No abstract

No abstract

No abstract

No abstract

In order to investigate the effects of different irrigation management on the textural properties of two different double-cropping late indica rice, the effects of three irrigation management including conventional irrigation (CK), constant irrigation (CI) and alternate wetting and drying (AWD) on textural properties has been researched under field conditions of two years. The results indicated that the firmness, cohesiveness and chewiness were decreased under AWD treatment, and the stickiness was increased compared with CK, while the textural properties under CI treatment showed the opposite trend with AWD treatment. Additionally, AWD treatment significantly improved the springiness of TY871 compared with CK and CI treatment, but had no significant effect in RYHZ, suggesting improvement of the cooking and eating quality of TY871 under AWD treatment. Correlation analysis showed that the chewiness was positively correlated with the firmness and cohesiveness, and the cohesiveness was positively correlated with the firmness. AWD could promote the textural properties of high-quality late indica rice in South China whereas CI treatment has shown the disadvantage of the textural properties, which will provide useful information for the improvement of cooking and eating quality of rice.

IntroductionThe threat of climate warming to global rice production has been widely addressed, but little is known about its influence on the quality of rice grains.MethodsA free-air temperature increase (FATI) facility with two widely-planted high-quality cultivars was used to explore the impact of warming on the grain quality of early rice in subtropical China over 3 consecutive years.ResultsCompared with the control, FATI increased diurnal canopy temperature by 1.5°, and thus, rice growth duration was shortened by 4.0 d under warming. We found that warming significantly reduced both the milled rice and head rice rates relative to the control, thereby leading to a decrease in the milled rice and head rice yield by 3.9 and 8.3%, respectively. The chalky grain rate and chalkiness were increased by 19.1 and 22.2% under warming compared with the control, respectively. The content of protein, essential amino acids, and non-essential amino acids were increased by 4.1, 5.4, and 4.9% under warming, respectively. Warming reduced the amylose content and setback by 2.0 and 47.5% but increasing peak viscosity, trough viscosity, breakdown, and final viscosity by 9.5, 13.6, 5.7, and 6.0%, respectively.ConclusionOur results suggest that the deteriorated milling and appearance quality induced by warming may be an upcoming challenge for high-quality early rice production in the future.

High temperature (HT) accompanied with strong light (SL) often occurs in early indica rice production during grout filling stage in southern China, which accelerates grain ripening. Two indica rice cultivars with different amylose content (Zhongjiazao17, ZJZ17, high amylose content; Xiangzaoxian45, XZX45, low amylose content) were grown under control (CK), HT, and HT+SL conditions during grout filling to determine the effects on grain yield and quality of rice. The results showed that compared with CK, HT and HT+SL significantly reduced the 1000-grain weight and filled grain rate whether in high or low amylose content early indica rice cultivars during grout filling, resulting in a significantly lower grain yield. Meanwhile, HT and HT+SL significantly decreased the milled rice rate, brown rice rate and head rice rate, whereas significantly increased chalky rate and chalky degree; and breakdown decreased and setback, pasting temperature increased in the cultivars, leading to the poor processing, appearance and cooking and eating quality of early indica rice cultivars. Compared with HT, the yield of ZJZ17 was significantly decreased under HT+SL, due to the lower 1000-grain weight. However, the effect of HT+SL on rice quality varied in the cultivars. In general, the yield and rice quality of ZJZ17 were relatively poor under HT+SL. Our results suggested that HT and HT+SL during grout filling had significant damage to the yield and quality of early indica rice cultivars, especially HT+SL, while the high amylose cultivar ZJZ17 showed a higher negative effect under HT+SL. KEYWORDSHigh temperature-strong light double stress; yield; appearance quality; cooking and eating quality Highlights HT and HT+SL during grout filling deteriorated yield and quality in the cultivars. High amylose cultivar ZJZ17 had relatively poor yield and quality of rice under HT+SL. SL can promote the synthesis of amylose in the cultivars under HT condition.

No abstract