两个腐烂茎线虫群体在越冬后大蒜上的侵染观察

Observation on Infection by Two Nematodes Populations of Ditylenchus destructor on Garlic after Overwintering

为明确腐烂茎线虫能否侵染大蒜和被大蒜携带,选择腐烂茎线虫的马铃薯群体(P-Dd)和甘薯群体(SP-Dd)作为接种源,于3—6月越冬后大蒜生长期开展田间试验。定期采样后,对大蒜根际土、蒜根、茎盘、鳞茎进行分离和根内线虫染色检测。结果表明:腐烂茎线虫的马铃薯群体(P-Dd)和甘薯群体(SP-Dd)均可对大蒜造成侵染。腐烂茎线虫可侵染大蒜的茎盘、蒜根和新生鳞茎。根际土中P-Dd和SP-Dd群体的最大群体密度均出现在5月2日,每10 g土壤分别含107.0条和65.6条;蒜根中P-Dd和SP-Dd的最大群体密度分别出现在3月14日和5月2日,每10 g根中分别含625.4条和1303.3条;茎盘中P-Dd和SP-Dd的最大群体密度分别出现在6月7日和6月15日,每10 g茎盘中分别含1681.8条和2983.3条;大蒜鳞茎只受到轻微侵染,P-Dd和SP-Dd群体的最大群体密度均出现在5月30日,每10 g鳞茎中分别有2.7条和1.6条。收获时,大蒜茎盘、鳞茎中均检测到腐烂茎线虫。尽管不同寄主来源的腐烂茎线虫对大蒜的侵染存在差异,但可以确定的是其均能够侵染大蒜,并可随受侵染的鲜蒜进行传播。

In order to clarify whether or not Ditylenchus destructor infected garlic and carried by it,potato population(P-Dd)and sweet potato population(SP-Dd)of the nematode were selected as inocula,and the fi eld plot experiment and investigation were carried out during the overwintering growth period of garlic from March to June.The rhizosphere soil,root,stem disc and bulb of garlic were periodically collected,the nematodes were examined after being extracted from soil and garlic tissues and stained in garlic roots.The results showed that both P-Dd and SP-Dd populations could infect garlic,and they could invade the stem disc,root and new bulb of garlic.In rhizosphere soil,the maximum population densities of P-Dd and SP-Dd occurred both on May 2nd and were 107.0 per 100 g of soil and 65.6 per 100 g of soil,respectively.In garlic root,the maximum population densities of P-Dd and SP-Dd occurred on March 14th and May 2nd and were 625.4 per 10 g of root and 1303.3 per 10 g of root,respectively.In stem disc,the maximum population densities of P-Dd and SP-Dd occurred on June 7th and June 15th and were 1681.8 per 10 g of stem disc and 2983.3 per 10 g of stem disc,respectively.The garlic bulbs were slightly infected,the maximum population densities of P-Dd and SP-Dd,both occurring on May 2nd,were 2.7 per 10 g of bulb and 1.6 per 10 g of bulb,respectively.At harvest,D.destructor was recovered from both stem disc and bulb of garlic.It was clarifi ed that the two different host-sourced populations of D.destructor did infect garlic and be spread by infected fresh garlics,although there were some differences in garlic infection between the two populations.