用加热四环素治疗柑桔黄龙病芽条的试验初报

PRELIMINARY REPORT ON THE EFFICACY OF HEATED TETRACYCLINE HYDROCHLORIDE SOLUTION IN TREATING CITRUS YELLOW SHOOT DISEASE

从甜橙、蕉柑和化州橙的病树上取具有典型黄龙病症状的芽条,分别用不同温度的1000ppm盐酸四环素溶液处理一定时间。试验结果表明:用44,46,48和50℃处理15min,45℃处理10,20和25min,47℃处理10和20min,49,50和51℃处理10min的病芽条,嫁接于无病红桔实生苗上,经连续3年观察,均未见发病。而用20℃1000ppm盐酸四环素溶液浸20min或20℃清水浸15和20min,以及分别用44,45,46和47℃热水处理15min,则有31.1％～95.1％的植株发病。柑桔芽条用45～48℃的四环素溶液处理10～15min,既保证治疗效果,又有较高的成活率,可在生产上推广应用。

Shoots of Citrus sinensis, Citrus tankan and Citrus sinensts var. Huazhouensis were cut from typically diseased trees and immersed in 1000ppm selution of tetracycline hydrochioride heated separately to 44,45,46. 47,48,49,50 and 51℃ for 10 15,20 and 25 imnutes. Three checks were set up:Check 1. diseased budslicks immersed in 1000ppm tetracycline hydrochioride at 20℃ for 20 minutes ;Check 2,diseased budsticks immersed in clean water at 20℃ for 15 or 20 minutes; Check 3. diseased budsticks treated with hot water at constant temperature of 45,46, 47,48,and 49℃ respectively for 15 minutes. Scions from above treatments carrying 2 -3 buds were grafted on to disease-free tangerine seedlings in an insect - proof screened house.Results of the experiment showed that the disinfecting efficacy of heated tetracycline hydrochioride was significant: Diseased budsticks after the treatments at 44℃ for 15 minutes or at 45,46,47,48 and 49℃ for 10,15,20,25 minutes, and at 51℃ for 10 minutes showed no sympton in their offshoots for 3 years in succession ;whereas in check 1,diseased budsticks immersed in 1000ppm tetracycline hydrochioride solution at 20℃ for 20 minutes showed symptoms at the rate of 30. 0% , in Check 2, the diseased budsticks dipped into clean water at 20℃ for 15 and 20 minutes showed symptoms in their offshoots at the rate of 61. 5%(C. tangan ) , 48- 3% ( C. sinensis )and 77. 8% (C. sinensis var. Huazhonensis) ,87. 5% (C. sinensis var. Hnazhouensis) ; in check 3,it showed that although the diseased budsticks treated with 48 and 49℃ hot water for 15 minutes had no occurrence of the disease,showing the therapautic effect to be also good,yet with the treatments of 44 . 45, 46 and 47℃ hot water the rates of occurrence were 80. 4% , 95. 1 % , 31. 1 % and 42.7% respectively, showing that hot water treatment was not as stable and reliable as that of heated tetracycline hydrochioride.