Comparison of grain yield and 2-acetyl-1-pyrroline (2AP) content in leaves and grain of two Thai fragrant rice cultivars cultivated at greenhouse and open-air conditions

Abstract

To verify how different growing environments affect the aroma quality and production yield of fragrant rice, two commercial Thai fragrant rice cultivars, Khao Dawk Mali 105 (KDML 105) and Pathum Thani 1 (PTT 1) were grown in a greenhouse and also open air. Between the two growing environments, the temperature difference averaged 6 ºC. Each rice cultivar was grown in clay loam and sandy loam soils. In addition, a water stress treatment was applied at the beginning of the grain filling stage and onward. Determination of 2-acetyl-1pyrroline (2AP) in both rice leaves and grain was accomplished using automated headspace-gas chromatography with selective nitrogen/phosphorus detection. The results showed that throughout all growth stages the rice leaf 2AP content was different for both rice cultivars depending on the soil type. The KDML 105 cultivar had higher 2AP content in clay loam soil compared to PTT 1. A reverse trend was observed in the sandy loam soil. The grain 2AP content and grain yield of both rice cultivars were lower for those plants grown in the greenhouse condition. The water stress treatment led to higher 2AP content in both the leaves and grain of the two rice cultivars, which averaged 19% higher for rice leaves and 22% higher for rice grain. However, the water stress treatment dramatically decreased grain yield for all growing conditions. The interaction effects of these environmental factors were analysed using a full-factorial design. The interaction between rice cultivar × temperature had the strongest effect on the 2AP content, whereas rice cultivar × soil type greatly affected rice grain yield.

Enhancement of the Aroma Compound 2-Acetyl-1-pyrroline in Thai Jasmine Rice (Oryza sativa) by Rhizobacteria under Salt Stress

“…The high 2AP level in the KDML105 rice leaves led to a high 2AP level in the rice grains grown in clay and sandy soil [56]. Therefore, in the present study, it was expected that the enhancement of the 2AP level in the leaves of KDML105 rice seedlings by ST-PGPR inoculation might lead to high 2AP in the rice grains.…”

Variation of the Impact Aroma Compound, 2-Acetyl-1-Pyrroline, Content in Thai Fragrant Rice Plants and its Enhanced Accumulation by Soil Nutritional Elements

“…Quantification of 2AP in samples was performed according to the method of Boontakham et al (2019). A static headspace auto-sampler (Model G1888, Agilent Technologies, CA, USA) coupled to an Agilent 6890 Series GC system equipped with an NPD detector was used.…”

“…Singh, & Khush, 2000). Water stress treatment of KDML 105 after heading increases the amount of 2AP by 18% in leaves and 22% in grains (Boontakham et al, 2019). Another report described the correlation between 22 different locations possessing eight different soil textures in the northeastern part of Thailand and the 2AP content of KDML 105 rice grains.…”

“…The majority of research has focused on the effects of mineral elements on rice plant morphology and grain quality (Zeng et al, 2005), but little research has focused on the 2AP content in rice plant parts and grain. Jongkaewwattana, Wangtueai, & Mahatheeranont, 2019). According to these reports, drought conditions and sandy soils are favourable for 2AP accumulation, although the predominant rice cultivation conditions are usually flooded clay soils (R. Singh, U.…”

Exogenous γ-aminobutyric acid (GABA) application at different growth stages regulates 2-acetyl-1-pyrroline, yield, quality and antioxidant attributes in fragrant rice

“…Rice aroma was regarded as one of the most critical quality characters (Das et al 2018), aroma intensities are closely related to the mixture of aroma compounds in rice (Sansenya et al 2018). The 2-acetyl-1-pyrroline (2AP) was reported as a crucial volatile compound involved in the intricate volatile chemistry of aroma in fragrant rice (Ren et al 2017;Boontakham et al 2019), which can be determined in all parts of fragrant rice excluding root (Maraval et al 2010;Mo et al 2015). In recent times, some studies focusing on the formation of aroma have revealed that the betaine-aldehyde dehydrogenase (BADH)-related gene is responsible for the biosynthesis and up-down regulation of 2AP (Bradbury et al 2005;Chen et al 2008).…”