低氮胁迫对不同基因型玉米根部性状的影响

Effects of Low Nitrogen Stress on the Root Traits of Different Genotypes in Maize

通过盆栽试验,在施氮(N+)和不施氮(N-)条件下,对不同基因型玉米在不同发育时期的根部性状进行了分析。结果表明,在拔节期、开花期和灌浆期,6种不同基因型之间在4个根部性状上均存在极显著或显著差异。除农大108外,许178表现突出,4个根部性状均居前列,高于或显著高于其他自交系;其他自交系在不同时期、不同性状上位次变化较大,如材料2的根系活力最差,但根体积仅次于许178;黄C的根体积较小,但主根数较多。各根部性状之间相互协调是许178保持优势的关键。与N-相比,N+条件下3个时期不同根部性状均有增加,但不同基因型增幅不一,农大108和许178增幅最小,表明许178对低氮胁迫不敏感,是低氮胁迫条件下氮高效利用基因型。

By using pot cultivation, an elite hybrid Nongda 108 and its parents as well as its three F2：4 family lines were grown under nitrogen applied（N＋） and no N applied（N-） conditions to analyze the root traits of maize with variance genotypes on different stages. The results showed that significant or highly significant differences existed in the 4 root traits among genotypes at elongation stage, flowering stage and grain filling stage. Beside for the hybrid Nongdal08 appearing obviously heterosis, the inbred line Xu178 was higher or significant higher in the 4 root traits than any other lines which ranked unstably in the root traits over stages, such as the line 2 was the poorest in root activity among the 5 lines, but its root volume was more larger, only smaller than that of Xu178, also the inbreed line Huang C was small in root Volume but with more main root numbers. Obviously, keeping co-regulatlon among the root traits Was the key for Xu178 to maintain excellence. The root traits appeared more higher over the 3 stages under N＋ than Ncondition, while the increasing rate varied with genotypes, Nongdal08 and Xu178 with little increasing rates which referred that Xu178 was insensitive to low nitrogen stress, and was a high nitrogen using efficiency genotype under low nitrogen condition and also which was the genetic basis for Nongdal08 to be a high nitrogen using efficiency hybrid.