Author/Authors :
Fathipour, Yaghoub Department of Entomology - Faculty of Agriculture - Tarbiat Modares University, Tehran, Iran , Kianpour, Roja Department of Entomology - Faculty of Agriculture - Tarbiat Modares University, Tehran, Iran , Bagheri, Abdoolnabi Plant Protection Research Department - Hormozgan Agricultural and Natural Resources Research and Education Center - Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Iran , Karimzadeh, Javad Plant Protection Research Department - Isfahan Agricultural and Natural Resources Research and Education Center - Agricultural Research Education and Extension Organization (AREEO), Isfahan, Iran , Hosseininaveh, Vahid Department of Plant Protection - College of Agriculture and Natural Resources - University of Tehran, Karaj, Iran , Mehrabadi, Mohammad Department of Entomology - Faculty of Agriculture - Tarbiat Modares University, Tehran, Iran
Abstract :
The diamondback moth, Plutella xylostella (L.) (Lepidoptera:
Plutellidae) is one of the most destructive insect pests, feeding exclusively on
wild and cultivated cruciferous species. The attacked plants produce
considerable amount of glucosinolates in response to insects’ feeding. Herein,
we studied digestive activities of P. xylostella on four different genotypes of
family Brassicaceae including two canola cultivars (SLM046 and RGS003) and
two cabbage cultivars (Green-Cornet and Glob-Master). The highest
proteolytic and amylolytic activities of P. xylostella were observed on Green-
Cornet and the lowest occurred on RGS003 and Glob-Master, respectively. The
highest activity of α-glucosidase and β-glucosidases were observed on Green-
Cornet and SLM046 and the lowest was observed on Glob-Master and RGS003.
The zymogram analysis revealed different isozymes of protease, trypsin-like
and α-amylase in the midgut extract of P. xylostella. Activity of the above
mentioned isozymes was inhibited in larvae feeding on RGS003 and Glob
Master as resistant host cultivars. Also, larvae feeding on the resistant
genotypes showed more glucosidase activities, indicating possibility of high
glycosinolate existence in the resistant genotypes. By these results we can state
that host plant property can affect insect digestive physiology through
inhibiting digestive enzyme activities. These findings provide insights into the
direct effects of host plants on insect physiology which are conducive to
change in insect fitness.
Keywords :
Plutella xylostella , plant resistance , digestive enzymes , Brassicaceae
