Analysis of Nitrogen Metabolism Related Enzymes and Related Physiological Indexes of Main Foxtail Millet Varieties Developed in North China

摘要

cqvip:[Objectives] This study was conducted to clarify the evolution characteristics of foxtail millet varieties in different ages and provide a basis for the breeding of new varieties. [Methods] A field experiment was carried out on 20 main foxtail millet varieties promoted in North China developed from the 1980 s to 2000 s. The physiological and biochemical indexes of different foxtail millet varieties in four ages were compared, including chlorophyll content, soluble protein content, glutamine synthetase(GS) activity and glutamate synthase(GOGAT) activity, and the correlation between enzyme activity and yield was analyzed. [Results] The chlorophyll SPAD values of the flag leaf and functional leaves of foxtail millet varieties decreased with the filling process. The SPAD values of the flag leaf, top second leaf and top third leaf were higher in the varieties developed in the 1990 s and 2000 s than those in the 1980 s and 2010 s. The activity of glutamine synthetase(GS) and glutamate synthase(GOGAT) showed a single-peak curve in different foxtail millet varieties developed in the recent 30 years, and the peaks of the two were at 7 d and at 7 or 14 d, respectively. The activity of GS and GOGAT increased with the breeding age. In the period from 7 d after anthesis to the mature period, the decreases in the soluble protein content followed an order of 2010 s, 2000 s, 1990 s and 1980 s from small to large, indicating that the degradation rate of various enzyme sources and metabolic regulators in foxtail millet plants decreased during the improvement process. At 35 d after anthesis, the correlation coefficient between GS activity and yield was-0.247, that is, there was a negative correlation with yield. And there was a significant positive correlation between GOGAT activity and yield, and the correlation coefficient was as high as 0.455 at 7 d after anthesis. [Conclusions] Changes in the GS activity, GOGAT activity and soluble protein content in the flag leaf of foxtail millet varieties developed in recent years have a certain impact on yield.