Abstract:

In order to explore the effects of plant growth regulator on photosynthetic characteristics, yield and quality of high-quality japonica rice, the experimental materials were selected as the Suijing 18, Kendao 12, and Sanjiang 6, and eleven plant growth regulators including abscisic acid (ABA), 6-benzylaminoadenine (6-BA), diethyl aminoethyl caproate (DA-6), spermidine (Spd), 3-indolebutyric acid (IBA), 3,5-dinitrosalicylic acid (SA), brassinolide (BL), zeatin (ZT), triacontanol (TRIA), methyl jasmonate (MeJA), and N6-furan methyl adenine (KT) were sprayed at the flag leaf expansion stage, in order to analyze the effects of plant growth regulator on yield, quality and photosynthetic characteristics of rice. The results showed spraying BL increased dry matter accumulation and stem-sheath matter transport after heading, increased grain weight per panicle, 1 000-grain weight, seed setting rate, and grain-grass ratio, with an average increase of 7.61% in two years, compared with control (CK). Spraying 6-BA could improve the photosynthetic characteristics after heading, prolong the duration of green leaf area from heading stage to waxy stage, increase the number of grains per panicle, grain weight per panicle, 1 000-grain weight, and grain-grass ratio, with an average increase of 6.40% in two years. However, the yield increase effect of DA-6, ZT, ABA, Spd, IBA, SA, and KT were different between years and varieties. In terms of quality, spraying DA-6 and ZT increased milled rice rate and head rice rate, and improved rice appearance quality. According to the comprehensive analysis, the application of BL and 6-BA in the development period of sword leaf is suitable for increasing the yield of test varieties, while the application of DA-6 and ZT is more suitable for improving the quality under the premise of stable yield or increasing the yield.

Key words: plant growth regulator, high-quality japonica rice, yield, quality, photosynthesis characteristic