Allelopathic Effects From The Root Exudates And Litters Of Carya. Illinoensis On Wheat And Soybean

Based on relationship between the Carya.illinoensis root and litter with the seed germination and seedling growth of wheat and soybean,this study test litter and root secretion of allelopathy of pecon.The main results were as follows:1.The root water extract prominently inhibited the seed germination and seedling growth of T.aestivum L.and G.max(L.)Merr with concentration effect(weak inhibition in low concentration,high inhibition in high concentration).The decreasing order of inhibition of water extract for germination rate,germination energy,germination index and vigor index of T.aestivum and G.max(L.)Merr was vigor index > germination energy > germination index > germination rate and vigor index > germination energy > germination rate > germination index.The decreasing order of allelopathic effects of water extract on shoot height,root length,fresh weight and dry weight of T.aestivum and G.max(L.)Merr were all is root length > shoot height > fresh weight > dry weight.Moreover the water extract prominently decreased the seedling root length,but had different impacts on the dry and fresh weight of receptor due to the differernt species.The order of the synthesis effects of water extraction from roots of C.illinoensis on 2 crops is T.Aestivum L.> G.max(L.)Merr.The activity of SOD in the seven days’ seedings was decreased,but the content of MDA,the activity of POD and CAT in them were increased with the increasing of concentration.It is indicated that the inhibition of the water extraction from roots of C.illinoensis is higher for T.Aestivum L.than G.max(L.)Merr.2.Rhizosphere Soil water extract inhibited the seed germination and seedling growth of T.aestivum L.and G.max(L.)Merr.Highest inhibition of vigor index for germination rate,germination energy,germination index and vigor index of T.aestivum and G.max(L.)Merr.Water extractions inhibited root length,shoot height,fresh weight of T.aestivum L.,but for its dry weight is improved in low levels,whereas inhibited in high levels.The water extractions inhibited root length,shoot height,fresh weight and dry weight of G.max(L.)Merr,and the root length is highest.The activity of SOD in the seven days’ seedings was decreased,but the content of MDA and CAT in them were increased with the increasing of concentration.3.The allelopathic effect of C.illinoensis litters exhibited an up-down trend with the prolonged decomposing duration.The inhibition of husk of C.illinoensis is higher than leaves for T.aestivum L.and G.max(L.)Merr.The higher inhibition of root length than the hoot height for T.aestivum L.and G.max(L.)Merr.of C.Illinoensis litters.The net photosynthetic rate o,transpiration rate and stomatal conductance were significantly(P < 0.05)than contrast of T.aestivum L.and G.max(L.)Merr in 70 d.The MDA of T.aestivum L.and G.max(L.)Merr is higher than contrast and the difference is very significant(P<0.01)in high levels in 70 d.4.Juglone was extracted from their root,leaves and husks was determined with chloroform thermal reflux and high(HPLC).Result showed that the content of juglone in root was 18.4μg/g,the content of juglone in husks and leaves was 10.5μg/g and 7.6μg/g.