化縣二林鎮、彰化縣芳苑鄉與台南市佳里區，所使用的水稻品種為「高雄139號」。病原菌接種處理分別為(1)在種子浸種前(種子接菌)，(2)種子發芽後 (胚根接菌)，(3)接於土壤中(土壤接菌)三種，接種源濃度依序為4.5 × 10^6 spores mL^(-1)、4.5 × 10^6 spores mL^(-1)與5.4 × 10^5 spores g-1 soil。水稻播種35 d後進行生長調查與死亡率調查，試驗結果顯示：3個接種病原菌方法中，以種子接菌處理之水稻徒長病死亡率最高，且該處理之水稻植株總乾物重亦最小。在種子接菌處理之8個土壤中，水稻徒長病死亡率以彰化縣芬園鄉土壤最高(66%)，其次為彰化縣和美鎮土壤(45%)，第三為屏東縣萬巒鄉土壤(29%)，第四為彰化縣線西鄉土壤(23%)。此外，水稻徒長病死亡率也分別與土壤pH值、有效性鈣含量及硼含量呈顯著直線負相關(P ＜ 5%)，其他土壤理化性質則與水稻徒長病死亡率無顯著直線相關(P ＞ 5%)。在胚根接菌與土壤接菌處理之8個土壤中，水稻徒長病死亡率皆以彰化縣芬園鄉土壤最高，分別為20%與12%，但這兩種接菌處理在其他7個土壤中對水稻之影響則與對照組無顯著差異。本試驗結果顯示：帶有徒長病原菌的水稻種子在彰化縣芬園鄉、彰化縣和美鎮、屏東縣萬巒鄉及彰化縣線西鄉四種土壤中具有較高發病的機率。

關鍵字

水稻徒長病； Fusarium fujikuroi ；土壤性質

並列摘要

In recent years, bakanae disease of rice caused by Fusarium fujikuroi Nirenberg seems getting worse and widespread in Taiwan. In order to explore the influence of soil physical and chemical properties on the disease occurrence, 3 inoculation methods in 8 soil samples were conducted in greenhouse at Taiwan Agricultural Research Institute. The 8 soil samples were collected respectively from 1. Fenyuan, Changhua county, 2. Wanluan, Pingtung county, 3. Hemei, Changhua county, 4. Siansi, Changhua county, 5. Chutang, Changhua county, 6. Erlin, Changhua county, 7. Fangyuan, Changhua county, and 8. Chiali, Tainan county. The tested rice cultivar was ‘Kaohsiung 139’. There were three pathogen inoculation treatments: 1. seed inoculation, rice seeds were submerged in spore suspension before soaked in water for producing radicals; 2. radical inoculation, the germinating seeds with radicals were submerged in spore suspension before planting; 3. soil inoculation, soils were directly mixed with spore suspension . The inoculation densities respectively were 4.5 × 10^6, 4.5 × 10^6, and 5.4 × 10^5 spores g^(-1) soil. Thirty five days after planting, plant growth and mortality of rice were surveyed. The results indicated that rice seed inoculation treatment, if compared with the other two treatments, showed the highest mortality rate and the lowest plant dry weight. Among the 8 testing soil samples, the highest mortality rate was found in Fenyuan 66%, followed by Hemei 45%, Wanluan 29%, and Siansi 23%. In addition, the mortality rates of seed inoculation in 8 soil samples showed a significantly negative linear correlation (P ＜ 0.05) between soil pH, available calcium and boron, respectively. As to the other soil physical and chemical properties, they did not show any significant linear correlation (P ＞ 0.05). The highest mortality rates in both radical inoculation and soil inoculation treatments were 20% and 12%, respectively, in Fenyuan soil; however, the mortality rates in the other 7 testing soil samples showed no significant difference if compared with control. In this experiment, the results suggested that high occurrence potential of bakanae disease may be precautious especially if the rice seeds were infested with Fusarium fujikuroi in the previous 4 soil sampling sites (Fenyuan, Hemei, Wanluan, and Siansi) or any location with similar soil physical and chemical properties.

並列關鍵字

Bakanae disease of rice ； Fusarium fujikuroi ； Soil properties

國際替代計量

土壤理化性質對水稻徒長病發生之影響

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