茶翅蝽对植原体的传播能力

Capacity of Halyomorpha picus Transmitting Phytoplasma Associated with Paulownia Witches′ Broom

经１９９６年至１９９８年室内接种试验，分别比较了人工饲养带毒和自然带毒的茶翅蝽成虫和若虫的传病特点。结果显示：室内人工饲养带毒的３龄、４龄若虫接种泡桐发病率分别达６１．７％ 和４６．５％ ，高于自然带毒的若虫１６％ 的传病率。室内饲养带毒成虫的接种发病率为１４．１％ ，高于自然带毒成虫４．５％ 的传病率。寄主体内病原的最短潜育期（ＭＩＰ）室内饲毒３龄若虫为３４ ｄ，４龄为４５ ｄ，成虫处理为２１９ ｄ；自然带毒若虫为２４３ ｄ，成虫处理为２５７ ｄ。６月接种苗多在当年表现病状，７月接种苗均在次年发病。３龄、４龄若虫接种后病原潜育期（ＩＰ）与泡桐苗累计发病率的关系分别为ｙ＝ ０．８４７ ２ｘ＋ ２３．０４４（Ｒ２＝ ０．８７４ ３），ｙ＝ ０．７５９ｘ＋ ２９．０２２ （Ｒ２＝ ０．８０１ ９）；由此得到相应的３龄潜育期中值ＬＰ５０＝ ６５．４０ ｄ 和４龄ＬＰ５０＝ ６６．４７２ ｄ。室内３龄、４龄若虫在充分吸食病组织后，其传病力差异不大，且传毒后病原在寄主体内的潜育期中值没有明显的差异。

Based on the indoor inoculation test conducted from 1996 to 1998,the characteristics of transmitting phytoplasma by Halyomorpha picus associated with paulownia witches′ broom were compared between insect groups (adults and nymphae) of reared pathogen acquisition (RA) and naturally pathogen acquisition (NA).The results showed that the rate of pathogen transmission to paulownia seedlings by third and fourth instar nymphae of RA was 61.7% and 41.4%,which were much higher than that by nymphae of NA (16%).For adults,the transmission rate was 14.1% of RA which was also higher than that of NA (4.5%). The minimum incubation period (MIP) of pathogen in vivo were 34 days and 45 days for third and fourth instar nymphae and 219 days for adults (RA),that for nymphae and adults (NA) were 243 days and 257 days respectively.The seedlings inoculated in June showed symptom of disease in the same year,while that inoculated in July showed symptom of disease in the next year.The incubation period (IP) had a positive relation with successive disease rate.For third instar nymphae,the equation of relation was y=0.847 2x+23.044 (R 2=0.874 3 ) and relevant LP50=65.40 days,that for fourth instar nymphae was y=0.759 x+29.022(R 2=0.801 9) and LP50=66.472 days.The feasibility of using RA nymphae for early assessment of paulownia genetic breeding against witches′ broom was discussed.