Detection of Pre-Harvest Sprouting in Rice Seeds by Using 1H-NMR

Ascorbic Acid Suppresses Germination and Dynamic States of Water in Wheat Seeds

“…Recently, we reported that T 2 is a suitable indicator for screening seeds for their resistance to PHS and for examining the degree of endosperm degradation in germinating seeds of rice (Ishibashi et al, 2005). Water contents of germinating seeds treated with distilled water, ABA, mannnitol and ascorbic acid were nearly the same (Fig.…”

“…T 2 was measured by the Carr-Purcell-Meiboom-Gill (CPMG) method. T 2 is determined from M 2nτ =M o exp(− 2nτ/T 2 ), where M o is the magnetization amplitude of the proton signal occurring at time 2τ after the initial 90º pulse in the CPMG (90ºx -τ-180ºy -2τ-180ºy-2τ ) pulse sequence (Iwaya-Inoue et al, 2004). The T 2 s were calculated based on 500 echo signals acquired by the accumulation of 32 scans.…”

“…NMR relaxation time (T 2 ) indicating dynamic states of water denotes degree of degradation of endosperm in germinating crop seeds (Ishibashi et al, 2005). Preharvest sprouting (PHS) in wheat causes devastating damage to the quality of wheat fl our due to the degradation of seed starch during germination.…”

“…Mobile and less mobile water molecules are distinguished from each other by their different NMR relaxation times (T 1 , T 2 ), and their relative amounts have been calculated in ryegrass leaves and roots (Iwaya-Inoue et al, 2004) and rice seeds . The aims of this study were (1) to fi nd a technique for suppressing germination, and (2) to investigate the effect of ascorbic acid on the germination process and dynamic states of water in seeds by using NMR.…”

Influence of Low/High Temperature on Water Status in Developing and Maturing Rice Grains

“…Spin-lattice relaxation time (T 1 ) and spin-spin relaxation time (T 2 ) are used as indicators of water status in biological tissues (Ishida et al, 2000;Chaughule et al, 2002;Iwaya-Inoue and Nonami, 2003). In our recent study, a close correlation of water content with water component indicated by T 1 and T 2 for long and short fractions was observed in grains of rice grown in the outdoor (Ishibashi et al, 2005). Moreover, T 1 and T 2 of water protons have been applied to the studies of higher plant tissues exposed to thermal stresses (Maheswari et al, 1999;Iwaya-Inoue et al, 2004a, b).…”