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Epoxiconazole is a triazole compound. However, the effects of epoxiconazole on crop productivity and quality were rarely reported. In this study, we investigated the effects of epoxiconazole application on yield formation, grain quality attributes, and 2-acetyl-1-pyrroline (2-AP) content in fragrant rice. A three-year field experiment was carried out with a fragrant rice variety, Meixiangzhan 2. At the heading stage, 0, 0.02, 0.04, 0.08, 0.16 and 0.32 g/L epoxiconazole solutions were foliar applied to fragrant rice plants, respectively. The results showed that epoxiconazole application significantly increased grain yield, seed-setting rate and 1000-grain weight. Chlorophyll content and net photosynthetic rate of fragrant rice during the grain-filling stage significantly increased due to epoxiconazole application. Foliar application of epoxiconazole at 0.08 g/L increased grain protein content and decreased both chalky rice rate and chalkiness area ratio of fragrant rice. Epoxiconazole also substantially increased grain 2-AP content by inducing the regulation in contents of related synthetic precursors, including proline, pyrroline-5- carboxylic acid, Δ1-pyrroline and methylglyoxal. Overall, foliar application of epoxiconazole could be used for the improvement in grain yield, grain quality and 2-AP content in fragrant rice production when applied concentration at 0.08–0.32 g/L. Our findings provided the new roles of epoxiconazole in crop production.

Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings. However, there is limited knowledge regarding the effects of the establishment of furrows on growth, lodging and yield, and their relationships with root traits. In this study, field experiments were conducted during 2012 and 2013 using two super rice varieties (hybrid rice Peizataifeng and inbred rice Yuxiangyouzhan) under three furrow establishment treatments (T1, both water and seed furrows were established by the machine; T2, only seed furrows were established by the machine; and T3, neither water nor seed furrows were established by the machine). Lodging index, lodging-related traits, grain yield, above-ground dry weight and root traits were measured. The results showed that the lodging index was significantly affected by the treatments with furrows (T1 and T2). The strongest lodging resistance was detected in the mechanical hill wet-seeded rice with furrow treatment (T1) in both 2012 and 2013. Lodging resistance was strongly related to the breaking resistance. No significant difference was found in grain yield or dry weight of the mechanical hill wet-seeded rice. Therefore, the mechanical hill wet-seeded rice with furrow treatment increased rice lodging resistance, which was related to root traits.

Rice cultivation under cadmium (Cd) contaminated soil often results in reduced growth with excess grain Cd concentrations. A pot experiment was conducted to assess the potential of ultrasonic seed treatment to alleviate Cd stress in rice. Seeds of two aromatic rice cultivars i.e., Xiangyaxiangzhan and Meixiangzhan 2 and two non-aromatic rice cultivars i.e., Huahang 31 and Guangyan 1 were exposed to ultrasonic waves for 1.5 min in 20-40 KHz mixing frequency. The experimental treatments were comprised of untreated seeds (U0) and ultrasonic treated seeds (U1) transplanted in un-contaminated soil (H0) and Cd-contaminated soil (H1). Results revealed that Cd contents and Cd accumulation in grain in U1 were 33.33-42.31% and 12.86-57.58% lower than U0 for fragrant rice cultivars under H1. Meanwhile, biomass production was higher in U1 than U0 under H0 and better yield was assessed in U1 for all cultivars under H1. The activity of peroxidase (POD) in flag leaves was increased by 8.28-115.65% for all cultivars while malondialdehyde (MDA) contents were significantly decreased in U1 compared with U0 under H0. Conclusively, ultrasonic treatment modulated Cd distribution and accumulation in different parts while improved physiological performance as well as yield and grain quality of rice under Cd contaminated conditions., (Copyright © 2021. Published by Elsevier Inc.)

Cloudy weather with low light is more common during rice growing season of South China which often leads reduced yield and aroma formations in fragrant rice. However, exogenous γ-aminobutyric acid (GABA) application could enhance the 2-acetyl-1-pyrroline (2AP) accumulations and yield of fragrant rice under low light conditions. Field and pot experiments were conducted with three fragrant rice cultivars i.e., Basmati and Yuxiangyouzhan (indica), and Yungengyou 14 (japonica) that were grown under three different treatments i.e., normal light + GABA 0 mg L -1 (CK), low light + GABA 0 mg L -1 (T1), and low light + GABA 250 mg L -1 (T2). The results revealed that the grain 2AP contents were increased by 14.67-34.83% and up to 29.34% under T1 and T2 treatments in pot and field experiments, respectively, as compared with CK. The T1 and T2 treatments improved aroma owing to regulation in the accumulation of micronutrients i.e., Na, Mn, and Fe and enzyme activities involved in 2AP biosynthesis. The grain yield was substantially reduced in T1 as compared with T2 treatment for all rice cultivars. On the other hand, GABA application improved the grain yield under low light conditions by regulating the plant growth, and related physiological and biochemical attributes in all rice cultivars. Thus, GABA could balance low light-induced 2AP content and grain yield by modulating morphological and yield related attributes as well as physio-biochemical responses of fragrant rice., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Cadmium (Cd) toxicity causes severe perturbations in nitrogen (N) uptake and assimilation, and thereby interrupts normal plant growth. Molybdenum (Mo), a necessary trace element, plays important roles in N metabolism through regulating N assimilatory enzymes activities and expressions in higher plants. Taking this into account, a pot experiment was performed to explore the role of Mo in alleviating Cd-induced inhibitory effects on physio-biochemical processes, N metabolism, yield attributes and grain quality characters of two fragrant rice cultivars; Guixiangzhan and Meixiangzhan-2. Both the fragrant rice cultivars were treated with two levels of each Cd concentrations (0 and 100 mg/kg) and Mo treatments (0 and 0.15 mg/kg). The results revealed that Cd toxicity significantly reduced (p < 0.05) plant dry biomass, gaseous exchange attributes, chlorophyll contents, N utilizing and assimilatory enzymes activities, 2-acetyl-1-pyrroline (2AP) contents and grain yield in both cultivars; however, more severe inhibitions were observed in Meixiangzhan-2 than Guixiangzhan. Nevertheless, Mo application alleviated Cd stress and enhanced 2AP content and grain yield by 75.05% and 67.94% in Guixiangzhan and 87.71% and 83.51% in Meixiangzhan-2, respectively compared with no Mo application. Moreover, Mo application improved photosynthesis, chloroplast configuration, soluble protein and proline contents and also strengthened the N assimilatory pathway through efficient NO 3 - utilization, higher nitrate reductase, nitrite reductase, glutamine synthetase and glutamate synthase activities and transcript levels under Cd stress. Collectively, our results imply that Mo-induced enhancement in N utilization and assimilation improved yield and grain quality characters of fragrant rice cultivars under Cd stress., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Cadmium (Cd) affects crop growth and productivity by disrupting normal plant metabolism. To determinate whether ultrasonic (US) seed treatment can alleviate Cd stress in rape (Brassica napus L.), the seeds of two oilseed rape cultivars i.e., 'Youyanzao18' and 'Zaoshu104' were exposed to ultrasonic waves for 1 min at 20 KHz frequency. Seeds without US treatment were taken as control (CK). Results revealed that the germination rate of both cultivars was significantly (P < 0.05) higher in US treatment than CK only at 0 and 10 mg Cd L -1 . The shoot and root length of both cultivars were significantly higher in US treatment than CK at all Cd treatments except the root length of Youyanzao18 at 50 mg Cd L -1 . The fresh weight Youyanzao18 was significantly (P < 0.05) higher in US than CK except for Youyanzao18 at 25 mg Cd L -1 . Moreover, the superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities and the proline, glutathione (GSH), and soluble protein contents in Youyanzao18 were relatively higher in the US treatment than CK. The malondialdehyde (MDA) contents were prominently reduced in US treatment than CK. The pods per plant, seeds per pod and rapeseed yield were increased by 15.9, 11.4, and 16.4% in Youyanzao18 and 10.3, 9.5, and 11.5% in Zaoshu104, respectively in US treatment, compared to CK. Moreover, the contents of Cd in root, stem, leaf, rape pod shell, and rapeseeds were comparatively less in US treatment than CK whereas the Cd concentrations in different plant parts of both rape cultivars were recorded as: leaf ˃ root ˃ stem ˃ rape pod shell ˃ rapeseed. In sum, the US treatment improved the morphological growth and rapeseed yield whereas reduced the Cd accumulation in different plant parts of rapeseed under Cd contaminated soil., (Copyright © 2019 Elsevier Inc. All rights reserved.)