Physiological And Biochemical Interactions Between Cruciferous Vegetables And Phyllotreta Striolata (Fabricius)

This paper was based on a chain cruciferous vegetables - striped flea beetle (SFB), Phyllotreta striolata to study the changes of the quality indexes, carbohydrate metabolism and nitrogen metabolism in 6 cruciferous vegetables under damage stress of SFB. These changes could lead to response of SFB's feeding amount, survival rate and enzyme activity in vivo.The results were as follows:The changes of soluble protein contents in 6 cruciferous vegetables caused by SFB damages were obviouse, while the differences of the contents of soluble protein among different cruciferous vegetables were not significant. When Raphanus sativus L. had been damaged by P. striolata for 6d, 8d and 10d, B . chinensis L. for 2d, 8d and 10d, B . oleracea L. for 6d and 10d, B . alboglabra Bailey and B . juncea L. for 12d, B . parachinensis Bailey for 8d and 12d, soluble protein contents of normal leaves, mild damaged leaves, moderate damaged leaves, severe damaged leaves were higher than the control. However, increased rates of soluble protein contents were not obvious as the damage degree increasing. Moreover, when B . chinensis L. had been damaged for 6d and 12d, B . oleracea L. for 2d, B . alboglabra Bailey for 2d and 4d, B . juncea L.for 4d and 6d, B . parachinensis Bailey for 2d, their soluble protein contents of leaves was lower than that of control.The changes of ascorbic acid contents of cruciferous vegetables caused by SFB damages were obviouse, while differences between different cruciferous vegetables were not obvious. Compared with the normal leaves, ascorbic acid contents of cruciferous vegetables mostly significantly decreased as the damage degree increasing and the time prolonging.The effect tendencies of Carbon and nitrogen metabolism of different cruciferous vegetables damaged by striped flea beetle were obvious.The contents of reducing sugar of cruciferous vegetables damaged by the striped flea beetles were increased, and the contents of sucrose and total soluble sugar were in a downward trend, and the differences became more obvious as the time prolonging and damage degree increasing. Compared with the normal leaves, total contents of free amino acids of different host plants damaged by the striped flea beetle were higer, showing increasing trends, by day 12, total contents of free amino acids of Raphanus sativus L.damaged severely increased by 95.05%, effects of total contents of free amino acids of cruciferous vegetables damaged by striped flea beetle were obviouse.Compared with the normal leaves, contents of free proline of different cruciferous vegetables damaged by the striped flea beetle were higer, showing increased trends.Changes of SFB's survival rates, feeding amount and enzyme activity in vivo after feeding different cruciferous vegetables proved that, by day 10, survival rates of SFB feeding different cruciferous vegetables had no significant difference, and on 14d, the order of survival rates of SFB feeding on six cruciferous vegetables was as follows: B . parachinensis Bailey equal to B . juncea L., R . sativus L. equal to B . chinensis L., B . alboglabra Bailey, B . oleracea, on 18d and 22d, the order of survival rates of SFB feeding on six cruciferous vegetables was as follows: B . parachinensis Bailey, B . juncea L., R . sativus L.equal to B . chinensis L., B . oleracea, B . alboglabra Bailey; The order of feeding amount (48d) of SFB feeding on different cruciferous vegetables was as follows: B . juncea L., B . parachinensis Bailey, B . chinensis L., R .sativus L., B . oleracea, B . alboglabra Bailey, feeding amounts of SFB feeding on B . juncea L. and other cruciferous vegetables had significant difference (P<0.01). After P . striolata feeding on cruciferous vegetables for 30d, the order of acetylcholinesterase activity was as follows: R . sativus L., B . juncea L., B . oleracea, B . chinensis L., B . alboglabra Bailey, B . parachinensis Bailey. The order of glutathione S - transferase activity was as follows: B. juncea L., R .sativus L., B. chinensis L., B. oleracea, B. parachinensis Bailey, B. alboglabra Bailey. The order of carboxylesterase activity as follows: B.juncea L., R..sativus L., B.chinensis L., B.oleracea, B.parachinensis Bailey, B.alboglabra Bailey, The activity of SFB feeding on B.juncea L.was the largest, and had very significant differences (P <0.01) from others.