优质地方品种鹅湖香稻耐低氮特性分析

Analysis of Low Nitrogen Tolerance Characteristics of High Quality Local Variety Ehuxiangdao

为充分挖掘水稻氮高效基因资源,提高氮素利用率,减轻环境污染,对现有的优质水稻核心种质进行氮素效率的筛选和评价具有重要的意义。选用优质耐低氮地方品种鹅湖香稻和同等生育期的优质品种外引七号作为试验材料,通过苗期水培和生育期桶栽的方法,严格控制施氮量,并依据苗期和不同生育期的耐低氮评价指标来比较两品种耐低氮特性。结果发现,在苗期水培条件下,低氮胁迫与正常施氮量比较,鹅湖香稻的株高、植株鲜质量、干质量、叶绿素和全氮含量均无显著差异;同时在生育期桶栽条件下,低氮胁迫与正常施氮量比较,鹅湖香稻叶绿素含量、全氮含量、株高、有效穗数和单株产量均无显著差异,而外引七号低氮条件下多数评价指标均显著低于正常氮条件。利用qRT-PCR检测两品种在不同施氮水平下的不同生长时期氮代谢相关基因的表达水平,结果表明,鹅湖香稻在低氮水平下,氮代谢途径中重要基因的表达量并未受到显著抑制,但耐低氮基因TOND1表达量显著增加。这些结果表明,优质地方品种鹅湖香稻具有耐低氮和氮高效利用特性。

In order to fully exploit high-efficient nitrogen gene resources,improve nitrogen utilization efficiency and reduce environmental pollution,it is very important to screen and evaluate the nitrogen efficiency of high quality rice from existing germplasm resources.The high-quality and low-nitrogen tolerant local variety Ehuxiangdao(EHXD),and the high-quality variety Waiyinqihao(WY7H)were took as the experiment materials,which has the same growth period with EHXD.The application amount of nitrogen was strictly controlled by water culture in seedling stage and barrel planting in growth stage.According to the evaluation index of low nitrogen tolerance in seedling stage and growth stage,we compared the low nitrogen tolerant characteristic of the two varieties.The results showed that there was no significant difference in plant height,fresh weight,dry weight,chlorophyll and total nitrogen content between the treatment of low nitrogen stress and the normal nitrogen treatment in the seedling stage of EHXD;and there was no significant difference in chlorophyll content,total nitrogen content plant height,panicle number and yield per plant under the treatment of low nitrogen stress and the normal nitrogen treatment in the growth stage of EHXD with barrel cultivation.However,most of the evaluation screening indexes of WY7H under the treatment of low nitrogen were significantly lower than that of normal nitrogen treatment.In addition,the major genes expression level in the nitrogen metabolism and assimilation pathway was not significantly suppressed but the low nitrogen tolerance gene(TOND1)was significantly upregulated in EHXD under the low nitrogen treatment.These results showed that EHXD had the characteristics of low nitrogen tolerance and the higher nitrogen efficiency.