The Study Of Relations Between Stay Green And N Efficiency Of The Maize Inbren Line

The usage of nitrogen fertilizer is steadily increased in our country now， but the growthrate of the efficiency of nitrogen fertilizer is lower than the usage of nitrogen fertilizer，so it isbound to cause to waste of nitrogen fertilizer and environmental pollution. A lot of breederrealize clearly the damage that excess nitrogen fertilize can do，so they think it is a necessaryapproach to solve these problem by reducing the dosages of nitrogen breeding maize varietyof highly NUE，but now screening variety of highly NUE moves slowly because of lack ofunified subprime index,so it is necessary to get a simple and effective unified subprime index.Our experiment study mainly the relation between stay green and nitrogen efficiency,and want to get a simple and effective unified subprime index. We sampled82inbred linesfrom common parents of Chinese maize cultivars in2011, then we choose thirty inbred linefrom the eighty two inbred lines in2012, and the systematic investigation of the traits relatedto stay green, the nitrogen content of the plant and the yield. We get some followingconclusions by statistic analysis:1. Finding the stay-green can be a standards to indentify the the stay green by analyzingthe relation among the traits related to the stay green.2. According to relative green leaf area at physiological maturity (MRGLA) under highN, we get23stay-green inbred lines like Q319, U8112,32mid-stay-green inbred lines likePH4WC, Y478and27non-stay-green inbred lines like K12, Huang zao4.3. Under two N levels， comparing to non-stay-green type， the stay-green type haslarger green leaf area， higher chlorophyll content， longer green leaf area duration， betterear traits，which is the reason that the stay-green type has high and stable yield character，soselecting stay-green inbred line is meaningful.4. Under two N levels， the stay-green type has higher nitrogen utilization, N efficiency，N uptake efficiency; the non-stay-green type has higher N transfer rate, N transfercontribution rate; there is not difference among the different inbred lines.5. According to N efficiency under two N levels, we get13inbred lines of efficient efficient like Shen137and Dan598,13inbred lines of no efficient-no efficient like HOO-108and L9801, and2efficient-no efficient inbred lines,2no efficient-efficient.6.9stay green inbred lines are efficient efficient inbred lines, only one is no efficient-noefficient inbred line; the mid-stay-green is not only efficient efficient inbred lines but also noefficient-no efficient; the non-stay-green inbred line is not high NUE inbred lines but only two.9stay green and NUE inbred line are the core foundation for getting the NUE variety ofmaize that is stay green inbred line. The9stay green maize inbred line belong to3groups, PB,Luda Red and Reid,5belong to PB,2belong to Luda Red and2belong to PA, so we shoulduse the3groups to get NUE maize inbred line, especially PB.7. By studying the correlation between the traits related to stay green and N efficiency,we find the stay-green traits are significantly positively correlated with N efficiency and Nup-take efficiency but N utilization efficiency, so the stay-green may be as a standard toscreening the N use efficiency’s inbred line.