Comprehensive Evaluation Of Pb Resistance Of Gramineous Forage Germplasm And Their Physiological Response To Pb Stress

In recent decades, with the rapid development of industry and agriculture, soil heavymetal pollution gradually aroused people’s attention. At present, the heavy metal pollution ofsoil area has reached20million hectares,1/5of the total area of arable land, of which lead(Pb) pollution of cultivated land area of about180000hectares. Hyperaccumulation plants forheavy metal contaminated soil repair using a low cost, does not produce secondary pollution,without destroying the soil structure, comprehensive utilization can be has become theresearch hot spot. This study perennial ryegrass, tall fescue, old mans wheat, cover with alkaligrass, goose grass, long ear ice grass, inflorescences of seven kinds of71gramineous grass asthe research object, by greenhouse seedling Pb2+stress test, to evaluate the lead resistance. Toextract the representative from each kind of material, the physiological response of Pb2+stressanalysis and research of Pb2+accumulation characteristics. The main results were as follows:(1) By71grass relative plant height, the relative tiller number and relative abovegroundbiomass, underground biomass and relative Ye Xian weight determination, the results showedthat the increase of concentration of Pb2+, relative plant height, tiller number and relativeaboveground biomass and relative Ye Xian were presented a trend of reducing the rise first,relative to the underground biomass was not a unified change law of some materials to reduceafter rising first, part of the material decreases gradually. Low concentration of lead stress ongramineae grassland stimulates the growth of the upper. By the method of subordinatefunction is used to evaluate the lead resistance of71found that Pb resistance the strongestmaterial for NO.12(Elymus sibiricus), resistance to lead the weakest for NO.53(Agropyronelongatum), other materials between the two.(2) Lead stress on gramineous forage germplasm antioxidant enzyme activity andproline content has a significant effect. With the increase of concentration of Pb2+, CATenzyme activity gradually decreased, POD and SOD enzyme activity increased before theyare reduced.7sets the proline contents of material are increased with the increase of theconcentration of Pb2+. When the concentration300mg/kg of Pb2+, the proline content of eachmaterial gain size of Dactylis glomerata> Agropyron elongatum> Festuca elata> Roegneriakamoji> Elymus sibiricu> Elymus dahuricus> Lolium perenne.(3) For14material root and aboveground Pb2+content determination results showedthat: with the enhancement of Pb2+stress, the root and aboveground Pb2+content is graduallyrising trend on the whole, the enrichment coefficient and transfer coefficient are graduallyreduce the trend, show enhanced Pb2+stress inhibits plant absorption and transfer of Pb2+.14 material enrichment coefficient of root were significantly higher than that of aboveground,shows that grass roots for Pb concentration of major organs.12copies of materials (two ofLolium perenne, Roegneria kamoji, Elymus sibiricu, Festuca elata, Dactylis glomerata, andAgropyron elongatum) transfer coefficient is less than1,2of the cover with Elymusdahuricus in Pb2+concentration of200mg/kg when transfer coefficient is greater than1,show that the beatles has strong alkali grass moving Pb2+from root to aboveground.(4) Of six wild different varieties of Elymus sibiricus germination bud lead stressresults show that: in early stage of the seed germination, low concentration of Pb2+stress(Pb2+concentration is less than1.0mol L-1) the germination rate and germinationpotential were higher than of control, the concentration has promoting effect to seedgermination (Pb2+concentration is more than2.5mol L-1) under the inhibition, germinationrate and germination potential were lower than controls.Part with the augmentation of thePb2+stress, germination index and vigor index of a downward trend, while a downward trendafter rising first, show the sensitivity of the different materials to Pb2+stress are different.Through comprehensive is concluded from the GuYuan series of Elymus sibiricusin Hebeiprovince showed the heavy metal lead strong tolerance;From WuLing mountain Elymussibiricus varieties in Hebei is weakest. Other materials somewhere in between.