Effects of Post-Anthesis Nitrogen Uptake and Translocation on Photosynthetic Production and Rice Yield

Abstract

Post-anthesis nitrogen uptake and translocation play critical roles in photosynthetic assimilation and grain filling. However, their effects on leaf stay-green characteristics, dry matter accumulation, and translocation after anthesis remain unclear. In this study, post-anthesis N uptake and translocation between two different rice genotypes (Yongyou12 and Zhongzheyou1) were compared through soil nitrogen leaching treatments at the meiosis stage (MST) and anthesis stage(AST) respectively, and their effects on leaf stay-green duration, photosynthesis, dry matter accumulation and translocation during ripening and yield formation were estimated. The results showed that the soil nitrate-N and ammonium-N contents in Yongyou12 pots decreased significantly, and post-anthesis N uptake was 2.0–3.4 fold higher in Yongyou12 than in Zhongzheyou1. The activities of N-metabolism enzymes and antioxidant enzymes were higher, and flag-leaf photosynthesis and dry matter accumulation during ripening were greater, in Yongyou12 than in Zhongzheyou1. However, insufficient available soil N led to significant decreases in the activities of N- metabolism enzymes, decreased flag-leaf photosynthesis, increased translocation of dry matter and N pre-anthesis, accelerated leaf senescence, shorter duration of the leaf stay-green period, and decreased dry matter accumulation and grain plumpness. In addition, the effect of N uptake after anthesis on yield is greater for rice genotypes that depend on post-anthesis dry matter accumulation and an expanded sink capacity.

The nitrogen topdressing mode of indica-japonica and indica hybrid rice are different after side-deep fertilization with machine transplanting

“…Nitrogen supplementation is important to maintain carbohydrate supply for grain ripening of indica–japonica hybrid rice 19 . In the present study, a larger reduction in grain weight was observed in YY1540 compared with that of TYHZ under the T 3 treatment.…”

“…An LI-3100C Area Meter (LI-COR, Inc., Lincoln, NE, USA) was used to measure the leaf area of each green leaf. The leaf area per square meter was calculated as the leaf area index following the method of Wu 19 . The SPAD value was determined at the maturity stage using a SPAD chlorophyII meter (SPAD-502PLUS, Spectrum Technologies, Aurora, IL, USA).…”

“…The nitrogen fertilizer application rate is important for dry matter accumulation, a high application rate is necessary in indica–japonica hybrid rice to obtain a higher yield than that attained with inbred hybrid rice 17 , 18 . In particular, nitrogen application must be sufficient to meet the demand for spikelet differentiation and the longer grain-ripening period 19 .…”

Coordination of carbon and nitrogen accumulation and translocation of winter wheat plant to improve grain yield and processing quality

“…Nitrogen accumulation and translocation, nitrogen efficiency. N content of the samples were determined using the Kjeldahl (K1100) procedure, and the accumulation and translocation of N in wheat plants were calculated as follows 22,46 :…”

Post-Anthesis Photosynthetic Properties Provide Insights into Yield Potential of Tartary Buckwheat Cultivars

“…Furthermore, photosynthesis reaches a peak after anthesis and over 70% of wheat yield is derived from photosynthesis during the period of grain growth [20,21]. Many researchers have reported that photosynthesis after anthesis is crucial determinant of yield in other crops, such as rice [22], maize [23], and soybean [24]. The contribution to photosynthesis of different leaves in the same plant can differ, and there is a difference among different crops in the contribution by functional leaves [25,26].…”