Research On Low Nitrogen Tolerance In Different Maize Germplasm Materials

In order to study the responses to different nitrogen levels of germplasm, this experiment used 10 maize drought-resistance groups as material(K15LF001, K15LF002, K15LF003, K15LF004, K15LF005, K15LF006, K15LF007, K15LF008, K15LF009, K15LF0010), which were offered by the Chinese Academy of Agricultural Sciences. We investigated and recorded agronomic characters of seedling, jointing, tasseling, powder, silking, maturity and main stage at two nitrogen level (nitrogen and no nitrogen).At maize maturing stage, the middle row of a small area was harvested after air drying, and tested grain yield, biological yield, spike length, spike diameter, spike number, kernel number per spike, and hundred grain weight, seed setting rate, seed yield, grain number per line and low nitrogen stress index.The results showed that the grain yields of K15LF004, K15LF005, K15LF006, and K15LF008 under the application of nitrogen were higher than the control (P< 0.05), which indicated that these four materials were sensitive to nitrogen. However, there were no significant difference on grain yield among K15LF002, K15LF003, K15LF007, K15LF009, K15LF0010, and the control, which showed that their response to nitrogen fertilizer were slow, and they can be used as nitrogen efficient materials. Meanwhile, grain yield of K15LF001 under nitrogen treatment was decreased by 9.13%. From all the variation coefficients of agronomic traits, the variation coefficient of spike length, seed-producing percentage, plant height,,hundred grain weight and biomass yield were higher than treatment under nitrogen fertilization,which indicated that maize materials was sensitive to nitrogen in terms of biomass yield. K15LF006, K15LF008 and K15LF009 and the biological yield was significantly higher than that of control, which belongs to the nitrogen sensitive material. The biological yield of K15LF001, K15LF003, K15LF004 and K15LF005, which was not sensitive to the reaction of N fertilizer. Spike position and plant height increased of the K15LF008 under nitrogen treatment significantly, which showing that K15LF008 was sensitive response to nitrogen fertilizer in terms of spike position and plant height, and had no resistance to low nitrogen material. The results showed that spike weight, hundred-kernel weight, spike length and seed setting length of K15LF004 were sensitive to the application of nitrogen. Spike grain weight of K15LF005 andK15LF006, hundred-kernel weight of K15LF004, and biomass yield of K15LF006, K15LF008, K15LF009 were higher than that of the control (P< 0.05), which indicated that they were sensitive to nitrogen. After low nitrogen stress index analysis, which was found that K15LF002 and K15LF005 two germplasm materials could form larger biomass and higher grain yield under low fertility conditions. The two germplasm materials of K15LF008 and K15LF009 could form higher grain yield.Comprehensive the above results, to determine the grain yield, biological yield, resistance to low nitrogen stress index, ear height, plant height as main parameters, ear length, 100 grain weight, line grain number, fruit length for secondary parameter of resistant germplasm materials of low nitrogen screening method.