Background

Water (W) and nitrogen (N) management generally cause regulations in the 2-acetyl-1-pyrroline (2AP) accumulation in fragrant rice; nevertheless, the feasibility of such management strategies at booting stage in improving 2AP accumulation has not been examined in details.

Methods

Field experiments were conducted in the early season (March–July) and repeated in the late season (July–November) in 2013. The treatments were applied urea (90 kg ha^− 1), calcium super phosphate (90 kg ha^− 1) and potassium chloride (195 kg ha^− 1) as basal fertilizer, and urea (65 kg ha^− 1) at tillering stage. Three N levels i.e., 0 kg N ha^− 1 (N1), 30 kg N ha^− 1 (N2), and 60 kg N ha^− 1 (N3) and three water levels i.e., W1 treatment (well-watered treatment with water layer of 2–4 cm), W2 treatment (soil water potential was − 15 ± 5 kPa), and W3 treatment (soil water potential was − 25 ± 5 kPa) at booting stage was set up for three rice varieties i.e., Nongxiang 18, Yungengyou 14 and Basmati. The grain yield, head milled rice yield, 2AP contents and the biochemical parameters related to 2AP formation were investigated.

Results

Result indicated that W and N dynamics regulated the grain yield, head milled rice yield, and 2AP contents in brown rice across three varieties. The N2 and N3 treatment significantly increased the 2AP contents in brown rice by 9.54% and 11.95%, and 8.88% and 32.54% in the early and the late season, respectively; improved grain yield and head milled rice yield. The W3 treatment improved grain yield, head milled rice yield and 2AP content. Significant W and N interaction effect on 2AP content in brown rice was detected, where the W3 N3 treatment showed the strongest interaction regarding improvement of 2AP contents in brown rice. The 2AP accumulation and its related biochemical parameters and their relationships in different plant tissues at different growth stages under W and N treatments had also been assessed. The 2AP content, P5C content and DAO activity during grain filling periods was highly related to the 2AP content in brown rice.

Conclusion

This study revealed that the 60 kg N ha^− 1 coupled with − 25 ± 5 kPa treatment showed the best positive effects on yield and aroma in fragrant rice, suggested that water and nitrogen management at booting stage can improve grain yield and fragrance in fragrant rice. However, further study to evaluate the metabolic and molecular basis of 2AP accumulation in fragrant rice is needed.

中文翻译：

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在孕穗期施用氮肥和不同的水分处理方式可改善香米的产量和2-乙酰基-1-吡咯啉（2AP）的形成。

背景

水（W）和氮（N）的管理通常会导致香米中2-乙酰基-1-吡咯啉（2AP）积累的规律；但是，在启动阶段，此类管理策略在改善2AP累积方面的可行性尚未得到详细检查。

方法

在2013年的早期（3月至7月）进行了田间试验，并于2013年后期（7月至11月）进行了重复试验。处理方法为施用尿素（90 kg ha ^{− 1}），过磷酸钙（90 kg ha ^{− 1}）。和氯化钾（195公斤公顷^{- 1}）作为基肥，和脲（65公斤公顷^{- 1}）在分蘖期。三种氮水平，即0 kg N ha ^-1（N1），30 kg N ha ^-1（N2）和60 kg N ha ^-1（N3）和三个水位，即W1处理（水层2–4 cm的浇水充分处理），W2处理（土壤水势为− 15±5 kPa）和W3处理（土壤水势为− 25）在启动期为农香18号，云耕油14号和印度香米3个水稻品种建立了（±5 kPa）。研究了籽粒产量，精米产量，2AP含量以及与2AP形成相关的生化参数。

结果

结果表明，W和N动态调节了三个品种糙米的籽粒产量，精米产量和2AP含量。N2和N3处理分别使糙米中2AP含量在早季和晚季分别提高了9.54％和11.95％，8.88％和32.54％。提高了谷物产量和精磨米的产量。W3处理提高了谷物产量，精米产量和2AP含量。检测到W和N交互作用对糙米中2AP含量具有显着影响，其中W3 N3处理显示出与改善糙米中2AP含量有关的最强相互作用。还评估了在W和N处理下，不同生长阶段不同植物组织中2AP的积累及其相关的生化参数及其关系。2AP的内容，

结论

这项研究表明，60 kg N ha ^-1加上− 25±5 kPa处理对香米的产量和香气表现出最好的正效应，表明在孕穗期进行水和氮管理可以提高香米的谷物产量和香气。 。但是，需要进一步研究来评估香米中2AP积累的代谢和分子基础。