水肥（氮）对水稻根构型参数的影响及其基因型差异

采用分根干旱胁迫 (PEG)营养液培养系统 ,研究干旱胁迫和部分根系供应硝态氮对水稻根长、根表面积、分根数等根系构型参数的影响及其基因型差异。结果表明 :水肥 (氮 )对水稻根系发育有明显的影响。全根培养无干旱胁迫下缺氮诱导总根长 (RL )增加 7%～ 13%、分根数 (RT)增加 7%～ 2 0 % ,根系表面积 (RS)无显著变化 ;而干旱胁迫下供氮诱导总根长、根表面积和分根数分别增加 16 %～ 34% ,4 %～ 35 %和 12 %～ 36 %。分根培养无干旱胁迫下 ,供氮诱导 RL ,RS和 RT分别增加 80 %～ 110 % ,6 0 %～ 2 30 %和 70 %～ 2 6 0 % ;干旱胁迫下分别增加5 0 %～ 14 0 % ,6 0 %～ 110 %和 70 %～ 2 6 0 %。水肥对根系形态发育存在明显的基因型差异和水肥交互效应 ,这种作用不仅与根系的水肥营养有关 ,而且还与是否全部根系受到胁迫有关。 IR15 5 2 ,Tesanai和 Azucena基因型 RL ,RS和 RT分根供氮的效应分别是全根的 3.3,14 .0 ,1.3,3.8,15 .0 ,9.8,3.0 ,7.3,2 .4倍。可以认为 ,干旱和部分根系缺氮共同作用下 ,缺氮可明显限制根系的发生发育。全部根系在受到适当干旱胁迫 ,并供应一定氮素的情况下 ,能诱导根系的发生发育

Effects of nitrogen fertilizer on parameters of rice (Oryza sativa L.) root architecture and their genotypic difference

Splitting root system and aquaculture was conducted to study the effects of drought stress and localized nitrogen (nitrate) supply on parameters of root architecture within three rice genotypes under drought stress (DS) simulated with 5% (w/w) of polyethylene glycol 6000 (PEG).Results showed that rice root morphology made an adaptive change responding to nitrogen supply and/or DS.In whole plant root culture,the parameters or morphological features such as total root length (RL),root and root tips (RT) were increased by 7% to 13% and 7% to 20% respectively induced by nitrogen deficiency under normal water condition.However,RL,total root surface area (RS) and RT induced by nitrogen under DS was increased by 16%~34%,4%~35% and 12%~36% separately.In splitting root culture,RL,RS and RT of N supplying side was increased by 80%~110%,60%~230% and 70%~260% under normal water circumstance,and by 50%~140%,60%~110% and 70%~260% under DS.There was significant genotypic difference about the effect of N and DS on those parameters and interaction between N supply and drought stress.The effectiveness of N on RL,RS and RT for IR1552,Tesanai and Azucena in splitting culture were 3.3,14.0,1.3,3.8,15.0,9.8,3.0,7.3,2.4 times of those in whole root culture respectively.Results showed that both DS and N deficiency affected root developing and growth.