The Studies On The Internal And External Control Mechanism Of Tiller Formation In Rice

Rice tillers as one of the important agronomic traits,directly affect the panicle number of rice,sequentially affect production.In this experiment,we chooses 7 different tillering characteristics of five Japonica varieties and 2 Indica rice cultivars,and making pot and field experiment,Analysis of rice growing middle stage nitrogen nutrition and tillering related gene transcription expression quantity and total nitrogen and soluble sugar content in plants relations with tillering formation,aim to provide a theoretical basis for elucidating the mechanism of rice tiller formation.Research indicates:The highest stem number and the number of spikelets is controlled by genetic factor,different types of rice the starting time of tiller and speed and the highest stem number are significant different,panicle number type varieties are more faster to produce tiller.Increase the tiller fertilizer made speed of tiller growth faster,and more tiller.While lower tiller fertilizer,made tiller growth slowly,and finally tiller few,although increased fertilizer rates would increase tiller number,following the ineffective tillers has increased,Reasonable tillering fertilizer application increased number of tiller and spike.At tillering stage,soluble sugar content and ratio of carbon and nitrogen in varieties with more stems was significantly higher than that in varieties with less stems.Increasing the amount of nitrogen applied by tillering fertilizer can increase the content of soluble sugar and the ratio of sugar to nitrogen in a certain range,but too high or too low tillering fertilizer nitrogen fertilizer is not conducive to the increase in soluble sugar content.At tillering stage,Os MADS57 in varieties with more stems was significantly higher than that in varieties with less stems,while it is opposite for the expression level of Os TB1,Os D3 and Os D14.Different types of rice tiller gene express time is also different,in tiller last time,Os TB1?Os D3 and Os D14 beginning up-regulated expression,while Os MADS57 down-regulated,compared with japonica rice,Indica rice,always in low expression.,while Os MADS57 higher expression.Tiller number is significantly positively correlated with soluble sugar content,ratio of carbon and nitrogen,and expression level of Os MADS57,and significantly correlated with the expression level of Os TB1,Os D3 and Os D14,but not significantly negatively correlated with total nitrogen content.Increasing plant nitrogen content will induce expression of Os TB1,Os D3 and Os D14 but inhibit expression of Os MADS57,however,increasing plant soluble sugar content will induce expression of Os MADS57 but inhibit expression of Os TB1,Os D3 and Os D14.The number of spike is significant positive correlation with SPAD?soil total nitrogen?nitrate nitrogen and ammonium nitrogen content,and increase chlorophyll content in leaf.and increase soil total nitrogen,nitrate nitrogen,ammonium nitrogen content would increase number of tiller in rice.