有毛野生甘蓝(Brassica incana)抗蚜虫特性研究

甘蓝(Brassica oleracea var.)是重要的十字花科芸薹属蔬菜,但生产中常遭受蚜虫危害,鉴定抗虫资源并了解其抗虫机制是抗虫育种的重要基础。课题组前期征集到1份周身覆盖浓密表皮毛的野生甘蓝(B.incana),为调查该材料是否具有蚜虫抗性,并明确其抗性是否与表皮毛有关,本研究利用该有毛野生甘蓝与1份无毛芥蓝(B.alboglabra)杂交,对双亲及其F2:3家系中有毛和无毛家系进行室内蚜虫接种发现,蚜虫在无表皮毛甘蓝上的平均产卵数(36.7枚)和存活天数(22.2 d)均显著高于有表皮毛甘蓝(平均产卵8.1枚,平均存活13.1 d)。为进一步明确该野生甘蓝对蚜虫是否具有化学毒杀或排拒作用,采用有毛和无毛甘蓝叶片的浸提液对蚜虫进行胃杀、触杀和拒食性调查发现,2种浸提液对蚜虫均无胃杀和触杀作用,但有毛甘蓝浸提液对蚜虫存在一定的趋避作用。表明野生甘蓝B.incana对蚜虫的抗性一方面源于其表皮毛的物理阻碍,另一方面与其体内化学物质的趋避作用有关。

Characterization of aphid-resistance of a hairy wild Brassica oleracea taxa,B.incana

Brassica oleracea contains important vegetables varieties in our daily life,however,the production of Brassica vegetables always suffers from aphids.Identifying resistant resource and understanding corresponding resistance mechanism are of great importance for resistance breeding of crops.In our previous study,a wild relative of B.incana with dense trichomes on leaves and stem was obtained.In the present study,to investigate the resistance of B.incana to aphids and to understand the role of trichomes in resistance,the two parental accessions and their F2:3 lines were inoculated with aphids in lab condition.The results showed that the egg production and lifespan of aphids on hairless leaves(36.7 eggs and 22.2 days)were significantly higher than corresponding values on hairy leaves(8.1 eggs and 13.1 days).To investigate whether a chemical role contributed to the resistance,the contact toxicity,gastric toxicity and anti-feeding ability of the leaf extracts were checked between hairy and glabrous F2:3 lines.None of the extract was found to be with significant contact toxicity and gastric toxicity to aphids,whereas the number of aphids on leaves treated with extract from hairy B.oleracea was significantly lower than that treated by extract of glabrous leaves.This study revealed that the resistance of B.incana to aphids might attribute to both the physical inhibition from trichomes and the avoidance role of its chemical compounds.