不同施氮水平对木薯源库关系的影响  

Effects of Nitrogen Level on Source-Sink Relationship of Cassava

作　　者：蒋强[1] 康亮[1] 张晓[1] 姚一华 梁琼月[1] 顾明华[1] 何冰[1] 

机构地区：[1]广西大学农学院,广西南宁530005

出　　处：《西南农业学报》2016年第9期2162-2166,共5页Southwest China Journal of Agricultural Sciences

基　　金：广西自然科学基金项目(2014GXNSFAA118077);广西壮族自治区教育厅高校科研重点项目(ZD2014002)

摘　　要：研究不同施氮水平对木薯源库关系的影响,旨在为木薯高产及氮肥高效利用提供理论依据。开展田间试验,以辐选01（FX01）和华南124（HN124）为材料,设6个不同施氮水平（0,18,36,72,108,144 kg N·hm-2）,分析施氮水平对不同品种木薯总生物量、块根产量、块根形态特征、叶片净光合速率以及薯茎比的影响。结果表明,木薯总生物量、块根产量、块根根数、根长、块根直径以及叶片净光合速率均随着施氮水平的增加而呈先升后降的变化趋势,施氮水平对总生物量、块根产量、块根形态及叶片净光合速率具有显著影响。通过二元二项式方程对施氮水平与块根产量的关系进行模拟,FX01和HN124的最高块根产量（干重）分别为854.6和681.2 g·plant-1,最适施氮水平约为72～75 kg·hm-2。薯茎比随着施氮水平的增加而呈不断下降的变化趋势,两者关系可用二元三项式方程进行模拟,FX01和HN124的薯茎比分别在29～86 kg·hm-2施氮水平、47～94 kg·hm-2施氮水平达到源库平衡期,此时薯茎比约为3.2。因此,氮肥水平对木薯源库关系建立、发展和平衡有显著影响。低氮使源叶生长不足,过量施氮又引起生长过旺、块根分化受抑,从而使源库失衡导致减产。适当施氮水平既促进源叶生长又促进块根分化与增粗,有利于源库关系达到平衡,从而实现木薯高产。Effects of nitrogen level on source-sink relationship of cassava were investigated for providing theoretical basis for efficient utilization of nitrogen fertilizer in the high yield cultivation of cassava. In the field research,FX01 and HN124,these two cultivars of cassava were planted respectively in soil with treatments of six nitrogen levels（ 0,18,36,72,108,144 kg N·hm- 2）. Effects of nitrogen level on cassava total biomass,root yield,root morphological characteristics,net photosynthetic rate of leaf and root/shoot ratio were analyzed. The results showed that the cassava total biomass,tuber yield,root number,root length,diameter of root and leaf net photosynthetic rate increased with the increase of nitrogen fertilizer at first,reached a peak,and then decreased. Nitrogen level significantly affected total biomass,tuber yield,root morphological characteristics and net photosynthetic rate of leaf. The relationship between nitrogen application amount and root tuber yield was simulated by a bivariate binomial equation. Through this equation,the highest tuber yields of FX01 and HN124 were estimated at 854. 6 g·plant- 1and 681. 2 g·plant- 1respectively,and the optimum nitrogen application amount was about 72- 75 kg N·hm- 2in this experiment. The root/shoot ratio of FX01 and HN124 showed a decreasing trend with the increase of N application,and reached a stable stage at 3. 2 when the N application was between 29- 86 kg N ·hm- 2and 47- 94 kg N·hm- 2,respectively. In short,nitrogen level had significant effects on the establishment and development of source-sink relationship. Low nitrogen application caused the inhibition of leaf growth,while excessive nitrogen application prompted excessive leaf growth and inhibition of root tuber differentiation,which led to imbalanced source-sink relationship and yield reduction. Therefore,only proper nitrogen application can promote leaf growth and tuber differentiation,which is beneficial to build balanced source-sink relationship and obtain the highest yield of cassava.

关 键 词：木薯 氮水平 源库关系 

分 类 号：S533[农业科学—作物学]