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12 华 中 农 业 大 学 学 报 第 44 卷

［49］ XU G H，FAN X R，MILLER A J.Plant nitrogen assimilation mate assimilation in non-photosynthetic roots of higher plants
and use efficiency［J］. Annual review of plant biology，2012， by studies of N-tracing，enzymes involved，reductant supply，
15
63：153-182. and nitrate signaling：a review and synthesis［J］.Plant physiolo­
［50］ YONEYAMA T，SUZUKI A.Exploration of nitrate-to-gluta­ gy and biochemistry，2019，136：245-254.

Screening of nitrogen efficient rice varieties mainly planted
in middle and lower reaches of Yangtze River and their

physiological and biochemical characteristics

MA Xiaonuo,HOU Xingyu,CAI Hongmei
College of Resources and Environment， Huazhong Agricultural University， Wuhan 430070，China

Abstract 57 rice varieties mainly planted in the middle and lower reaches of Yangtze River were
used to study the physiological and biochemical characteristics of nitrogen efficient rice varieties mainly
planted in this region.Hydroponic culture was conducted to screen the nitrogen efficiency of rice.The nitro­
gen-efficient and nitrogen-inefficient rice varieties screened were further used to analyze the differences in
growth， yield formation， absorption and utilization of nitrogen， activity of enzymes， metabolites， and ex­
pression level of related genes with hydroponic culture， soil pot， and field trials.The results showed that
the nitrogen efficient and nitrogen inefficient rice variety was determined to be Quanyousimiao（5#） and
Wuyoujingsimiao（8#）.5# had better root architecture and biomass under both +N and −N treatments，
with significantly higher plant height， root length， number of root tips， total surface area and volume of
roots， and dry weight of roots and shoots compared to that of 8#.The effective number of spikes， spike
length， thousand-grain weight， seed setting rate， grain yield， and absorption and utilization of nitrogen of
5# was higher than that of 8#.The content of nitrogen， accumulation of roots and shoots， the absorption of
15 − 15 +
NO 3 and NH 4 ， nitrogen utilization index， and distribution ratio in grains of 5# was significantly higher
than that of 8#.The expression level of most genes involved in the absorption， transport， reduction， and as­
similation of nitrogen in 5# was significantly higher than that in 8#.The activity of NR in root and activity
of GOGAT in shoot， the content of soluble protein and sugar in 5# was significantly higher than that in 8#.
It is indicated that excellent architecture of root， stronger absorption capacity of nitrogen， efficiently trans­
porting nitrogen to shoot， timely reducing and assimilating nitrogen， and distributing more nitrogen to
grains are important characteristics of nitrogen-efficient rice variety.
Keywords rice； nitrogen utilization efficiency； nitrogen absorption and utilization； nitrogen reduction
and assimilation； root system architecture； gene expression；enzyme activity； yield

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